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Sample records for asphalt concrete mixes

  1. User's guide: Hot-mix recycling of asphalt concrete pavements

    NASA Astrophysics Data System (ADS)

    Shoenberger, James E.

    1993-05-01

    This guide provides the technical information required to implement the application of hot-mix recycling of asphalt concrete pavements. Included are details on application, benefits/advantages, limitations/disadvantages, and costs associated with this technology. Information is provided on three demonstration sites at Fort Gillem, Georgia; Fort Leavenworth, Kansas; and Fort Benjamin Harrison, Indiana. Also provided is information concerning funding, procurement, maintenance, and performance monitoring. A fact sheet on recycling, contract specification example, and references are provided in the appendices.

  2. Production variability analysis of hot-mixed asphalt concrete containing reclaimed asphalt pavement. Final research report

    SciTech Connect

    Solaimanian, M.; Kennedy, T.W.

    1995-02-01

    A research project was undertaken to evaluate the production and construction variability of Hot Mix Asphalt Concrete (HMAC) containing high quantities of reclaimed asphalt pavement (RAP) material. Four construction projects were selected for this purpose. Two of the projects used 35 percent RAP material (both type-C mixes), while the other two used 40 percent (a type-B mix) and 50 percent (a type-D mix) of the RAP material, respectively. The projects differed in sizes, with total construction tonnage ranging from 10.9 million kg to 27.2 million kg (12,000 to 30,000 tons). In all cases, dedicated stockpiles of RAP material were used. Analysis was performed on the results obtained from the tests. The gradation and asphalt content deviations, air voids, penetration and viscosities, and stabilities, were included in the analysis. Pay adjustment factors were determined for gradation and asphalt content deviation, as well as for air voids (based on TxDOT Specification 3007). In general, these high-percent RAP projects indicated a variability higher than that of a typical HMAC without RAP. The pay adjustment factors for gradation and asphalt content deviation were lower than typical values. The construction gradations were finer than the job-mix formula target gradations, possibly a result of aggregate crushing during the milling operation.

  3. User's guide: Cold-mix recycling of asphalt concrete pavements. Final report

    SciTech Connect

    Shoenberger, J.E.

    1992-09-01

    This guide provides the technical information required to implement the application of cold-mix recycling of asphalt concrete pavements. Included are details on areas on application, benefits/advantages, limitations/disadvantages, and costs associated with this technology. Information is provided on two demonstration sites at Fort Gillem, Georgia, and Fort Leavenworth, Kansas. Also provided is information concerning funding, procurement, maintenance, and performance monitoring. A fact sheet on recycling, contract specification example, and references are provided in the appendixes.... Asphalt pavement recycling, Emulsified asphalt cement, Cold milling, In-place cold-mix asphalt recycling, Cold-mix asphalt recycling, Recycling of asphalt.

  4. Evaluation of properties of recycled asphalt concrete hot mix

    SciTech Connect

    Brown, E.R.

    1983-01-01

    This study was undertaken to evaluate the laboratory performance of recycled asphalt concrete mixtures and to compare these results to those measured for conventional asphalt concrete mixtures. To make these comparisons, samples of aged asphalt concrete were obtained from three locations where recycling was planned. These samples were blended with new aggregate and new asphalt materials to produce six different recycled mixtures. Two aggregate types, a crushed gravel and a crushed limestone, were used to produce two conventional mixtures and to blend with the reclaimed asphalt pavement to produce the six recycled mixtures. Three asphalt materials which were obtained to produce the various mixtures being evaluated consisted of AC-20 for preparing the conventional mixtures and AC-5 and a recycling agent for preparing the recycled mixtures. The Shell BISAR computer program was used to predict the stesses and strains for two typical pavement sections under a given loading conditions. The computed stresses and strains were then analyzed along with the laboratory fatigue tests to predict the fatigue performance of the various mixtures. The results of this study indicated a satisfactory comparison between laboratory performance of recycled mixtures and conventional mixtures. Fatigue analysis indicated that the conventional mixtures would provide the greatest fatigue resistance in thick asphalt concrete layers at lower temperatures while the recycled mixtures would provide the greatest fatigue resistance in thin asphalt layers at higher temperatures.

  5. Correlation between permanent deformation-related performance parameters of asphalt concrete mixes and binders

    NASA Astrophysics Data System (ADS)

    Adorjányi, Kálmán; Füleki, Péter

    2013-09-01

    This paper examines methods to predict the performance of hot asphalt concrete mixes based on performance parameters of binders. Specifically, relationships between binder parameters determined from multiple stress creep and recovery tests were correlated to the creep parameters of hot asphalt concrete mixes obtained from cyclic load compression testing. For the determination of creep parameters, a modified expression of the creep curve is proposed to cover the entire spectrum of permanent deformation; including the tertiary creep phase. Non-recoverable compliance, unrecovered strain, and recoverable strain of binders show good correlation to creep parameters of hot asphalt concrete mixes such as creep rate and high temperature performance ratio. Additionally, unrecovered strain and non-recoverable compliance of binders correlates well with mean rut depth of asphalt concrete mixes. However, no correlation has been detected between the difference in non-recoverable compliance of binders and permanent deformation parameters of asphalt concrete mixes.

  6. Specifications and Construction Methods for Asphalt Concrete and Other Plant-Mix Types, 3rd Edition.

    ERIC Educational Resources Information Center

    Asphalt Inst., College Park, MD.

    The purpose of this publication is to assist engineers in the analysis, design and control of paving projects that use asphalt concrete and other asphalt plant-mixes. The scope of this new third edition has been enlarged, and changes necessitated by advances in asphalt technology have been incorporated. Chapters I and II and Appendices A and B…

  7. Performance evaluation of high modulus asphalt concrete mixes

    NASA Astrophysics Data System (ADS)

    Haritonovs, V.; Tihonovs, J.; Zaumanis, M.

    2016-04-01

    Dolomite is one of the most available sedimentary rocks in the territory of Latvia. Dolomite quarries contain about 1000 million tons of this material. However, according to Latvian Road Specifications, this dolomite cannot be used for average and high intensity roads because of its low quality (mainly, LA index). Therefore, mostly imported magmatic rocks (granite, diabase, gabbro, basalt) or imported dolomite are used which makes asphalt expensive. However, practical experience shows that even with these high quality materials roads exhibit rutting, fatigue and thermal cracks. The aim of the research is to develop a high performance asphalt concrete for base and binder courses using only locally available aggregates. In order to achieve resistance against deformations at a high ambient temperature, a hard grade binder was used. Workability, fatigue and thermal cracking resistance, as well as sufficient water resistance is achieved by low porosity (3-5%) and higher binder content compared to traditional asphalt mixtures. The design of the asphalt includes a combination of empirical and performance based tests, which in laboratory circumstances allow simulating traffic and environmental loads. High performance AC 16 base asphalt concrete was created using local dolomite aggregate with polymer modified (PMB 10/40-65) and hard grade (B20/30) bitumen. The mixtures were specified based on fundamental properties in accordance to EN 13108-1 standard.

  8. Performance testing of asphalt concrete containing crumb rubber modifier and warm mix additives

    NASA Astrophysics Data System (ADS)

    Ikpugha, Omo John

    Utilisation of scrap tire has been achieved through the production of crumb rubber modified binders and rubberised asphalt concrete. Terminal and field blended asphalt rubbers have been developed through the wet process to incorporate crumb rubber into the asphalt binder. Warm mix asphalt technologies have been developed to curb the problem associated with the processing and production of such crumb rubber modified binders. Also the lowered production and compaction temperatures associated with warm mix additives suggests the possibility of moisture retention in the mix, which can lead to moisture damage. Conventional moisture sensitivity tests have not effectively discriminated good and poor mixes, due to the difficulty of simulating field moisture damage mechanisms. This study was carried out to investigate performance properties of crumb rubber modified asphalt concrete, using commercial warm mix asphalt technology. Commonly utilised asphalt mixtures in North America such as dense graded and stone mastic asphalt were used in this study. Uniaxial Cyclic Compression Testing (UCCT) was used to measure permanent deformation at high temperatures. Indirect Tensile Testing (IDT) was used to investigate low temperature performance. Moisture Induced Sensitivity Testing (MiST) was proposed to be an effective method for detecting the susceptibility of asphalt mixtures to moisture damage, as it incorporates major field stripping mechanisms. Sonnewarm(TM), Sasobit(TM) and Evotherm(TM) additives improved the resistance to permanent deformation of dense graded mixes at a loading rate of 0.5 percent by weight of the binder. Polymer modified mixtures showed superior resistance to permanent deformation compared to asphalt rubber in all mix types. Rediset(TM) WMX improves low temperature properties of dense graded mixes at 0.5 percent loading on the asphalt cement. Rediset LQ and Rediset WMX showed good anti stripping properties at 0.5 percent loading on the asphalt cement. The

  9. The use of natural sand from lampusatu beach, kabupatenmerauke, papua for mixed asphalt concrete

    NASA Astrophysics Data System (ADS)

    Huwae, D. D. M.; Parera, L. R.; Alpius; Tanijaya, J.

    2017-05-01

    The natural sand from LampuSatu Beach, KabupatenMerauke, Papua, is often used as building material by local people. This research aims to test the use of this natural sand for mixed asphalt concrete. Asphalt Concrete Wearing Course (AC-WC) with bitumen penetration 60/70 and variations of asphalt content 5%, 6%, 7%, 8% and 9% are used in this research. Testing result shows the stability 1372.17 kg, VIM 3.95%, VMA 16.81%, Flow 4.14 mm, and MQ 332.89 kg/mm. It has fulfilled the standard requirements set by Indonesian Director General for Highways. The percentage of Optimum Asphalt Content (OAC) is 7% and the Index of Retained Strength (IRS) is 107.84% (≥ 75%). These indicate that the mixture can fulfill the Stability and Marshall Immersion Test.

  10. Utilization of recycled asphalt concrete with warm mix asphalt and cost-benefit analysis.

    PubMed

    Oner, Julide; Sengoz, Burak

    2015-01-01

    The asphalt paving industries are faced with two major problems. These two important challenges are generated with an increase in demand for environmentally friendly paving mixtures and the problem of rapidly rising raw materials. Recycling of reclaimed asphalt pavement (RAP) is a critical necessity to save precious aggregates and reduce the use of costly bitumen. Warm Mix Asphalt (WMA) technology provides not only the option of recycling asphalt pavement at a lower temperature than the temperature maintained in hot mixtures but also encourages the utilization of RAP and therefore saves energy and money. This paper describes the feasibility of utilizing three different WMA additives (organic, chemical and water containing) at recommended contents with different percentages of RAP. The mechanical properties and cost-benefit analysis of WMA containing RAP have been performed and compared with WMA without RAP. The results indicated that, 30%, 10% and 20% can be accepted as an optimum RAP addition related to organic, chemical and water containing additives respectively and organic additive with 30% RAP content has an appreciable increase in tensile strength over the control mix. It was also concluded that the RAP with WMA technology is the ability to reduce final cost compared to HMA and WMA mixtures.

  11. Utilization of Recycled Asphalt Concrete with Warm Mix Asphalt and Cost-Benefit Analysis

    PubMed Central

    Oner, Julide; Sengoz, Burak

    2015-01-01

    The asphalt paving industries are faced with two major problems. These two important challenges are generated with an increase in demand for environmentally friendly paving mixtures and the problem of rapidly rising raw materials. Recycling of reclaimed asphalt pavement (RAP) is a critical necessity to save precious aggregates and reduce the use of costly bitumen. Warm Mix Asphalt (WMA) technology provides not only the option of recycling asphalt pavement at a lower temperature than the temperature maintained in hot mixtures but also encourages the utilization of RAP and therefore saves energy and money. This paper describes the feasibility of utilizing three different WMA additives (organic, chemical and water containing) at recommended contents with different percentages of RAP. The mechanical properties and cost-benefit analysis of WMA containing RAP have been performed and compared with WMA without RAP. The results indicated that, 30%, 10% and 20% can be accepted as an optimum RAP addition related to organic, chemical and water containing additives respectively and organic additive with 30% RAP content has an appreciable increase in tensile strength over the control mix. It was also concluded that the RAP with WMA technology is the ability to reduce final cost compared to HMA and WMA mixtures. PMID:25574851

  12. Value-added utilisation of recycled concrete in hot-mix asphalt

    SciTech Connect

    Wong, Yiik Diew; Sun, Darren Delai . E-mail: ddsun@ntu.edu.sg; Lai, Dickson

    2007-07-01

    The feasibility of partial substitution of granite aggregate in hot-mix asphalt (HMA) with waste concrete aggregate was investigated. Three hybrid HMA mixes incorporating substitutions of granite fillers/fines with 6%, 45% untreated, and 45% heat-treated concrete were evaluated by the Marshall mix design method; the optimum binder contents were found to be 5.3%, 6.5% and 7.0% of grade Pen 60/70 bitumen, respectively. All three hybrid mixes satisfied the Marshall criteria of the Singapore Land Transport Authority (LTA) W3B wearing course specification. The hybrid mix with 6% concrete fillers gave comparable resilient modulus and creep resistance as the conventional W3B mix, while hybrid mixes with higher concrete substitutions achieved better performance. X-ray diffraction (XRD) showed the distinct presence of free lime in the heat-treated concrete, while the scanning electron microscope (SEM) provided an in-depth perspective of the concrete grains in the HMA matrix. The results suggest feasible use of waste concrete as partial aggregate substitution in HMA.

  13. Value-added utilisation of recycled concrete in hot-mix asphalt.

    PubMed

    Wong, Yiik Diew; Sun, Darren Delai; Lai, Dickson

    2007-01-01

    The feasibility of partial substitution of granite aggregate in hot-mix asphalt (HMA) with waste concrete aggregate was investigated. Three hybrid HMA mixes incorporating substitutions of granite fillers/fines with 6%, 45% untreated, and 45% heat-treated concrete were evaluated by the Marshall mix design method; the optimum binder contents were found to be 5.3%, 6.5% and 7.0% of grade Pen 60/70 bitumen, respectively. All three hybrid mixes satisfied the Marshall criteria of the Singapore Land Transport Authority (LTA) W3B wearing course specification. The hybrid mix with 6% concrete fillers gave comparable resilient modulus and creep resistance as the conventional W3B mix, while hybrid mixes with higher concrete substitutions achieved better performance. X-ray diffraction (XRD) showed the distinct presence of free lime in the heat-treated concrete, while the scanning electron microscope (SEM) provided an in-depth perspective of the concrete grains in the HMA matrix. The results suggest feasible use of waste concrete as partial aggregate substitution in HMA.

  14. Asphalt additives in thick hot mixed asphalt-concrete pavements. Research report (Interim), Sep 86-Oct 90

    SciTech Connect

    Button, J.W.; Prapnnachari, S.

    1991-01-01

    Asphalt concrete field test pavements were placed in District 19 north of Texarkana on US-59/71 in 1987 and 1988 to evaluate the ability of certain asphalt additives to enhance resistance to cracking and rutting. Two 10-inch thick and 0.9 mile (approx.) long test pavements and a similar untreated control section were constructed in the northbound and southbound lanes for a total of 6 field trials. Asphalt additives were incorporated in both the 8-inch base and the overlying 2-inch surface layers. The additives evaluated included Goodyear LPF 5812, Chemkrete-CTI 102, Exxon Polybilt 102, and Styrelf 13. Samples of paving materials including aggregates, asphalts, compacted mixes, and pavement cores were collected, conveyed to the laboratory, and tested to provide detailed documentation of their properties. Tests included rheological properties of the binders before and after artificial aging, characterization of aggregate, Hveem and Marshall stability, stiffness as a function of temperature, tensile properties before and after moisture conditioning and artificial aging, air void content, creep, and permanent deformation. Field tests and visual evaluations have been conducted to objectively evaluate field performance. Results of these tests are reported herein. Within 6 months after construction of the base layers and prior to placement of the surface course, the Chemkrete modified base became severely cracked. As a result, the surface mix placed on this base section was treated with Goodyear latex rather than Chemkrete. All other modified pavements and the control section have performed well and exhibited essentially equivalent performance after 2 1/2 years in service.

  15. Multiscale imaging and characterization of the effect of mixing temperature on asphalt concrete containing recycled components.

    PubMed

    Cavalli, M C; Griffa, M; Bressi, S; Partl, M N; Tebaldi, G; Poulikakos, L D

    2016-10-01

    When producing asphalt concrete mixture with high amounts of reclaimed asphalt pavement (RAP), the mixing temperature plays a significant role in the resulting spatial distribution of the components as well as on the quality of the resulting mixture, in terms of workability during mixing and compaction as well as in service mechanical properties. Asphalt concrete containing 50% RAP was investigated at mixing temperatures of 140, 160 and 180°C, using a multiscale approach. At the microscale, using energy dispersive X-ray spectroscopy the RAP binder film thickness was visualized and measured. It was shown that at higher mixing temperatures this film thickness was reduced. The reduction in film thickness can be attributed to the loss of volatiles as well as the mixing of RAP binder with virgin binder at higher temperatures. X-ray computer tomography was used to characterize statistically the distribution of the RAP and virgin aggregates geometric features: volume, width and shape anisotropy. In addition using X-ray computer tomography, the packing and spatial distribution of the RAP and virgin aggregates was characterized using the nearest neighbour metric. It was shown that mixing temperature may have a positive effect on the spatial distribution of the aggregates but did not affect the packing. The study shows a tendency for the RAP aggregates to be more likely distributed in clusters at lower mixing temperatures. At higher temperatures, they were more homogeneously distributed. This indicates a higher degree of blending both at microscale (binder film) and macroscale (spatial distribution) between RAP and virgin aggregates as a result of increasing mixing temperatures and the ability to quantify this using various imaging techniques. © 2016 The Authors Journal of Microscopy © 2016 Royal Microscopical Society.

  16. Effect of gilsonite-modified asphalt on hot-mix asphaltic concrete mixes used in District 12, Houston, Texas

    SciTech Connect

    Wong, C.; Ho, M.K.

    1990-06-01

    Gilsonite is a naturally occurring black hydrocarbon from Utah with a high asphaltene content and an unusual amount of nitrogen compounds. Because of its composition, it is believed that the addition of gilsonite will increase the viscosity, stability, water susceptibility and durability of the asphalt mix. The District 12 laboratory conducted tests on two hot mix designs using gilsonite-modified asphalts. A control batch and batches containing 4%, 6% and 8% gilsonite by weight of asphalt were tested. The appropriate gilsonite-aggregate mixtures were molded and evaluated for stability, specific gravity, indirect tensile strength and water susceptibility. From the results of the laboratory tests, it was evident that gilsonite-modified asphalt mixes did increase dry and wet tensile strength but did not increase H veem stability. Since there is no overwhelming proof of gilsonite's ability as an anti-stripping agent, it has been recommended that gilsonite be used with an anti-stripping agent to combat stripping and rutting. It is further recommended that the field performance of gilsonite be evaluated before approval is given for its use.

  17. Noise characteristics of hot mix asphalt and Portland cement concrete pavements in United States

    NASA Astrophysics Data System (ADS)

    Hanson, Douglas I.

    2005-09-01

    In today's society, traffic noise is a serious problem that generally is considered an environmental pollution because it lowers the standard of living. Research in Europe and in the United States has indicated that it is possible to build pavement surfaces that will reduce the level of noise generated on roadways. In January of 2002 the National Center for Asphalt Technology initiated a research study with the objective to develop safe, quiet and durable asphalt pavement surfaces. As a part of that study over 300 pavement surfaces [both Portland Cement Concrete (PCCP) and Hot Mix Asphalt (HMA)] throughout the United States have been tested using a close-proximity noise trailer. The study has shown that in general PCCP surfaces have a higher noise level than HMA surfaces. But, it has also shown that by properly choosing the surface texture of the PCCP surface significant reductions in the noise level of a PCCP surface can be achieved. The study has shown that it is possible to construct low-noise HMA mixes and that in general the smaller the nominal maximum size for those mixes (regards whether they are dense graded, SMA or OFGC mixes) the lower the noise level.

  18. Evaluation of Properties of Recycled Asphalt Concrete Hot Mix.

    DTIC Science & Technology

    1984-02-01

    the literature, it is difti ult to compare test results among the various laboratories. Whitcomb evaluated a simplified method of mix design for...proposed ASTM test method under jurisdiction of ASTM Subcom- mittee D04.20). A nomograph was used to select the type of recycling agent needed to...in viscosity with aging. The thin-film oven test and rolling thin-film oven test have been used in durability tests . These two test methods are used

  19. Investigation of modified asphalt concrete

    NASA Astrophysics Data System (ADS)

    Zimich, Vita

    2016-01-01

    Currently the problem of improving the asphalt quality is very urgent. It is used primarily as topcoats exposed to the greatest relative to the other layers of the road, dynamic load - impact and shear. The number of cars on the road, the speed of their movement, as well as the traffic intensity increase day by day. We have to upgrade motor roads, which entails a huge cost. World experience shows that the issue is urgent not only in Russia, but also in many countries in Europe, USA and Asia. Thus, the subject of research is the resistance of asphalt concrete to water and its influence on the strength of the material at different temperatures, and resistance of pavement to deformation. It is appropriate to search for new modifiers for asphaltic binder and mineral additives for asphalt mix to form in complex the skeleton of the future asphalt concrete, resistant to atmospheric condensation, soil characteristics of the road construction area, as well as the growing road transport load. The important task of the work is searching special modifying additives for bitumen binder and asphalt mixture as a whole, which will improve the quality of highways, increasing the period between repairs. The methods described in the normative-technical documentation were used for the research. The conducted research allowed reducing the frequency of road maintenance for 7 years, increasing it from 17 to 25 years.

  20. Assessment of the aging level of rejuvenated hot mixed asphalt concrete pavements

    NASA Astrophysics Data System (ADS)

    McGovern, Megan; Buttlar, William G.; Reis, Henrique

    2016-04-01

    The efficacy of asphalt rejuvenator on restoring the properties of oxidatively aged asphalt was tested via a non-collinear ultrasonic subsurface wave mixing technique modified for field use. Longitudinal transducers were mounted on angle wedges to generate subsurface dilatational waves to allow for pavement evaluation when there is only access to one side. Because in the field the asphalt concrete (AC) pavement properties (i.e., ultrasonic velocities and attenuations) are unknown, a pre-determined fixed incident angle (based on the AC mixture type) was used, which allows for practical implementation in the field. Oxidative aged AC specimens were coated with rejuvenator (10% by weight of the binder) and left to dwell for varying amounts of time. Once the dwell time reached the desired amount, the specimen was immediately ultrasonically tested. The frequency ratio, f2/f1, at which the interaction took place and the normalized nonlinear wave generation parameter, β/β0, were recorded and compared against a reference plot. It was observed that the rejuvenator had the effect of restoring the nonlinear properties to those corresponding to a virgin sample after a sufficient amount of dwell time. The ability of the rejuvenator to fully penetrate and act on the binder was observed to be dependent on the porosity and aggregate structure, and thus varied for each specimen. As a result, some portions of the binder were restored to a greater extent than others. This non-uniform nature was captured via the nonlinear ultrasonic technique.

  1. Assessment of the potential suitability of southwest Brooklyn incinerator residue in asphaltic-concrete mixes. Final report

    SciTech Connect

    Chesner, W.H.; Collins, R.J.; Fung, T.

    1988-02-01

    The results of a one-year incinerator residue sampling program at the Southwest Brooklyn Incinerator in New York City are reported. The program was designed to characterize the physical properties of incinerator residue. Asphalt mixes were prepared using blends of sampled incinerator residue with conventional aggregate, to determine the suitability of using incinerator residue in asphaltic concrete for road paving applications. The results of the investigation are compared with those of previous studies. Engineering and processing requirements are presented for converting residue into a usable aggregate material. Capital costs, operating costs, potential revenues and net annual costs are provided for a full-scale residue processing facility at the Southwest Brooklyn Incinerator. Environmental issues associated with residue recycling are identified and discussed. Recommendations are provided for additional laboratory work and field applications needed to demonstrate the use of residue in asphalt mixes.

  2. Evaluation of steel slag coarse aggregate in hot mix asphalt concrete.

    PubMed

    Ahmedzade, Perviz; Sengoz, Burak

    2009-06-15

    This paper presents the influences of the utilization of steel slag as a coarse aggregate on the properties of hot mix asphalt. Four different asphalt mixtures containing two types of asphalt cement (AC-5; AC-10) and coarse aggregate (limestone; steel slag) were used to prepare Marshall specimens and to determine optimum bitumen content. Mechanical characteristics of all mixtures were evaluated by Marshall stability, indirect tensile stiffness modulus, creep stiffness, and indirect tensile strength tests. The electrical sensitivity of the specimens were also investigated in accordance with ASTM D257-91. It was observed that steel slag used as a coarse aggregate improved the mechanical properties of asphalt mixtures. Moreover, volume resistivity values demonstrated that the electrical conductivity of steel slag mixtures were better than that of limestone mixtures.

  3. Multiscale Constitutive Modeling of Asphalt Concrete

    NASA Astrophysics Data System (ADS)

    Underwood, Benjamin Shane

    Multiscale modeling of asphalt concrete has become a popular technique for gaining improved insight into the physical mechanisms that affect the material's behavior and ultimately its performance. This type of modeling considers asphalt concrete, not as a homogeneous mass, but rather as an assemblage of materials at different characteristic length scales. For proper modeling these characteristic scales should be functionally definable and should have known properties. Thus far, research in this area has not focused significant attention on functionally defining what the characteristic scales within asphalt concrete should be. Instead, many have made assumptions on the characteristic scales and even the characteristic behaviors of these scales with little to no support. This research addresses these shortcomings by directly evaluating the microstructure of the material and uses these results to create materials of different characteristic length scales as they exist within the asphalt concrete mixture. The objectives of this work are to; 1) develop mechanistic models for the linear viscoelastic (LVE) and damage behaviors in asphalt concrete at different length scales and 2) develop a mechanistic, mechanistic/empirical, or phenomenological formulation to link the different length scales into a model capable of predicting the effects of microstructural changes on the linear viscoelastic behaviors of asphalt concrete mixture, e.g., a microstructure association model for asphalt concrete mixture. Through the microstructural study it is found that asphalt concrete mixture can be considered as a build-up of three different phases; asphalt mastic, fine aggregate matrix (FAM), and finally the coarse aggregate particles. The asphalt mastic is found to exist as a homogenous material throughout the mixture and FAM, and the filler content within this material is consistent with the volumetric averaged concentration, which can be calculated from the job mix formula. It is also

  4. Current Practices on Nighttime Pavement Construction Asphaltic Concrete.

    DTIC Science & Technology

    1982-07-01

    foot width. This production amounted to approximately 1520 tons per night. 9. Equipment: a. Asphalt Spreader. The Contractor utilized one Blaw Knox ...Diego, CA. to monitor the testing of the Port Authority requirements. 11. Grade Control Requirements. a. Ski. The Blaw Knox paving machine was specified...q 16. Crack Reflection Membrane: None. 17. Hot Mix Asphaltic Concrete Overlay Placing: a. Asphalt Spreaders Operating in Echelon. Only one Blaw - Knox

  5. Development of a rapid test method for asphalt concrete content determination in hot-mix paving mixtures

    NASA Astrophysics Data System (ADS)

    Chavez, J. J. M.

    1984-01-01

    A rapid test method was developed for the determination of asphalt cement content in hot-mix bituminous paving mixtures. It is based on the extraction of asphalt cement from mixtures with trichloroethylene and subsequent measurement of the transmittance of light through the extracted solution. A good correlation was found between the results obtained using the rapid test and those obtained using the standard test (ASTM D-2172, Method E1) for samples tested in the field at asphalt mix plants. The test uses a portable spectrophotometer and a metal can for extraction. The asphalt content can be determined in less than ten minutes. The possibility of using the rapid test on materials containing emulsified asphalt, slag aggregate, unusually high amounts of fine material and recycled material was also studied.

  6. Influence of roofing shingles on asphalt concrete mixture properties. Final report, 1992-1993

    SciTech Connect

    Newcomb, D.; Stroup-Gardiner, M.; Weikle, B.; Drescher, A.

    1993-06-01

    The objective of the study was to evaluate the use of waste shingles from manufacturing and roof reconstruction projects in hot mix asphalt concrete mixtures. In dense-graded asphalt mixtures, it was hypothesized that the waste material might serve as an extender for the new asphalt in the mix as well as a fiber reinforcement. In the stone mastic asphalt (SMA), it could serve as the binder stiffener typically used to prevent the asphalt from draining out of these types of mixtures.

  7. Development of a crumb rubber modified (CRM) asphalt concrete mix design. Final report, June 1993-May 1995

    SciTech Connect

    Hossain, M.; Swartz, S.E.; Hoque, M.E.; Funk, L.P.

    1995-05-01

    The objective of this project was to develop an asphalt mix design method incorporating crumb rubber and using the `Wet` or `Dry` method of producing Crumb Rubber Modified Asphalt (CRM). Several resurfacing projects have been constructed using both the `Wet` and `Dry` methods. Based on this study, KDOT could use CRM mixes with a binder content between 7.5% and 9.0% depending on the percent air voids, with 19% to 22% rubber content. In this study, it was observed that using 24% rubber produced mixed were too sticky to manage. With a rubber content of less than 18% combined with AC-5 it was difficult to satisfy the minimum requirements. Fracture tests can be used as a basis to determine the optimum binder content for any asphalt-rubber mix.

  8. Petroleum contaminated soil in Oman: evaluation of bioremediation treatment and potential for reuse in hot asphalt mix concrete.

    PubMed

    Jamrah, Ahmad; Al-Futaisi, Ahmed; Hassan, Hossam; Al-Oraimi, Salem

    2007-01-01

    This paper presents a study that aims at evaluating the leaching characteristics of petroleum contaminated soils as well as their application in hot mix asphalt concrete. Soil samples are environmentally characterized in terms of their total heavy metals and hydrocarbon compounds and leachability. The total petroleum hydrocarbon (TPH) present in the PCS before and after treatment was determined to be 6.8% and 5.3% by dry weight, indicating a reduction of 1% in the TPH of PCS due to the current treatment employed. Results of the total heavy metal analysis on soils indicate that the concentrations of heavy metals are lower when extraction of the soil samples is carried out using hexane in comparison to TCE. The results show that the clean soils present in the vicinity of contaminated sites contain heavy metals in the following decreasing order: nickel (Ni), followed by chromium (Cr), zinc (Zn), copper (Cu), lead (Pb), and vanadium (V). The current treatment practice employed for remediation of the contaminated soil reduces the concentrations of nickel and chromium, but increases the concentrations of all remaining heavy metals.

  9. Voids characteristics of asphaltic concrete containing coconut shell

    NASA Astrophysics Data System (ADS)

    Ezree Abdullah, Mohd; Hannani Madzaili, Amirah; Putra Jaya, Ramadhansyah; Yaacob, Haryati; Hassan, Norhidayah Abdul; Nazri, Fadzli Mohamed

    2017-07-01

    Asphalt durability is often linked to the thickness of the asphalt coating on the aggregate particles. In order to have adequate film thickness in asphaltic concrete, there must be sufficient space between the aggregate particles in the compacted pavement. This void space is referred to as voids in total mix (VTM), voids with filled bitumen (VFB), and voids in mineral aggregate (VMA). Hence, this study investigates the performance of coconut shell (CS) as coarse aggregate replacement on voids characteristics of asphaltic concrete. Four CS were used as coarse aggregates replacement in asphalt mixture namely 0%, 10%, 20%, 30%, and 40% (by weight volume). The voids properties of asphalt mixture were determined based on Marshall Mix design test. Test results show that VTM and VMA values were decrease with the increasing bitumen content where VFB was increase with increasing bitumen content. Furthermore, increasing the percentage of coconut shell in asphalt mixture was found to increases the voids value up to a peak level and then decreases with further additions of CS.

  10. Use of recycled chunk rubber asphalt concrete (CRAC) on low volume roads and use of recycled crumb rubber modifier in asphalt pavements. Final report, June 1993-June 1995

    SciTech Connect

    Hossain, M.; Funk, L.P.; Sadeq, M.A.; Marucci, G.

    1995-06-01

    The major objective of this project was to formulate a Chunk Rubber Asphalt Concrete (CRAC) mix for use on low volume roads. CRAC is a rubber modified asphalt concrete product produced by the `dry process` where rubber chunks of 1/2 inch size are used as aggregate in a cold mix with a type C fly ash. The second objective of this project was to develop guidelines concerning the use of rubber modified asphalt concrete hot mix to include: (1) Design methods for use of asphalt-rubber mix for new construction and overlay, (2) Mix design method for asphalt-rubber, and (3) Test method for determining the amount of rubber in an asphalt-rubber concrete for quality control purposes.

  11. 7 CFR 3201.65 - Concrete and asphalt cleaners.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 15 2014-01-01 2014-01-01 false Concrete and asphalt cleaners. 3201.65 Section 3201... PROCUREMENT Designated Items § 3201.65 Concrete and asphalt cleaners. (a) Definition. Chemicals used in..., rust, and dirt from concrete, asphalt, stone and other hard porous surfaces. Products within this item...

  12. 7 CFR 3201.65 - Concrete and asphalt cleaners.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 15 2013-01-01 2013-01-01 false Concrete and asphalt cleaners. 3201.65 Section 3201... PROCUREMENT Designated Items § 3201.65 Concrete and asphalt cleaners. (a) Definition. Chemicals used in..., rust, and dirt from concrete, asphalt, stone and other hard porous surfaces. Products within this item...

  13. 7 CFR 3201.65 - Concrete and asphalt cleaners.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 15 2012-01-01 2012-01-01 false Concrete and asphalt cleaners. 3201.65 Section 3201... PROCUREMENT Designated Items § 3201.65 Concrete and asphalt cleaners. (a) Definition. Chemicals used in..., rust, and dirt from concrete, asphalt, stone and other hard porous surfaces. Products within this item...

  14. Modified Asphalt Binder with Natural Zeolite for Warm Mix Asphalt

    NASA Astrophysics Data System (ADS)

    Dubravský, Marián; Mandula, Ján

    2015-11-01

    In recent years, warm mix asphalt (WMA) is becoming more and more used in the asphalt industry. WMA provide a whole range of benefits, whether economic, environmental and ecological. Lower energy consumption and less pollution is the most advantages of this asphalt mixture. The paper deals with the addition of natural zeolite into the sub base asphalt layers, which is the essential constituent in the construction of the road. Measurement is focused on basic physic - mechanical properties declared according to the catalog data sheets. The aim of this article is to demonstrate the ability of addition the natural zeolite into the all asphalt layers of asphalt pavement. All asphalt mixtures were compared with reference asphalt mixture, which was prepared in reference temperature.

  15. Crumb rubber modified asphalt concrete in Oregon. Summary report. Report for 1985-94

    SciTech Connect

    Hunt, E.; Peters, W.

    1995-07-01

    Over the last nine years, the Oregon Department of Transportation (ODOT) has constructed 13 projects using crumb rubber modifiers (CRM) in asphalt concrete pavements using both the wet and dry process. State and federal legislation may require the use of recycled rubber in asphalt concrete, therefore, the Oregon Department of Transportation is interested in determining the most cost -effective crumb rubber modified asphalt concrete. The report includes a literature review on the use of crumb rubber modifiers in asphalt concrete pavement; a review on non-ODOT CRM paving projects constructed by Oregon counties and cities; and the Washington Department of Transportation. In additon, the report summarizes the data collected on all CRM hot mix asphalt concrete pavement projects constructed by ODOT. The ODOT information includes background constitution, cost, and performance data for each of the test and control sections. Finally, the future activities of the project are reviewed.

  16. High Modulus Asphalt Concrete with Dolomite Aggregates

    NASA Astrophysics Data System (ADS)

    Haritonovs, V.; Tihonovs, J.; Smirnovs, J.

    2015-11-01

    Dolomite is one of the most widely available sedimentary rocks in the territory of Latvia. Dolomite quarries contain about 1,000 million tons of this material. However, according to Latvian Road Specifications, this dolomite cannot be used for average and high intensity roads because of its low quality, mainly, its LA index (The Los Angeles abrasion test). Therefore, mostly the imported magmatic rocks (granite, diabase, gabbro, basalt) or imported dolomite are used, which makes asphalt expensive. However, practical experience shows that even with these high quality materials roads exhibit rutting, fatigue, and thermal cracks. The aim of the research is to develop a high performance asphalt concrete for base and binder courses using only locally available aggregates. In order to achieve resistance against deformations at a high ambient temperature, a hard grade binder was used. Workability, fatigue and thermal cracking resistance, as well as sufficient water resistance is achieved by low porosity (3-5%) and higher binder content compared to traditional asphalt mixtures. The design of the asphalt includes a combination of empirical and performance based tests, which in laboratory circumstances allow simulating traffic and environmental loads. High performance AC 16 base asphalt concrete was created using local dolomite aggregate with polymer modified (PMB 10/40-65) and hard grade (B20/30) bitumen. The mixtures were specified based on fundamental properties in accordance with EN 13108-1 standard.

  17. State-of-the-art and prospect for self-healing asphalt concrete

    NASA Astrophysics Data System (ADS)

    Xiao, Dong

    2017-08-01

    In order to solve the problem of asphalt concrete pavement cracks, this paper summarizes the principle of self-healing asphalt concrete, and describes asphalt concrete self-healing technology in various countries. This paper also analyses the factors of influencing the self-healing ability of asphalt concrete and the evaluation index, and describes the prospect of asphalt concrete self-healing technology.

  18. 7 CFR 3201.36 - Concrete and asphalt release fluids.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 15 2013-01-01 2013-01-01 false Concrete and asphalt release fluids. 3201.36 Section... PROCUREMENT Designated Items § 3201.36 Concrete and asphalt release fluids. (a) Definition. Products that are designed to provide a lubricating barrier between the composite surface materials (e.g., concrete...

  19. 7 CFR 2902.36 - Concrete and asphalt release fluids.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 15 2011-01-01 2011-01-01 false Concrete and asphalt release fluids. 2902.36 Section... PROCUREMENT Designated Items § 2902.36 Concrete and asphalt release fluids. (a) Definition. Products that are designed to provide a lubricating barrier between the composite surface materials (e.g., concrete...

  20. 7 CFR 3201.36 - Concrete and asphalt release fluids.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 15 2014-01-01 2014-01-01 false Concrete and asphalt release fluids. 3201.36 Section... PROCUREMENT Designated Items § 3201.36 Concrete and asphalt release fluids. (a) Definition. Products that are designed to provide a lubricating barrier between the composite surface materials (e.g., concrete...

  1. 7 CFR 2902.36 - Concrete and asphalt release fluids.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 15 2010-01-01 2010-01-01 false Concrete and asphalt release fluids. 2902.36 Section... PROCUREMENT Designated Items § 2902.36 Concrete and asphalt release fluids. (a) Definition. Products that are designed to provide a lubricating barrier between the composite surface materials (e.g., concrete...

  2. 7 CFR 3201.36 - Concrete and asphalt release fluids.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 15 2012-01-01 2012-01-01 false Concrete and asphalt release fluids. 3201.36 Section... PROCUREMENT Designated Items § 3201.36 Concrete and asphalt release fluids. (a) Definition. Products that are designed to provide a lubricating barrier between the composite surface materials (e.g., concrete...

  3. Evaluation of the benefits of adding waste fiberglass roofing shingles to Hot-Mix asphalt. Final report

    SciTech Connect

    Abdulshafi, O.; Kedzierski, B.; Fitch, M.G.; Mukhtar, H.

    1997-07-03

    The decreased availability of landfills, growing concern over waste disposal, and rising cost of asphalt cement, resulted in an increased interest in incorporating waste asphalt roofing shingles in the production of asphalt concrete mixes. This project addressed Hot-Mix, surface course asphalt concrete mixes produced with an addition of waste fiberglass asphalt roofing shingles that were obtained from the shingle manufacturing process. A total of twenty-six asphalt concrete mixes were studied. The variables included: aggregate type, shingle producers, level of shingle addition (0, 5, 10, and 15%), and type of shingle size reduction. Properties of the produced asphalt concrete mixes were evaluated based on the results of applicable tests that were performed.

  4. Characterisation of Asphalt Concrete Using Nanoindentation.

    PubMed

    Barbhuiya, Salim; Caracciolo, Benjamin

    2017-07-18

    In this study, nanoindentation was conducted to extract the load-displacement behaviour and the nanomechanical properties of asphalt concrete across the mastic, matrix, and aggregate phases. Further, the performance of hydrated lime as an additive was assessed across the three phases. The hydrated lime containing samples have greater resistance to deformation in the mastic and matrix phases, in particular, the mastic. There is strong evidence suggesting that hydrated lime has the most potent effect on the mastic phase, with significant increase in hardness and stiffness.

  5. Characterisation of Asphalt Concrete Using Nanoindentation

    PubMed Central

    Barbhuiya, Salim; Caracciolo, Benjamin

    2017-01-01

    In this study, nanoindentation was conducted to extract the load-displacement behaviour and the nanomechanical properties of asphalt concrete across the mastic, matrix, and aggregate phases. Further, the performance of hydrated lime as an additive was assessed across the three phases. The hydrated lime containing samples have greater resistance to deformation in the mastic and matrix phases, in particular, the mastic. There is strong evidence suggesting that hydrated lime has the most potent effect on the mastic phase, with significant increase in hardness and stiffness. PMID:28773181

  6. Use of waste toner in asphaltic concrete. Research report (Final)

    SciTech Connect

    Solaimanian, M.; Kennedy, T.W.; McGennis, R.B.

    1997-02-01

    Every year, a tremendous amount of toner is produced for copiers and printers by toner manufacturing companies throughout the United States. Some of this toner does not meet quality specifications and consequently becomes a waste product of the manufacturing process. This manufacturing waste, along with the spent toner (residue) from copiers and printer cartridges, is dumped into landfills for lack of a better way utilizing the material. A cooperative research project undertaken by the Texas Department of Transportation and The University of Texas at Austin investigated the feasibility and potential benefits of utilizing waste toner in hot-mix asphalt concrete. The research program included procuring a number of different waste and spent toners, blending them with asphalt cement at different ratios, and evaluating the binder and mixtures properties resulting from the waste toner addition.

  7. A study on engineering characteristics of asphalt concrete using filler with recycled waste lime.

    PubMed

    Sung Do, Hwang; Hee Mun, Park; Suk keun, Rhee

    2008-01-01

    This study focuses on determining the engineering characteristics of asphalt concrete using mineral fillers with recycled waste lime, which is a by-product of the production of soda ash (Na(2)CO(3)). The materials tested in this study were made using a 25%, 50%, 75%, and 100% mixing ratio based on the conventional mineral filler ratio to analyze the possibility of using recycled waste lime. The asphalt concretes, made of recycled waste lime, hydrated lime, and conventional asphalt concrete, were evaluated through their fundamental engineering properties such as Marshall stability, indirect tensile strength, resilient modulus, permanent deformation characteristics, moisture susceptibility, and fatigue resistance. The results indicate that the application of recycled waste lime as mineral filler improves the permanent deformation characteristics, stiffness and fatigue endurance of asphalt concrete at the wide range of temperatures. It was also determined that the mixtures with recycled waste lime showed higher resistance against stripping than conventional asphalt concrete. It was concluded from various test results that a waste lime can be used as mineral filler and, especially, can greatly improve the resistance of asphalt concrete to permanent deformation at high temperatures.

  8. Effect of Warm Mix Asphalt on Aging of Asphalt Binders

    NASA Astrophysics Data System (ADS)

    Abbas, Ala R.; Nazzal, Munir; Kaya, Savas; Akinbowale, Sunday; Subedi, Bijay; Qtaish, Lana Abu

    This paper evaluated the rheological and chemical properties of asphalt binders recovered from short-term and long-term aged foamed warm mix asphalt (WMA) and traditional hot mix asphalt (HMA). AASHTO R 30 was utilized to simulate the short-term and long-term aging of the laboratory-prepared asphalt mixtures. The dynamic shear rheometer (DSR) was used to characterize the rheological properties of the unaged and aged asphalt binders. Fourier-transform infrared (FTIR) spectroscopy was used to identify and quantify the amount of functional groups present in these binders. Gel permeation chromatography (GPC) was utilized to determine the molecular size distribution within these binders. The asphalt binders recovered from short-term and long-term oven aged HMA mixtures exhibited slightly higher G*/sinδ and G*sinδ values than those recovered from foamed WMA mixtures. The FTIR and GPC test results agreed with those obtained in the DSR. This indicates that foamed WMA mixtures undergo less aging than traditional HMA mixtures.

  9. Low permeability asphalt concrete gamma ray shielding properties.

    PubMed

    Binney, S E; Sykes, K L

    1997-01-01

    Energy-dependent gamma ray shielding properties were measured as a function of gamma ray energy for a low permeability asphalt concrete that is used as a cap to prevent water infiltration into radioactive waste sites. Experimental data were compared to ISO-PC point kernel shielding calculations. Calculated dose equivalent rates compared well with experimental values, especially considering the poor detector resolution involved. The shielding properties of the asphalt concrete closely resembled those of aluminum. The results presented can be used to determine the asphalt concrete thickness required to reduce dose equivalent rates from several gamma ray emitting radionuclides.

  10. Viscoelastic behaviour of cold recycled asphalt mixes

    NASA Astrophysics Data System (ADS)

    Cizkova, Zuzana; Suda, Jan

    2017-09-01

    Behaviour of cold recycled mixes depends strongly on both the bituminous binder content (bituminous emulsion or foamed bitumen) and the hydraulic binder content (usually cement). In the case of cold recycled mixes rich in bitumen and with low hydraulic binder content, behaviour is close to the viscoelastic behaviour of traditional hot mix asphalt. With decreasing bituminous binder content together with increasing hydraulic binder content, mixes are characteristic with brittle behaviour, typical for concrete pavements or hydraulically bound layers. The behaviour of cold recycled mixes with low content of both types of binders is similar to behaviour of unbound materials. This paper is dedicated to analysing of the viscoelastic behaviour of the cold recycled mixes. Therefore, the tested mixes contained higher amount of the bituminous binder (both foamed bitumen and bituminous emulsion). The best way to characterize any viscoelastic material in a wide range of temperatures and frequencies is through the master curves. This paper includes interesting findings concerning the dependency of both parts of the complex modulus (elastic and viscous) on the testing frequency (which simulates the speed of heavy traffic passing) and on the testing temperature (which simulates the changing climate conditions a real pavement is subjected to).

  11. 40 CFR 443.20 - Applicability; description of the asphalt concrete subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... asphalt concrete subcategory. 443.20 Section 443.20 Protection of Environment ENVIRONMENTAL PROTECTION... MATERIALS (TARS AND ASPHALT) POINT SOURCE CATEGORY Asphalt Concrete Subcategory § 443.20 Applicability; description of the asphalt concrete subcategory. The provisions of this subpart are applicable to...

  12. 40 CFR 443.20 - Applicability; description of the asphalt concrete subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... asphalt concrete subcategory. 443.20 Section 443.20 Protection of Environment ENVIRONMENTAL PROTECTION... MATERIALS (TARS AND ASPHALT) POINT SOURCE CATEGORY Asphalt Concrete Subcategory § 443.20 Applicability; description of the asphalt concrete subcategory. The provisions of this subpart are applicable to...

  13. 40 CFR 443.20 - Applicability; description of the asphalt concrete subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... asphalt concrete subcategory. 443.20 Section 443.20 Protection of Environment ENVIRONMENTAL PROTECTION... ROOFING MATERIALS (TARS AND ASPHALT) POINT SOURCE CATEGORY Asphalt Concrete Subcategory § 443.20 Applicability; description of the asphalt concrete subcategory. The provisions of this subpart are applicable to...

  14. 40 CFR 443.20 - Applicability; description of the asphalt concrete subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... asphalt concrete subcategory. 443.20 Section 443.20 Protection of Environment ENVIRONMENTAL PROTECTION... ROOFING MATERIALS (TARS AND ASPHALT) POINT SOURCE CATEGORY Asphalt Concrete Subcategory § 443.20 Applicability; description of the asphalt concrete subcategory. The provisions of this subpart are applicable to...

  15. 40 CFR 443.20 - Applicability; description of the asphalt concrete subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... asphalt concrete subcategory. 443.20 Section 443.20 Protection of Environment ENVIRONMENTAL PROTECTION... ROOFING MATERIALS (TARS AND ASPHALT) POINT SOURCE CATEGORY Asphalt Concrete Subcategory § 443.20 Applicability; description of the asphalt concrete subcategory. The provisions of this subpart are applicable to...

  16. Performance of recycled asphalt concrete airport pavement surfaces

    NASA Astrophysics Data System (ADS)

    Cline, G. D.; Hironaka, M. C.

    1986-10-01

    The objective of this research was to make an assessment of the relative performance of recycled versus new asphalt concrete pavement surfaces constructed for airport facilities. To make this assessment, pavement condition index (PCI) surveys and tests on core samples from the hot-mix recycled pavements located on the airports at Needles, California, and Valley City, North Dakota were conducted. Both pavements have a condition rating of very good. The survey and test data were compared with those for recycled highway and virgin material Navy airfield pavements. The recycle pavement at Needles is performing as good as those Navy pavements constructed with virgin material. The recycled pavement at Valley City has a higher deterioration rate than the Navy pavements but this could be attributed to the harsh climate found in North Dakota. The results of this study show that hot-mix recycling was successful at these airports but additional studies are required to determine the applicability of Asphalt Concrete (AC) recycling for reconstruction at all airports.

  17. Wavelet-based asphalt concrete texture grading and classification

    NASA Astrophysics Data System (ADS)

    Almuntashri, Ali; Agaian, Sos

    2011-03-01

    In this Paper, we introduce a new method for evaluation, quality control, and automatic grading of texture images representing different textural classes of Asphalt Concrete (AC). Also, we present a new asphalt concrete texture grading, wavelet transform, fractal, and Support Vector Machine (SVM) based automatic classification and recognition system. Experimental results were simulated using different cross-validation techniques and achieved an average classification accuracy of 91.4.0 % in a set of 150 images belonging to five different texture grades.

  18. Criteria for Asphalt-Rubber Concrete in Civil Airport Pavements. Volume 2. Evaluation of Asphalt-Rubber Concrete.

    DTIC Science & Technology

    1987-03-01

    194 ix LIST OF TABLES Table Page 1 1977 FAA Aggregate Grading Band for Bituminous Surface Course with 1/2" (12.5m) Maximum Particle Size* ...... 6 2...Asphalt Concrete and Asphalt-Rubber Concrete. . . . . . . . . . . . . . . . . . . . . . . . . 106 xi LIST OF FthJiJRf1 Figure Page 1 1977 FAA...were blended to meet the 1977 FAA aggregate grading specification for pavements with a bituminous surface course and designed to accommodate aircraft

  19. Thermal behavior of crumb-rubber modified asphalt concrete mixtures

    NASA Astrophysics Data System (ADS)

    Epps, Amy Louise

    Thermal cracking is one of the primary forms of distress in asphalt concrete pavements, resulting from either a single drop in temperature to an extreme low or from multiple temperature cycles above the fracture temperature of the asphalt-aggregate mixture. The first mode described is low temperature cracking; the second is thermal fatigue. The addition of crumb-rubber, manufactured from scrap tires, to the binder in asphalt concrete pavements has been suggested to minimize both types of thermal cracking. Four experiments were designed and completed to evaluate the thermal behavior of crumb-rubber modified (CRM) asphalt-aggregate mixtures. Modified and unmodified mixture response to thermal stresses was measured in four laboratory tests. The Thermal Stress Restrained Specimen Test (TSRST) and the Indirect Tensile Test (IDT) were used to compare mixture resistance to low temperature cracking. Modified mixtures showed improved performance, and cooling rate did not affect mixture resistance according to the statistical analysis. Therefore results from tests with faster rates can predict performance under slower field rates. In comparison, predicted fracture temperatures and stresses (IDT) were generally higher than measured values (TSRST). In addition, predicted fracture temperatures from binder test results demonstrated that binder testing alone is not sufficient to evaluate CRM mixtures. Thermal fatigue was explored in the third experiment using conventional load-induced fatigue tests with conditions selected to simulate daily temperature fluctuations. Test results indicated that thermal fatigue may contribute to transverse cracking in asphalt pavements. Both unmodified and modified mixtures had a finite capacity to withstand daily temperature fluctuations coupled with cold temperatures. Modified mixtures again exhibited improved performance. The fourth experiment examined fracture properties of modified and unmodified mixtures using a common fracture toughness test

  20. Characteristics and applications of high-performance fiber reinforced asphalt concrete

    NASA Astrophysics Data System (ADS)

    Park, Philip

    Steel fiber reinforced asphalt concrete (SFRAC) is suggested in this research as a multifunctional high performance material that can potentially lead to a breakthrough in developing a sustainable transportation system. The innovative use of steel fibers in asphalt concrete is expected to improve mechanical performance and electrical conductivity of asphalt concrete that is used for paving 94% of U. S. roadways. In an effort to understand the fiber reinforcing mechanisms in SFRAC, the interaction between a single straight steel fiber and the surrounding asphalt matrix is investigated through single fiber pull-out tests and detailed numerical simulations. It is shown that pull-out failure modes can be classified into three types: matrix, interface, and mixed failure modes and that there is a critical shear stress, independent of temperature and loading rate, beyond which interfacial debonding will occur. The reinforcing effects of SFRAC with various fiber sizes and shapes are investigated through indirect tension tests at low temperature. Compared to unreinforced specimens, fiber reinforced specimens exhibit up to 62.5% increase in indirect tensile strength and 895% improvements in toughness. The documented improvements are the highest attributed to fiber reinforcement in asphalt concrete to date. The use of steel fibers and other conductive additives provides an opportunity to make asphalt pavement electrically conductive, which opens up the possibility for multifunctional applications. Various asphalt mixtures and mastics are tested and the results indicate that the electrical resistivity of asphaltic materials can be manipulated over a wide range by replacing a part of traditional fillers with a specific type of graphite powder. Another important achievement of this study is development and validation of a three dimensional nonlinear viscoelastic constitutive model that is capable of simulating both linear and nonlinear viscoelasticity of asphaltic materials. The

  1. An assessment of SBS modified asphalt concrete pavements performance features performing numerical analysis

    NASA Astrophysics Data System (ADS)

    Karakas, Ahmet Sertac; Bozkurt, Tarik Serhat; Sayin, Baris; Ortes, Faruk

    2017-07-01

    In passenger and freight traffic on the roads, which has the largest share of the hot mix asphalt (HMA) prepared asphalt concrete pavement is one of the most preferred type of flexible superstructure. During the service life of the road, they must provide the performance which is expected to show. HMA must be high performance mix design, comfortable, safe and resistance to degradation. In addition, it becomes a critical need to use various additives materials for roads to be able to serve long-term against environmental conditions such as traffic and climate due to the fact that the way of raw materials is limited. Styrene Butadiene Styrene (SBS) polymers are widely used among additives. In this study, the numerical analysis of SBS modified HMA designed asphalt concrete coatings prepared with different thicknesses with SBS modified HMA is performed. After that, stress and deformation values of the three pavement models are compared and evaluated.

  2. Impulse radar evaluation of concrete, asphalt and waterproofing membrane

    NASA Astrophysics Data System (ADS)

    Chung, T.; Carter, C. R.; Masliwec, T.; Manning, D. G.

    1994-04-01

    Impulse radar has proved to be effective in the nondestructive testing of bridge decks composed of layers of dielectric materials such as asphalt, waterproofing membrane, and reinforced concrete. In this work, the waveforms reflected from these materials are modeled and analyzed theoretically. The relative dielectric constants are measured using sample blocks, and the reflected radar waveforms are related to the actual physical structures. It is found that asphalt thickness and cover over reinforcement can be accurately determined.

  3. The use of waste materials in asphalt concrete mixtures.

    PubMed

    Tuncan, Mustafa; Tuncan, Ahmet; Cetin, Altan

    2003-04-01

    The purpose of this study was to investigate (a) the effects of rubber and plastic concentrations and rubber particle sizes on properties of asphalt cement, (b) on properties of asphalt concrete specimens and (c) the effects of fly ash, marble powder, rubber powder and petroleum contaminated soil as filler materials instead of stone powder in the asphalt concrete specimens. One type of limestone aggregate and one penetration-graded asphalt cement (75-100) were used. Three concentrations of rubber and plastic (i.e. 5%, 10% and 20% of the total weight of asphalt cement), three rubber particle sizes (i.e. No. 4 [4.75mm] - 20 [0.85 mm], No. 20 [0.85mm] - 200 [0.075mm] and No. 4 [4.75mm] - 200 [0.075mm]) and one plastic particle size (i.e. No. 4 [4.75mm] - 10 [2.00mm]) were also used. It was found that while the addition of plastic significantly increased the strength of specimens, the addition of rubber decreased it. No. 4 [4.75mm] - 200 [0.075mm] rubber particles showed the best results with respect to the indirect tensile test. The Marshall stability and indirect tensile strength properties of plastic modified specimens increased. Marble powder and fly ash could be used as filler materials instead of stone powder in the asphalt concrete pavement specimens.

  4. Asphaltic concrete overlays of rigid and flexible pavements

    NASA Astrophysics Data System (ADS)

    Kinchen, R. W.; Temple, W. H.

    1980-10-01

    The development of a mechanistic approach to overlay thickness selection is described. The procedure utilizes a deflection analysis to determine pavement rehabilitation needs. Design guides for selecting the overlay thickness are presented. Tolerable deflection-traffic load relationships and the deflection attenuation properties of asphaltic concrete were developed, representing the subgrade support conditions and properties of materials used in Louisiana. All deflection measurements on asphaltic concrete were corrected for the effect of temperature. Deflection measurements taken before and after overlay were also adjusted to minimize the effects of seasonal subgrade moisture variation.

  5. Evaluation of low temperature properties of warm mix asphalt

    NASA Astrophysics Data System (ADS)

    Wen, Jin; Liu, Zhifei; Wu, Shaopeng

    2009-12-01

    Warm mix asphalt (WMA), which reduces the mixing and compaction temperature of conventional hot mix asphalt (HMA), is becoming an attractive paving material. It is critical to identify the low temperature properties of warm mix asphalt. In this study, the three-point bending, bending creep tests and indirect tensile tests were conducted to test the low-temperature properties of warm mix asphalt as well as the conventional hot mix asphalt, which was used as the control mixture. Sasobit and Aspha-min were used as additives for warm mix asphalt, which was mixed and compacted lower than the traditional hot mix asphalt about 25°C dosages accounted for 3% of asphalt, and 0.3% of mixture, respectively. The results of bending strength, bending modulus, and creep rate indicate that warm mix asphalt using Sasobit and Aspha-min slightly affects the resistance property to cracking compared with the conventional hot mix asphalt. The results suggest that the warm mix asphalt can maintain the low temperature properties of hot mix asphalt.

  6. Evaluation of low temperature properties of warm mix asphalt

    NASA Astrophysics Data System (ADS)

    Wen, Jin; Liu, Zhifei; Wu, Shaopeng

    2010-03-01

    Warm mix asphalt (WMA), which reduces the mixing and compaction temperature of conventional hot mix asphalt (HMA), is becoming an attractive paving material. It is critical to identify the low temperature properties of warm mix asphalt. In this study, the three-point bending, bending creep tests and indirect tensile tests were conducted to test the low-temperature properties of warm mix asphalt as well as the conventional hot mix asphalt, which was used as the control mixture. Sasobit and Aspha-min were used as additives for warm mix asphalt, which was mixed and compacted lower than the traditional hot mix asphalt about 25°C dosages accounted for 3% of asphalt, and 0.3% of mixture, respectively. The results of bending strength, bending modulus, and creep rate indicate that warm mix asphalt using Sasobit and Aspha-min slightly affects the resistance property to cracking compared with the conventional hot mix asphalt. The results suggest that the warm mix asphalt can maintain the low temperature properties of hot mix asphalt.

  7. Research on fracture performance of epoxy asphalt concrete based on double-K fracture criterion

    NASA Astrophysics Data System (ADS)

    Zhang, M.; Qian, Z. D.; Xue, Y. C.

    2017-01-01

    After cracks appear on steel bridge deck epoxy asphalt concrete pavement, cracks propagate fast under vehicle load. This paper studied the fracture performance of epoxy asphalt concrete, utilized single edge notched beam (SEB) three-point bending test, measured the load (P) exerted on epoxy asphalt SEB; utilized digital camera to record the fracture process of epoxy asphalt SEB, extracted the images according to the required sampling frequency and utilized Image-Pro Plus to measure the crack mouth opening displacement (CMOD) of epoxy asphalt SEB on the extracted images; calculated the double-K fracture parameters according to the P-CMOD curve. Results indicate that of epoxy asphalt concrete is 1.11 MPa and of epoxy asphalt concrete is 2.31 MPa at -15°C of epoxy asphalt concrete is 1.02 MPa and of epoxy asphalt concrete is 1.83 MPa at -5°C of epoxy asphalt concrete is 0.77 MPa and of epoxy asphalt concrete is 1.82 MPa at 5°C. The double-K fracture parameters of epoxy asphalt concrete increase slightly when the temperature decreases at the scope of -15°C to 5°C. The relation of and is .

  8. Asphalt and asphalt additives. Transportation research record

    SciTech Connect

    Not Available

    1992-01-01

    Contents: use of asphalt emulsions for in-place recycling: oregon experience; gap-graded cold asphalt concrete: benefits of polymer-modified asphalt cement and fibers; cold in-place recycling for rehabilitation and widening of low-volume flexible pavements in indiana; in situ cold recycling of bituminous pavements with polymer-modified high float emulsions; evaluation of new generation of antistripping additives; correlation between performance-related characteristics of asphalt cement and its physicochemical parameters using corbett's fractions and hpgc; reaction rates and hardening susceptibilities as determined from pressure oxygen vessel aging of asphalts; evaluation of aging characteristics of asphalts by using tfot and rtfot at different temperature levels; summary of asphalt additive performance at selected sites; relating asphalt absorption to properties of asphalt cement and aggregate; study of the effectiveness of styrene-butadiene rubber latex in hot mix asphalt mixes; stability of straight and polymer-modified asphalts.

  9. A Multiscale Virtual Fabrication and Lattice Modeling Approach for the Fatigue Performance Prediction of Asphalt Concrete

    NASA Astrophysics Data System (ADS)

    Dehghan Banadaki, Arash

    Predicting the ultimate performance of asphalt concrete under realistic loading conditions is the main key to developing better-performing materials, designing long-lasting pavements, and performing reliable lifecycle analysis for pavements. The fatigue performance of asphalt concrete depends on the mechanical properties of the constituent materials, namely asphalt binder and aggregate. This dependent link between performance and mechanical properties is extremely complex, and experimental techniques often are used to try to characterize the performance of hot mix asphalt. However, given the seemingly uncountable number of mixture designs and loading conditions, it is simply not economical to try to understand and characterize the material behavior solely by experimentation. It is well known that analytical and computational modeling methods can be combined with experimental techniques to reduce the costs associated with understanding and characterizing the mechanical behavior of the constituent materials. This study aims to develop a multiscale micromechanical lattice-based model to predict cracking in asphalt concrete using component material properties. The proposed algorithm, while capturing different phenomena for different scales, also minimizes the need for laboratory experiments. The developed methodology builds on a previously developed lattice model and the viscoelastic continuum damage model to link the component material properties to the mixture fatigue performance. The resulting lattice model is applied to predict the dynamic modulus mastercurves for different scales. A framework for capturing the so-called structuralization effects is introduced that significantly improves the accuracy of the modulus prediction. Furthermore, air voids are added to the model to help capture this important micromechanical feature that affects the fatigue performance of asphalt concrete as well as the modulus value. The effects of rate dependency are captured by

  10. Emissions Reductions Associated with the Use of Warm-Mix Asphalt as Compared to Hot-Mix Asphalt

    DTIC Science & Technology

    2014-06-01

    gas, light fuel oils, or waste fuel oils and its sulfur content (NPI 1999). In counter-flow drum-mix plants, the liquid asphalt , aggregate, and...ER D C/ G SL T R- 14 -1 9 Emissions Reductions Associated with the Use of Warm-Mix Asphalt as Compared to Hot-Mix Asphalt G eo te ch ni...Reductions Associated with the Use of Warm-Mix Asphalt as Compared to Hot-Mix Asphalt Mariely Mejías-Santiago Geotechnical and Structures

  11. Effect of Material Composition and Environmental Condition on Thermal Characteristics of Conductive Asphalt Concrete.

    PubMed

    Pan, Pan; Wu, Shaopeng; Hu, Xiaodi; Liu, Gang; Li, Bo

    2017-02-23

    Conductive asphalt concrete with high thermal conductivity has been proposed to improve the solar energy collection and snow melting efficiencies of asphalt solar collector (ASC). This paper aims to provide some insight into choosing the basic materials for preparation of conductive asphalt concrete, as well as determining the evolution of thermal characteristics affected by environmental factors. The thermal properties of conductive asphalt concrete were studied by the Thermal Constants Analyzer. Experimental results showed that aggregate and conductive filler have a significant effect on the thermal properties of asphalt concrete, while the effect of asphalt binder was not evident due to its low proportion. Utilization of mineral aggregate and conductive filler with higher thermal conductivity is an efficient method to prepare conductive asphalt concrete. Moreover, change in thermal properties of asphalt concrete under different temperature and moisture conditions should be taken into account to determine the actual thermal properties of asphalt concrete. There was no noticeable difference in thermal properties of asphalt concrete before and after aging. Furthermore, freezing-thawing cycles strongly affect the thermal properties of conductive asphalt concrete, due to volume expansion and bonding degradation.

  12. Effect of Material Composition and Environmental Condition on Thermal Characteristics of Conductive Asphalt Concrete

    PubMed Central

    Pan, Pan; Wu, Shaopeng; Hu, Xiaodi; Liu, Gang; Li, Bo

    2017-01-01

    Conductive asphalt concrete with high thermal conductivity has been proposed to improve the solar energy collection and snow melting efficiencies of asphalt solar collector (ASC). This paper aims to provide some insight into choosing the basic materials for preparation of conductive asphalt concrete, as well as determining the evolution of thermal characteristics affected by environmental factors. The thermal properties of conductive asphalt concrete were studied by the Thermal Constants Analyzer. Experimental results showed that aggregate and conductive filler have a significant effect on the thermal properties of asphalt concrete, while the effect of asphalt binder was not evident due to its low proportion. Utilization of mineral aggregate and conductive filler with higher thermal conductivity is an efficient method to prepare conductive asphalt concrete. Moreover, change in thermal properties of asphalt concrete under different temperature and moisture conditions should be taken into account to determine the actual thermal properties of asphalt concrete. There was no noticeable difference in thermal properties of asphalt concrete before and after aging. Furthermore, freezing–thawing cycles strongly affect the thermal properties of conductive asphalt concrete, due to volume expansion and bonding degradation. PMID:28772580

  13. Test of LOX compatibility for asphalt and concrete runway materials

    NASA Technical Reports Server (NTRS)

    Moyers, C. V.; Bryan, C. J.; Lockhart, B. J.

    1973-01-01

    A literature survey and a telephone canvass of producers and users of LOX is reported which yielded one report of an accident resulting from a LOX spill on asphalt, one discussion of hazardous conditions, and an unreferenced mention of an incident. Laboratory tests using standard LOX impact apparatus yielded reactions with both old and new alphalt, but none with concrete. In the final test, using a larger sample of asphalt, the reaction caused extensive damage to equipment. Initial field experiments using 2-meter square asphalt slabs covered with LOX, conducted during rainy weather, achieved no reaction with plummets, and limited reaction with a blasting cap as a reaction initiator. In a final plummet-initiated test on a dry slab, a violent reaction, which appeared to have propagated over the entire slab surface, destroyed the plummet fixture and threw fragments as far as 48 meters.

  14. Leachability of dissolved chromium in asphalt and concrete surfacing materials.

    PubMed

    Kayhanian, Masoud; Vichare, Akshay; Green, Peter G; Harvey, John

    2009-08-01

    Leachate metal pollutant concentrations produced from different asphalt and concrete pavement surfacing materials were measured under controlled laboratory conditions. The results showed that, in general, the concentrations of most metal pollutants were below the reporting limits. However, dissolved chromium was detected in leachate from concrete (but not asphalt) specimens and more strongly in the early-time leachate samples. As the leaching continued, the concentration of Cr decreased to below or close to the reporting limit. The source of the chromium in concrete pavement was found to be cement. The concentration of total Cr produced from leachate of different cement coming from different sources that was purchased from retail distributors ranged from 124 to 641mug/L. This result indicates that the potential leachability of dissolved Cr from concrete pavement materials can be reduced through source control. The results also showed that the leachability of dissolved Cr in hardened pavement materials was substantially reduced. For example, the concentration of dissolved Cr measured in actual highway runoff was found to be much lower than the Cr concentration produced from leachate of both open and dense graded concrete pavement specimens under controlled laboratory study. It was concluded that pavement materials are not the source of pollutants of concern in roadway runoff; rather most pollutants in roadway surface runoff are generated from other road-use or land-use sources, or from (wet or dry) atmospheric deposition.

  15. Behavior of asphalt concrete mixtures in triaxial compression

    SciTech Connect

    Tan Siewann; Low Boonhwee; Fwa Tienfang . Dept. of Civil Engineering)

    1994-05-01

    The triaxial compression test is one of the most common standard tests for determining the stress-strain behavior and strength parameters of soil under drained and undrained conditions. The use of the test method in asphaltic mixtures is less well known and seldom practiced. This paper describes the use of the triaxial compression test for asphaltic mixtures for determining their engineering properties such as the friction angle [phi], the cohesion, c, and the elastic compression modulus, E. Effects of test temperatures, strain rates, and confining pressures on the compressive behavior of asphalt concrete were studied. The results showed that the friction angle is primarily a function of aggregate friction and interlocking being independent of test temperature and strain rate. The cohesion, on the other hand, is largely dependent on the binder and fines mixture being sensitive to both test temperature and strain rate changes. The confining pressures have no influence on c and [phi], but have significant influence on the compression modulus, E. The tests can be conducted at controlled temperatures, constant strain-rate, and confining pressures so as to allow the determination of the basic engineering stress-strain and strength properties of these materials under controlled environmental conditions. Using these properties, a constitutive plasticity model based on the Drucker-Prager yield condition can then be applied in the axisymmetric finite element model to describe the mechanical behavior of the asphaltic material in triaxial compression.

  16. Graded Viscoelastic Approach for Modeling Asphalt Concrete Pavements

    NASA Astrophysics Data System (ADS)

    Dave, Eshan V.; Buttlar, William G.; Paulino, Glaucio H.; Hilton, Harry H.

    2008-02-01

    Asphalt concrete pavements exhibit severely graded properties through their thickness due to oxidative aging effects, which are most pronounced at the surface of the pavement and decrease rapidly with depth from the surface. Most of the literature to date has focused on use of layered-elastic models for the consideration of age stiffening. In the current work, a graded viscoelastic model has been implemented within a numerical framework for the simulation of asphalt pavement responses under thermal and mechanical loading. The graded viscoelastic work is extension of the previous work by Paulino and Jin [1], Mukherjee and Paulino [2], and Buttlar et al. [3]. A functionally graded generalized Maxwell model has been used in the development of a constitutive model for asphalt concrete considering aging and temperature gradients. The aging gradient data from laboratory test results reported by Apeagyei [4] is used for obtaining material properties for the graded viscoelastic model. Finite element implementation of the constitutive model incorporates the generalized iso-parametric formulation (GIF) proposed by Kim and Paulino [5], which leads to the graded viscoelastic elements used in this work.

  17. Research on Surfactant Warm Mix Asphalt Construction Technology

    NASA Astrophysics Data System (ADS)

    Li, Guoliang; Sun, Jingxin; Guo, Xiufeng

    Discharging temperature of hot asphalt mixture is about 150°C-185°C, volatilization of asphalt fume harms people's health and fuel cost is high. Jinan Urban Construction Group applies PTL/01 asphalt warm mix agent to produce warm mix asphalt to construction of urban roads' asphalt bituminous pavement. After comparing it with performance of traditional hot asphalt mixture, mixing temperature may be reduced by 30°C-60°C, emission of poisonous gas is reduced, energy conservation and environmental protection are satisfied, construction quality reaches requirements of construction specifications and economic, social and environmental benefits are significant. Thus, it can be used for reference for green construction of urban roads.

  18. A Study of Thermal Properties and the Heating Process in Asphaltic Concrete.

    DTIC Science & Technology

    1984-02-01

    PROPERTIES AND THE HEATING FINAL PROCESS IN ASPHALTIC CONCRETE 1 Jul 1982 - 31 Dec. 19R3 6. PERFORMING O1G. REPORT NUMBER 7. AUTHOR(e) 8. CONTRACT OR GRANT...OFFICE NAME AND ADDRESS 12. REPORT DATE AIR FORCE OFFICE OF SCIENTIFIC RESEARCH /NA February 1984 BOLLING AFB, DC 20332 15. NUMBEROFPAGES 157 14...asphalt and asphaltic concrete have been reported in the literature for at least 55 years (14), much of the data is un- documented in that variables

  19. Durable high strength cement concrete topping for asphalt roads

    NASA Astrophysics Data System (ADS)

    Vyrozhemskyi, Valerii; Krayushkina, Kateryna; Bidnenko, Nataliia

    2017-09-01

    Work on improving riding qualities of pavements by means of placing a thin cement layer with high roughness and strength properties on the existing asphalt pavement were conducted in Ukraine for the first time. Such pavement is called HPCM (High Performance Cementitious Material). This is a high-strength thin cement-layer pavement of 8-9 mm thickness reinforced with metal or polymer fiber of less than 5 mm length. Increased grip properties are caused by placement of stone material of 3-5 mm fraction on the concrete surface. As a result of the research, the preparation and placement technology of high-strength cement thin-layer pavement reinforced with fiber was developed to improve friction properties of existing asphalt pavements which ensures their roughness and durability. It must be emphasized that HPCM is a fundamentally new type of thin-layer pavement in which a rigid layer of 10 mm thickness is placed on a non-rigid base thereby improving riding qualities of asphalt pavement at any season of a year.

  20. Use of plastic waste (poly-ethylene terephthalate) in asphalt concrete mixture as aggregate replacement.

    PubMed

    Hassani, Abolfazl; Ganjidoust, Hossein; Maghanaki, Amir Abedin

    2005-08-01

    One of the environmental issues in most regions of Iran is the large number of bottles made from poly-ethylene terephthalate (PET) deposited in domestic wastes and landfills. Due to the high volume of these bottles, more than 1 million m3 landfill space is needed for disposal every year. The purpose of this experimental study was to investigate the possibility of using PET waste in asphalt concrete mixes as aggregate replacement (Plastiphalt) to reduce the environmental effects of PET disposal. For this purpose the mechanical properties of plastiphalt mixes were compared with control samples. This study focused on the parameters of Marshall stability, flow, Marshall quotient (stability-to-flow ratio) and density. The waste PET used in this study was in the form of granules of about 3 mm diameter which would replace (by volume) a portion of the mineral coarse aggregates of an equal size (2.36-4.75 mm). In all prepared mixes the determined 6.6% optimum bitumen content was used. In this investigation, five different percentages of coarse aggregate replacement were used. The results showed that the aggregate replacement of 20% by volume with PET granules would result in a reduction of 2.8% in bulk compacted mix density. The value of flow in the plastiphalt mix was lower than that of the control samples. The results also showed that when PET was used as partial aggregate replacement, the corresponding Marshall stability and Marshall quotient were almost the same as for the control samples. According to most of specification requirement, these results introduce an asphalt mix that has properties that makes it suitable for practical use and furthermore, the recycling of PET for asphalt concrete roads helps alleviate an environmental problem and saves energy.

  1. Analysis of Load Stress for Asphalt Pavement of Lean Concrete Base

    NASA Astrophysics Data System (ADS)

    Lijun, Suo; Xinwu, Wang

    The study revealed that whether it is early distresses in asphalt pavement or not depends largely on working performance of base. In the field of asphalt pavement, it is widely accepted that lean concrete base, compared with the general semi-rigid base, has better working performance, such as high strength and good eroding resistance. Problem of early distresses in asphalt pavement, which caused by more traffic loadings, can be settled effectively when lean concrete is used in asphalt pavement. Traffic loading is important parameter used in the analysis of the new pavement design. However, few studies have done extensive and intensive research on the load stress for asphalt pavement of lean concrete base. Because of that, it is necessary to study the load stress for the asphalt pavement. In the paper, first of all, three-dimension finite element model of the asphalt pavement is created for the aim of doing mechanical analysis for the asphalt pavement. And then, the two main objectives of this study are investigated. One is analysis for load stress of lean concrete base, and the other is analysis for load stress of asphalt surface. The results show that load stress of lean concrete base decreases, decrease and increase with increase of base's thickness, surface's thickness and ratio of base's modulus to foundation's modulus respectively. So far as the asphalt surface is concerned, maximum shearing stress, which is caused by load, is evident in asphalt surface which is located in transverse contraction joint of lean concrete base of asphalt pavement. Maximum shearing stress decrease, decrease, decrease and increase respectively with increase of the surface's modulus, the surface's thickness, base's thickness and ratio of base's modulus to foundation's modulus.

  2. Characteristics of permanent deformation rate of warm mix asphalt with additives variation (BNA-R and zeolite)

    NASA Astrophysics Data System (ADS)

    Wahjuningsih, Nurul; Hadiwardoyo, Sigit Pranowo; Sumabrata, R. Jachrizal

    2017-06-01

    Permanent deformation is one of the criteria of failure on asphalt concrete mixture. The nature of the bitumen melt at high temperatures, this condition causes the asphalt concrete mixture tends to soften due to an increase in temperature of the road surface. The increase in surface temperature and the load wheel that has repeated itself on the same trajectory causes deformation groove has formed. Conditions rutting due to permanent deformation has resulted in inconvenience to the passengers and can lead to high costs of road maintenance. On the road planning process required a prediction of the rate of the permanent deformation of asphalt concrete mixtures. It is important to know early on the road surface damage due to vehicle load and surface temperature during service life. Asphalt has been mixed with the additive BNA-R and Zeolite intended to make variations in the characteristics of bitumen in this study. This variation is further combined with variations in the composition of aggregate in order to obtain a combination of asphalt-aggregate mixture. This mixture using warm mix, and to determine the permanent deformation of asphalt mix with material combinations was performed through the wheel tracking test machine with 3,780 cycles or 7,560 tracks for 3 hours. Another analysis to determine the characteristics of asphalt concrete mixtures have also been carried out changes in the surface temperature at the time of the test track. From the results of the test track to nearly 8 thousand passes has seen permanent deformation characteristics of asphalt concrete mixture with a variation of the characteristics of bitumen and aggregate variation. Groove of deformation due to a wheel load from the initial until the last passes shows that there are influence of compaction temperature on the variation of bitumen and aggregate composition to the relationship of permanent deformation of the wheel groove, especially on the road surface temperature changes.

  3. Design and Properties of Asphalt Concrete Mixtures Using Renewable Bioasphalt Binder

    NASA Astrophysics Data System (ADS)

    Setyawan, A.; Djumari; Irfansyah, P. A.; Shidiq, A. M.; Wibisono, I. S.; Fauzy, M. N.; Hadi, F. N.

    2017-02-01

    The needs of petroleum asphalt as materials for pavement is very large, while the petroleum classified as natural resources that cannot be renewable. As a result of petroleum dwindling and prices tend to be more expensive. So that requiring other alternative materials as a substitute for conventional asphalt derived from biomass or often called bioasphalt. This study aims to know the volumetric and Marshall characteristics on Asphalt Cement ( AC ) using the Damar asphalt modification to substitute 60/70 penetration asphalt as a binder. The volumetric and Marshall characteristic are porosity, density, flow, stability, and Marshall quotient. The characteristic of asphalt concrete at optimum bitumen content are compared to the conditions from highway agency 1987 and the general specification of asphalt concrete Bina Marga 2010 the third revision. The research uses experimental method in the laboratory with the samples made using the dasphalt modification as binder and incorporating the aggregate gradation no. VII SNI 03-1737-1989. The research is using 15 samples divided into 5 contents of damar asphalt, they are 5%, 5,5%, 6%, 6,5%, dan 7%. Tests carried out using Marshall test equipment to get the value of flow and stability and then be searched the value of optimum damar asphalt content. The result of asphalt concrete analysis using dasphalt modification as binder gives the value of optimum dasphalt content at 5,242%. The most characteristics already met the requirements and specifications.

  4. Evaluation of Warm Mix Asphalt Additives for Use in Modified Asphalt Mixtures

    NASA Astrophysics Data System (ADS)

    Chamoun, Zahi

    The objective of this research effort is to evaluate the use of warm-mix additives with polymer modified and terminal blend tire rubber asphalt mixtures from Nevada and California. The research completed over two stages: first stage evaluated two different WMA technologies; Sasobit and Advera, and second stage evaluated one additional WMA technology; Evotherm. The experimental program covered the evaluation of resistance of the mixtures to moisture damage, the performance characteristics of the mixtures, and mechanistic analysis of mixtures in simulated pavements. In the both stages, the mixture resistance to moisture damage was evaluated using the indirect tensile test and the dynamic modulus at multiple freeze-thaw cycles, and the resistance of the various asphalt mixtures to permanent deformation using the Asphalt Mixture Performance Tester (AMPT). Resistance of the untreated mixes to fatigue cracking using the flexural beam fatigue was only completed for the first stage. One source of aggregates was sampled in, two different batches, three warm mix asphalt technologies (Advera, Sasobit and Evotherm) and three asphalt binder types (neat, polymer-modified, and terminal blend tire rubber modified asphalt binders) typically used in Nevada and California were evaluated in this study. This thesis presents the resistance of the first stage mixtures to permanent deformation and fatigue cracking using two warm-mix additives; Advera and Sasobit, and the resistance to moisture damage and permanent deformation of the second stage mixtures with only one warm-mix additive; Evotherm.

  5. Reinforcement of asphalt concrete pavement by segments of exhausted fiber used for sorption of oil spill

    NASA Astrophysics Data System (ADS)

    Lukashevich, V. N.; Efanov, I. N.

    2015-01-01

    The paper is aimed at construction of the experimental road pavement made of dispersed reinforced asphalt concrete. Electronic paramagnetic resonance, infrared spectroscopy and fluorescent bitumen studies were used to prove that disperse reinforcement of asphalt concrete mixtures with fibers of exhausted sorbents reduce the selective filtration of low polymeric fractions of petroleum bitumen and improve its properties in the adsorption layer. Sesquioxides are neutralized as catalysts aging asphalt binder. This leads to improvement in the elasticity of bitumen films at low temperatures and provide better crack resistance of coatings to reduce the intensity of the aging of asphalt binder, and, therefore, to increase the durability of road pavements. The experimental road pavement made of dispersed reinforced asphalt concrete operated during 4 years and demonstrated better transport- performance properties in comparison with the analogue pavements.

  6. Damage detection and artificial healing of asphalt concrete after trafficking with a load simulator

    NASA Astrophysics Data System (ADS)

    Bueno, M.; Arraigada, M.; Partl, M. N.

    2016-08-01

    Artificial healing of asphalt concrete by induction heating requires the addition of electrically conductive and/or magnetic materials into the asphalt mixture. Hence, bitumen can be heated up by an alternating electromagnetic field, decreasing therefore its viscosity and allowing it to flow for closing cracks and recover bonding among the mineral aggregates.

  7. High temperature performance of scrap tire rubber modified asphalt concrete

    SciTech Connect

    Coomarasamy, A.; Manolis, S.; Hesp, S.

    1996-12-31

    Wheel track rutting tests on mixes modified with 30 mesh, 80 mesh, and very fine colloidal crumb rubber particles show that a very significant improvement in performance occurs with a reduction in the rubber particle size. The SHRP binder test for rutting, which was originally developed for homogeneous systems only, does not predict the performance improvement for smaller rubber particles. If these new scrap rubber binder systems are to be used in pavements then rutting tests on the asphalt-aggregate mixture should be conducted in order to accurately predict high temperature performance.

  8. Effect of Crumb Rubber and Warm Mix Additives on Asphalt Aging, Rheological, and Failure Properties

    NASA Astrophysics Data System (ADS)

    Agrawal, Prashant

    Asphalt-rubber mixtures have been shown to have useful properties with respect to distresses observed in asphalt concrete pavements. The most notable change in properties is a large increase in viscosity and improved low-temperature cracking resistance. Warm mix additives can lower production and compaction temperatures. Lower temperatures reduce harmful emissions and lower energy consumption, and thus provide environmental benefits and cut costs. In this study, the effects of crumb rubber modification on various asphalts such as California Valley, Boscan, Alaska North Slope, Laguna and Cold Lake were also studied. The materials used for warm mix modification were obtained from various commercial sources. The RAF binder was produced by Imperial Oil in their Nanticoke, Ontario, refinery on Lake Erie. A second commercial PG 52-34 (hereafter denoted as NER) was obtained/sampled during the construction of a northern Ontario MTO contract. Some regular tests such as Dynamic Shear Rheometer (DSR) and Bending Beam Rheometer (BBR), Multiple Stress Creep Recovery (MSCR) and some modified new protocols such as the extended BBR test (LS-308) and the Double-Edge Notched Tension (DENT) test (LS-299) are used to study, the effect of warm mix and a host of other additives on rheological, aging and failure properties. A comparison in the properties of RAF and NER asphalts has also been made as RAF is good quality asphalt and NER is bad quality asphalt. From the studies the effect of additives on chemical and physical hardening tendencies was found to be significant. The asphalt samples tested in this study showed a range of tendencies for chemical and physical hardening.

  9. Size-dependent enrichment of waste slag aggregate fragments abraded from asphalt concrete.

    PubMed

    Takahashi, Fumitake; Shimaoka, Takayuki; Gardner, Kevin; Kida, Akiko

    2011-10-30

    Authors consider the environmental prospects of using melted waste slag as the aggregate for asphalt pavement. In particular, the enrichment of slag-derived fragments in fine abrasion dust particles originated from slag asphalt concrete and its size dependency were concerned. A series of surface abrasion tests for asphalt concrete specimens, containing only natural aggregates as reference or 30 wt% of substituted slag aggregates, were performed. Although two of three slag-asphalt concretes generated 1.5-3.0 times larger amount of abrasion dust than the reference asphalt concrete did, it could not be explained only by abrasion resistance of slag. The enrichment of slag-derived fragments in abrasion dust, estimated on the basis of the peak intensity of quartz and heavy metal concentrations, had size dependency for all slag-asphalt concretes. Slag-derived fragments were enriched in abrasion dust particles with diameters of 150-1000 μm. Enrichment factors were 1.4-2.1. In contrast, there was no enrichment in abrasion dust particles with diameter less than 75 μm. This suggests that prior airborne-size fragmentation of substituted slag aggregates does not need to be considered for tested slag aggregates when environmental risks of abrasion dust of slag-asphalt pavement are assessed. Copyright © 2011 Elsevier B.V. All rights reserved.

  10. Study of Asphaltic Concrete Produced in Dryer Drum Mixers for Airport Pavements.

    DTIC Science & Technology

    1976-10-01

    STWDARDS-163- w S 4 -- , ,a, i I Report No-c FAA-RD-76-165 STUDY OF ASPHALTIC CONCRETE PRODUCED IN DRYER DRUM MIXERS FOR AIRPORT PAVEMENTS 0 E. T...PREFACE This study was supported by the Systems Research and Development Service of the Federal Aviation Administration. This is a final report presenting...the asphaltic concrete . In September, 1976 the Alaskan Region of FAA reported that the runway pavement had transverse thermal cracks approximately 200

  11. A multiscale model for predicting the viscoelastic properties of asphalt concrete

    NASA Astrophysics Data System (ADS)

    Garcia Cucalon, Lorena; Rahmani, Eisa; Little, Dallas N.; Allen, David H.

    2016-08-01

    It is well known that the accurate prediction of long term performance of asphalt concrete pavement requires modeling to account for viscoelasticity within the mastic. However, accounting for viscoelasticity can be costly when the material properties are measured at the scale of asphalt concrete. This is due to the fact that the material testing protocols must be performed recursively for each mixture considered for use in the final design.

  12. Ice melting properties of steel slag asphalt concrete with microwave heating

    NASA Astrophysics Data System (ADS)

    Li, Bin; Sun, Yihan; Liu, Quantao; Fang, Hao; Wu, Shaopeng; Tang, Jin; Ye, Qunshan

    2017-03-01

    The ice on the surface of asphalt pavement in winter significantly influences the road transportation safety. This paper aims at the improvement of the ice melting efficiency on the surface of asphalt pavement. The steel slag asphalt concrete was prepared and the high ice melting efficiency was achieved with the microwave heating. A series of experiments were conducted to evaluate the ice melting performance of steel slag asphalt concrete, including the heating test, ice melting test, thermal conductivity test and so on. The results indicated that the microwave heating of steel slag concrete can improve the efficiency of deicing, mainly because the heating rates of steel slag asphalt mixture are much better than traditional limestone asphalt mixture. According to different thickness lever of ice, the final temperatures of each sample were very close to each other at the end of melting test. It is believed the thickness of the ice has a limited impact on the ice melting efficiency. According to the heating tests results, the bonding of ice and asphalt concrete is defined failure at the moment when the surface temperature of the ice reached 3 °C.

  13. Characteristics of asphalt mixes with FT additive

    NASA Astrophysics Data System (ADS)

    Štefunková, S.

    2012-03-01

    This article is focused on low-temperature asphalt mixture technologies using FT additive and RAP. The modern production and use of asphalt mixture technologies with reduced temperatures has many advantages. These advantages mainly help to save energy and the environment. Lower temperatures enable a reduction in energy consumption, a more acceptable working environment for workers, a reduction in negative environmental effects, such as greenhouse gas emissions, and an improvement in the workability of mixtures and a prolongation of their duration. This technology is currently becoming popular in many countries.

  14. Experimental evaluation of high performance base course and road base asphalt concrete with electric arc furnace steel slags.

    PubMed

    Pasetto, Marco; Baldo, Nicola

    2010-09-15

    The paper presents the results of a laboratory study aimed at verifying the use of two types of electric arc furnace (EAF) steel slags as substitutes for natural aggregates, in the composition of base course and road base asphalt concrete (BBAC) for flexible pavements. The trial was composed of a preliminary study of the chemical, physical, mechanical and leaching properties of the EAF steel slags, followed by the mix design and performance characterization of the bituminous mixes, through gyratory compaction tests, permanent deformation tests, stiffness modulus tests at various temperatures, fatigue tests and indirect tensile strength tests. All the mixtures with EAF slags presented better mechanical characteristics than those of the corresponding asphalts with natural aggregate and satisfied the requisites for acceptance in the Italian road sector technical standards, thus resulting as suitable for use in road construction.

  15. Furfuryl alcohol polymer concretes for use in all-weather repairs of concrete and asphalt surfaces. Revision

    SciTech Connect

    Kukacka, L.E.; Sugama, T.

    1985-04-01

    A furfuryl alcohol-based polymer concrete (FA-PC) has been developed for use as an all-weather repair material for concrete and asphalt surfaces. A formulation consisting of furfuryl alcohol monomer (FA), ..cap alpha.., ..cap alpha.., ..cap alpha..-trichlorotoluene, pyridine, silane, zinc chloride, silica filler, and coarse aggregate meets requirements. Optimized formulations were established for use with premixed and percolation placement methods. The working time for the FA-PC slurry can be controlled at greater than or equal to 15 min from -20/sup 0/C to 52/sup 0/C by simply varying the ..cap alpha.., ..cap alpha.., ..cap alpha..-trichlorotoluene catalyst concentration while holding all of the other constituents constant. Below -20/sup 0/C, slight increases in FA and ZnCl/sub 2/ concentrations are needed to yield optimum properties. Prototype equipment for the mixing and placement of FA-PC was constructed and used in a series of tests up to a size of 6-m x 6-m x 0.15-m. Field tests were performed under rainfall and dry conditions from -15/sup 0/ to 35/sup 0/C. The mixing and placement equipment performed well and the FA-PC slurries exhibited self-leveling characteristics. Test results from proxy samples and cores taken after simulated aircraft trafficking, indicated that the property requirements at an age of 1 h were attained.

  16. Asphaltic Concrete Performance Under Heavy Fighter Aircraft Loading

    DTIC Science & Technology

    1993-02-01

    compacted to determine the effects of overfilling and underfilling the voids in the aggregate. Density and voids filled with binder are two of the...concrete were also taken at different pass levels to determine the change in air voids with traffic. Damage parameters were defined to provide a...149 I 89 Voids Total Mix Data and Interpolated Values Versus Station .............................................. 150 90 Voids Filled

  17. Quantification of the inherent uncertainty in the relaxation modulus and creep compliance of asphalt mixes

    NASA Astrophysics Data System (ADS)

    Kassem, Hussein A.; Chehab, Ghassan R.; Najjar, Shadi S.

    2017-08-01

    Advanced material characterization of asphalt concrete is essential for realistic and accurate performance prediction of flexible pavements. However, such characterization requires rigorous testing regimes that involve mechanical testing of a large number of laboratory samples at various conditions and set-ups. Advanced measurement instrumentation in addition to meticulous and accurate data analysis and analytical representation are also of high importance. Such steps as well as the heterogeneous nature of asphalt concrete (AC) constitute major factors of inherent variability. Thus, it is imperative to model and quantify the variability of the needed asphalt material's properties, mainly the linear viscoelastic response functions such as: relaxation modulus, E(t), and creep compliance, D(t). The objective of this paper is to characterize the inherent uncertainty of both E(t) and D(t) over the time domain of their master curves. This is achieved through a probabilistic framework using Monte Carlo simulations and First Order approximations, utilizing E^{*} data for six AC mixes with at least eight replicates per mix. The study shows that the inherent variability, presented by the coefficient of variation (COV), in E(t) and D(t) is low at small reduced times, and increases with the increase in reduced time. At small reduced times, the COV in E(t) and D(t) are similar in magnitude; however, differences become significant at large reduced times. Additionally, the probability distributions and COVs of E(t) and D(t) are mix dependent. Finally, a case study is considered in which the inherent uncertainty in D(t) is forward propagated to assess the effect of variability on the predicted number of cycles to fatigue failure of an asphalt mix.

  18. Evaluation of Warm Mix Asphalt Technologies and Recycled Asphalt Pavements in Truckee Meadows, Nevada

    NASA Astrophysics Data System (ADS)

    Diaz Montecino, Cristian

    This study evaluated the properties and laboratory-performance of Hot Mix Asphalt (HMA) and Warm Mix Asphalt (WMA) mixtures with different levels of Recycled Asphalt Pavements (RAP) content: none for control mixtures, around 15% by dry weight of aggregates, and more than 30% by dry weight of aggregates. The rheological properties were evaluated for virgin and recovered RAP asphalt binders. The target amount of RAP in the mixtures was determined by using Blending Charts and Mortar Experiments. The mixtures are design through the guidelines established in Marshall Mix Design Method considering additional modifications for RAP and WMA from Superpave Mix Design. The mixtures are evaluated for their resistance to moisture damage by means of measuring the Dynamic Modulus |E*| after three freeze/thaw cycles and the indirect tensile strength after one and three freeze/thaw cycles. The resistance of the mixtures to permanent deformation was also evaluated by using the Asphalt Mixture Performance Tester (AMPT) to measure the flow number (FN). For this study, it was determined that the resistance to moisture damage decreases as the number of freeze/thaw cycles increases for most of the evaluated mixtures. Mixtures exhibited an increase in dynamic modulus as the RAP percentage increased. A decrease in the resistance to moisture damage was detected with the increase in RAP content for most of the mixtures. HMA mixtures exhibited a better performance in rutting than the WMA mixtures. An increase in rutting resistance was observed with the increase in RAP percentage for HMA mixtures whereas an inconsistent trend was observed for WMA mixtures. Further study is needed to validate the use of the high percentage of RAP in Washoe County.

  19. Epoxy asphalt concrete is a perspective material for the construction of roads

    NASA Astrophysics Data System (ADS)

    Vyrozhemskyi, Valerii; Kopynets, Ivan; Kischynskyi, Sergii; Bidnenko, Nataliia

    2017-09-01

    An effective way to increase the durability of asphalt concrete pavements that are subject to high traffic loads and adverse weather and climatic factors is the use of polymer additives which drastically improve the rheological and physical-mechanical properties of bitumen. The use of thermosetting polymers including epoxy resins for asphalt and bitumen modification is seen as a perspective solution for this issue. Conducted at DerzhdorNDI SE studies have proved high riding qualities of asphalt pavements that contain epoxy resins. When replacing 20-35% of bitumen with epoxy component, a significant improvement in strength characteristics of asphalt pavement is noted, especially at elevated temperatures. Specific feature of epoxy asphalt concrete is its ability to gain strength over a long-term operation. Thus, despite the increased cost of epoxy asphalt concrete, long service life of pavements on its basis (up to 30 years as predicted) ensures a high profitability of using this material, especially on the roads with heavy traffic and severe traffic conditions.

  20. Effects of reclaimed asphalt pavement on indirect tensile strength test of foamed asphalt mix tested in dry condition

    NASA Astrophysics Data System (ADS)

    Yati Katman, Herda; Rasdan Ibrahim, Mohd; Yazip Matori, Mohd; Norhisham, Shuhairy; Ismail, Norlela

    2013-06-01

    Indirect tensile strength (ITS) test was conducted to analyse strength of the foamed asphalt mixes incorporating reclaimed asphalt pavement. Samples were tested for ITS after cured in the oven at 40°C for 72 hours. This testing condition known as dry condition or unconditioned. Laboratory results show that reclaimed asphalt pavement (RAP) contents insignificantly affect the ITS results. ITS results significantly affected by foamed bitumen contents.

  1. Asphalt mix reinforced with vegetable fibers

    NASA Astrophysics Data System (ADS)

    Gallo, Peter

    2017-09-01

    The use of a larger share of renewable materials in road construction is a trend that in the long term cannot be avoided. In some cases, due to this pressure, new innovative opportunities are generated. This article attempts to outline and bring one of such opportunity. The article describes selection and the use of special natural fibers from renewable natural resources adapted for use in various types of asphalt mixtures to improve the range of properties. Experimental results showed an improvement in stiffness modulus, indirect tensile strength (ITS) and good resistance to permanent deformation of blends containing vegetable fibers. This is a new topic in the road construction. But the results have so far proven that the used type of fibers can be a perspective way, as simple and in line with the policy of sustainable development, to improve the properties (reinforce) of the asphalt mixtures.

  2. The shakeout scenario: Meeting the needs for construction aggregates, asphalt, and concrete

    USGS Publications Warehouse

    Langer, W.H.

    2011-01-01

    An Mw 7.8 earthquake as described in the ShakeOut Scenario would cause significantdamage to buildings and infrastructure. Over 6 million tons of newly mined aggregate would be used for emergency repairs and for reconstruction in the five years following the event. This aggregate would be applied mostly in the form of concrete for buildings and bridges, asphalt or concrete for pavement, and unbound gravel for applications such as base course that goes under highway pavement and backfilling for foundations and pipelines. There are over 450 aggregate, concrete, and asphalt plants in the affected area, some of which would be heavily damaged. Meeting the increased demand for construction materials would require readily available permitted reserves, functioning production facilities, a supply of cement and asphalt, a source of water, gas, and electricity, and a trained workforce. Prudent advance preparations would facilitate a timely emergency response and reconstruction following such an earthquake. ?? 2011, Earthquake Engineering Research Institute.

  3. Investigation of Primary Causes of Load-Related Cracking in Asphalt Concrete Pavement in North Carolina

    NASA Astrophysics Data System (ADS)

    Park, Hong Joon

    This dissertation presents causes of cracking in asphalt concrete pavement in North Carolina through field investigation and laboratory experiments with field extracted material. North Carolina is experiencing higher than anticipated rates of fatigue cracking compared to other state. These higher than expected rates could be reflective of the national trends in mix design practice or could be caused by structural pavement failures. The problems associated with premature cracking in North Carolina pavements point to the need to evaluate the North Carolina Department of Transportation (NCDOT) mixes, processes, and measures to ensure that these factors properly balance the goals of preventing cracking and minimizing permanent deformation. Without solid data from in-service pavements, any conclusions regarding the causes of these failures might be pure conjecture. Accordingly, this research examines material properties through laboratory experiments using field-extracted materials and investigates in situ pavements and pavement structure. In order to assess condition of existing pavement, alligator cracking index (ACI) was developed. The asphalt content in the top layer that exhibits top-down cracking or bottom-up cracking has a proportional relationship to ACI values. The air void content in a bottom layer that exhibits top-down cracking or bottom-up cracking shows an inverse proportional relationship to ACI values. These observations reflect reasonable results. A comparison between ACI and asphalt film thickness values does not produce noteworthy findings, but somewhat reasonable results are evident once the range of comparison is narrowed down. Thicker film thicknesses show higher ACI values. From field core visual observations, road widening is identified as a major cause of longitudinal cracking. Regions with observed layer interface separation tend to have low ACI values. Through tensile strain simulation based on actual field conditions, it is observed that

  4. Experimental testing of hot mix asphalt mixture made of recycled aggregates.

    PubMed

    Rafi, Muhammad Masood; Qadir, Adnan; Siddiqui, Salman Hameed

    2011-12-01

    The migration of population towards big cities generates rapid construction activities. These activities not only put pressure on natural resources but also produce construction, renovation and demolition waste. There is an urgent need to find out ways to handle this waste owing to growing environmental concerns. This can reduce pressure on natural resources as well. This paper presents the results of experimental studies which were carried out on hot mix asphalt mixture samples. These samples were manufactured by adding recycled aggregates (RA) with natural crushed stone aggregates (CSA). Three levels of addition of RA were considered in the presented studies. RA were obtained from both the concrete waste of construction, renovation and demolition activities and reclaimed asphalt pavement. Separate samples were manufactured with the coarse and fine aggregate fractions of both types of RA. Samples made with CSA were used as control specimens. The samples were prepared and tested using the Marshall method. The performance of the samples was investigated in terms of density-void and stability/flow analysis and was compared with the performance criteria as given by National Highway Authority for wearing course material in Pakistan. Based on this data optimum asphalt contents were determined. All the samples made by adding up to 50% RA conform to the specification requirements of wearing course material as given by National Highway Authority in terms of optimum asphalt contents, voids in mineral aggregates and stability/flow. A statistical analysis of variation of these samples confirmed that addition is also possible statistically.

  5. 26. Evening view of concrete mixing plant, concrete placement tower, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    26. Evening view of concrete mixing plant, concrete placement tower, cableway tower, power line and derrick. Photographer unknown, 1927. Source: MWD. - Waddell Dam, On Agua Fria River, 35 miles northwest of Phoenix, Phoenix, Maricopa County, AZ

  6. Hot in-place recycling of asphalt concrete. Final report

    SciTech Connect

    Button, J.W.; Little, D.N.; Estakhri, C.K.; Mason, L.S.

    1994-01-01

    ;Contents: Hot in place recycling processes and equipment; HIPR as a tool for asphalt pavement rehabilitation; Mixture design for HIPR processes; Relative performance of HIPR pavements; Guidelines for effective use of HIPR; and Conclusions and recommendations.

  7. Performance of skid resistance of warm-mix asphalt with buton natural asphalt-rubber (BNA-R) and zeolite additives as a result of road surface temperature changes

    NASA Astrophysics Data System (ADS)

    Anagi, Natasha; Hadiwardoyo, Sigit Pranowo; Sumabrata, R. Jachrizal; Wahjuningsih, Nurul

    2017-06-01

    Roughness of the road surface acts as an obstacle for the vehicle wheel slip on the road surface especially in wet conditions. Road surface roughness can be generated from the properties of the aggregate or bitumen as a characteristic of asphalt mixture. Various types of added material have been used to improve the performance of hot mix asphalt mixture as well as the warm mix asphalt. The addition of BNA-R and zeolite on the warm asphalt mixtures has been investigated, particularly related with its effect on the value of the skid surface due to the wheels track of the vehicle. The study was conducted in an asphalt mixture before and after the traversed wheel condition. In this study, 7.560 trajectory path using the Wheel Tracking Machine and skid resistance test using a modified British Pendulum Tester, were conducted. Skid resistance test involved various temperatures on the surface of the specimen. The results showed that the addition of BNA-R can increase the value of the skid at the beginning of the track, but at the last track, skid resistance performance was stagnant. Zeolite additive material in warm mix asphalt has improved skid resistance, especially the resistance of asphalt concrete mixture to temperature changes.

  8. About the sizes of elastomer particles in the asphalt concrete binder providing the maximum service life of pavements

    NASA Astrophysics Data System (ADS)

    Kaplan, A. M.; Chekunaev, N. I.

    2014-05-01

    It is noted that the durability of asphalt concrete pavements is determined by the time of the trunk cracks formation in the polymer-containing composites - in the modified by elastomers (e.g., by rubber) bitumenous binder of asphalt. Developed by the authors previously the theory of the cracks propagation in heterosystems [1] has allowed to investigate the problem of the cracks propagation in the rubber-bitumen composite. This investigations show that most effectively to prevente the trunk cracks formation in asphalt concrete can ultrafine rubber particles (150-750 nm) in a bitumenos binder of asphalt.

  9. Use of scrap rubber in asphalt pavement surfaces. Special report

    SciTech Connect

    Eaton, R.A.; Roberts, R.J.; Blackburn, R.R.

    1991-12-01

    Scrap tire rubber was mixed into an asphalt concrete wearing course to study the effect of ice disbonding from the pavement surface under traffic. Rubber contents of 0, 3, 6, and 12% by weight were studied. Initial laboratory ice disbonding test results led to the development of a new paving material, Chunk Rubber Asphalt Concrete (CRAC), that uses larger pieces of rubber in a much denser asphalt concrete mix. Strength values doubled and ice disbonding performance was enhanced.

  10. Evaluation of permanent deformation and durability of epoxidized natural rubber modified asphalt mix

    NASA Astrophysics Data System (ADS)

    Al-Mansob, Ramez A.; Ismail, Amiruddin; Rahmat, Riza Atiq O. K.; Nazri Borhan, Muhamad; Alsharef, Jamal M. A.; Albrka, Shaban Ismael; Rehan Karim, Mohamed

    2017-09-01

    The road distresses have caused too much in maintenance cost. However, better understandings of the behaviours and properties of asphalt, couples with greater development in technology, have allowed paving technologists to examine the benefits of introducing additives and modifiers. As a result, modifiers such as polymers are the most popular modifiers used to improve the performance of asphalt mix. This study was conducted to investigate the use of epoxidized natural rubber (ENR) to be mixed with asphalt mix. Tests were conducted to investigate the performance characteristics of ENR-asphalt mixes, where the mixes were prepared according to the wet process. Mechanical testing on the ENR-asphalt mixes have demonstrated that the asphalt mix permanent deformation performance at high temperature was found to be improved compared to the base mixes. However, the durability studies have indicated that ENR-asphalt mixes are slightly susceptible with the presence of moisture. The durability of the ENR-asphalt mixes were found to be enhanced in term of permanent deformation at high and intermediate temperatures compared to the base asphalt mixes. As conclusion, asphalt pavement performance can be enhanced by using ENR as modifier to face the major road distresses.

  11. Asphalt pavement surfaces and asphalt mixtures. Transportation research record

    SciTech Connect

    1996-12-31

    The papers in this volume, which deal with asphalt pavement surfaces and asphalt mixtures, should be of interest to state and local construction, design, materials, and research engineers as well as contractors and material producers. The papers in Part 1 include discussions of pavement smoothness specifications and skidding characteristics. The first four papers in Part 2 were submitted in response to a call for papers for a session at the 75th Annual Meeting of the Transportation Research Board on low-temperature properties of hot-mix asphalt. The next eight are on the influence of volumetric and strength properties on the performance of hot-mix asphalt. In the following three papers, the topics covered are the complex modulus of asphalt concrete, cold in-place asphalt recycling, and polymer modification of asphalt pavements in Ontario. The last two papers were presented in a session on relationship of materials characterization to accelerated pavement performance testing.

  12. Evaluation of the effects of crumb rubber and SBR on rutting resistance of asphalt concrete

    SciTech Connect

    Shih, Chuang-Tsair; Tia, Mang; Ruth, B.E.

    1996-12-31

    This paper presents the results of a study to evaluate the effects of addition of crumb rubber (CR) and styrene-butadiene rubber (SBR) on the rutting resistance of asphalt concrete. These two additives were blended with an AC-20 and an AC-30 grade asphalt cements at different levels of concentrations. These modified and unmodified asphalt blends were tested at intermediate and high temperatures to evaluate their rutting resistance characteristics. They were also used to make Florida type S-I structural surface mixtures. These mixtures were made into Marshall-size specimens by using Gyratory Testing Machine (GTM) equipped with air-roller to compact and density to three compaction levels which simulate three different conditions in the pavement. The FDOT`s (Florida Department of Transportation) Loaded Wheel Tester was also used to evaluate the rutting resistance of these asphalt mixtures. The test results indicate that the modified asphalt mixtures show relatively better rutting resistance and shear resistance as compared with the unmodified asphalt mixtures.

  13. Predicting the behavior of asphalt concrete pavements in seasonal frost areas using nondestructive techniques

    NASA Astrophysics Data System (ADS)

    Janoo, Vincent C.; Berg, Richard L.

    1990-11-01

    Four different pavement test sections were subjected to freeze-thaw cycling in the Frost Effects Research Facility (FERF). The test sections, each 610 cm in length, consisted of 15.2 cm of asphalt concrete pavement over a clay subgrade; 15.2 cm of asphalt concrete over 10.2 cm of crushed gravel over a clay subgrade; 5.1 cm of asphalt over 17.8 cm of crushed gravel over 20.3 cm of clean sand over a clay subgrade; and 5.1 cm of asphalt concrete over 25.4 cm of crushed gravel over 12.7 cm of clean sand over clay subgrade. Thermocouples were imbedded throughout the pavement structure and subgrade. During the thawing periods, deflection measurements were made at four locations in each test section using a Dynatest Falling Weight Deflectometer (FWD). The results of the deflection measurement are presented here. An analysis was done to qualify the subgrade strength based solely on FDW measurements. It was also shown that a relationship existed between thaw depth and FWD measurement in the subgrade.

  14. Effects of two warm-mix additives on aging, rheological and failure properties of asphalt cements

    NASA Astrophysics Data System (ADS)

    Omari, Isaac Obeng

    Sustainable road construction and maintenance could be supported when excellent warm-mix additives are employed in the modification of asphalt. These warm-mix additives provide remedies for today's requirements such as fatigue cracking resistance, durability, thermal cracking resistance, rutting resistance and resistance to moisture damage. Warm-mix additives are based on waxes and surfactants which reduce energy consumption and carbon dioxide emissions significantly during the construction phase of the pavement. In this study, the effects of two warm mix additives, siloxane and oxidised polyethylene wax, on roofing asphalt flux (RAF) and asphalt modified with waste engine oil (655-7) were investigated to evaluate the rheological, aging and failure properties of the asphalt binders. In terms of the properties of these two different asphalts, RAF has proved to be superior quality asphalt whereas 655-7 is poor quality asphalt. The properties of the modified asphalt samples were measured by Superpave(TM) tests such as Dynamic Shear Rheometer (DSR) test and Bending Beam Rheometer (BBR) test as well as modified protocols such as the extended BBR (eBBR) test (LS-308) and the Double- Edge-Notched Tension (DENT) test (LS-299) after laboratory aging. In addition, the Avrami theory was used to gain an insight on the crystallization of asphalt or the waxes within the asphalt binder. This study has however shown that the eBBR and DENT tests are better tools for providing accurate specification tests to curb thermal and fatigue cracking in contemporary asphalt pavements.

  15. Review of crumb-rubber modified asphalt concrete technology. Final research report

    SciTech Connect

    Papagiannakis, A.T.; Lougheed, T.J.

    1995-11-01

    This study presents an analysis of the characteristics of crumb-rubber modified (CRM) asphalt pavements. It is comprised of a state-of-the-art literature review and laboratory testing conducted with a Brookfield viscometer. The reaction that occurs between the rubber and asphalt is not a chemical reaction, but rather a diffusion process that includes the physical absorption of aromatic oils from the asphalt into the polymer chain of the rubber. The presence of CRM in asphalt produces a thicker binder, which increases aging and oxidation resistance. The presence of carbon black in CRM improves binder durability. The temperature susceptibility of the mix is reduced, causing more uniform fatigue characteristics. CRM applications have been met with various degrees of success because existing quality control and quality assurance methods have not been developed enough to ensure desired binder properties in the field.

  16. Environmental performance and mechanical analysis of concrete containing recycled asphalt pavement (RAP) and waste precast concrete as aggregate.

    PubMed

    Erdem, Savaş; Blankson, Marva Angela

    2014-01-15

    The overall objective of this research project was to investigate the feasibility of incorporating 100% recycled aggregates, either waste precast concrete or waste asphalt planning, as replacements for virgin aggregates in structural concrete and to determine the mechanical and environmental performance of concrete containing these aggregates. Four different types of concrete mixtures were designed with the same total water cement ratio (w/c=0.74) either by using natural aggregate as reference or by totally replacing the natural aggregate with recycled material. Ground granulated blast furnace slag (GGBS) was used as a mineral addition (35%) in all mixtures. The test results showed that it is possible to obtain satisfactory performance for strength characteristics of concrete containing recycled aggregates, if these aggregates are sourced from old precast concrete. However, from the perspective of the mechanical properties, the test results indicated that concrete with RAP aggregate cannot be used for structural applications. In terms of leaching, the results also showed that the environmental behaviour of the recycled aggregate concrete is similar to that of the natural aggregate concrete.

  17. Attenuation of foot pressure during running on four different surfaces: asphalt, concrete, rubber, and natural grass.

    PubMed

    Tessutti, Vitor; Ribeiro, Ana Paula; Trombini-Souza, Francis; Sacco, Isabel C N

    2012-01-01

    The practice of running has consistently increased worldwide, and with it, related lower limb injuries. The type of running surface has been associated with running injury etiology, in addition other factors, such as the relationship between the amount and intensity of training. There is still controversy in the literature regarding the biomechanical effects of different types of running surfaces on foot-floor interaction. The aim of this study was to investigate the influence of running on asphalt, concrete, natural grass, and rubber on in-shoe pressure patterns in adult recreational runners. Forty-seven adult recreational runners ran twice for 40 m on all four different surfaces at 12 ± 5% km · h(-1). Peak pressure, pressure-time integral, and contact time were recorded by Pedar X insoles. Asphalt and concrete were similar for all plantar variables and pressure zones. Running on grass produced peak pressures 9.3% to 16.6% lower (P < 0.001) than the other surfaces in the rearfoot and 4.7% to 12.3% (P < 0.05) lower in the forefoot. The contact time on rubber was greater than on concrete for the rearfoot and midfoot. The behaviour of rubber was similar to that obtained for the rigid surfaces - concrete and asphalt - possibly because of its time of usage (five years). Running on natural grass attenuates in-shoe plantar pressures in recreational runners. If a runner controls the amount and intensity of practice, running on grass may reduce the total stress on the musculoskeletal system compared with the total musculoskeletal stress when running on more rigid surfaces, such as asphalt and concrete.

  18. Concrete Mixing Methods and Concrete Mixers: State of the Art.

    PubMed

    Ferraris, C F

    2001-01-01

    As for all materials, the performance of concrete is determined by its microstructure. Its microstructure is determined by its composition, its curing conditions, and also by the mixing method and mixer conditions used to process the concrete. This paper gives an overview of the various types of mixing methods and concrete mixers commercially available used by the concrete industry. There are two main types of mixers used: batch mixers and continuous mixers. Batch mixers are the most common. To determine the mixing method best suited for a specific application, factors to be considered include: location of the construction site (distance from the batching plant), the amount of concrete needed, the construction schedule (volume of concrete needed per hour), and the cost. Ultimately, the quality of the concrete produced determines its performance after placement. An important measure of the quality is the homogeneity of the material after mixing. This paper will review mixing methods in regards to the quality of the concrete produced. Some procedures used to determine the effectiveness of the mixing will be examined.

  19. Concrete Mixing Methods and Concrete Mixers: State of the Art

    PubMed Central

    Ferraris, Chiara F.

    2001-01-01

    As for all materials, the performance of concrete is determined by its microstructure. Its microstructure is determined by its composition, its curing conditions, and also by the mixing method and mixer conditions used to process the concrete. This paper gives an overview of the various types of mixing methods and concrete mixers commercially available used by the concrete industry. There are two main types of mixers used: batch mixers and continuous mixers. Batch mixers are the most common. To determine the mixing method best suited for a specific application, factors to be considered include: location of the construction site (distance from the batching plant), the amount of concrete needed, the construction schedule (volume of concrete needed per hour), and the cost. Ultimately, the quality of the concrete produced determines its performance after placement. An important measure of the quality is the homogeneity of the material after mixing. This paper will review mixing methods in regards to the quality of the concrete produced. Some procedures used to determine the effectiveness of the mixing will be examined. PMID:27500029

  20. Performance properties of asphalt mixes for rich bottom layers (RBL)

    NASA Astrophysics Data System (ADS)

    Bureš, Petr; Fiedler, Jiří; Kašpar, Jiří; Sýkora, Michal; Hýzl, Petr

    2017-09-01

    The binder content of asphalt mixes has an important influence on the performance properties. Higher binder content improves fatigue resistance. That is why the concept of RBL was developed in USA and applied for “perpetual pavements”. However excessive binder content could lead to the decrease of the mix stiffness and to permanent deformations of asphalt pavement during hot summer. The advantages and limitations of RBL concept have been studied in research project CESTI. Fatigue tests of mixes with road bitumen and polymer modified bitumen and RBL were realised. Deformation behaviour of these mixes was also evaluated. The experience from the test section with RBL laid in 2015 will be presented. The results corresponded to expectations. However, low void content was obtained on one subsection. In spite of it, there were no permanent deformations during summer 2016. The analysis of methods for the prediction of the permanent deformation was also undertaken in research project CESTI. Some information about the results of these analysis related to the use of RBL will be also briefly mentioned.

  1. Rheology of crumb-rubber modified asphalt binders and mixes

    NASA Astrophysics Data System (ADS)

    Sheth, Vikas Rameshchandra

    Laboratory test procedures are presented to determine the rheological properties of crumb rubber modified asphalt (CRMA) binders and mixes. These tests provide simple, fast, and cost-effective alternatives to evaluate the performance (rutting and cracking potential) of binders and mixes used for pavement construction. Viscoelastic properties of CRMA binders are measured using dynamic shear analysis. Master curves were generated using the principle of time-temperature superposition to evaluate the effects of aging, rubber concentration, and curing conditions on the rheology of the modified binder. Results indicate that the rheology of CRMA binders can be divided into three regions of viscoelasticity: glassy region at high frequencies, transition/viscoelastic region at intermediate frequencies, and viscous region at low frequencies. Modification of the asphalt by addition of rubber leads to an improvement in both the high and low temperature properties, as reflected by changes in Gsp' and Gsp{''}, which causes the binder to have a greater resistance to specific pavement failure mechanisms. Both transient and dynamic properties of CRMA mixes were measured in the laboratory using the creep and recovery, direct tension, and frequency sweep tests. Rheological properties of the mix generated from the test data were compared to those of the binder to evaluate the effect of aging, rubber concentration, and curing conditions on mix performance. Several rheological parameters have been identified to characterize the rutting and cracking potential of mixes. A power law equation was found to give good correlations between several mix rheological parameters. Analysis of binder and mix failure energies show that work of cohesion of the binder is negligible compared to the failure energies. A unique relationship between Paris law material parameters has been confirmed. It is also shown that mix failure properties bear a one-to-one correlation with binder failure properties. Based

  2. Influence of the Cohesive Zone Model Shape Parameter on Asphalt Concrete Fracture Behavior

    NASA Astrophysics Data System (ADS)

    Song, Seong Hyeok; Paulino, Glaucio H.; Buttlar, William G.

    2008-02-01

    A cohesive zone model (CZM) has been effective in exploring fracture behavior in various materials. In general, the cohesive parameters associated with material strength and cohesive fracture energy are considered more important than a CZM softening shape. However, the influence of the CZM softening shape becomes significant as the relative size of the fracture process zone compared to the structure size increases, which is relevant for asphalt concrete and other quasi-brittle materials. In this study, the power-law CZM is employed to investigate the influence of the CZM softening shape on asphalt concrete fracture. Three dimensional disk-shaped compact tension (DC(T)) test simulation is performed considering bulk (background) material viscoelasticity.

  3. Early-life study of the FA409 full-depth asphalt-concrete pavement sections

    SciTech Connect

    Hill, H.J.

    1988-01-01

    The Illinois Department of Transportation (IDOT) is currently implementing a mechanistic thickness-design procedure for full-depth asphalt-concrete pavements. This thesis is an early design-life investigation of full-depth asphalt-concrete pavements, constructed on FA409 near Carlyle, Illinois in 1986. Included in the study are: sampling and testing of paving and subgrade materials; extensive non-destructive testing (NDT) using the Falling Weight Deflectometer (FWD); development of techniques for interpreting NDT data; determination of as-built structural characteristics of the various pavement sections; evaluation of subsurface drainage and lime-treated soil behavior; and examination of the validity of the ILLI-PAVE computer model. The simplicity of a full-depth asphalt-concrete pavement allows useful information regarding pavement structure to be determined from FWD surface-deflection data. The ILLI-PAVE model was used in conjunction with statistical methods to quantify, in the form of regression equations or algorithms, the relationship between pavement structure (Tac, Eac, and Eri) and pavement response to FWD loading. Testing of pavement and subgrade material samples as used to validate these algorithms.

  4. Engineering characterisation of epoxidized natural rubber-modified hot-mix asphalt.

    PubMed

    Al-Mansob, Ramez A; Ismail, Amiruddin; Yusoff, Nur Izzi Md; Rahmat, Riza Atiq O K; Borhan, Muhamad Nazri; Albrka, Shaban Ismael; Azhari, Che Husna; Karim, Mohamed Rehan

    2017-01-01

    Road distress results in high maintenance costs. However, increased understandings of asphalt behaviour and properties coupled with technological developments have allowed paving technologists to examine the benefits of introducing additives and modifiers. As a result, polymers have become extremely popular as modifiers to improve the performance of the asphalt mix. This study investigates the performance characteristics of epoxidized natural rubber (ENR)-modified hot-mix asphalt. Tests were conducted using ENR-asphalt mixes prepared using the wet process. Mechanical testing on the ENR-asphalt mixes showed that the resilient modulus of the mixes was greatly affected by testing temperature and frequency. On the other hand, although rutting performance decreased at high temperatures because of the increased elasticity of the ENR-asphalt mixes, fatigue performance improved at intermediate temperatures as compared to the base mix. However, durability tests indicated that the ENR-asphalt mixes were slightly susceptible to the presence of moisture. In conclusion, the performance of asphalt pavement can be enhanced by incorporating ENR as a modifier to counter major road distress.

  5. Engineering characterisation of epoxidized natural rubber-modified hot-mix asphalt

    PubMed Central

    Al-Mansob, Ramez A.; Ismail, Amiruddin; Yusoff, Nur Izzi Md.; Rahmat, Riza Atiq O. K.; Borhan, Muhamad Nazri; Albrka, Shaban Ismael; Azhari, Che Husna; Karim, Mohamed Rehan

    2017-01-01

    Road distress results in high maintenance costs. However, increased understandings of asphalt behaviour and properties coupled with technological developments have allowed paving technologists to examine the benefits of introducing additives and modifiers. As a result, polymers have become extremely popular as modifiers to improve the performance of the asphalt mix. This study investigates the performance characteristics of epoxidized natural rubber (ENR)-modified hot-mix asphalt. Tests were conducted using ENR–asphalt mixes prepared using the wet process. Mechanical testing on the ENR–asphalt mixes showed that the resilient modulus of the mixes was greatly affected by testing temperature and frequency. On the other hand, although rutting performance decreased at high temperatures because of the increased elasticity of the ENR–asphalt mixes, fatigue performance improved at intermediate temperatures as compared to the base mix. However, durability tests indicated that the ENR–asphalt mixes were slightly susceptible to the presence of moisture. In conclusion, the performance of asphalt pavement can be enhanced by incorporating ENR as a modifier to counter major road distress. PMID:28182724

  6. Furfuryl alcohol polymer concretes for use in all-weather repairs of concrete and asphalt surfaces

    SciTech Connect

    Kukacka, L.E.; Sugama, T.

    1985-04-01

    The following criteria were established: high strength at an age of 1 h, placement of the materials must be possible during heavy precipitation over temperatures ranging from -32/sup 0/ to 52/sup 0/C, and the chemical constituents should be low cost and have long-term stability when contained in a maximum of three packages during storage. A formulation consisting of furfuryl alcohol monomer (FA), ..cap alpha..,..cap alpha..,..cap alpha..- trichlorotoluene, pyridine, silane, zinc chloride, silica filler, and coarse aggregate meets these requirements. Optimized formulations were established for use with premixed and percolation placement methods. The premixed formulation is compatible with moisture contents up to 4% by weight of the total mass, which simulates placement in a 2.54 cm/h rainfall. The working time for the FA-PC slurry can be controlled at greater than or equal to 15 min over the entire operating temperature range by simply varying the ..cap alpha..,..cap alpha..,..cap alpha..-trichlorotoluene catalyst concentration while holding all of the other constituents constant. Prototype equipment for the mixing and placement of FA-PC was demonstrated: a concrete transit mix supply of mixed aggregate, a hopper-fed volumetric feed screw which supplied aggregate at a known rate to a mixing screw, and a monomer pump and spray nozzle. The unit mixed and delivered FA-PC at approx.182 kg/min. The practicability of using equipment currently employed for the continuous placement of conventional portland cement concrete was proven. Field tests were performed under rainfall and dry conditions at temperatures ranging from -15/sup 0/ to 35/sup 0/C. The mixing and placement equipment performed well and the FA-PC slurries exhibited self-leveling characteristics. Test results from proxy samples prepared during the placement of the patches and cores taken after simulated aircraft trafficking, indicated that the property requirements at an age of 1 hr were attained.

  7. Asphalt Concrete for Cold Regions, A Comparative Laboratory Study and Analysis of Mixtures Containing Soft and Hard Grades of Asphalt Cement,

    DTIC Science & Technology

    1980-01-01

    ilto n aggregate ................................................................................................. ... 4 4 . B razil test eq u ipm en...t .................................................................................................... 5 5. D iagram o f B razil test...80 B J1 DEMPSEY, J INGERSOLL, T CJOHNSON UNCLAS7SIFIED CRREL-80-5 N ’~EVEL. Asphalt concrete tor cold regions Cold DTIC o , ELECTE i i L MAR 2 5 1980

  8. Nonlinearly viscoelastic analysis of asphalt mixes subjected to shear loading

    NASA Astrophysics Data System (ADS)

    Huang, Chien-Wei; Masad, Eyad; Muliana, Anastasia H.; Bahia, Hussain

    2007-06-01

    This study presents the characterization of the nonlinearly viscoelastic behavior of hot mix asphalt (HMA) at different temperatures and strain levels using Schapery’s model. A recursive-iterative numerical algorithm is generated for the nonlinearly viscoelastic response and implemented in a displacement-based finite element (FE) code. Then, this model is employed to describe experimental frequency sweep measurements of two asphalt mixes with fine and coarse gradations under several combined temperatures and shear strain levels. The frequency sweep measurements are converted to creep responses in the time domain using a phenomenological model (Prony series). The master curve is created for each strain level using the time temperature superposition principle (TTSP) with a reference temperature of 40°C. The linear time-dependent parameters of the Prony series are first determined by fitting a master curve created at the lowest strain level, which in this case is 0.01%. The measurements at strain levels higher than 0.01% are analyzed and used to determine the nonlinear parameters. These parameters are shown to increase with increasing strain levels, while the time temperature shift function is found to be independent of strain levels. The FE model with the calibrated time-dependent and nonlinear material parameters is used to simulate the creep experimental tests, and reasonable predictions are shown.

  9. Investigation of Self Consolidating Concrete Containing High Volume of Supplementary Cementitious Materials and Recycled Asphalt Pavement Aggregates

    NASA Astrophysics Data System (ADS)

    Patibandla, Varun chowdary

    The use of sustainable technologies such as supplementary cementitiuous materials (SCMs), and/or recycled materials is expected to positively affect the performance of concrete mixtures. However, it is important to study and qualify such mixtures and check if the required specifications of their intended application are met before they can be implemented in practice. This study presents the results of a laboratory investigation of Self Consolidating concrete (SCC) containing sustainable technologies. A total of twelve concrete mixtures were prepared with various combinations of fly ash, slag, and recycled asphalt pavement (RAP). The mixtures were divided into three groups with constant water to cementitiuous materials ratio of 0.37, and based on the RAP content; 0, 25, and 50% of coarse aggregate replaced by RAP. All mixtures were prepared to achieve a target slump flow equal to or higher than 500 mm (24in). A control mixture for each group was prepared with 100% Portland cement whereas all other mixtures were designed to have up to 70% of portland cement replaced by a combination of supplementary cementitiuous materials (SCMs) such as class C fly ash and granulated blast furnace slag. The properties of fresh concrete investigated in this study include flowability, deformability; filling capacity, and resistance to segregation. In addition, the compressive strength at 3, 14, and 28 days, the tensile strength, and the unrestrained shrinkage up to 80 days was also investigated. As expected the inclusion of the sustainable technologies affected both fresh and hardened concrete properties. Analysis of the experimental data indicated that inclusion of RAP not only reduces the ultimate strength, but it also affected the compressive strength development rate. Moreover, several mixes satisfied compressive strength requirements for pavements and bridges; those mixes included relatively high percentages of SCMs and RAP. Based on the results obtained in this study, it is not

  10. Reclaimed manufacturer asphalt roofing shingles in asphalt mixtures. Final research report

    SciTech Connect

    Reed, A.B.

    1999-04-23

    The purpose of this project was to pave a test section using hot mix asphalt with roofing shingle pieces in the wearing and binder courses and to evaluate. The test project near Allentown, PA plus two other test projects in 1998 provide evidence of very good pavement performance. The bituminous concrete mix was modified with shredded shingles with a maximum size of 1/2 inch which added 1% of the asphalt content. The Department issued a statewide Provisional Specification titled Reclaimed Manufacturer Asphalt Roofing Shingles in Plant-Mixed Bituminous Concrete Courses'' on March 15, 1999. New manufacturer asphalt roofing shingle scrap including tab punch-outs can be successfully incorporated in bituminous concrete pavements if the shingles are shredded to 100% passing the 3/4 inch sieve. To take full advantage of the potential to replace a portion of the asphalt and therefore, reduce mix costs, shingles should be shredded to 100% passing minus 1/2 inch sieve.

  11. Effects of reclaimed asphalt pavement on indirect tensile strength test of conditioned foamed asphalt mix

    NASA Astrophysics Data System (ADS)

    Yati Katman, Herda; Rasdan Ibrahim, Mohd; Yazip Matori, Mohd; Norhisham, Shuhairy; Ismail, Norlela

    2013-06-01

    This paper presents the results of Indirect Tensile Strength (ITS) Test for samples prepared with reclaimed asphalt pavement (RAP). Samples were conditioned in water at 25°C for 24 hours prior to testing. Results show that recycled aggregate from reclaimed asphalt pavement performs as well as virgin aggregate.

  12. Laboratory and field evaluation of hot mix asphalt with high contents of reclaimed asphalt pavement

    NASA Astrophysics Data System (ADS)

    Van Winkle, Clinton Isaac

    Currently in Iowa, the amount of RAP materials allowed for the surface layer is limited to 15% by weight. The objective of this project was to develop quality standards for inclusion of RAP content higher than 15% in asphalt mixtures. To meet Superpave mix design requirements, it was necessary to fractionate the RAP materials. Based on the extensive sieve-by-sieve analysis of RAP materials, the optimum sieve size to fractionate RAP materials was identified. To determine if the higher percentage of RAP materials than 15% can be used in Iowa's state highway, three test sections with 30.0%, 35.5% and 39.2% of RAP materials were constructed on Highway 6 in Iowa City. The construction of the field test sections was monitored and the cores were obtained to measure field densities of test sections. Field mixtures collected from test sections were compacted in the laboratory in order to test the moisture sensitivity using a Hamburg Wheel Tracking Device. The binder was extracted from the field mixtures with varying amounts of RAP materials and tested to determine the effects of RAP materials on the PG grade of a virgin binder. Field cores were taken from the various mix designs to determine the percent density of each test section. A condition survey of the test sections was then performed to evaluate the short-term performance.

  13. A review of changes in composition of hot mix asphalt in the United States.

    PubMed

    Mundt, Diane J; Marano, Kristin M; Nunes, Anthony P; Adams, Robert C

    2009-11-01

    This review researched the materials, methods, and practices in the hot mix asphalt industry that might impact future exposure assessments and epidemiologic research on road paving workers. Since World War II, the U.S. interstate highway system, increased traffic volume, transportation speeds, and vehicle axle loads have necessitated an increase in demand for hot mix asphalt for road construction and maintenance, while requiring a consistent road paving product that meets state-specific physical performance specifications. We reviewed typical practices in hot mix asphalt paving in the United States to understand the extent to which materials are and have been added to hot mix asphalt to meet specifications and how changes in practices and technology could affect evaluation of worker exposures for future research. Historical documents were reviewed, and industry experts from 16 states were interviewed to obtain relevant information on industry practices. Participants from all states reported additive use, with most being less than 2% by weight. Crumb rubber and recycled asphalt pavement were added in concentrations approximately 10% per unit weight of the mix. The most frequently added materials included polymers and anti-stripping agents. Crumb rubber, sulfur, asbestos, roofing shingles, slag, or fly ash have been used in limited amounts for short periods of time or in limited geographic areas. No state reported using coal tar as an additive to hot mix asphalt or as a binder alternative in hot mix pavements for high-volume road construction. Coal tar may be present in recycled asphalt pavement from historical use, which would need to be considered in future exposure assessments of pavers. Changes in hot mix asphalt production and laydown emission control equipment have been universally implemented over time as the technology has become available to reduce potential worker exposures. This work is a companion review to a study undertaken in the petroleum refining

  14. Generation of urban road dust from anti-skid and asphalt concrete aggregates.

    PubMed

    Tervahattu, Heikki; Kupiainen, Kaarle J; Räisänen, Mika; Mäkelä, Timo; Hillamo, Risto

    2006-04-30

    Road dust forms an important component of airborne particulate matter in urban areas. In many winter cities the use of anti-skid aggregates and studded tires enhance the generation of mineral particles. The abrasion particles dominate the PM10 during springtime when the material deposited in snow is resuspended. This paper summarizes the results from three test series performed in a test facility to assess the factors that affect the generation of abrasion components of road dust. Concentrations, mass size distribution and composition of the particles were studied. Over 90% of the particles were aluminosilicates from either anti-skid or asphalt concrete aggregates. Mineral particles were observed mainly in the PM10 fraction, the fine fraction being 12% and submicron size being 6% of PM10 mass. The PM10 concentrations increased as a function of the amount of anti-skid aggregate dispersed. The use of anti-skid aggregate increased substantially the amount of PM10 originated from the asphalt concrete. It was concluded that anti-skid aggregate grains contribute to pavement wear. The particle size distribution of the anti-skid aggregates had great impact on PM10 emissions which were additionally enhanced by studded tires, modal composition, and texture of anti-skid aggregates. The results emphasize the interaction of tires, anti-skid aggregate, and asphalt concrete pavement in the production of dust emissions. They all must be taken into account when measures to reduce road dust are considered. The winter maintenance and springtime cleaning must be performed properly with methods which are efficient in reducing PM10 dust.

  15. Analyzing the stripping potential of warm mix asphalt using imaging technique

    NASA Astrophysics Data System (ADS)

    Rafiq Kakar, Muhammad; Othman Hamzah, Meor; Valentin, Jan

    2017-09-01

    In asphalt mixtures, stripping occurs when the bond between the asphalt and the aggregate is broken due to the intrusion of water within the asphalt aggregate interface. Warm mix asphalt (WMA) is a technology that allows significant reduction in mixing and compaction temperatures of conventional hot mix asphalt. However, WMA is susceptible to moisture damage due to its lower production temperature. This can cause adhesive failure, hence stripping of asphalt binder from the aggregates. In this study, direct tensile strength (DTS) and indirect tensile strength (ITS) tests were applied to fracture the mixture specimen. Imaging technique was applied on the fractured faces of asphalt mixture to quantify the adhesive failure susceptibility due to the destructive effects of moisture. The results showed that adhesive failure increased with the number of freeze and thaw cycles and mixtures prepared with PG-76 binder exhibited lower adhesive failure compared to PG-64 binder. From fractured ITS samples, most of broken aggregates were found located in the vicinity where the indirect tensile load was applied. On the other hand, high adhesive failure was obtained at the center portion where maximum tensile stresses were developed. The image analysis method employed in this work has proven to be very effective to analyze the deterioration of asphalt mixtures subjected to moisture conditioning.

  16. Behavior of sulfur mustard in sand, concrete, and asphalt matrices: Evaporation, degradation, and decontamination.

    PubMed

    Jung, Hyunsook; Choi, Seungki

    2017-07-24

    The evaporation, degradation, and decontamination of sulfur mustard on environmental matrices including sand, concrete, and asphalt are described. A specially designed wind tunnel and thermal desorber in combination with gas chromatograph (GC) produced profiles of vapor concentration obtained from samples of the chemical agent deposited as a drop on the surfaces of the matrices. The matrices were exposed to the chemical agent at room temperature, and the degradation reactions were monitored and characterized. A vapor emission test was also performed after a decontamination process. The results showed that on sand, the drop of agent spread laterally while evaporating. On concrete, the drop of the agent was absorbed immediately into the matrix while spreading and evaporating. However, the asphalt surface conserved the agent and slowly released parts of the agent over an extended period of time. The degradation reactions of the agent followed pseudo first order behavior on the matrices. Trace amounts of the residual agent present at the surface were also released as vapor after decontamination, posing a threat to the exposed individual and environment.

  17. Chemical aspects of incorporating contaminated soil into cold-mix asphalt

    SciTech Connect

    Testa, S.M.

    1994-12-31

    The chemical aspects associated with the incorporation of petroleum hydrocarbons- and metals-affected soil has been extensively studied in regards to pavement properties, leaching behavior, sensitivities to moisture-damage and function group analysis. These studies provide information that can be used to evaluate the stability of these constituents in soil that have been incorporated as an ingredient in asphalt. These studies also indicate that cold-mix asphalt incorporating contaminated soil will be highly stable and perform adequately as an end product. Maximum chemical performance is achieved when the asphalt is comprised of high contents of pyridinic, phenolic and ketone groups, which can be achieved by selectively choosing the source material. If the situation requires special stability or redundancy, small amounts of shale oil and lime can be used as additives. Situations and conditions which favor the presence of inorganic sulfur, monovalent salts and high strength solutions in the asphalt should be avoided since these conditions decrease the chemical stability of the asphalt cement by disruption of the functional group-aggregate bonds and by increasing the overall permeability. However, these conditions are not typically expected in the anticipated uses of asphalt cement to stabilize contaminants in soil using Environmentally Processed Asphalt{trademark} (EPA{trademark}) or Asphaltic Metals Stabilization{trademark} (AMS{trademark}) remedial technologies.

  18. Environmental impacts of asphalt mixes with electric arc furnace steel slag.

    PubMed

    Milačič, Radmila; Zuliani, Tea; Oblak, Tina; Mladenovič, Ana; Ančar, Janez Šč

    2011-01-01

    Electric arc furnace (EAF) steel slag can be used as an alternative high-quality material in road construction. Although asphalts with slag aggregates have been recognized as environmentally acceptable, there is a lack of data concerning the potential leaching of toxic Cr(VI) due to the highly alkaline media of EAF slag. Leaching of selected water extractable metals from slag indicated elevated concentrations of total chromium and Cr(VI). To estimate the environmental impacts of asphalt mixes with slag, leachability tests based on diffusion were performed using pure water and salt water as leaching agents. Compact and ground asphalt composites with natural aggregates, and asphalt composites in which the natural aggregates were completely replaced by slag were prepared. The concentrations of total chromium and Cr(VI) were determined in leachates over a time period of 6 mo. After 1 and 6 mo, the concentrations of some other metals were also determined in the leachates. The results indicated that chromium in leachates from asphalt composites with the addition of slag was present almost solely in its hexavalent form. However, the concentrations were very low (below 25 μg L) and did not represent an environmental burden. The leaching of other metals from asphalt composites with the addition of slag was negligible. Therefore, the investigated EAF slag can be considered as environmentally safe substitute for natural aggregates in asphalt mixes. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  19. Exposing the nonlinear viscoelastic behavior of asphalt-aggregate mixes

    NASA Astrophysics Data System (ADS)

    Levenberg, Eyal; Uzan, Jacob

    2012-05-01

    In this study asphalt-aggregate mixes are treated as both viscoelastic and viscoplastic. Following a damage mechanics approach, a nonlinear viscoelastic constitutive formulation is generated from a linear formulation by replacing `applied stresses' with `effective viscoelastic stresses'. A non-dimensional scalar entity called `relative viscoelastic stiffness' is introduced; it is defined as the ratio of applied to effective viscoelastic stress and encapsulates different types of nonlinearities. The paper proposes a computational scheme for exposing these nonlinearities by uncovering, through direct analysis of any test data, changes experienced by the `relative viscoelastic stiffness'. In general terms, the method is based on simultaneous application of creep and relaxation formulations while preserving the interrelationship between the corresponding time functions. The proposed scheme is demonstrated by analyzing a uniaxial tension test and a uniaxial compression test (separately). Results are presented and discussed, unveiling and contrasting the character of viscoelastic nonlinearities in both cases. A conceptual viewpoint is offered to explain the observations, illustrating the requirements from any candidate constitutive theory.

  20. Evaluation of mix ingredients on the performance of rubber-modified asphalt mixtures

    SciTech Connect

    Takallou, H.B.

    1987-01-01

    In rubber-modified asphalt pavements ground recycled tire particles are added to a gap-graded aggregate and then mixed with hot asphalt cement. In view of the significant reductions in wintertime stopping distances under icy or frosty road surface conditions, the use of coarse rubber in asphalt pavements should be seriously considered. This research project consisted of a laboratory study of mix properties as a function of variables such as rubber gradation and content, void content, aggregate graduation, mix process, temperature, and asphalt content. Twenty different mix combinations were evaluated for diametral modulus and fatigue at two different temperatures. Also, five different mix combinations were evaluated for static creep and permanent deformation. The findings of the laboratory study indicate that the rubber gradation and content, aggregate gradation, and use of surcharge during sample preparation have considerable effect on modulus and fatigue life of the mix. The results of static creep and permanent deformation tests indicate that the rubber asphalt mixes had low stability and high elasticity. Also, due to greater allowable tensile strain in rubber-modified mixtures, the thickness of the modified mixture can be reduced, using a layer equivalency of 1.4 to 1.0

  1. Field investigation of low-temperature cracking and stiffness moduli on selected roads with conventional and high modulus asphalt concrete

    NASA Astrophysics Data System (ADS)

    Judycki, Józef; Jaczewski, Mariusz; Ryś, Dawid; Pszczoła, Marek; Jaskuła, Piotr; Glinicki, Adam

    2017-09-01

    High Modulus Asphalt Concrete (HMAC) was introduced in Poland as a one of the solutions to the problem of rutting, type of deterioration common in the 1990s. After first encouraging trials in 2002 HMAC was widely used for heavily loaded national roads and motorways. However some concerns were raised about low-temperature cracking of HMAC. This was the main reason of the studies presented in this article were started. The article presents the comparison of performance of pavements constructed in typical contract conditions with the road bases made of HMAC and conventional asphalt concrete (AC). The field investigation was focused on the number of low-temperature cracks, bearing capacity (based on FWD test) of road sections localized in coldest region of Poland. Also load transfer efficiency of selected low-temperature cracks was assessed. FWD test confirmed lower deflections of pavements with HMAC and two times higher stiffness modulus of asphalt courses in comparison to pavements constructed with conventional AC mixtures. Relation of stiffness of asphalt layers and amount of low-temperature cracks showed that the higher stiffness modulus of asphalt layers could lead to increase of the number of low-temperature cracks. FWD test results showed that the load transfer efficiency of low-temperature cracks on pavements with HMAC presents very low values, very close to lack of load transfer. It was surprising as section with HMAC road base were aged from 2 to 5 years and presented very good bearing capacity.

  2. Black curves and creep behaviour of crumb rubber modified binders containing warm mix asphalt additives

    NASA Astrophysics Data System (ADS)

    Gallego, Juan; Rodríguez-Alloza, Ana María; Giuliani, Felice

    2016-08-01

    Warm mix asphalt (WMA) is a new research topic in the field of road pavement materials. This technology allows lower energy consumption and greenhouse gas (GHG) emissions by reducing compaction and placement temperatures of the asphalt mixtures. However, this technology is still under study, and the influence of the WMA additives has yet to be investigated thoroughly and clearly identified, especially in the case of crumb rubber modified (CRM) binders.

  3. Development of a stress-mode sensitive viscoelastic constitutive relationship for asphalt concrete: experimental and numerical modeling

    NASA Astrophysics Data System (ADS)

    Karimi, Mohammad M.; Tabatabaee, Nader; Jahanbakhsh, H.; Jahangiri, Behnam

    2016-11-01

    Asphalt binder is responsible for the thermo-viscoelastic mechanical behavior of asphalt concrete. Upon application of pure compressive stress to an asphalt concrete specimen, the stress is transferred by mechanisms such as aggregate interlock and the adhesion/cohesion properties of asphalt mastic. In the pure tensile stress mode, aggregate interlock plays a limited role in stress transfer, and the mastic phase plays the dominant role through its adhesive/cohesive and viscoelastic properties. Under actual combined loading patterns, any coordinate direction may experience different stress modes; therefore, the mechanical behavior is not the same in the different directions and the asphalt specimen behaves as an anisotropic material. The present study developed an anisotropic nonlinear viscoelastic constitutive relationship that is sensitive to the tension/compression stress mode by extending Schapery's nonlinear viscoelastic model. The proposed constitutive relationship was implemented in Abaqus using a user material (UMAT) subroutine in an implicit scheme. Uniaxial compression and indirect tension (IDT) testing were used to characterize the viscoelastic properties of the bituminous materials and to calibrate and validate the proposed constitutive relationship. Compressive and tensile creep compliances were calculated using uniaxial compression, as well as IDT test results, for different creep-recovery loading patterns at intermediate temperature. The results showed that both tensile creep compliance and its rate were greater than those of compression. The calculated deflections based on these IDT test simulations were compared with experimental measurements and were deemed acceptable. This suggests that the proposed viscoelastic constitutive relationship correctly demonstrates the viscoelastic response and is more accurate for analysis of asphalt concrete in the laboratory or in situ.

  4. Development of a stress-mode sensitive viscoelastic constitutive relationship for asphalt concrete: experimental and numerical modeling

    NASA Astrophysics Data System (ADS)

    Karimi, Mohammad M.; Tabatabaee, Nader; Jahanbakhsh, H.; Jahangiri, Behnam

    2017-08-01

    Asphalt binder is responsible for the thermo-viscoelastic mechanical behavior of asphalt concrete. Upon application of pure compressive stress to an asphalt concrete specimen, the stress is transferred by mechanisms such as aggregate interlock and the adhesion/cohesion properties of asphalt mastic. In the pure tensile stress mode, aggregate interlock plays a limited role in stress transfer, and the mastic phase plays the dominant role through its adhesive/cohesive and viscoelastic properties. Under actual combined loading patterns, any coordinate direction may experience different stress modes; therefore, the mechanical behavior is not the same in the different directions and the asphalt specimen behaves as an anisotropic material. The present study developed an anisotropic nonlinear viscoelastic constitutive relationship that is sensitive to the tension/compression stress mode by extending Schapery's nonlinear viscoelastic model. The proposed constitutive relationship was implemented in Abaqus using a user material (UMAT) subroutine in an implicit scheme. Uniaxial compression and indirect tension (IDT) testing were used to characterize the viscoelastic properties of the bituminous materials and to calibrate and validate the proposed constitutive relationship. Compressive and tensile creep compliances were calculated using uniaxial compression, as well as IDT test results, for different creep-recovery loading patterns at intermediate temperature. The results showed that both tensile creep compliance and its rate were greater than those of compression. The calculated deflections based on these IDT test simulations were compared with experimental measurements and were deemed acceptable. This suggests that the proposed viscoelastic constitutive relationship correctly demonstrates the viscoelastic response and is more accurate for analysis of asphalt concrete in the laboratory or in situ.

  5. Dielectric characterization of hot-mix asphalt at the smart road using GPR

    NASA Astrophysics Data System (ADS)

    Al-Qadi, Imad L.; Loulizi, A.; Lahouar, S.

    2000-04-01

    To better interpret collected ground penetrating radar (GPR) data, a project is currently underway at the Virginia Smart Road. Twelve different flexible pavement sections and a continuously reinforced concrete rigid pavement section are incorporated in the road design. Thirty-five copper plates were placed at different layer interfaces throughout the pavement sections. The copper plates serve as a reflecting material and thus allow the determination of layers' dielectric constant over the GPR frequency range. An initial development of a method to calculate the complex dielectric constant of hot-mix asphalt over the frequency range of 750 to 1750 MHz using an air-coupled GPR system is presented. Utilizing GPR data, this method will be used to predict changes of the dielectric properties of the different SuperPaveTM mixes used at the Smart Road over time. The method is based on equating the overall reflection coefficient as obtained from the radar measurements with the calculated reflection coefficient using electromagnetic theory. The measured overall reflection coefficient is obtained by dividing the reflected frequency spectrum over the incident one. The theoretical overall reflection coefficient is obtained using the multiple reflection model. A Gauss-Newton method is then used to solve for the complex dielectric constant.

  6. Characterizing the low strain complex modulus of asphalt concrete specimens through optimization of frequency response functions.

    PubMed

    Gudmarsson, Anders; Ryden, Nils; Birgisson, Björn

    2012-10-01

    Measured and finite element simulated frequency response functions are used to characterize the low strain (~10(-7)) complex moduli of an asphalt concrete specimen. The frequency response functions of the specimen are measured at different temperatures by using an instrumented hammer to apply a load and an accelerometer to measure the dynamic response. Theoretical frequency response functions are determined by modeling the specimen as a three-dimensional (3D) linear isotropic viscoelastic material in a finite element program. The complex moduli are characterized by optimizing the theoretical frequency response functions against the measured ones. The method is shown to provide a good fit between the frequency response functions, giving an estimation of the complex modulus between minimum 500 Hz and maximum 18|000 Hz depending on the temperature. Furthermore, the optimization method is shown to give a good estimation of the complex modulus master curve.

  7. A study of sound absorption by street canyon boundaries and asphalt rubber concrete pavement

    NASA Astrophysics Data System (ADS)

    Drysdale, Graeme Robert

    A sound field model, based on a classical diffusion equation, is extended to account for sound absorption in a diffusion parameter used to model sound energy in a narrow street canyon. The model accounts for a single sound absorption coefficient, separate accommodation coefficients and a combination of separate absorption and accommodation coefficients from parallel canyon walls. The new expressions are compared to the original formula through numerical simulations to reveal the effect of absorption on sound diffusion. The newly established analytical formulae demonstrate satisfactory agreement with their predecessor under perfect reflection. As well, the influence of the extended diffusion parameter on normalized sound pressure levels in a narrow street canyon is in agreement with experimental data. The diffusion parameters are used to model sound energy density in a street canyon as a function of the sound absorption coefficient of the street canyon walls. The acoustic and material properties of conventional and asphalt rubber concrete (ARC) pavement are also studied to assess how the crumb rubber content influences sound absorption in street canyons. The porosity and absolute permeability of compacted specimens of asphalt rubber concrete are measured and compared to their normal and random incidence sound absorption coefficients as a function of crumb rubber content in the modified binder. Nonlinear trends are found between the sound absorption coefficients, porosity and absolute permeability of the compacted specimens and the percentage of crumb rubber in the modified binders. The cross-sectional areas of the air voids on the surfaces of the compacted specimens are measured using digital image processing techniques and a linear relationship is obtained between the average void area and crumb rubber content. The measured material properties are used to construct an empirical formula relating the average porosity, normal incidence noise reduction coefficients and

  8. Fatigue and Fracture Characterization of GlasGridRTM Reinforced Asphalt Concrete Pavement

    NASA Astrophysics Data System (ADS)

    Safavizadeh, Seyed Amirshayan

    The purpose of this research is to develop an experimental and analytical framework for describing, modeling, and predicting the reflective cracking patterns and crack growth rates in GlasGridRTM-reinforced asphalt pavements. In order to fulfill this objective, the effects of different interfacial conditions (mixture and tack coat type, and grid opening size) on reflective cracking-related failure mechanisms and the fatigue and fracture characteristics of fiberglass grid-reinforced asphalt concrete beams were studied by means of four- and threepoint bending notched beam fatigue tests (NBFTs) and cyclic and monotonic interface shear tests. The digital image correlation (DIC) technique was utilized for obtaining the displacement and strain contours of specimen surfaces during each test. The DIC analysis results were used to develop crack tip detection methods that were in turn used to determine interfacial crack lengths in the shear tests, and vertical and horizontal (interfacial) crack lengths in the notched beam fatigue tests. Linear elastic fracture mechanics (LEFM) principles were applied to the crack length data to describe the crack growth. In the case of the NBFTs, a finite element (FE) code was developed and used for modeling each beam at different stages of testing and back-calculating the stress intensity factors (SIFs) for the vertical and horizontal cracks. The local effect of reinforcement on the stiffness of the system at a vertical crack-interface intersection or the resistance of the grid system to the deflection differential at the joint/crack (hereinafter called joint stiffness) for GlasGrid-reinforced asphalt concrete beams was determined by implementing a joint stiffness parameter into the finite element code. The strain level dependency of the fatigue and fracture characteristics of the GlasGrid-reinforced beams was studied by performing four-point bending notched beam fatigue tests at strain levels of 600, 750, and 900 microstrain. These beam

  9. Ice melting properties of steel fiber modified asphalt mixtures with induction heating

    NASA Astrophysics Data System (ADS)

    Fang, Hao; Sun, Yihan; Liu, Quantao; Li, Bin; Wu, Shaopeng; Tang, Jin

    2017-03-01

    In this paper, the ice melting performance of asphalt concrete with steel fibers was studied. Steel fiber modified asphalt mixtures were prepared, five different fiber amount of steel fiber modified asphalt mixtures were mixed to study their induction heating rate. The samples covered with different thickness of ice were heated with induction heating to study their ice melting efficency. It was proved that the induction heating of steel fiber modified asphalt mixtures could significantly improve their ice melting efficency compared with the natural condition. And it was found that the thickness of the ice had little influence on the induction heating rate of the asphalt concrete.

  10. Assessment of low temperature cracking in asphalt pavement mixes and rheological performance of asphalt binders

    NASA Astrophysics Data System (ADS)

    Sowah-Kuma, David

    Government spends a lot of money on the reconstruction and rehabilitation of road pavements in any given year due to various distresses and eventual failure. Low temperature (thermal) cracking, one of the main types of pavement distress, contributes partly to this economic loss, and comes about as a result of accumulated tensile strains exceeding the threshold tensile strain capacity of the pavement. This pavement distress leads to a drastic reduction of the pavement's service life and performance. In this study, the severity of low temperature (thermal) cracking on road pavements selected across the Province of Ontario and its predicted time to failure was assessed using the AASTHO Mechanistic-Empirical Pavement Design Guide (MEPDG) and AASHTOWARE(TM) software, with inputs such as creep compliance and tensile strength from laboratory test. Highway 400, K1, K2, Y1, Sasobit, Rediset LQ, and Rediset WMX were predicted to have a pavement in-service life above 15 years. Additionally, the rheological performance of the recovered asphalt binders was assessed using Superpave(TM) tests such as the dynamic shear rheometer (DSR) and bending beam rheometer (BBR). Further tests using modified standard protocols such as the extended bending beam rheometer (eBBR) (LS-308) test method and double-edge notched tension (DENT) test (LS-299) were employed to evaluate the failure properties associated with in service performance. The various rheological tests showed K1 to be the least susceptible to low temperature cracking compared to the remaining samples whiles Highway 24 will be highly susceptible to low temperature cracking. X-ray fluorescence (XRF) analysis was performed on the recovered asphalt binders to determine the presence of metals such as zinc (Zn) and molybdenum (Mo) believed to originate from waste engine oil, which is often added to asphalt binders. Finally, the severity of oxidative aging (hardening) of the recovered asphalt binders was also evaluated using the

  11. Thickness and air voids measurement on asphalt concrete pavements using ground-penetrating radar

    NASA Astrophysics Data System (ADS)

    Dhakal, Sharad Raj

    Layer thickness and air voids are important parameters in quality assurance of newly paved hot mix asphalt (HMA) pavements. A non-destructive testing (NDT) technique was used to collect layer thickness information. The thicknesses estimated by the technique were compared with core thicknesses. Ground penetrating radar (GPR) system with air coupled antennas was used for on-site pavement data collection. Two application softwares - RADAN and ROAD DOCTOR - were used to process the field data for estimating layer thicknesses and air voids along the scanned pavements. 150 mm diameter cores taken from random locations on the pavements were tested in the laboratory to determine layer thickness and air voids. Statistical analyses were conducted to compare thicknesses and generate a regression equation relating air voids and dielectric constant of the pavement material. No significant differences were found between thickness estimates from RADAN and ROAD DOCTOR softwares when compared to the core measurements. However, RADAN and ROAD DOCTOR results are marginally significantly different from each other. ROAD DOCTOR software was used to generate air voids for the pavements scanned. Laboratory results from cores were utilized to determine calibration factors for the air voids -- dielectric equation. A relationship between air voids and dielectric constant is presented. It is concluded that GPR system with air coupled antennas used alongside a reduced core testing has a potential for quality control of newly paved hot mixed asphalt pavements.

  12. On the representative volume element of asphalt concrete at low temperature

    NASA Astrophysics Data System (ADS)

    Marasteanu, Mihai; Cannone Falchetto, Augusto; Velasquez, Raul; Le, Jia-Liang

    2016-08-01

    The feasibility of characterizing asphalt mixtures' rheological and failure properties at low temperatures by means of the Bending Beam Rheometer (BBR) is investigated in this paper. The main issue is the use of thin beams of asphalt mixture in experimental procedures that may not capture the true behavior of the material used to construct an asphalt pavement.

  13. Effects of asphalt rejuvenator on thermal and mechanical properties on oxidized hot mixed asphalt pavements

    NASA Astrophysics Data System (ADS)

    Farace, Nicholas A.; Buttlar, William G.; Reis, Henrique

    2016-04-01

    The utilization of asphalt rejuvenator, and its effectiveness for restoring thermal and mechanical properties was investigated via Disk-shaped Compact Tension (DC(T)) and acoustic emission (AE) testing for determining mechanical properties and embrittlement temperatures of the mixtures. During the DC(T) testing the fracture energies and peak loads were used to measure the resistance of the rejuvenated asphalt to low temperature cracking. The AE testing monitored the acoustic emission activity while the specimens were cooled from room temperature to -40 °C to estimate the temperature at which thermal cracking began (i.e. the embrittlement temperature). First, a baseline response was obtained by obtaining the mechanical and thermal response of virgin HMA samples and HMA samples that had been exposed to oxidative aging for 36 hours at 135°C. The results showed the virgin samples had much higher peak loads and fracture energies than the 36 hours aged samples. Acoustic Emission showed similar results with the virgin samples having embrittlement temperatures 10 °C cooler than the 36 hours aged specimens. Then, overaged for 36 hours specimens were treated different amounts of rejuvenator (10%, 15%, and 20% by weight of binder content) and left to dwell for increased amount of time periods varying from one to eight weeks. It was observed that the AE results showed an improvement of embrittlement temperature with increasing with the dwell times. The 8 weeks specimens had cooler embrittlement temperatures than the virgin specimens. Finally, the low temperature effects on fracture energy and peak load of the rejuvenated asphalt was investigated. Rejuvenator was applied (10% by weight of binder) to specimens aged 36 hours at 135 °C, and the dwell time was varied from 1 to 4 weeks. The results showed that the peak loads were restored to levels of the virgin specimens, and the fracture energies improved to levels beyond that of the virgin specimens. The results also showed a

  14. Development of guidelines and performance for asphalt concrete containing recycled rubber. Final report

    SciTech Connect

    Mahboub, K.C.; Hancher, D.E.

    1994-12-01

    The primary objective of this study was to investigate the feasibility of implementation of the crumb rubber technology in Kentucky. The impetus for this study was provided by the Intermodal Surface Transportation Efficiency Act of 1991 (ISTEA). In July 1993, a field trial project was constructed on a portion of the US 421, Franklin County, Kentucky. The project involved milling of approximately 2.54 cm (one-inch) of the wearing surface followed up by a nominally 2.54 cm (one-inch) overlay. The four-lane trial project (two lanes in each direction) was divided into two approximately 0.8 km (half-mile) sections. This allowed for a comparison of performance between the CRM hot mix asphalt (HMA) and the conventional HMA.

  15. Evaluation of Asphalt Mixes Workability and Compactability Using Laboratory and Accelerated Field Testing

    NASA Astrophysics Data System (ADS)

    Dessouky, Samer; Diaz, Manuel

    Polymer-modified asphalt have been proven to improve mechanical characteristics of asphalt mixes, however there are concerns that mixes become drier and more difficult to compact. This study aims to develop compaction indices using routine laboratory compaction procedure to evaluate the workability and compactability of hot and warm mixes prior to laydown. Workability is reflected in the ease of blending while compactability is reflected in the mixes' stability and resistance to densification. To quantify thresholds for the indices, laboratory and accelerated field testing were implemented. The workability index was tentatively found to be a minimum of 4.5 while the compactability indices were tentatively found to be a maximum of 0.5 and a minimum of 20. The compactability indices were capable of predicting mix resistance to permanent deformation.

  16. Development of a simplified asphalt mix stability procedure for use in Superpave volumetric mix design

    NASA Astrophysics Data System (ADS)

    Hafez, Ihab Hussein Fahmy

    Over the last five decades, two common test methods (Marshall and Hveem) have evolved for the design of asphaltic mixes. These design methods have been historically found to be generally reliable and reasonable for most application in design. However, premature distress in many flexible pavements suggests that these empirical methods of design do not guarantee a stable mix. Recently, many studies have been carried out in order to develop a rational mix design procedure that accounts for both the mix volumetric properties as well as fundamental engineering properties. Among those is the Superpave design procedure, which was originally divided into three, hierarchical levels termed the volumetric mix design (level I), the abbreviated mix design (level II), and the full mix design (level III). In the volumetric design, the entire mix design process is based upon the volumetric properties and does not include a test method to evaluate the stability/strength of the mix. Although both the abbreviated level and the full level of design included test methods that considered the engineering properties in a complete and a comprehensive manner; they required the purchase of very expensive equipment and a large number of samples to be tested. The objective of this research was to develop a new rational "fundamental" mix strength (stability) test for the design of dense graded mixes to overcome the limitations of the Hveem and Marshall empirical methods and to fill the gaps and major deficiencies in the current Superpave volumetric mix design. The new procedure is based upon the Superpave volumetric design (level I) but is augmented by the simple, but fundamental mix strength (stability) test. Such a test is now currently absent in the existing Superpave approach. The new procedure introduces the flow time as a fundamental engineering design criterion in the mix design. This parameter is defined as the time (in seconds) at which plastic flow in a mix occurs under creep loading

  17. MIX DESIGN FOR SMALL-SCALE MODELS OF CONCRETE STRUCTURES

    DTIC Science & Technology

    An easily applied method of mix design was developed for concretes suitable for use in small -scale models of concrete structures. By use of the...properties were collected for model concretes with portland cement and gypsum cement bases. These concretes had maximum aggregate sizes of No. 4...strength, the model concretes using approximately scaled aggregate were found to have about the same splitting-tensile strength and flexural strength, a

  18. A novel technique for the production of cool colored concrete tile and asphalt shingle roofing products

    SciTech Connect

    Levinson, Ronnen; Akbari, Hashem; Berdahl, Paul; Wood, Kurt; Skilton, Wayne; Petersheim, Jerry

    2009-11-20

    The widespread use of solar-reflective roofing materials can save energy, mitigate urban heat islands and slow global warming by cooling the roughly 20% of the urban surface that is roofed. In this study we created prototype solar-reflective nonwhite concrete tile and asphalt shingle roofing materials using a two-layer spray coating process intended to maximize both solar reflectance and factory-line throughput. Each layer is a thin, quick-drying, pigmented latex paint based on either acrylic or a poly(vinylidene fluoride)/acrylic blend. The first layer is a titanium dioxide rutile white basecoat that increases the solar reflectance of a gray-cement concrete tile from 0.18 to 0.79, and that of a shingle surfaced with bare granules from 0.06 to 0.62. The second layer is a 'cool' color topcoat with weak near-infrared (NIR) absorption and/or strong NIR backscattering. Each layer dries within seconds, potentially allowing a factory line to pass first under the white spray, then under the color spray. We combined a white basecoat with monocolor topcoats in various shades of red, brown, green and blue to prepare 24 cool color prototype tiles and 24 cool color prototypes shingles. The solar reflectances of the tiles ranged from 0.26 (dark brown; CIELAB lightness value L* = 29) to 0.57 (light green; L* = 76); those of the shingles ranged from 0.18 (dark brown; L* = 26) to 0.34 (light green; L* = 68). Over half of the tiles had a solar reflectance of at least 0.40, and over half of the shingles had a solar reflectance of at least 0.25.

  19. Seismic joint analysis for non-destructive testing of asphalt and concrete slabs

    USGS Publications Warehouse

    Ryden, N.; Park, C.B.

    2005-01-01

    A seismic approach is used to estimate the thickness and elastic stiffness constants of asphalt or concrete slabs. The overall concept of the approach utilizes the robustness of the multichannel seismic method. A multichannel-equivalent data set is compiled from multiple time series recorded from multiple hammer impacts at progressively different offsets from a fixed receiver. This multichannel simulation with one receiver (MSOR) replaces the true multichannel recording in a cost-effective and convenient manner. A recorded data set is first processed to evaluate the shear wave velocity through a wave field transformation, normally used in the multichannel analysis of surface waves (MASW) method, followed by a Lambwave inversion. Then, the same data set is used to evaluate compression wave velocity from a combined processing of the first-arrival picking and a linear regression. Finally, the amplitude spectra of the time series are used to evaluate the thickness by following the concepts utilized in the Impact Echo (IE) method. Due to the powerful signal extraction capabilities ensured by the multichannel processing schemes used, the entire procedure for all three evaluations can be fully automated and results can be obtained directly in the field. A field data set is used to demonstrate the proposed approach.

  20. Microstructure of the pulp and paper additives for stone-mastic asphalt concrete

    NASA Astrophysics Data System (ADS)

    Yastremsky, Dmitry; Chepur, Petr; Abaidullina, Tatiana

    2017-01-01

    The paper is focused on investigation of the nature and size of cellulose fibers in the structure of stabilizing additives for stone-mastic asphalt concrete, as well as on determination of fibers retention capacity based on their geometric parameters. To obtain the results a scanning electron microscope JSM-6510LV was used, with the help of which 15 to 20 photomicrographs were obtained. It was found out that in all inspected samples of stabilizing additives over 80% of pulp and paper fibers have a band structure with filaments from 0.56 to 1.4 micrometer in length. The fiber thickness in all cases slightly varies within the range of 0.008 to 0.021 micrometer. For a more detailed analysis of the additives the X-ray microanalysis was carried out. The results showed that in all cases the component distribution of the chemical elements present in the additive is inhomogeneous and has two fundamental differences in the oxygen (O) and carbon (C) content. ARMIDON additives contain more than 79% carbon (C) and just 6-13% oxygen (O). VIATOP 66 and SD-1 additives contain up to 61% carbon (C) and up to 48% oxygen (O). Tests to determine the runoff of the organic binder showed that additives with cellulose fiber filaments up to 0.6 micrometers in length hold bitumen worse than additives with cellulose fiber filaments 1.4 micrometers in length.

  1. Recycling of contaminated soils by the AMREC cold-mix, asphalt-emulsion process

    SciTech Connect

    Camougis, G.

    1993-12-31

    This paper describes the management of contaminated soils by recycling with a cold-mix, asphalt-emulsion process developed by the American Reclamation Corporation (AmRec). This is a soil recycling/reuse process in which soils contaminated with petroleum products and other contaminants can be processed into asphalt products with beneficial uses. Most of the discussion will center on soils contaminated with petroleum products. However, the recycling of soils with other contaminants (e.g., heavy metals) will also be discussed. AmRec has produced approximately 500,000 tons of asphalt products with recycled materials. These products have been used beneficially in roadways, access roads, parking areas and landfills throughout the northwest.

  2. Design and Properties of Thin Surfacing Hot Mix Asphalt Containing Crumb Rubber as Partial Aggregate Replacement

    NASA Astrophysics Data System (ADS)

    Setyawan, Ary; Febrianto, Nugroho; Sarwono, Djoko

    2017-07-01

    Road damage caused as a result of the traffic load and environment. One method to improve the road condition is from an overlay. But the new layer on the top of the pavement structure is thick enough and elevate the surface of the pavement, so it will cause some impact on the user safety and engineering. The use of a thin layer of hot mix asphalt is an alternative to anticipate the thickness problem. Crumb rubber is a waste material that has a flexible nature, these materials are used as an aggregate replacement in the hot mix asphalt thin layer. The research was conducted to find the optimum bitumen content and optimum crumb rubber content on asphalt mixtures by the Marshall procedure. Finally, it was concluded that the addition of crumb rubber in a thin layer of hot mix asphalt indicates the better the interlocking between aggregates so that gave the better Marshall stability, the higher the flow rate, the lower the marshall quotient, reduce the void ratio. The results show that the addition of crumb rubber content as an aggregate replacement leads to the use of less optimum bitumen content.

  3. Influence of fundamental material properties and air void structure on moisture damage of asphalt mixes

    NASA Astrophysics Data System (ADS)

    Arambula Mercado, Edith

    2007-12-01

    Moisture damage in asphalt mixes refers to the loss of serviceability due to the presence of moisture. The extent of moisture damage, also called moisture susceptibility, depends on internal and external factors. The internal factors relate to the properties of the materials and the microstructure distribution, while the external factors include the environmental conditions, production and construction practices, pavement design, and traffic level. The majority of the research on moisture damage is based on the hypothesis that infiltration of surface water is the main source of moisture. Of the two other principal mechanisms of water transport, permeation of water vapor and capillary rise of subsurface water, the latter has been least explored. A laboratory test and analysis methods based on X-ray computed tomography (CT) were established to assess the capillary rise of water. The amount and size of air voids filled with water were used in the capillary rise equation to estimate the distribution of the contact angles between the water and the mastic. The results were able to show the influence of air void size on capillary rise and contact angles. The relationship between air void structure and moisture susceptibility was evaluated using a fundamental fracture model based on dissipated energy of viscoelastic materials. Detailed description is provided in this dissertation on the deduction of the model equation, the selection of the model parameters, and the required testing protocols. The model parameters were obtained using mechanical tests and surface energy measurements. The microstructure of asphalt mixes prepared in the laboratory having different air void structures was captured using X-ray CT, and image analysis techniques were used to quantify the air void structure and air void connectivity. The air void structure was found to influence the mix resistance to moisture damage. To validate the fracture model, asphalt mixes with known field performance were

  4. Part 1. Characterization of roadway asphalts by solubility studies. Part 2. Development of concrete applicant organo-functional silanes

    SciTech Connect

    Lee, W.D.

    1993-01-01

    Part 1. Solubility profiles describe the chemical constitution of asphalt in terms of internal solubility phenomena. In this study the solubility parameter (r) which is related to hydrogen bonding or associative interactions and the volume dependent solubility parameter (V) which is related to London dispersion forces (non-polar interactions) and the dipole-dipole polar interactions. The plot by the solubility coordinates (r, V) of the solvents and the solubility of the asphalt is termed the solubility profile. Solubility profile data can be related to roadway performance. Roadway asphalt aging can be followed visually and mathematically by the detailed analysis of time-lapsed solubility profiles of roadway core asphalts. The profiles can be used to describe the gross chemical changes without the need to identify or isolate pure substances. This report investigates thirty-two roadway projects constructed between February 1983 and August 1987 which have been monitored for condition and followed by a series of solubility profiles for up to 60 months. Part 2. A variety of organosilanes have been used as applicants to roadway surfaces thereby extending the life or service of the roadway. The aim of this research project is to synthesize and characterize several organosilane compounds with potential concrete roadway applications. Alkyltrialkoxysilanes can be used to stop salt from penetrating concrete and resultant rebar corrosion. The first area this project deals with the optimization of the catalytic synthesis of n-octyltrichloro-and n-decyltrichlorosilane and their alkoxy derivatives. The investigation includes a study of the type and amount of catalyst and a study of varying reaction conditions. The second area of research involves the synthesis and characterization of a set of UV-absorbing/VIS-emitting organosiloxanes. These compounds have potential use as roadway delineation or roadway obstruction demarkation product enhancements.

  5. The Effect of Dustler on Reducing Stripping Failure in Hot Mix Asphalt Mixture

    NASA Astrophysics Data System (ADS)

    Baizura Hamid, Nor; Ezree Abdullah, Mohd; Erwan Sanik, Mohd; Mokhtar, Mardiha; Kaamin, Masiri; Syazwani Saari, Nur

    2017-08-01

    Hot mix asphalt (HMA) is one type of premix widely used in road construction worldwide. Aggregates for HMA are usually classified by size as coarse aggregates, fine aggregates, or mineral fillers. Moisture damage or stripping is one of the major concerns in HMA industry. The existence of water in asphalt pavement is often one of the major factors affecting the durability of HMA. The water- induced damage in HMA layers may be associated with two mechanisms a loss of adhesion and loss of cohesion. The main focus of this study based on these two objectives which is to develop HMA that involves used of dustler in asphalt mixture and to investigate the performance of dustler against stripping failure. The asphalt mixture of combination virgin aggregate and this waste material was studied. The percentages of dustler used in this study were 0.5%, 1.0% and 2.0% respectively. The method used in this study was Superpave mix design method. From the laboratory test, the indirect tensile strength (ITS) test was conducted to show the stripping performance. The result from that test showed that the value of ITS for dry sample is higher compared to wet sample for all percentages. The moisture sensitivity was determined through tensile strength ratio (TSR) test. From the results, it showed that the percentages of dustler were fulfilled the minimum requirement of AASHTO T283 which is 80% minimum requirement of moisture susceptibility. The highest value of TSR is 0.5% of dustler sample which is 98.55% compared to 1.0% of dustler sample, control sample and 2.0% of dustler sample. So, it can be concluded that dustler inhibits great potential on reducing stripping failure in hot mix asphalt.

  6. Life Cycle Cost Analysis of Ready Mix Concrete Plant

    NASA Astrophysics Data System (ADS)

    Topkar, V. M.; Duggar, A. R.; Kumar, A.; Bonde, P. P.; Girwalkar, R. S.; Gade, S. B.

    2013-11-01

    India, being a developing nation is experiencing major growth in its infrastructural sector. Concrete is the major component in construction. The requirement of good quality of concrete in large quantities can be fulfilled by ready mix concrete batching and mixing plants. The paper presents a technique of applying the value engineering tool life cycle cost analysis to a ready mix concrete plant. This will help an investor or an organization to take investment decisions regarding a ready mix concrete facility. No economic alternatives are compared in this study. A cost breakdown structure is prepared for the ready mix concrete plant. A market survey has been conducted to collect realistic costs for the ready mix concrete facility. The study establishes the cash flow for the ready mix concrete facility helpful in investment and capital generation related decisions. Transit mixers form an important component of the facility and are included in the calculations. A fleet size for transit mixers has been assumed for this purpose. The life cycle cost has been calculated for the system of the ready mix concrete plant and transit mixers.

  7. Clogging evaluation of porous asphalt concrete cores in conjunction with medical x-ray computed tomography

    NASA Astrophysics Data System (ADS)

    Su, Yu-Min; Hsu, Chen-Yu; Lin, Jyh-Dong

    2014-03-01

    This study was to assess the porosity of Porous Asphalt Concrete (PAC) in conjunction with a medical X-ray computed tomography (CT) facility. The PAC was designed as the surface course to achieve the target porosity 18%. There were graded aggregates, soils blended with 50% of coarse sand, and crushed gravel wrapped with geotextile compacted and served as the base, subbase, and infiltration layers underneath the PAC. The test site constructed in 2004 is located in Northern of Taiwan in which the daily traffic has been light and limited. The porosity of the test track was investigated. The permeability coefficient of PAC was found severely degraded from 2.2×10-1 to 1.2×10-3 -cm/sec, after nine-year service, while the permeability below the surface course remained intact. Several field PAC cores were drilled and brought to evaluate the distribution of air voids by a medical X-ray CT nondestructively. The helical mode was set to administrate the X-ray CT scan and two cross-sectional virtual slices were exported in seconds for analyzing air voids distribution. It shows that the clogging of voids occurred merely 20mm below the surface and the porosity can reduce as much about 3%. It was also found that the roller compaction can decrease the porosity by 4%. The permeability reduction in this test site can attribute to the voids of PAC that were compacted by roller during the construction and filled by the dusts on the surface during the service.

  8. Construction and testing of crumb rubber modified hot mix asphalt pavement. Interim report

    SciTech Connect

    Albritton, G.E.; Gatlin, G.R.

    1996-08-01

    This study was structured towards addressing that portion of ISTEA which directs the individual states to conduct studies on the recyclability of crumb rubber modified hot mix asphalt (CRMHMA), and the technical performance of CRMHMA pavement by monitoring the construction and evaluating the performance of highway test sections in which CRMHA is removed by cold milling and recycled into new HMA through a hot mix asphalt plant. This project is to be constructed in two phases, the CRMHMA will be built in the first phase and approximately one year later it will be recycled. This report deals with the first phase in which the objective was to further document the construction, engineering characteristics, and performace of CRMHMA.

  9. Time resolved analysis of water drainage in porous asphalt concrete using neutron radiography.

    PubMed

    Poulikakos, L D; Sedighi Gilani, M; Derome, D; Jerjen, I; Vontobel, P

    2013-07-01

    Porous asphalt as a road surface layer controls aquaplaning as rain water can drain through its highly porous structure. The process of water drainage through this permeable layer is studied using neutron radiography. Time-resolved water configuration and distribution within the porous structure are reported. It is shown that radiography depicts the process of liquid water transport within the complex geometry of porous asphalt, capturing water films, filled dead end pores and water islands. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. Slow dynamic diagnosis of asphalt concrete specimen to determine level of damage caused by static low temperature conditioning

    NASA Astrophysics Data System (ADS)

    Bekele, Abiy; Birgisson, Björn; Ryden, Nils; Gudmarsson, Anders

    2017-02-01

    The phenomenon of slow dynamics has been observed in a variety of materials which are considered as relatively homogeneous that exhibit nonlinearity due to the presence of defects or cracks within them. Experimental realizations in previous work suggest that slow dynamics can be in response to acoustic drives with relatively larger amplitude as well as rapid change of temperature. Slow dynamics as a nonlinear elastic response of damaged materials is manifested as a sharp drop and then recovery of resonance frequency linearly with logarithmic time. In this work, slow dynamics recovery is intended to be used as a means of identifying and evaluating thermal damage on an asphalt concrete specimen. The experimental protocol for measuring slow dynamics is based on the technique of nonlinear resonance spectroscopy and is set up with non-contact excitation using a loud speaker and the data acquisition tool box of Matlab. Sweeps of frequency with low amplitude are applied in order to probe the specimen at its linear viscoelastic state. The drop and then recovery in fundamental axially symmetric resonance frequency is observed after the specimen is exposed to sudden temperature change. The investigation of the viscoelastic contribution to the change in resonance frequency and slow dynamics can help identify micro-damage in asphalt concrete samples.

  11. Contributions crumb rubber in hot mix asphalt to the resilient modulus

    NASA Astrophysics Data System (ADS)

    Ariyapijati, Raden Hendra; Hadiwardoyo, Sigit Pranowo; Sumabrata, R. Jachrizal

    2017-06-01

    Pavement on the structure of the surface layer receives direct load from the vehicles. Road surfaces are designed to withstand the wear from vehicle loads. Therefore, we need a way to improve the durability of the pavement. Road damage may reduce the life of roads and increase the maintenance costs. The retention rate of road surface material is affected by the environmental conditions, one of them is temperature. To overcome the issues related to temperature, material additives are added to the asphalt mixture. These additive materials would change the binding properties of bitumen and the characteristics of strain and stress before the damage due to repeated traffic loading. Crumb rubber (CR) is a type of polymer additives and thermoplastic elastomers are obtained from scrap tires and rubber waste that is utilized in order to preserve the environment. This study investigated the contribution of the crumb rubber in terms of the value of resilient modulus and resistance to deformation. Hot mix asphalt used was asphalt Pen 60/70, coarse aggregate, fine aggregate and filler. Crumb rubber was made from scrap tire rubber, in the form of fine powder with sieve no. 30 (0.6 mm). CR additive was added to the base asphalt at several rates of 5%, 10%, 15%, and 20% at a temperature of 177° C. The test data used the indirect tensile test with a tool UMATTA at temperatures of 25°, 35°, and 45° C. The test results showed that the levels of crumb rubber on the asphalt decreased the penetration rate, increased the bitumen softening point, and improved the resistance to permanent deformation. The addition of additive materials was evidenced to improve the penetration index, reduce the temperature sensitivity, and increase the viscosity. Subsequently, it can extend the temperature range of viscoelasticity. The contributions of crumb rubber in hot mix asphalt included the increase of the recoverable deformation and the decrease of the value of resilient modulus. This study

  12. Characterization of asphalt and asphalt recyclability

    SciTech Connect

    Painter, P.C.

    1993-10-01

    The goal of the research program was to construct a simple model and computer programs that will allow at least a qualitative understand of the phase behavior of asphalt (i.e., how asphalt components mix with one another), mixtures of different types of asphalt (i.e., in recycling) and mixtures of asphalt with other materials, such as synthetic polymers. The authors have constructed such a model and computer programs (for Macintosh computers) that allow such calculations to be performed easily.

  13. Plastometry for the Self-Compacting Concrete Mixes

    NASA Astrophysics Data System (ADS)

    Lapsa, V. Ā.; Krasnikovs, A.; Lusis, V.; Lukasenoks, A.

    2015-11-01

    Operative determination of consistence of self-compacting concrete mixes at plant or in construction conditions is an important problem in building practice. The Abram's cone, the Vebe's device, the U-box siphon, L-box or funnel tests are used in solving this problem. However, these field methods are targeted at determination of some indirect parameters of such very complicated paste-like material like concrete mix. They are not physical characteristics suitable for the rheological calculations of the coherence between the stress and strains, flow characteristics and the reaction of the concrete mix in different technological processes. A conical plastometer having higher precision and less sensitive to the inaccuracy of the tests in construction condition has been elaborated at the Concrete Mechanics Laboratory of RTU. In addition, a new method was elaborated for the calculation of plasticity limit τ0 taking into account the buoyancy force of the liquid or non-liquid concrete mix. In the present investigation rheological test of the concrete mix by use the plastometer and the method mentioned earlier was conducted for different self-compacting and not self-compacting concrete mixes.

  14. Prediction of frequency for simulation of asphalt mix fatigue tests using MARS and ANN.

    PubMed

    Ghanizadeh, Ali Reza; Fakhri, Mansour

    2014-01-01

    Fatigue life of asphalt mixes in laboratory tests is commonly determined by applying a sinusoidal or haversine waveform with specific frequency. The pavement structure and loading conditions affect the shape and the frequency of tensile response pulses at the bottom of asphalt layer. This paper introduces two methods for predicting the loading frequency in laboratory asphalt fatigue tests for better simulation of field conditions. Five thousand (5000) four-layered pavement sections were analyzed and stress and strain response pulses in both longitudinal and transverse directions was determined. After fitting the haversine function to the response pulses by the concept of equal-energy pulse, the effective length of the response pulses were determined. Two methods including Multivariate Adaptive Regression Splines (MARS) and Artificial Neural Network (ANN) methods were then employed to predict the effective length (i.e., frequency) of tensile stress and strain pulses in longitudinal and transverse directions based on haversine waveform. It is indicated that, under controlled stress and strain modes, both methods (MARS and ANN) are capable of predicting the frequency of loading in HMA fatigue tests with very good accuracy. The accuracy of ANN method is, however, more than MARS method. It is furthermore shown that the results of the present study can be generalized to sinusoidal waveform by a simple equation.

  15. Prediction of Frequency for Simulation of Asphalt Mix Fatigue Tests Using MARS and ANN

    PubMed Central

    Fakhri, Mansour

    2014-01-01

    Fatigue life of asphalt mixes in laboratory tests is commonly determined by applying a sinusoidal or haversine waveform with specific frequency. The pavement structure and loading conditions affect the shape and the frequency of tensile response pulses at the bottom of asphalt layer. This paper introduces two methods for predicting the loading frequency in laboratory asphalt fatigue tests for better simulation of field conditions. Five thousand (5000) four-layered pavement sections were analyzed and stress and strain response pulses in both longitudinal and transverse directions was determined. After fitting the haversine function to the response pulses by the concept of equal-energy pulse, the effective length of the response pulses were determined. Two methods including Multivariate Adaptive Regression Splines (MARS) and Artificial Neural Network (ANN) methods were then employed to predict the effective length (i.e., frequency) of tensile stress and strain pulses in longitudinal and transverse directions based on haversine waveform. It is indicated that, under controlled stress and strain modes, both methods (MARS and ANN) are capable of predicting the frequency of loading in HMA fatigue tests with very good accuracy. The accuracy of ANN method is, however, more than MARS method. It is furthermore shown that the results of the present study can be generalized to sinusoidal waveform by a simple equation. PMID:24688400

  16. Photoactive roadways: Determination of CO, NO and VOC uptake coefficients and photolabile side product yields on TiO2 treated asphalt and concrete

    NASA Astrophysics Data System (ADS)

    Toro, C.; Jobson, B. T.; Haselbach, L.; Shen, S.; Chung, S. H.

    2016-08-01

    This work reports uptake coefficients and by-product yields of ozone precursors onto two photocatalytic paving materials (asphalt and concrete) treated with a commercial TiO2 surface application product. The experimental approach used a continuously stirred tank reactor (CSTR) and allowed for testing large samples with the same surface morphology encountered with real urban surfaces. The measured uptake coefficient (γgeo) and surface resistances are useful for parametrizing dry deposition velocities in air quality model evaluation of the impact of photoactive surfaces on urban air chemistry. At 46% relative humidity, the surface resistance to NO uptake was ∼1 s cm-1 for concrete and ∼2 s cm-1 for a freshly coated older roadway asphalt sample. HONO and NO2 were detected as side products from NO uptake to asphalt, with NO2 molar yields on the order of 20% and HONO molar yields ranging between 14 and 33%. For concrete samples, the NO2 molar yields increased with the increase of water vapor, ranging from 1% to 35% and HONO was not detected as a by-product. Uptake of monoaromatic VOCs to the asphalt sample set displayed a dependence on the compound vapor pressure, and was influenced by competitive adsorption from less volatile VOCs. Formaldehyde and acetaldehyde were detected as byproducts, with molar yields ranging from 5 to 32%.

  17. Asphalt coking method

    SciTech Connect

    Bonilla, J.A.; Elliott, J.D.

    1987-08-11

    A process is described for treating a heavy hydrocarbon fluid containing asphaltenes comprising: contacting the heavy hydrocarbon fluid with a solvent, wherein the solvent is light naphtha, C/sub 4/ hydrocarbons, C/sub 5/ hydrocarbons, C/sub 6/ hydrocarbons, or a mixture of any of light naphtha and C/sub 4/, C/sub 5/ and C/sub 6/ hydrocarbons, to obtain an asphalt mix, containing asphalt and the solvent, and deasphalted oil mix, containing deasphalted oil and the solvent; feeding the asphalt mix to a delayed coking process to form coke, wherein the asphalt mix is heated by passing the asphalt mix through conduit means in a heater in the delayed coking process. The flow of the asphalt mix through the conduit means is assisted by vaporization in the heater of the solvent in the asphalt mix, and the asphalt mix includes sufficient solvent to provide a residence time of the asphalt mix in the heater adequate for heating the asphalt mix for coking while reducing the formation of coke in the heater; separating the solvent in the deasphalted oil mix from the deasphalted oil mix to yield deasphalted oil; and recovering the deasphalted oil, bypassing the delayed coking process.

  18. Analysis of Adhesive Characteristics of Asphalt Based on Atomic Force Microscopy and Molecular Dynamics Simulation.

    PubMed

    Xu, Meng; Yi, Junyan; Feng, Decheng; Huang, Yudong; Wang, Dongsheng

    2016-05-18

    Asphalt binder is a very important building material in infrastructure construction; it is commonly mixed with mineral aggregate and used to produce asphalt concrete. Owing to the large differences in physical and chemical properties between asphalt and aggregate, adhesive bonds play an important role in determining the performance of asphalt concrete. Although many types of adhesive bonding mechanisms have been proposed to explain the interaction forces between asphalt binder and mineral aggregate, few have been confirmed and characterized. In comparison with chemical interactions, physical adsorption has been considered to play a more important role in adhesive bonding between asphalt and mineral aggregate. In this study, the silicon tip of an atomic force microscope was used to represent silicate minerals in aggregate, and a nanoscale analysis of the characteristics of adhesive bonding between asphalt binder and the silicon tip was conducted via an atomic force microscopy (AFM) test and molecular dynamics (MD) simulations. The results of the measurements and simulations could help in better understanding of the bonding and debonding procedures in asphalt-aggregate mixtures during hot mixing and under traffic loading. MD simulations on a single molecule of a component of asphalt and monocrystalline silicon demonstrate that molecules with a higher atomic density and planar structure, such as three types of asphaltene molecules, can provide greater adhesive strength. However, regarding the real components of asphalt binder, both the MD simulations and AFM test indicate that the colloidal structural behavior of asphalt also has a large influence on the adhesion behavior between asphalt and silicon. A schematic model of the interaction between asphalt and silicon is presented, which can explain the effect of aging on the adhesion behavior of asphalt.

  19. Preparation of capsules containing rejuvenators for their use in asphalt concrete.

    PubMed

    García, Alvaro; Schlangen, Erik; van de Ven, Martin; Sierra-Beltrán, Guadalupe

    2010-12-15

    Every year, there is a demand of more than 110 million metric tons of asphalt all around the world. This represents a huge amount of money and energy, from which a good part is for the preservation and renovation of the existing pavements. The problem of asphalt is that it oxidizes with time and therefore its beneficial properties disappear. Traditionally, rejuvenators spread in the road surface, are used to restore the original properties of the pavement. The problem is that, for a rejuvenator to be successful, it must penetrate the pavement surface. Furthermore, application of a rejuvenator will reduce the skid resistance of the pavement and, besides, rejuvenators have many aromatic compounds that can be harmful for the environment. To solve these problems this paper introduces a new concept in road construction: encapsulated rejuvenators. The basic principle is that when the stress in capsules embedded in the asphalt reaches a certain threshold value, the capsules break and some rejuvenator is released, restoring the original properties of the pavement. This paper will show how to prepare such capsules and how to determine their characteristics. This is one of the first steps towards intelligent pavements.

  20. 2D and 3D Ground Penetrating Radar monitoring of a reinforced concrete asphalt plate affected by mechanical deformation.

    NASA Astrophysics Data System (ADS)

    Bavusi, M.; Dumoulin, J.; Loperte, A.; Rizzo, E.; Soldovieri, F.

    2012-04-01

    The main facility of Hydrogeosite Laboratory of the Italian National Research Council (Marsico Nuovo, CNR) is a 3m x 7m x 10m reinforced concrete pool filled by siliceous sand designed for hydrologic experiments. One of its peculiarities is the possibility to vary the water table depth by using a proper hydraulic system [1]. In the framework of the FP7 ISTIMES project (Integrated System for Transport Infrastructure surveillance and Monitoring by Electromagnetic Sensing), a 3m x 3m layered structure has been purposely built and placed in the pool of the Hydrogeosite Laboratory with the aim to carry out a long term monitoring, by using jointly several electromagnetic sensing technologies, during two different phases simulating the rising of the water table and a mechanical solicitation. Several layers composed the structure from the top to the bottom, such as: 5 cm of asphalt; 5-10 cm of reinforced concrete; 20-25 cm of conglomerate, 55 cm of sand. Moreover, in the sand layer, three (metallic and plastic) pipes of different size were buried to simulate utilities. Ground Penetrating Radar (GPR) surveys were performed by using a the GSSI SIR 3000 system equipped with 400 MHz and 1500 MHz central frequency antennas. Surveys carried out by means of 400 MHz antenna allowed to detect and localize the three pipes (one in plastic and two in metal) and to investigate the effects of the sand water content on their radar signature. Surveys carried out by using 1500 MHz antenna were focused to characterize the shallower layers of the structure. The Hydrogeosite experiment consisted in following stages: • Arising of a water table by infiltration from the bottom; • Water gravity infiltration condescendingly; • Infiltration by peristaltic pump in the very shallow layers of the structure; • Water table drawdown; • Mechanical structure deformation; • Asphalt plate restoration after mechanical solicitation. After each stage a series of GPR surveys was performed. Moreover

  1. Predictors of dermal exposures to polycyclic aromatic compounds among hot-mix asphalt paving workers.

    PubMed

    Cavallari, Jennifer M; Osborn, Linda V; Snawder, John E; Kriech, Anthony J; Olsen, Larry D; Herrick, Robert F; McClean, Michael D

    2012-03-01

    The primary objective of this study was to identify the source and work practices that affect dermal exposure to polycyclic aromatic compounds (PACs) among hot-mix asphalt (HMA) paving workers. Four workers were recruited from each of three asphalt paving crews (12 workers) and were monitored for three consecutive days over 4 weeks for a total of 12 sampling days per worker (144 worker days). Two sampling weeks were conducted under standard conditions for dermal exposures. The third week included the substitution of biodiesel for diesel oil used to clean tools and equipment and the fourth week included dermal protection through the use of gloves, hat and neck cloth, clean pants, and long-sleeved shirts. Dermal exposure to PACs was quantified using two methods: a passive organic dermal (POD) sampler specifically developed for this study and a sunflower oil hand wash technique. Linear mixed-effects models were used to evaluate predictors of PAC exposures. Dermal exposures measured under all conditions via POD and hand wash were low with most samples for each analyte being below the limit of the detection with the exception of phenanthrene and pyrene. The geometric mean (GM) concentrations of phenanthrene were 0.69 ng cm(-2) on the polypropylene layer of the POD sampler and 1.37 ng cm(-2) in the hand wash sample. The GM concentrations of pyrene were 0.30 ng cm(-2) on the polypropylene layer of the POD sampler and 0.29 ng cm(-2) in the hand wash sample. Both the biodiesel substitution and dermal protection scenarios were effective in reducing dermal exposures. Based on the results of multivariate linear mixed-effects models, increasing frequency of glove use was associated with significant (P < 0.0001) reductions for hand wash and POD phenanthrene and pyrene concentrations; percent reductions ranged from 40 to 90%. Similar reductions in hand wash concentrations of phenanthrene (P = 0.01) and pyrene (P = 0.003) were observed when biodiesel was substituted for diesel oil

  2. Mixed Mode Crack Propagation in Concrete

    DTIC Science & Technology

    1990-02-01

    Engineering, American Society of Civil Engineers, vol 108, no. STl, Jan 1982, pp 207-224. 21. Z.P. Bazant and B.H. Oh. "Crack band theory for fracture of...transfer is traditionally neglected on the assumption that this would be a conservative simplification. However, Bazant et al. showed that this...under biaxial stresses," American Concrete Institute Journal, vol 66, 1969, pp 656-666. 15. Z.P. Bazant and T. Tsubaki. "Optimum slip-free limit

  3. Use of selected waste materials in concrete mixes.

    PubMed

    Batayneh, Malek; Marie, Iqbal; Asi, Ibrahim

    2007-01-01

    A modern lifestyle, alongside the advancement of technology has led to an increase in the amount and type of waste being generated, leading to a waste disposal crisis. This study tackles the problem of the waste that is generated from construction fields, such as demolished concrete, glass, and plastic. In order to dispose of or at least reduce the accumulation of certain kinds of waste, it has been suggested to reuse some of these waste materials to substitute a percentage of the primary materials used in the ordinary portland cement concrete (OPC). The waste materials considered to be recycled in this study consist of glass, plastics, and demolished concrete. Such recycling not only helps conserve natural resources, but also helps solve a growing waste disposal crisis. Ground plastics and glass were used to replace up to 20% of fine aggregates in concrete mixes, while crushed concrete was used to replace up to 20% of coarse aggregates. To evaluate these replacements on the properties of the OPC mixes, a number of laboratory tests were carried out. These tests included workability, unit weight, compressive strength, flexural strength, and indirect tensile strength (splitting). The main findings of this investigation revealed that the three types of waste materials could be reused successfully as partial substitutes for sand or coarse aggregates in concrete mixtures.

  4. Use of selected waste materials in concrete mixes

    SciTech Connect

    Batayneh, Malek Marie, Iqbal; Asi, Ibrahim

    2007-07-01

    A modern lifestyle, alongside the advancement of technology has led to an increase in the amount and type of waste being generated, leading to a waste disposal crisis. This study tackles the problem of the waste that is generated from construction fields, such as demolished concrete, glass, and plastic. In order to dispose of or at least reduce the accumulation of certain kinds of waste, it has been suggested to reuse some of these waste materials to substitute a percentage of the primary materials used in the ordinary portland cement concrete (OPC). The waste materials considered to be recycled in this study consist of glass, plastics, and demolished concrete. Such recycling not only helps conserve natural resources, but also helps solve a growing waste disposal crisis. Ground plastics and glass were used to replace up to 20% of fine aggregates in concrete mixes, while crushed concrete was used to replace up to 20% of coarse aggregates. To evaluate these replacements on the properties of the OPC mixes, a number of laboratory tests were carried out. These tests included workability, unit weight, compressive strength, flexural strength, and indirect tensile strength (splitting). The main findings of this investigation revealed that the three types of waste materials could be reused successfully as partial substitutes for sand or coarse aggregates in concrete mixtures.

  5. Modeling of viscoplastic rate-dependent hardening-softening behavior of hot mix asphalt in compression

    NASA Astrophysics Data System (ADS)

    Yun, Taeyoung; Kim, Y. Richard

    2011-02-01

    The objective of this paper is to model viscoplastic rate-dependent hardening-softening behavior that is experimentally observed from hot mix asphalt (HMA) under repetitive creep and recovery loading in compression. A differential equation is utilized to incorporate the effects of the stress history into yield stress, and an internal variable representing rate dependence in the equation is set as a function of the viscoplastic strain rate to address the change in rate dependence of the material due to gradual hardening. Also, a separate rate-dependent function concept is adopted to describe the difference in rate dependence of the yield stress during unloading and loading. The developed viscoplastic model is applied using the time-temperature superposition principle and shows good agreement with the measured viscoplastic responses of HMA under repetitive creep and recovery loading with various load levels and rest periods.

  6. 11. Buttress rising above stream bed elevation. Concrete mixing plant ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    11. Buttress rising above stream bed elevation. Concrete mixing plant is at right, west tower and placement tower boom are visible. Photographer unknown, November 24, 1926. Source: Ralph Pleasant. - Waddell Dam, On Agua Fria River, 35 miles northwest of Phoenix, Phoenix, Maricopa County, AZ

  7. Measurement of Workability of Fresh Concrete Using a Mixing Truck.

    PubMed

    Amziane, Sofiane; Ferraris, Chiara F; Koehler, Eric P

    2005-01-01

    The main objective of this study is to evaluate the workability of fresh portland cement concrete while it is still in the mixing truck by determining fundamental rheological parameters (plastic viscosity and yield stress). Nine concrete mixtures with different values of yield stress and plastic viscosity were tested in a concrete truck. The measurements made with the truck were based on the typical method of determining the flow behavior in a traditional fluid rheometer; that is, the shear rate in the mixing truck was swept from high to low by varying the rotation speed of the drum. The results of these experiments are discussed and compared with data provided by the ICAR rheometer, a portable rheometer designed for measuring concrete rheology. The test results indicate that the mixing truck equipment is sufficiently sensitive to detect differences in yield stress, slump, and plastic viscosity. However, the plastic viscosity determined by the truck measurement did not correlate with plastic viscosity as measured by the ICAR rheometer, while the yield stress determined by the truck measurement did correlate well with the measured slump and the ICAR rheometer results Suggestions are given on how to improve the mixing truck for better use as a rheometer.

  8. Measurement of Workability of Fresh Concrete Using a Mixing Truck

    PubMed Central

    Amziane, Sofiane; Ferraris, Chiara F.; Koehler, Eric P.

    2005-01-01

    The main objective of this study is to evaluate the workability of fresh portland cement concrete while it is still in the mixing truck by determining fundamental rheological parameters (plastic viscosity and yield stress). Nine concrete mixtures with different values of yield stress and plastic viscosity were tested in a concrete truck. The measurements made with the truck were based on the typical method of determining the flow behavior in a traditional fluid rheometer; that is, the shear rate in the mixing truck was swept from high to low by varying the rotation speed of the drum. The results of these experiments are discussed and compared with data provided by the ICAR rheometer, a portable rheometer designed for measuring concrete rheology. The test results indicate that the mixing truck equipment is sufficiently sensitive to detect differences in yield stress, slump, and plastic viscosity. However, the plastic viscosity determined by the truck measurement did not correlate with plastic viscosity as measured by the ICAR rheometer, while the yield stress determined by the truck measurement did correlate well with the measured slump and the ICAR rheometer results Suggestions are given on how to improve the mixing truck for better use as a rheometer. PMID:27308103

  9. Evaluation of concrete recycling system efficiency for ready-mix concrete plants.

    PubMed

    Vieira, Luiz de Brito Prado; Figueiredo, Antonio Domingues de

    2016-10-01

    The volume of waste generated annually in concrete plants is quite large and has important environmental and economic consequences. The use of fresh concrete recyclers is an interesting way for the reuse of aggregates and water in new concrete production. This paper presents a study carried out for over one year by one of the largest ready-mix concrete producers in Brazil. This study focused on the evaluation of two recyclers with distinct material separation systems, herein referred to as drum-type and rotary sieve-type equipment. They were evaluated through characterization and monitoring test programs to verify the behaviour of recovered materials (aggregates, water, and slurry). The applicability of the recovered materials (water and aggregates) was also evaluated in the laboratory and at an industrial scale. The results obtained with the two types of recyclers used were equivalent and showed no significant differences. The only exception was in terms of workability. The drum-type recycler generated fewer cases that required increased pumping pressure. The analysis concluded that the use of untreated slurry is unfeasible because of its intense negative effects on the strength and workability of concrete. The reclaimed water, pre-treated to ensure that its density is less than 1.03g/cm(3), can be used on an industrial scale without causing any harm to the concrete. The use of recovered aggregates consequently induces an increase in water demand and cement consumption to ensure the workability conditions of concrete that is proportional to the concrete strength level. Therefore, the viability of their use is restricted to concretes with characteristic strengths lower than 25MPa.

  10. Environmental impact of highway construction and repair materials on surface and ground waters. Case study: crumb rubber asphalt concrete.

    PubMed

    Azizian, Mohammad F; Nelson, Peter O; Thayumanavan, Pugazhendhi; Williamson, Kenneth J

    2003-01-01

    The practice of incorporating certain waste products into highway construction and repair materials (CRMs) has become more popular. These practices have prompted the National Academy of Science, National Cooperative Highway Research Program (NCHRP) to research the possible impacts of these CRMs on the quality of surface and ground waters. State department of transportations (DOTs) are currently experimenting with use of ground tire rubber ( crumb rubber) in bituminous construction and as a crack sealer. Crumb rubber asphalt concrete (CR-AC) leachates contain a mixture of organic and metallic contaminants. Benzothiazole and 2(3H)-benzothiazolone (organic compounds used in tire rubber manufacturing) and the metals mercury and aluminum were leached in potentially harmful concentrations (exceeding toxic concentrations for aquatic toxicity tests). CR-AC leachate exhibited moderate to high toxicity for algae ( Selenastrum capriconutum) and moderate toxicity for water fleas ( Daphnia magna). Benzothiazole was readily removed from CR-AC leachate by the environmental processes of soil sorption, volatilization, and biodegradation. Metals, which do not volatilize or photochemically or biologically degrade, were removed from the leachate by soil sorption. Contaminants from CR-AC leachates are thus degraded or retarded in their transport through nearby soils and ground waters.

  11. Quality and seasonal variation of rainwater harvested from concrete, asphalt, ceramic tile and green roofs in Chongqing, China.

    PubMed

    Zhang, Qianqian; Wang, Xiaoke; Hou, Peiqiang; Wan, Wuxing; Li, Ruida; Ren, Yufen; Ouyang, Zhiyun

    2014-01-01

    There is an urgent requirement to examine the quality of harvested rainwater for potable and non-potable purposes, based on the type of roofing material. In this study, we examined the effect on the quality of harvested rainwater of conventional roofing materials (concrete, asphalt and ceramic tile roofs) compared with alternative roofing materials (green roof). The results showed that the ceramic tile roof was the most suitable for rainwater-harvesting applications because of the lower concentrations of leachable pollutants. However, in this study, the green roof was not suitable for rainwater harvesting applications. In addition, seasonal trends in water quality parameters showed that pollutants in roof runoff in summer and autumn were lower than those in winter and spring. This study revealed that the quality of harvested rainwater was significantly affected by the roofing material; therefore, local government and urban planners should develop stricter testing programs and produce more weathering resistant roofing materials to allow the harvesting of rainwater for domestic and public uses. Copyright © 2013 Elsevier Ltd. All rights reserved.

  12. Characterization of cold recycled asphalt mixtures

    SciTech Connect

    Tia, M.

    1982-01-01

    In this study, the long-term behavior of the cold-recycled asphalt mixtures was investigated through nine experimental designs. The scope of the study covered two types of pavement material, three levels of oxydized condition of the old binder and one type of virgin aggregate. The added softening agents included a high-float asphalt emulsion AE-150, a foamed asphalt, and the rejuvenating agents, Reclamite, Mobilsol and DUTREX 739. The Water Sensitivity Test was used to evaluate the resistance of the recycled mixes to water. The results of the study indicated that most of the rejuvenating action of the added binder on the old binder took place during the compaction process. The binders of the recycled mixes which underwent the initial softening during the compaction process generally increased in stiffness with increasing curing time. The results indicated that the gyratory stability index and the gyratory elasto-plastic index could be used to determine the optimum binder content of a recycled mix. However, they could not be used to estimate the resilient modulus or the Marshall stability of the mix.A higher compactive effort generally produced a higher resilient modulus and Marshall stability of the recycled mix. When the binder content is too high, a higher compactive effort generally produces a lower Hveem R-value.The structural performance of these recycled mixes was compared to that of an asphalt concrete using a linear elastic multilayer analysis.

  13. Recycled materials in asphalt pavements. (Latest citations from the NTIS bibliographic database). Published Search

    SciTech Connect

    Not Available

    1994-05-01

    The bibliography contains citations concerning the recycling of asphalt pavement materials, and the use of other recycled materials to manufacture asphalt pavement. Articles discuss methods used for recycling bituminous pavement including hot-mix and cold-mix. Materials used to improve recycled pavement, and recycled materials used in asphalt pavement include latexes, rubber scrap such as tires, glass shards, concretes, dusts, waste oils, roofing wastes, sulfur, and metal refining sludges. Testing and evaluation of recycled pavements both in laboratories and in test cases are considered. (Contains a minimum of 160 citations and includes a subject term index and title list.)

  14. Emissions of polycyclic aromatic hydrocarbons from batch hot mix asphalt plants.

    PubMed

    Lee, Wen-Jhy; Chao, Wen-Hui; Shih, Minliang; Tsai, Cheng-Hsien; Chen, Thomas Jeng-Ho; Tsai, Perng-Jy

    2004-10-15

    This study was set out to assess the characteristics of polycyclic aromatic hydrocarbon (PAH) emissions from batch hot mix asphalt (HMA) plants and PAH removal efficiencies associated with their installed air pollution control devices. Field samplings were conducted on six randomly selected batch HMA plants. For each selected plant, stack flue gas samples were collected from both stacks of the batch mixer (n = 5) and the preheating boiler (n = 5), respectively. PAH samples were also collected from the field to assess PAHs that were directly emitted from the discharging chute (n = 3). To assess PAH removal efficiencies of the installed air pollution control devices, PAH contents in both cyclone fly ash (n=3) and bag filter fly ash (n = 3) were analyzed. Results show that the total PAH concentration (mean; RSD) in the stack flue gas of the batch mixer (354 microg/Nm3; 78.5%) was higher than that emitted from the discharging chute (107 microg/Nm3; 70.1%) and that in the stack flue gas of the preheating boiler (83.7 microg/Nm3; 77.6%). But the total BaPeq concentration of that emitted from the discharging chute (0.950 microg/Nm3; 84.4%) was higher than contained in the stack flue gas of the batch mixer (0.629 microg/Nm3; 86.8%) and the stack flue gas of the preheating boiler (= 0.112 microg/Nm3; 80.3%). The mean total PAH emission factor for all selected batch mix plants (= 139 mg/ton x product) was much higher than that reported by U.S. EPA for the drum mix asphalt plant (range = 11.8-79.0 mg/ton x product). We found the overall removal efficiency of the installed air pollution control devices (i.e., cyclone + bag filter) on total PAHs and total BaPeq were 22.1% and 93.7%, respectively. This implies that the installed air pollution control devices, although they have a very limited effect on the removal of total PAHs, do significantly reduce the carcinogenic potencies associated with PAH emissions from batch HMA plants.

  15. Excess Foundry Sand Characterization and Experimental Investigation in Controlled Low-Strength Material and Hot-Mixing Asphalt

    SciTech Connect

    Pauul J. Tikalsky

    2004-10-31

    This report provides technical data regarding the reuse of excess foundry sand. The report addresses three topics: (1) a statistically sound evaluation of the characterization of foundry sand, (2) a laboratory investigation to qualify excess foundry sand as a major component in controlled low-strength material (CLSM), and (3) the identification of the best methods for using foundry sand as a replacement for natural aggregates for construction purposes, specifically in asphalt paving materials. The survival analysis statistical technique was used to characterize foundry sand over a full spectrum of general chemical parameters, metallic elements, and organic compounds regarding bulk analysis and leachate characterization. Not limited to characterization and environmental impact, foundry sand was evaluated by factor analyses, which contributes to proper selection of factor and maximization of the reuse marketplace for foundry sand. Regarding the integration of foundry sand into CLSM, excavatable CLSM and structural CLSM containing different types of excess foundry sands were investigated through laboratory experiments. Foundry sand was approved to constitute a major component in CLSM. Regarding the integration of foundry sand into asphalt paving materials, the optimum asphalt content was determined for each mixture, as well as the bulk density, maximum density, asphalt absorption, and air voids at N{sub ini}, N{sub des}, and N{sub max}. It was found that foundry sands can be used as an aggregate in hot-mix asphalt production, but each sand should be evaluated individually. Foundry sands tend to lower the strength of mixtures and also may make them more susceptible to moisture damage. Finally, traditional anti-stripping additives may decrease the moisture sensitivity of a mixture containing foundry sand, but not to the level allowed by most highway agencies.

  16. Excess Foundry Sand Characterization and Experimental Investigation in Controlled Low-Strength Material and Hot-Mixing Asphalt

    SciTech Connect

    Tikalsky, Paul J.; Bahia, Hussain U.; Deng, An; Snyder, Thomas

    2004-10-15

    This report provides technical data regarding the reuse of excess foundry sand. The report addresses three topics: a statistically sound evaluation of the characterization of foundry sand, a laboratory investigation to qualify excess foundry sand as a major component in controlled low-strength material (CLSM), and the identification of the best methods for using foundry sand as a replacement for natural aggregates for construction purposes, specifically in asphalt paving materials. The survival analysis statistical technique was used to characterize foundry sand over a full spectrum of general chemical parameters, metallic elements, and organic compounds regarding bulk analysis and leachate characterization. Not limited to characterization and environmental impact, foundry sand was evaluated by factor analyses, which contributes to proper selection of factor and maximization of the reuse marketplace for foundry sand. Regarding the integration of foundry sand into CLSM, excavatable CLSM and structural CLSM containing different types of excess foundry sands were investigated through laboratory experiments. Foundry sand was approved to constitute a major component in CLSM. Regarding the integration of foundry sand into asphalt paving materials, the optimum asphalt content was determined for each mixture, as well as the bulk density, maximum density, asphalt absorption, and air voids at Nini, Ndes, and Nmax. It was found that foundry sands can be used as an aggregate in hot-mix asphalt production, but each sand should be evaluated individually. Foundry sands tend to lower the strength of mixtures and also may make them more susceptible to moisture damage. Finally, traditional anti-stripping additives may decrease the moisture sensitivity of a mixture containing foundry sand, but not to the level allowed by most highway agencies.

  17. Oxidation and photooxidation of asphalts

    SciTech Connect

    Mill, T.; Tse, D. )

    1990-07-01

    Oxidation of asphalt is a major cause of pavement failure owing to hardening of the asphalt binder with accompanying changes in viscosity, separation of components, embrittlement and loss of cohesion and adhesion of the asphalt in the mix. However oxidation of asphalt-aggregate mixes at high temperature is deliberately done to partly harden the mix prior to laydown; hardening then continues during cooling. Excessive hardening at this point is undesirable because of embrittlement and cracking. Slow oxidation of asphalt continues during the service life of the roadbed at a rate that appears to be partly determined by the void volume of the roadbed, as well as the properties of the asphalt and (possibly) the properties of the aggregate. The authors focused their efforts on understanding the mechanistic basis for slow oxidation of asphalt under service conditions in order to predict how rapidly an asphalt will oxidize, based on its composition, and to find better ways to inhibit the process under service conditions.

  18. State of the practice: Design and construction of asphalt paving materials with crumb-rubber modifier. Final report

    SciTech Connect

    Heitzman, M.A.

    1992-05-01

    The document is a comprehensive overview of the terminology, processes, products, and applications of crumb rubber modifier (CRM) technology. The technology includes any use of scrap tire rubber in asphalt paving materials. In general, CRM technology can be divided into two categories--the wet process and the dry process. When CRM is incorporated into an asphalt paving material, it will modify the properties of the binder (asphalt rubber) and/or act as a rubber aggregate (rubber modified hot mix asphalt). The five concepts for using CRM discussed in the report are McDonald, PlusRide, generic dry, chunk rubber asphalt concrete, and continuous blending asphalt rubber. There are two principal unresolved engineering issues related to the use of CRM in asphalt paving materials. On the national level, the ability to recycle asphalt paving mixes containing CRM has not been demonstrated. At the State and local levels, these modified asphalt mixes must be field evaluated to establish expected levels of performance. The appendices provide guidelines for material specifications, mix design, and construction specifications. An experimental work plan for monitoring performance and a stack emission testing program are also included.

  19. A methodology for use of digital image correlation for hot mix asphalt testing

    NASA Astrophysics Data System (ADS)

    Ramos, Estefany

    Digital Image Correlation (DIC) is a relatively new technology which aids in the measurement of material properties without the need for installation of sensors. DIC is a noncontact measuring technique that requires the specimen to be marked with a random speckled pattern and to be photographed during the test. The photographs are then post-processed based on the location of the pattern throughout the test. DIC can aid in calculating properties that would otherwise be too difficult even with other measuring instruments. The objective of this thesis is to discuss the methodology and validate the use of DIC in different hot mix asphalt (HMA) tests, such as, the Overlay Tester (OT) Test, Indirect Tensile (IDT) Test, and the Semicircular Bending (SCB) Test. The DIC system provides displacements and strains in any visible surface. The properly calibrated 2-D or 3-D DIC data can be used to understand the complex stress and strain distributions and the modes of the initiation and propagation of cracks. The use of this observational method will lead to further understanding of the complex boundary conditions of the different test, and therefore, allowing it to be implemented in the analysis of other materials. The use of digital image correlation will bring insight and knowledge onto what is happening during a test.

  20. Analysis of the binder yield energy test as an indicator of fatigue behaviour of asphalt mixes

    NASA Astrophysics Data System (ADS)

    O’Connell, Johan; Mturi, Georges A. J.; Komba, Julius; Du Plessis, Louw

    2017-09-01

    Empirical binder testing has increasingly failed to predict pavement performance in South Africa, with fatigue cracking being one of the major forms of premature pavement distress. In response, it has become a national aspiration to incorporate a performance related fatigue test into the binder specifications for South Africa. The Binder Yield Energy Test (BYET) was the first in a series of tests analysed for its potential to predict the fatigue performance of the binder. The test is performed with the dynamic shear rheometer, giving two key parameters, namely, yield energy and shear strain at maximum shear stress (γτmax). The objective of the investigation was to perform a rudimentary evaluation of the BYET; followed by a more in-depth investigation should the initial BYET results prove promising. The paper discusses the results generated from the BYET under eight different conditions, using six different binders. The results are then correlated with four point bending beam fatigue test results obtained from asphalt mix samples that were manufactured from the same binders. Final results indicate that the BYET is not ideal as an indicator of fatigue performance.

  1. Laboratory Performance Testing of Warm-Mix Asphalt Technologies for Airfield Pavements

    DTIC Science & Technology

    2013-12-01

    2.4.3  Hamburg Loaded Wheel Tracker (HLWT) ................................................................ 11  2.4.4  Asphalt Pavement Analyzer ( APA ...21  3.5  APA wheel tracking...34  4.5  APA wheel tracking

  2. 78 FR 51267 - Hours of Service of Drivers: National Ready Mixed Concrete Association; Application for Exemption

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-20

    ... Concrete Association; Application for Exemption AGENCY: Federal Motor Carrier Safety Administration (FMCSA... it has received an application from the National Ready Mixed Concrete Association (NRMCA) for an... carriers and CMV drivers operating ready-mixed concrete trucks. Due to the nature of their operation,...

  3. Innovative reuse of concrete slurry waste from ready-mixed concrete plants in construction products.

    PubMed

    Xuan, Dongxing; Zhan, Baojian; Poon, Chi Sun; Zheng, Wei

    2016-07-15

    Concrete slurry waste (CSW) is generated from ready-mixed concrete plants during concrete production and is classified as a corrosive hazardous material. If it is disposed of at landfills, it would cause detrimental effects for our surrounding environment and ecosystems due to its high pH value as well as heavy metal contamination and accumulation. A new method in this study has been introduced to effectively reuse CSW in new construction products. In this method, the calcium-silicate rich CSW in the fresh state was considered as a cementitious paste as well as a CO2 capture medium. The experimental results showed that the pH values of the collected CSWs stored for 28 days ranged from 12.5 to 13.0 and a drastic decrease of pH value was detected after accelerated mineral carbonation. The theoretically calculated CO2 sequestration extent of CSWs was from 27.05% to 31.23%. The practical water to solid ratio in the fresh CSW varied from 0.76 to 1.12, which had a significant impact on the compressive strength of the mixture with CSWs. After subjecting to accelerated mineral carbonation, rapid initial strength development and lower drying shrinkage for the prepared concrete mixture were achieved.

  4. Coal-based synthetic asphalts

    SciTech Connect

    Kang, J.H.

    1986-01-01

    The study investigated the technical and economic feasibility of producing a specification-grade, local-based asphalt from a raw coal available in the United States. Bench-scale hydrogenation experiments were performed in a one-gallon autoclave to produce asphalts from Illinois No. 6 bituminous coal and Clovis Point subbituminous coal. Samples from the process streams of a continuous coal liquefaction pilot plant at Wilsonville, AL were also evaluated to determine the potential for making a paving asphalt. The results showed that coal-based asphalts have a higher age-hardening rate than petroleum asphalts; also, they have a higher viscosity-temperature susceptibility (VTS) number. The high age-hardening rate of coal-based asphalts could be offset satisfactorily via catalytic hydrogenation. The VTS of these asphalts could be markedly reduced by adding a certain amount of styrene/butadiene copolymer. As a result, a specification grade, coal-based asphalt was successfully made via catalytic hydrogenation of coal combined with the incorporation of ca. 3 wt% styrene/butadiene copolymer into the coal-based asphalt. Marshall stability testing showed that coal based asphalt/aggregate compacted mixes had excellent resistance to plastic flow. Immersion compression testing revealed that the compacted mixes had a high initial compression strength and retained strength. A two-stage coal-based asphalt process was designed for producing 1000 tons/day. Economic analyses showed that the coal-based asphalt would be more expensive than currently used petroleum asphalt.

  5. Beneficial uses of recycled asphalt-stabilized products as landfill cover and capping systems

    SciTech Connect

    Camougis, G.

    1996-12-31

    The American Reclamation Corporation (AMREC{reg_sign}) has played a major role in the development of new programs for the recycling of discarded materials from construction, demolition, remediation and manufacturing operations. Excavated petroleum-contaminated soils (oily soils), asphalt paving, concrete rubble, and discarded asphalt roofing shingles have been processed and recycled into beneficially useful construction products. AMREC uses a cold-mix, asphalt-emulsion technology to process many of the recyclables received at its recycling facility in Charlton, MA. Recyclable materials are processed and blended to produce recycled, asphalt-stabilized products. In addition, recycled, asphalt-stabilized products are being investigated and tested for other beneficial uses. This includes their uses as capping materials and as containment materials.

  6. Recycled materials in asphalt pavements, January 1980-June 1991 (citations from the NTIS database). Rept. for Jan 80-Jun 91

    SciTech Connect

    Not Available

    1991-06-01

    The bibliography contains citations concerning the recycling of asphalt pavement materials, and the use of other recycled materials to manufacture asphalt pavement. Articles discuss methods used for recycling bituminous pavement including hot-mix and cold-mix. Materials used to improve recycled pavement, and recycled materials used in asphalt pavement include latexes, rubber scrap such as tires, glass shards, concretes, dusts, waste oils, roofing wastes, sulfur, and metal refining sludges. Testing and evaluation of recycled pavements both in laboratories and in test cases are considered. (The bibliography contains 75 citations.) (Also includes title list and subject index.)

  7. Personal breathing zone exposures among hot-mix asphalt paving workers; preliminary analysis for trends and analysis of work practices that resulted in the highest exposure concentrations.

    PubMed

    Osborn, Linda V; Snawder, John E; Kriech, Anthony J; Cavallari, Jennifer M; McClean, Michael D; Herrick, Robert F; Blackburn, Gary R; Olsen, Larry D

    2013-01-01

    An exposure assessment of hot-mix asphalt (HMA) paving workers was conducted to determine which of four exposure scenarios impacted worker exposure and dose. Goals of this report are to present the personal-breathing zone (PBZ) data, discuss the impact of substituting the releasing/cleaning agent, and discuss work practices that resulted in the highest exposure concentration for each analyte. One-hundred-seven PBZ samples were collected from HMA paving workers on days when diesel oil was used as a releasing/cleaning agent. An additional 36 PBZ samples were collected on days when B-100 (100% biodiesel, containing no petroleum-derived products) was used as a substitute releasing/cleaning agent. Twenty-four PBZ samples were collected from a reference group of concrete workers, who also worked in outdoor construction but had no exposure to asphalt emissions. Background and field blank samples were also collected daily. Total particulates and the benzene soluble fraction were determined gravimetrically. Total organic matter was determined using gas chromatography (GC) with flame ionization detection and provided qualitative information about other exposure sources contributing to worker exposure besides asphalt emissions. Thirty-three individual polycyclic aromatic compounds (PACs) were determined using GC with time-of-flight mass spectrometry; results were presented as either the concentration of an individual PAC or a summation of the individual PACs containing either 2- to 3-rings or 4- to 6-rings. Samples were also screened for PACs containing 4- to 6-rings using fluorescence spectroscopy. Arithmetic means, medians, and box plots of the PBZ data were used to evaluate trends in the data. Box plots illustrating the diesel oil results were more variable than the B-100. Also, the highest diesel oil results were much higher in concentration than the highest B-100 results. An analysis of the highest exposure results and field notes revealed a probable association between

  8. Personal Breathing Zone Exposures among Hot-Mix Asphalt Paving Workers; Preliminary Analysis for Trends and Analysis of Work Practices That Resulted in the Highest Exposure Concentrations

    PubMed Central

    Osborn, Linda V.; Snawder, John E.; Kriech, Anthony J.; Cavallari, Jennifer M.; McClean, Michael D.; Herrick, Robert F.; Blackburn, Gary R.; Olsen, Larry D.

    2015-01-01

    An exposure assessment of hot-mix asphalt (HMA) paving workers was conducted to determine which of four exposure scenarios impacted worker exposure and dose. Goals of this report are to present the personal-breathing zone (PBZ) data, discuss the impact of substituting the releasing/cleaning agent, and discuss work practices that resulted in the highest exposure concentration for each analyte. One-hundred-seven PBZ samples were collected from HMA paving workers on days when diesel oil was used as a releasing/cleaning agent. An additional 36 PBZ samples were collected on days when B-100 (100% biodiesel, containing no petroleum-derived products) was used as a substitute releasing/cleaning agent. Twenty-four PBZ samples were collected from a reference group of concrete workers, who also worked in outdoor construction but had no exposure to asphalt emissions. Background and field blank samples were also collected daily. Total particulates and the benzene soluble fraction were determined gravimetrically. Total organic matter was determined using gas chromatography (GC) with flame ionization detection and provided qualitative information about other exposure sources contributing to worker exposure besides asphalt emissions. Thirty-three individual polycyclic aromatic compounds (PACs) were determined using GC with time-offlight mass spectrometry; results were presented as either the concentration of an individual PAC or a summation of the individual PACs containing either 2- to 3-rings or 4- to 6-rings. Samples were also screened for PACs containing 4- to 6-rings using fluorescence spectroscopy. Arithmetic means, medians, and box plots of the PBZ data were used to evaluate trends in the data. Box plots illustrating the diesel oil results were more variable than the B-100. Also, the highest diesel oil results were much higher in concentration than the highest B-100 results. An analysis of the highest exposure results and field notes revealed a probable association between

  9. 7 CFR 3201.77 - Asphalt restorers.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 15 2013-01-01 2013-01-01 false Asphalt restorers. 3201.77 Section 3201.77... Designated Items § 3201.77 Asphalt restorers. (a) Definition. Products designed to seal, protect, or restore poured asphalt and concrete surfaces. (b) Minimum biobased content. The Federal preferred procurement...

  10. 7 CFR 3201.77 - Asphalt restorers.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 15 2014-01-01 2014-01-01 false Asphalt restorers. 3201.77 Section 3201.77... Designated Items § 3201.77 Asphalt restorers. (a) Definition. Products designed to seal, protect, or restore poured asphalt and concrete surfaces. (b) Minimum biobased content. The Federal preferred procurement...

  11. The urban heat island effect, its causes, and mitigation, with reference to the thermal properties of asphalt concrete.

    PubMed

    Mohajerani, Abbas; Bakaric, Jason; Jeffrey-Bailey, Tristan

    2017-04-13

    The Urban Heat Island (UHI) is a phenomenon that affects many millions of people worldwide. The higher temperatures experienced in urban areas compared to the surrounding countryside has enormous consequences for the health and wellbeing of people living in cities. The increased use of manmade materials and increased anthropogenic heat production are the main causes of the UHI. This has led to the understanding that increased urbanisation is the primary cause of the urban heat island. The UHI effect also leads to increased energy needs that further contribute to the heating of our urban landscape, and the associated environmental and public health consequences. Pavements and roofs dominate the urban surface exposed to solar irradiation. This review article outlines the contribution that pavements make to the UHI effect and analyses localized and citywide mitigation strategies against the UHI. Asphalt Concrete (AC) is one of the most common pavement surfacing materials and is a significant contributor to the UHI. Densely graded AC has low albedo and high volumetric heat capacity, which results in surface temperatures reaching upwards of 60 °C on hot summer days. Cooling the surface of a pavement by utilizing cool pavements has been a consistent theme in recent literature. Cool pavements can be reflective or evaporative. However, the urban geometry and local atmospheric conditions should dictate whether or not these mitigation strategies should be used. Otherwise both of these pavements can actually increase the UHI effect. Increasing the prevalence of green spaces through the installation of street trees, city parks and rooftop gardens has consistently demonstrated a reduction in the UHI effect. Green spaces also increase the cooling effect derived from water and wind sources. This literature review demonstrates that UHI mitigation techniques are best used in combination with each other. As a result of the study, it was concluded that the current mitigation

  12. Bacteria and asphalt stripping. Final report, December 1983-August 1987

    SciTech Connect

    Ramamurti, K.; Jayaprakash, G.P.

    1987-08-01

    Major types of bituminous pavement distress were rutting, cracking (longitudinal, transverse, and alligator) and stripping. The rubble and loosely bound material contained bacteria. The deterioration lessened upward from the pavement-soil interface. The soil appears to be the prime source of the bacteria. Most of the bacterial cells were sausage shaped with polar flagellation. They appeared to belong to the genus Pseudomonas, which is a known user of asphaltic hydrocarbons. Cocci-type bacteria and a virus were also noted. Increasing the density of some asphaltic concrete and strengthening the bond between aggregate and asphalt are considered as the preferred alternatives to using chemical biocides. Anything to reduce pavement cracking would help. Adding lime to asphalt mixes may be one effective means of improving aggregate-asphalt bond and controlling biodeterioration. Lime stabilization of soils under asphalt pavements may provide an added protection against bacterial attack by rendering the soil more hostile to bacterial habitat. Full-depth hot-mix recycling would be more effective than partial-depth recycling in retarding bacterial decay at cracks.

  13. Numerical Study on Mixed-mode Fracture in Reinforced Concrete

    SciTech Connect

    Yu, Rena C.; Saucedo, Luis; Ruiz, Gonzalo

    2010-05-21

    The object of this work is to model the propagation of fracture in mixed-mode in lightly reinforced concrete beams. When a notched beam does not have enough shear reinforcement, fracture can initiate and propagate unstably and lead to failure through diagonal tension. In order to study this phenomenon numerically, a model capable of dealing with both static and dynamic crack propagation as well as the natural transition of those two regimes is necessary. We adopt a cohesive model for concrete fracture and an interface model for the deterioration between concrete and steel re-bar, both combined with an insertion algorithm. The static process is solved by dynamic relaxation (DR) method together with a modified technique to enhance convergence rate. The same DR method is used to detect a dynamic process and switch to a dynamic calculation. The numerically obtained load-displacement curves, load-CMOD curves and crack patterns fit reasonably well with their experimental counterparts, having in mind that we fed the calculations only with parameters measured experimentally.

  14. Effect of soil pollution on water for mixing of concrete

    NASA Astrophysics Data System (ADS)

    Muñoz, M. Cecilia Soto; Tapia Alvarez, Carolina; Decinti Weiss, Alejandra; Zamorano Vargas, Macarena; Corail Sanchez, Camila; Hurtado Nuñez, Camilo; Guzman Hermosilla, Matías; Pardo Fabregat, Francisco; Vidal, Manuel Miguel Jordan; Borras, Jaume Bech; Roca, Nuria

    2016-04-01

    ISO 12439, in addition to chemical and physical requirements, establishes maximum levels for harmful substances that may be present in the mixing water of concrete, when they come from natural sources from contaminated soils. These harmful substances considered in the ISO are sugars, phosphates (P2O5), nitrate (NO3-), lead (P2+) and zinc (Zn2+). As an alternative to the maximum values, ISO verifies the effect of these substances in water from contaminated soils. This measurement is made on the effect on the mechanical strength of the concrete (compression at 7 and 28 days) and the setting times (start and end setting). This paper presents the results obtained on samples of concrete made with smaller, similar and more content to the maximum levels set by ISO 12439 are presented. The results establish that in the case of nitrate, a substance present in many contaminated soils margins resistance variation or setting times allowed by ISO 12439 are not met. Finally, it is concluded that in case of presence of these pollutants should be performed strength tests and setting times before authorizing the use of water. Keywords: Harmful substances, contaminated soils, water pollution.

  15. Study of the Technical Feasibility of Increasing the Amount of Recycled Concrete Waste Used in Ready-Mix Concrete Production.

    PubMed

    Fraile-Garcia, Esteban; Ferreiro-Cabello, Javier; López-Ochoa, Luis M; López-González, Luis M

    2017-07-18

    The construction industry generates a considerable amount of waste. Faced with this undesirable situation, the ready-mix concrete sector, in particular, has invested energy and resources into reusing its own waste in its production process as it works towards the goal of more sustainable construction. This study examines the feasibility of incorporating two types of concrete waste, which currently end up in landfill, into the production process of ready-mix concrete: the waste generated during the initial production stage (ready-mix concrete waste), and waste created when demolition waste is treated to obtain artificial aggregate. The first phase of the study's methodology corroborates the suitability of the recycled aggregate through characterization tests. After this phase, the impact of incorporating different percentages of recycled coarse aggregate is evaluated by examining the performance of the produced concrete. The replacement rate varied between 15% and 50%. The results indicate that recycled aggregates are, indeed, suitable to be incorporated into ready-mix concrete production. The impact on the final product's performance is different for the two cases examined herein. Incorporating aggregates from generic concrete blocks led to a 20% decrease in the produced concrete's strength performance. On the other hand, using recycled aggregates made from the demolition waste led to a smaller decrease in the concrete's performance: about 8%. The results indicate that with adequate management and prior treatment, the waste from these plants can be re-incorporated into their production processes. If concrete waste is re-used, concrete production, in general, becomes more sustainable for two reasons: less waste ends up as landfill and the consumption of natural aggregates is also reduced.

  16. Experimental study on the strength parameter of Quarry Dust mixed Coconut Shell Concrete adding Coconut Fibre

    NASA Astrophysics Data System (ADS)

    Matangulu Shrestha, Victor; Anandh, S.; Sindhu Nachiar, S.

    2017-07-01

    Concrete is a heterogeneous mixture constitute of cement as the main ingredient with a different mix of fine and coarse aggregate. The massive use of conventional concrete has a shortfall in its key ingredients, natural sand and coarse aggregate, due to increased industrialisation and globalisation. To overcome the shortage of material, an alternate material with similar mechanical properties and composition has to be studied, as replacement of conventional concrete. Coconut shell concrete is a prime option as replacement of key ingredients of conventional concrete as coconut is produced in massive quantity in south East Asia. Coconut shell concrete is lightweight concrete and different research is still ongoing concerning about its mix design and composition in the construction industry. Concrete is weak in tension as compared to compression, hence the fibre is used to refrain the crack in the concrete. Coconut fibre is one of many fibres which can be used in concrete. The main aim of this project is to analyse the use of natural by-products in the construction industry, make light weight concrete and eco-friendly construction. This project concerns with the comparison of the mechanical properties of coconut shell concrete and conventional concrete, replacing fine aggregate with quarry dust using coconut fibre. M25 grade of concrete was adopted and testing of concrete was done at the age of 3, 7 and 28 days. In this concrete mix, sand was replaced completely in volumetric measurement by quarry dust. The result was analysed and compared with addition of coconut fibre at varying percentage of 1%, 2%, 3%, 4% and 5%. From the test conducted, coconut shell concrete with quarry dust has the maximum value at 4% of coconut fibre while conventional concrete showed the maximum value at 2% of coconut fibre.

  17. Improving Asphalt Mixtures Performance by Mitigating Oxidation Using Anti-Oxidants Additives

    NASA Astrophysics Data System (ADS)

    Dessouky, Samer; Diaz, Manuel

    Polymer modified additives are typically used to improve rheological properties of asphalt binder as well as mechanical properties of asphalt concrete mix. In this study, polymer-modified binder PG70-22 is mixing with two co-polymers enhanced with anti-oxidant agents namely; Solution Styrene-Butadiene Rubber (SSBR) and Solution Ethylene-Butylene/Styrene (SEBS). The objective of this study is to characterize the effect of those additives into the rheological properties of the asphalt binder using temperature sweep test and mechanical properties of asphalt mixes. The aging index is determined to evaluate the role of additives to reduce brittleness after aging of the binder. The performance of asphalt mixes were characterized by Hamburg Wheel Tracking Test for moisture damage, Beam Fatigue Test for fatigue properties and Flow Number Test for rutting performance. It is found that the asphalt mixes with enhanced binders are improving its rutting and moisture resistance but decreased its fatigue life compared to the control mix.

  18. Modifiers for Asphalt Concrete

    DTIC Science & Technology

    1990-11-01

    approximately correct for bituminous mixtures, where the particulate character and granular nature of the material is wc1- r1czsognized. Earlier work on fiber...still exist; however, these correlations could be improved if the appropriate constitutive law is utilized. Advances in the fields of material ...development of constitutive relationships that better replicate material responses such as viscoelasticity and vis- coplasticity (i.e., viscous elastic-plastic

  19. Non-destructive assessment of Hot Mix Asphalt density with a Step Frequency Radar - Case study

    NASA Astrophysics Data System (ADS)

    Fauchard, Cyrille; Beaucamp, Bruno

    2013-04-01

    The density of Hot Mix Asphalt (HMA) layers is a key parameter for assessing newly paved roads. It allows the quality control and ensures the time performance of the road layers. The standard methods for measuring the in-place HMA density are destructive and based on cores testing. Knowing the specific gravity of the HMA (data provided by builder), the bulk density can be determined in the laboratory either by weighting cores methods or by measuring the absorption ratio of gamma rays through road samples. Non destructive (ND) methods are highly needed in order to gain time and to avoid the strong constraints due to the nuclear gauges use. The Step Frequency Radar (SFR) is an electromagnetic method based on wave propagation in matter, similar in its principle to the Ground Penetrating Radar (GPR). It can use wide band and higher frequencies than GPR, allowing a thinner spatial resolution, but with a lower speed of acquisition. It is used in the present work as a tool providing the dielectric constant of HMA. Recent results in the laboratory have shown that the density can be relied on HMA dielectric constant with the use of a dielectric model (Complex Refractive Index model, or CRI model) taking into account the volume concentration and the dielectric constant of each HMA component. In this approach, the knowledge of the rock dielectric constant that composes the main part of HMA is required. If not, the in-place measurements can be calibrated according to one or more core drillings and the previous approach is still available. The main objective of this paper is to apply the methodology developed in the laboratory on a new HMA layer (case study located on A13 highway, nearby the city of Cagny, Normandie, France) for assessing the HMA density. The SFR system is composed of a vector network analyser sweeping a large frequency band [1.4 GHz - 20 GHz] and an ultra wide band antenna placed above the HMA surface. The whole system is pc-controlled and embedded in a

  20. Study of the Technical Feasibility of Increasing the Amount of Recycled Concrete Waste Used in Ready-Mix Concrete Production

    PubMed Central

    Ferreiro-Cabello, Javier; López-González, Luis M.

    2017-01-01

    The construction industry generates a considerable amount of waste. Faced with this undesirable situation, the ready-mix concrete sector, in particular, has invested energy and resources into reusing its own waste in its production process as it works towards the goal of more sustainable construction. This study examines the feasibility of incorporating two types of concrete waste, which currently end up in landfill, into the production process of ready-mix concrete: the waste generated during the initial production stage (ready-mix concrete waste), and waste created when demolition waste is treated to obtain artificial aggregate. The first phase of the study’s methodology corroborates the suitability of the recycled aggregate through characterization tests. After this phase, the impact of incorporating different percentages of recycled coarse aggregate is evaluated by examining the performance of the produced concrete. The replacement rate varied between 15% and 50%. The results indicate that recycled aggregates are, indeed, suitable to be incorporated into ready-mix concrete production. The impact on the final product’s performance is different for the two cases examined herein. Incorporating aggregates from generic concrete blocks led to a 20% decrease in the produced concrete’s strength performance. On the other hand, using recycled aggregates made from the demolition waste led to a smaller decrease in the concrete’s performance: about 8%. The results indicate that with adequate management and prior treatment, the waste from these plants can be re-incorporated into their production processes. If concrete waste is re-used, concrete production, in general, becomes more sustainable for two reasons: less waste ends up as landfill and the consumption of natural aggregates is also reduced. PMID:28773183

  1. Recycled materials in asphalt pavements. October 1973-November 1989 (Citations from the NTIS data base). Report for October 1973-November 1989

    SciTech Connect

    Not Available

    1989-12-01

    This bibliography contains citations concerning the recycling of asphalt-pavement materials, and the use of other recycled materials to manufacture asphalt pavement. Articles discuss methods used for recycling bituminous pavement including hot-mix and cold-mix. Materials used to improve recycled pavement, and recycled materials used in asphalt pavement include latexes, rubber scrap such as tires, glass shards, concretes, dusts, waste oils, roofing wastes, sulfur, and metal refining sludges. Testing and evaluation of recycled pavements both in laboratories and in test cases are considered. (Contains 110 citations fully indexed and including a title list.)

  2. Stripping in hot mix asphalt produced by aggregates from construction and demolition waste.

    PubMed

    Pérez, I; Pasandín, A R; Gallego, J

    2012-01-01

    This paper analyses the effect of water on the durability of hot asphalt mixtures made with recycled aggregates from construction and demolition debris. Indirect tensile stress tests were carried out to evaluate stripping behaviour. The mixtures tested were fabricated with 0, 20, 40 and 60% recycled aggregates. Two types of natural aggregates were used: schist and calcite dolomite. An increase in the percentage of recycled aggregates was found to produce a decrease in the tensile stress ratio of the hot asphalt mixtures. To study this phenomenon, two and three factor analyses of variance (ANOVA) were performed with indirect tensile stress being used as the dependent variable. The factors studied were the percentage of recycled aggregates (0, 20, 40 and 60%), the moisture state (dry, wet) and the type of natural aggregate (schist, calcite). On the basis of the ANOVA results, it was found that the most important factor affecting resistance was the moisture state (dry, wet) of the specimens. The percentage of recycled aggregate also affected indirect tensile stress, especially in the dry state. The type of natural aggregate did not have a significant effect on indirect tensile stress. The hot asphalt mixture specimens made with different percentages of recycled aggregates from construction and demolition debris and of natural quarry aggregates showed poor stripping behaviour. This stripping behaviour can be related to both the poor adhesion of the recycled aggregates and the high absorption of the mortar of cement adhered to them.

  3. Effect of Cement on Properties of Over-Burnt Brick Bituminous Concrete Mixes

    NASA Astrophysics Data System (ADS)

    Sarkar, Dipankar; Pal, Manish

    2016-06-01

    The present investigation is carried out to propose the use of cement coated over burnt brick aggregate in the preparation of bituminous concrete mix. The effect of cement on various mechanical properties such as Marshall stability, flow, Marshall quotient (stability to flow ratio), indirect tensile strength, stripping, rutting and fatigue life of bituminous concrete overlay has been evaluated. In this study, different cement percentages such as 2, 3, 4 and 5 % by weight of aggregate have been mixed with Over Burnt Brick Aggregate (OBBA). The laboratory results indicate that bituminous concrete prepared by 4 % cement coated OBBA gives the highest Marshall stability. The bituminous concrete mix with 4 % cement shows considerable improvement in various mechanical properties of the mix compared to the plain OBBA concrete mix.

  4. Study on infrared differential thermal non-destructive testing technology of the permeability of hot mix asphalt pavements

    NASA Astrophysics Data System (ADS)

    Wang, Duanyi; Shi, Jicun

    2017-06-01

    In order to non-destructive test (NDT) the permeability coefficient of hot mix asphalt (HMA) pavements fast, A methodology for assessing the permeability coefficient was proposed by infrared differential thermal testing of pavement after rain. The relationship between permeability coefficient and air voids of HMA specimen deter-mined. Finite element method (FEM) models were built to calculate the surface temperature difference with different exposure time after precipitation. Simulated solar radiation source and fully saturated plate specimens were set in laboratory, tests verify that the different exposure time the specimen surface temperature difference. Infrared differential thermal detection permeable pavement hardware and corresponding software developed. Based on many test results, the evaluation index and criteria of permeability coefficient of HMA pavements tested by infrared differential thermal were developed. The results showed that: There is correlation between air voids and permeability coefficient of HMA specimen. Permeability coefficient of HMA pavements can be determined by different surface temperature at different exposure time. 9:00 am - 14:00 pm is the best time to detect permeability coefficient by infrared differential thermal NDT. Permeable asphalt pavement permeability can be achieved by infrared detector quickly and continuously, a lane testing; Per the permeable assessment criteria, in-place pavements permeability coefficients can be accurately evaluated.

  5. Investigation of factors affecting asphalt pavement recycling and asphalt compatibility

    SciTech Connect

    Venable, R.L.; Petersen, J.C.; Robertson, R.E.; Plancher, H.

    1983-03-01

    Both economic and environmental factors dictate that asphalt pavement be recycled. Many recycling projects have been completed using a variety of recycling additives, but little work has been done on the physiochemical aspects of pavement recycling. The present exploratory study was undertaken to better define the physiochemical variables of recycling. Objectives of the present study include: (1) to determine if molecular structuring in the asphalt binder could be observed in oxidized (air-aged) asphalt-aggregate briquets, and if so, how was structuring affected during briquits, and if so, how was structuring affected during briquet recycling and (2) to determine if recycling agents penetrate the strongly adsorbed asphalt layer on the aggregate surface. Differences were seen in asphalt component compatibility as judged by the state of peptization parameters. In extreme cases the values of the parameters correlated with properties of asphalts of known compatibility; however, a relationship between the parameters determined on a series of asphalts in pavements was not established. The parameters might be useful in evaluating additives for pavement recycling; however, more systems need to be studied to fully assess their potential usefulness. Finally, the parameters need to be correlated with performance-related measurements such as asphalt rheological and mix properties. Examination of the parameters and their changes on asphalt oxidative aging may also be informative with regard to asphalt durability inasmuch as oxidation-induced changes are a major cause of asphalt pavement failure.

  6. Inferring strength and deformation properties of hot mix asphalt layers from the GPR signal: recent advances

    NASA Astrophysics Data System (ADS)

    Tosti, Fabio; Benedetto, Andrea; Bianchini Ciampoli, Luca; Adabi, Saba; Pajewski, Lara

    2015-04-01

    , of both the different strength provision of each layer composing the hot mix asphalt pavement structure, and of the attenuation occurring to electromagnetic waves during their in-depth propagation. Promising results are achieved by matching modelled and measured elastic modulus data. This continuous statistically-based model enables to consider the whole set of information related to each single depth, in order to provide a more comprehensive prediction of the strength and deformation behavior of such a complex multi-layered medium. Amongst some further developments to be tackled in the near future, a model improvement could be reached through laboratory activities under controlled conditions and by adopting several frequency bandwidths suited for purposes. In addition, the perspective to compare electromagnetic data with mechanical measurements retrieved continuously, i.e., by means of specifically equipped lorries, could pave the way to considerable enhancements in this field of research. Acknowledgements - This work has benefited from networking activities carried out within the EU funded COST Action TU1208 "Civil Engineering Applications of Ground Penetrating Radar".

  7. Latex improvement of recycled asphalt pavement

    NASA Astrophysics Data System (ADS)

    Drennon, C.

    1982-08-01

    The performance of a single unmodified milled recycled asphalt concrete was compared to milled asphalt concrete modified by addition of three types of rubber latex. Latex was added at 2, 3, 5, and 8 percent latex by weight of asphalt in the asphalt concrete. Lattices used were a styrene butadiene (SBR), a natural rubber (NR), an acrylonitrile butadiene (NBR), and four varieties of out of specification SBR lattices. Marshall tests, while indecisive, showed a modest improvement in properties of SBR and NR added material at 3 and 5 percent latex. Addition of NBR latex caused deterioration in Marshall stability and flow over that of control. Repeated load tests were run using the indirect tensile test, analyzed by the VESYS program, which computes life of pavements. Repeated load tests showed improvement in asphalt concrete life when 3 and 5 percent SBR was added. Improvement was also shown by the out of specification SBR.

  8. Full-Scale Accelerated Pavement Testing of Warm-Mix Asphalt (WMA) for Airfield Pavements

    DTIC Science & Technology

    2014-01-01

    software and Pavement Engineering Utility (PSEVEN) were used 50 ft 65 ft 130 ft 24 ft Item 3 Sasobit ® Item 4 Evotherm 3G Item 1 HMA... Evotherm 3G Air Top Mid-depth Bottom Target temperature = 109 ºF ERDC/GSL TR-14-3 25 The target pavement temperature for this study was 109 ºF, and it is...the locations of the I-buttons and their layout in relation to the vents. 90 95 100 105 110 115 120 HMA Foamed Asphalt Sasobit Evotherm 3G Av er ag e

  9. Neutron radiation shielding properties of polymer incorporated self compacting concrete mixes.

    PubMed

    Malkapur, Santhosh M; Divakar, L; Narasimhan, Mattur C; Karkera, Narayana B; Goverdhan, P; Sathian, V; Prasad, N K

    2017-07-01

    In this work, the neutron radiation shielding characteristics of a class of novel polymer-incorporated self-compacting concrete (PISCC) mixes are evaluated. Pulverized high density polyethylene (HDPE) material was used, at three different reference volumes, as a partial replacement to river sand in conventional concrete mixes. By such partial replacement of sand with polymer, additional hydrogen contents are incorporated in these concrete mixes and their effect on the neutron radiation shielding properties are studied. It has been observed from the initial set of experiments that there is a definite trend of reductions in the neutron flux and dose transmission factor values in these PISCC mixes vis-à-vis ordinary concrete mix. Also, the fact that quite similar enhanced shielding results are recorded even when reprocessed HDPE material is used in lieu of the virgin HDPE attracts further attention. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Investigation of the Microstructural Mechanisms of Relaxation and Fracture Healing in Asphalt

    DTIC Science & Technology

    1991-10-30

    asphalt concrete. The methodology has been verified by testing ’ thirteen’ differe~nt asphalts with widely varying compositions and chemistries. This... method of establishing the amount of fracture healing that occurs in asphalt concrete as the result’ of rest periods is being used to establish the...Process .......... ... ... ..... 24 Task 5 - Relaxation and Healing Testing of Asphalt’ Samples . . 26 m Task 6 - Produce Specific Asphalts by

  11. Using pyrolized carbon black from waste tires in asphalt pavement. Part 1. Limestone aggregate. Final report, September 1993-May 1995

    SciTech Connect

    Park, T.; Lovell, C.W.

    1996-02-20

    The study presents the viability of using pyrolyzed carbon black (PCB) as an additive in hot mix asphalt concrete. Different ratios of PCB (5%, 10%, 15%, 20% by weight of asphalt) were blended with two grades of asphalt (AC-10 and AC-20). The complete behaviors of the PCB modified asphalt concrete were investigated by comprehensive laboratory testing and evaluation. The Marshall method was used to determine the optimum binder content, and the mechanical properties and void relationships were investigated by this method. The Gyratory Testing Machine was used to define the stress-strain relationships of the PCB mixtures. The rutting potential of PCB mixtures was investigated using the Dynamic Creep Testing. The performance of the PCB mixtures at low temperature (5 degrees C) was determined by the Indirect Tensile Testing. The strength performance of the PCB mixtures at intermediate temperatures (5 degrees C and 25 degrees C) was examined by the Resilient Modulus Test. The Hamburg Wheel Tracking Device was employed to ascertain the stripping potential of the PCB mixtures. The findings of the study show beneficial effects of added PCB for asphalt mixture. Specifically, test results show that PCB contents of 10% to 15% by weigh of asphalt produce a number of significant 0mprovements. The rutting potential, the temperature susceptibility and the stripping potential can be reduced by the inclusion of PCB in the asphalt mixture. Added material costs of about 6% may well be justified by expected improvements in performance.

  12. Upscaling the Use of Mixed Recycled Aggregates in Non-Structural Low Cement Concrete

    PubMed Central

    López-Uceda, Antonio; Ayuso, Jesús; Jiménez, José Ramón; Agrela, Francisco; Barbudo, Auxiliadora; De Brito, Jorge

    2016-01-01

    This research aims to produce non-structural concrete with mixed recycled aggregates (MRA) in upscaled applications with low-cement content. Four slabs were executed with concrete made with different ratios of coarse MRA (0%, 20%, 40% and 100%), using the mix design, the mixing procedures and the facilities from a nearby concrete production plant. The analysis of the long-term compressive and splitting tensile strengths in concrete cores, extracted from the slabs, allowed the highlighting of the long-term high strength development potential of MRA incorporation. The study of cast specimens produced in situ under the same conditions as the slabs showed, firstly, that the use of MRA has a great influence on the properties related to durability, secondly, that the loss of compressive strength for total MRA incorporation relative to control concrete increases proportionally with the class strength, and, thirdly, that the mechanical properties (including Schmidt hammer results) from the concrete slabs showed no significant differences relative to the control concrete for coarse aggregates replacements up to 40%. Therefore, this upscaled experimental study supports the application of concrete with 100% coarse MRA incorporation and low cement content in non-structural civil works such as bike lanes, gutters, ground slabs, leveling surfaces, and subgrades for foundations. To the best of the authors’ knowledge, there have not been any upscaled applications of concrete with MRA and low cement content. PMID:28787892

  13. Upscaling the Use of Mixed Recycled Aggregates in Non-Structural Low Cement Concrete.

    PubMed

    López-Uceda, Antonio; Ayuso, Jesús; Jiménez, José Ramón; Agrela, Francisco; Barbudo, Auxiliadora; De Brito, Jorge

    2016-02-02

    This research aims to produce non-structural concrete with mixed recycled aggregates (MRA) in upscaled applications with low-cement content. Four slabs were executed with concrete made with different ratios of coarse MRA (0%, 20%, 40% and 100%), using the mix design, the mixing procedures and the facilities from a nearby concrete production plant. The analysis of the long-term compressive and splitting tensile strengths in concrete cores, extracted from the slabs, allowed the highlighting of the long-term high strength development potential of MRA incorporation. The study of cast specimens produced in situ under the same conditions as the slabs showed, firstly, that the use of MRA has a great influence on the properties related to durability, secondly, that the loss of compressive strength for total MRA incorporation relative to control concrete increases proportionally with the class strength, and, thirdly, that the mechanical properties (including Schmidt hammer results) from the concrete slabs showed no significant differences relative to the control concrete for coarse aggregates replacements up to 40%. Therefore, this upscaled experimental study supports the application of concrete with 100% coarse MRA incorporation and low cement content in non-structural civil works such as bike lanes, gutters, ground slabs, leveling surfaces, and subgrades for foundations. To the best of the authors' knowledge, there have not been any upscaled applications of concrete with MRA and low cement content.

  14. Recycling asphalt proves economical for paving contractors

    SciTech Connect

    Not Available

    1982-09-01

    Methods of recyclig asphalt to repair roads are described and evaluated. Need for recycling is caused by the escalating price of asphalt (an oil product). The economics and efficiency of the various processes used are evaluated. Methods described are: (1) cold-mix recycling in which the road is crushed, mixed with a new asphalt emulsion and reapplied; (2) hot mix, which involves ripping up pavement, trucking it to an asphalt plant, and mixing the old pavement material with virgin paving materials; and (3) cold planing (when only the top few inches of the road are deteriorated). Mining of asphalt roads, by removing top layers from old roads which are thick from many repair jobs, is described as well as mining of old airstrips. Value of asphalt available has been estimated as high as $50 billion. Recycling processes for asphalt are described briefly. (MJJ)

  15. Development of criteria for the use of asphalt-rubber as a Stress-Absorbing Membrane Interlayer (SAMI)

    NASA Astrophysics Data System (ADS)

    Newcomb, D. E.; McKeen, R. G.

    1983-12-01

    This report documents over 2 years of research efforts to characterize asphalt-rubber mixtures to be used in Stress-Absorbing Membrane Interlayers (SAMI). The purpose of these SAMIs is to retard or prevent reflection cracking in asphalt-concrete overlays. Several laboratory experiments and one field trial were conducted to define significant test methods and parameters for incorporation into construction design and specification documents. Test methods used in this study included a modified softening point test, force-ductility, and Schweyer viscosity. Variables investigated included (1) Laboratory-mixing temperature; (2) Rubber type; (3) Laboratory storage time; (4) Laboratory storage condition; (5) Laboratory batch replication; (6) Laboratory mixing time; (7) Field mixing time; (8) Laboratory test temperature; (9) Force-Ductility elongation rates; and (10) Asphalt grade. It was found that mixing temperature, mixing time, rubber type, and asphalt grade all have significant effects upon the behavior of asphalt-rubber mixtures. Significant variability was also noticed in different laboratory batch replications. Varying laboratory test temperature and force-ductility elongation rate revealed further differences in asphalt-rubber mixtures.

  16. Nature of the chemical reaction for furfural modified asphalt

    SciTech Connect

    Memon, G.M.; Chollar, B.H.

    1994-12-31

    Three of the most serious problems of asphalt pavements today are rutting, cracking, and susceptibility to moisture damage (stripping). Asphalt manufacturers have been mixing asphalts with polymers to produce polymer-modified asphalts with improved rheological properties. However, the costs for these improved polymer-modified asphalts are almost double that of regular asphalts. FHWA researchers have found that asphalt modified by the chemical, furfural (which is prepared by simple elimination reaction of aldopentoses obtained from oat hulls), exhibited better stripping properties and was less temperature susceptible than the virgin asphalt while costing less than polymer-modified asphalts. This paper discusses the possible structure of the furfural-modified asphalt, data for the virgin and furfural-modified asphalts and their Corbett fractions, data from a model reaction between phenol and furfural, and a possible explanation of this structure based on these data.

  17. Use of Residual Solids from Pulp and Paper Mills for Enhancing Strength and Durability of Ready-Mixed Concrete

    SciTech Connect

    Tarun R. Naik; Yoon-moon Chun; Rudolph N. Kraus

    2003-09-18

    This research was conducted to establish mixture proportioning and production technologies for ready-mixed concrete containing pulp and paper mill residual solids and to study technical, economical, and performance benefits of using the residual solids in the concrete. Fibrous residuals generated from pulp and paper mills were used, and concrete mixture proportions and productions technologies were first optimized under controlled laboratory conditions. Based on the mixture proportions established in the laboratory, prototype field concrete mixtures were manufactured at a ready-mixed concrete plant. Afterward, a field construction demonstration was held to demonstrate the production and placement of structural-grade cold-weather-resistant concrete containing residual solids.

  18. Utility of Wastage Material as Steel Fibre in Concrete Mix M-20

    NASA Astrophysics Data System (ADS)

    Parashar, Ashish Kumar; Parashar, Rinku

    2012-10-01

    Fiber Reinforced Concrete (FRC) is a composite material consisting of cement based matrix with an ordered or random distribution of fiber which can be steel, nylon, polythene etc. The addition of steel fibre increases the properties of concrete, viz., flexural strength, impact strength and shrinkage properties to name a few. A number of papers have already been published on the use of steel fibres in concrete and a considerable amount of research has been directed towards studying the various properties of concrete as well as reinforced concrete due to the addition of steel fibres. Hence, an attempt has been made in the present investigations to study the influence of addition of Lathe Machines wastematerial as fibers at a dosage of 5% to 30% by weight of cement. The properties studied include compressive strength. The studies were conducted on a M20 mix and tests have been carried out. The results are compared and conclusions are made.

  19. Field and laboratory study of cold-asphalt-mix recycling in Ohio. Final report

    SciTech Connect

    Majidzadeh, K.; Ilves, G.J.; Abdulshafi, A.; Kaloush, K.

    1987-09-01

    The report presents a study initiated in 1984 to develop specification guidelines and mix-design recommendations and to obtain performance data on cold-mix recycling projects in Ohio. Two mainline, low-volume roads and one shoulder pavement were selected for the study. Documentation and evaluation of the projects are discussed generally in two parts. The first part includes the site-selection criteria, pre-construction evaluation, mix designs, construction specifications and construction monitoring. The second part discusses performance evaluation through field inspection, data collection, and laboratory evaluation of material properties.

  20. Performance of volcanic ash and pumice based blended cement concrete in mixed sulfate environment

    SciTech Connect

    Hossain, K.M.A. . E-mail: ahossain@ryerson.ca; Lachemi, M.

    2006-06-15

    The deterioration of concrete structures due to the presence of mixed sulfate in soils, groundwater and marine environments is a well-known phenomenon. The use of blended cements incorporating supplementary cementing materials and cements with low C{sub 3}A content is becoming common in such aggressive environments. This paper presents the results of an investigation on the performance of 12 volcanic ash (VA) and finely ground volcanic pumice (VP) based ASTM Type I and Type V (low C{sub 3}A) blended cement concrete mixtures with varying immersion period of up to 48 months in environments characterized by the presence of mixed magnesium-sodium sulfates. The concrete mixtures comprise a combination of two Portland cements (Type I and Type V) and four VA/VP based blended cements with two water-to-binder ratio of 0.35 and 0.45. Background experiments (in addition to strength and fresh properties) including X-ray diffraction (XRD), Differential scanning calorimetry (DSC), mercury intrusion porosimetry (MIP) and rapid chloride permeability (RCP) were conducted on all concrete mixtures to determine phase composition, pozzolanic activity, porosity and chloride ion resistance. Deterioration of concrete due to mixed sulfate attack and corrosion of reinforcing steel were evaluated by assessing concrete weight loss and measuring corrosion potentials and polarization resistance at periodic intervals throughout the immersion period of 48 months. Plain (Type I/V) cement concretes, irrespective of their C{sub 3}A content performed better in terms of deterioration and corrosion resistance compared to Type I/V VA/VP based blended cement concrete mixtures in mixed sulfate environment.

  1. Mixed Consolidation Solution for a Reinforced Concrete Structure

    NASA Astrophysics Data System (ADS)

    Lute, M.

    2016-06-01

    During the last years, reinforced concrete structures become subject for rehabilitation due to two factors: their long life span and large change in norms that leaded to a large increase of seismic loads in Eastern Europe. These lead to a necessity for rehabilitation of existing building stock in order to use them during their entire life span at the maximum potential. The present paper proposes a solution for rehabilitation for three reinforced concrete building of a hospital, that consumed a half of their life span and do not correspond anymore to present norms. The chosen solution is a combination between CFRP rehabilitation and increase of structural elements cross section in order to achieve the stiffness balance in the structure nodes that is required by present norms. As a further matter, correction in stiffness of local elements diminished the lateral drifts of the structure and improved the global seismic response of the building.

  2. Evaluation and improvement of micro-surfacing mix design method and modelling of asphalt emulsion mastic in terms of filler-emulsion interaction

    NASA Astrophysics Data System (ADS)

    Robati, Masoud

    This Doctorate program focuses on the evaluation and improving the rutting resistance of micro-surfacing mixtures. There are many research problems related to the rutting resistance of micro-surfacing mixtures that still require further research to be solved. The main objective of this Ph.D. program is to experimentally and analytically study and improve rutting resistance of micro-surfacing mixtures. During this Ph.D. program major aspects related to the rutting resistance of micro-surfacing mixtures are investigated and presented as follow: 1) evaluation of a modification of current micro-surfacing mix design procedures: On the basis of this effort, a new mix design procedure is proposed for type III micro-surfacing mixtures as rut-fill materials on the road surface. Unlike the current mix design guidelines and specification, the new mix design is capable of selecting the optimum mix proportions for micro-surfacing mixtures; 2) evaluation of test methods and selection of aggregate grading for type III application of micro-surfacing: Within the term of this study, a new specification for selection of aggregate grading for type III application of micro-surfacing is proposed; 3) evaluation of repeatability and reproducibility of micro-surfacing mixture design tests: In this study, limits for repeatability and reproducibility of micro-surfacing mix design tests are presented; 4) a new conceptual model for filler stiffening effect on asphalt mastic of micro-surfacing: A new model is proposed, which is able to establish limits for minimum and maximum filler concentrations in the micro-surfacing mixture base on only the filler important physical and chemical properties; 5) incorporation of reclaimed asphalt pavement and post-fabrication asphalt shingles in micro-surfacing mixture: The effectiveness of newly developed mix design procedure for micro-surfacing mixtures is further validated using recycled materials. The results present the limits for the use of RAP and RAS

  3. Application of orthogonal test method in mix proportion design of recycled lightweight aggregate concrete

    NASA Astrophysics Data System (ADS)

    Zhao, Zhanshan; An, Le; Zhang, Yijing; Yuan, Jie

    2017-03-01

    Recycled lightweight aggregate concrete was made with construction waste and ceramsite brick mainly including brick. Using the orthogonal test method, the mix proportion of recycled lightweight aggregate concrete was studied, and the Influence regularity and significance of water binder ratio, fly ash, sand ratio, the amount of recycled aggregate proportion on the compressive strength of concrete, the strong influence of mass ratio, slump expansion degree was studied. Through the mean and range analysis of the test results, the results show that the water binder ratio has the greatest influence on the 28d intensity of recycled lightweight aggregate concrete. Secondly, the fly ash content, the recycled aggregate replacement rate and the sand ratio have little influence. For the factors of expansion: the proportion of fly ash = water binder ratio sand >sand rate> recycled aggregate replacement rate. When the content of fly ash is about 30%, the expanded degree of recycled lightweight aggregate concrete is the highest, and the workability of that is better and the strength of concrete with 28d and 56d are the highest. When the content of brickbat is about 40% brick particles, the strength of concrete reaches the highest.

  4. The Concrete and Pavement Challenge

    ERIC Educational Resources Information Center

    Roman, Harry T.

    2012-01-01

    The modern world is characterized by the extensive use of concrete and asphalt pavement. Periodically, these materials are replaced and the old materials disposed of. In this challenge, students will be asked to develop ways to reuse the old materials. It is important for students to understand how concrete and asphalt are made and applied, as…

  5. The Concrete and Pavement Challenge

    ERIC Educational Resources Information Center

    Roman, Harry T.

    2012-01-01

    The modern world is characterized by the extensive use of concrete and asphalt pavement. Periodically, these materials are replaced and the old materials disposed of. In this challenge, students will be asked to develop ways to reuse the old materials. It is important for students to understand how concrete and asphalt are made and applied, as…

  6. Properties of Non-Structural Concrete Made with Mixed Recycled Aggregates and Low Cement Content

    PubMed Central

    López-Uceda, Antonio; Ayuso, Jesús; López, Martin; Jimenez, José Ramón; Agrela, Francisco; Sierra, María José

    2016-01-01

    In spite of not being legally accepted in most countries, mixed recycled aggregates (MRA) could be a suitable raw material for concrete manufacturing. The aims of this research were as follows: (i) to analyze the effect of the replacement ratio of natural coarse aggregates with MRA, the amount of ceramic particles in MRA, and the amount of cement, on the mechanical and physical properties of a non-structural concrete made with a low cement content; and (ii) to verify if it is possible to achieve a low-strength concrete that replaces a greater amount of natural aggregate with MRA and that has a low cement content. Two series of concrete mixes were manufactured using 180 and 200 kg/m3 of CEM II/A-V 42.5 R type Portland cement. Each series included seven concrete mixes: one with natural aggregates; two MRA with different ceramic particle contents; and one for each coarse aggregate replacement ratio (20%, 40%, and 100%). To study their properties, compressive and splitting tensile strength, modulus of elasticity, density, porosity, water penetration, and sorptivity, tests were performed. The results confirmed that the main factors affecting the properties analyzed in this research are the amount of cement and the replacement ratio; the two MRAs used in this work presented a similar influence on the properties. A non-structural, low-strength concrete (15 MPa) with an MRA replacement ratio of up to 100% for 200 kg/m3 of cement was obtained. This type of concrete could be applied in the construction of ditches, sidewalks, and other similar civil works. PMID:28787874

  7. Properties of Non-Structural Concrete Made with Mixed Recycled Aggregates and Low Cement Content.

    PubMed

    López-Uceda, Antonio; Ayuso, Jesús; López, Martin; Jimenez, José Ramón; Agrela, Francisco; Sierra, María José

    2016-01-26

    In spite of not being legally accepted in most countries, mixed recycled aggregates (MRA) could be a suitable raw material for concrete manufacturing. The aims of this research were as follows: (i) to analyze the effect of the replacement ratio of natural coarse aggregates with MRA, the amount of ceramic particles in MRA, and the amount of cement, on the mechanical and physical properties of a non-structural concrete made with a low cement content; and (ii) to verify if it is possible to achieve a low-strength concrete that replaces a greater amount of natural aggregate with MRA and that has a low cement content. Two series of concrete mixes were manufactured using 180 and 200 kg/m³ of CEM II/A-V 42.5 R type Portland cement. Each series included seven concrete mixes: one with natural aggregates; two MRA with different ceramic particle contents; and one for each coarse aggregate replacement ratio (20%, 40%, and 100%). To study their properties, compressive and splitting tensile strength, modulus of elasticity, density, porosity, water penetration, and sorptivity, tests were performed. The results confirmed that the main factors affecting the properties analyzed in this research are the amount of cement and the replacement ratio; the two MRAs used in this work presented a similar influence on the properties. A non-structural, low-strength concrete (15 MPa) with an MRA replacement ratio of up to 100% for 200 kg/m³ of cement was obtained. This type of concrete could be applied in the construction of ditches, sidewalks, and other similar civil works.

  8. Recycled rubber, aggregate, and filler in asphalt paving mixtures. Transportation research record

    SciTech Connect

    1996-12-31

    ;Contents(Partial): Evaluation Systems for Crumb Rubber Modified Binders and Mixtures; Hot Mix Asphalt Rubber Applications in Virginia; Evaluation of Pyrolized Carbon Black from Scrap Tires as Additive in Hot Mix Asphalt; Use of Scrap Tire Chips in Asphaltic Membrane; Effects of Mineral Fillers on Properties of Stone Matrix Asphalt Mixtures; and Quantitative Analysis of Aggregate Based on Hough Transform.

  9. Evaluation of the Structural Performance of CTS Rapid Set Concrete Mix

    DTIC Science & Technology

    2016-08-01

    setting concrete (Priddy et al. 2013). Per manufacturer’s recommendation, bulk citric acid can be added to the mix water to increase the working time of...repairs was due to a heavy rain received between November 2013 and mid-March 2014. Immediately following the failure of these original repairs...approximately 12.5 lb of citric acid was added to each water tank. ERDC/GSL TR-16-20 25 Before placement of the concrete cap, the repair void, including

  10. Sustainable asphalt pavement: Application of slaughterhouse waste oil and fly ash in asphalt binder

    NASA Astrophysics Data System (ADS)

    Sanchez Ramos, Jorge Luis

    Increasing energy costs, lack of sufficient natural resources and the overwhelming demand for petroleum has stimulated the development of alternative binders to modify or replace petroleum-based asphalt binders. In the United States, the petroleum-based asphalt binder is mainly used to produce the Hot Mix Asphalt (HMA). There are approximately 4000 asphalt plants that make 500 million tons of asphalt binder valued at roughly 3 billion/year. The instability of the world's oil market has pushed oil prices to more than 80 per barrel in 2012, which increased the cost of asphalt binder up to $570 per ton. Therefore, there is a timely need to find alternative sustainable resources to the asphalt binder. This paper investigates the possibility of the partial replacement of the asphalt binder with slaughterhouse waste and/or fly ash. In order to achieve this objective, the asphalt binder is mixed with different percentages of waste oil and/or fly ash. In order to investigate the effect of these additives to the performance of the asphalt binder, a complete performance grade test performed on multiple samples. The results of the performance grade tests are compared with a control sample to observe how the addition of the waste oil and/or fly ash affects the sample. Considering the increasing cost and demand of asphalt, the use of slaughterhouse waste oil and/or fly ash as a partial replacement may result in environmental and monetary improvements in the transportation sector.

  11. Development of high-strength concrete mix designs in support of the prestressed concrete reactor vessel design for a HTGR steam cycle/cogeneration plant

    SciTech Connect

    Naus, D.J.; Oland, C.B.

    1985-01-01

    Design optimization studies indicate that a significant reduction in the size of the PCRV for a 2240 MW(t) HTGR plant can be effected through utilization of high-strength concrete in conjunction with large capacity prestressing systems. A three-phase test program to develop and evaluate high-strength concretes (>63.4 MPa) is described. Results obtained under Phase I of the investigation related to materials selection-evaluation and mix design development are presented. 3 refs., 4 figs.

  12. The Asphalt Handbook.

    ERIC Educational Resources Information Center

    Asphalt Inst., College Park, MD.

    The new and completely revised edition of the Asphalt Handbook, a standard reference work in the field of asphalt technology and construction, summarizes with reference the information contained in other Asphalt Institute technical manuals. Major areas discussed include the following--(1) uses of asphalt, (2) terms relating to asphalt and its…

  13. The Asphalt Handbook.

    ERIC Educational Resources Information Center

    Asphalt Inst., College Park, MD.

    The new and completely revised edition of the Asphalt Handbook, a standard reference work in the field of asphalt technology and construction, summarizes with reference the information contained in other Asphalt Institute technical manuals. Major areas discussed include the following--(1) uses of asphalt, (2) terms relating to asphalt and its…

  14. Predictors of airborne exposures to polycyclic aromatic compounds and total organic matter among hot-mix asphalt paving workers and influence of work conditions and practices.

    PubMed

    Cavallari, Jennifer M; Osborn, Linda V; Snawder, John E; Kriech, Anthony J; Olsen, Larry D; Herrick, Robert F; McClean, Michael D

    2012-03-01

    We evaluated personal airborne exposures to polycyclic aromatic compounds (PACs) and total organic matter (TOM) among hot-mix asphalt (HMA) paving workers. The primary objectives of this study were to identify predictors of airborne PAC exposures, identify PAC exposure sources, and characterize how work practices may affect personal airborne exposure to PACs. Four workers were recruited from each of three asphalt paving crews (12 workers) and were monitored for three consecutive days over 4 weeks for a total of 12 sampling days per worker (144 worker-days). Three sampling weeks were conducted while maintaining standard working conditions with regard to airborne exposures. The fourth week included the substitution of biodiesel for diesel oil used to clean tools and equipment. Linear mixed-effects models were used to evaluate predictors of airborne exposures including weather parameters (air temperature, wind speed, and relative humidity), worksite conditions (HMA application temperature, work rate, asphalt grade, and biodiesel use), and personal factors (minutes sampled, minutes of downtime, and smoking status). Concentrations of the 33 individual PACs measured in personal air samples were generally below detection limits under all conditions with the exception of fluorene [geometric mean (GM) = 65 ng m(-3)], naphthalene (GM = 833 ng m(-3)), phenanthrene (GM = 385 ng m(-3)), and pyrene (GM = 57 ng m(-3)). The summary measures of TOM (GM = 864 μg m(-3)) and four- to six-ring PAC (GM = 0.13 μg m(-3)) were detected in the majority of air samples. Although task was not a predictor of airborne exposures, job site characteristics such as HMA application temperature were found to significantly (P ≤ 0.001) affect summary and individual PAC exposures. Based on the results of multivariate linear mixed-effects models, substituting biodiesel for diesel oil as a cleaning agent was associated with significant (P ≤ 0.01) reductions in TOM, four- to six-ring PACs, and

  15. The study of pervious concrete mix proportion by the method of specific surface area of aggregate

    NASA Astrophysics Data System (ADS)

    Xiao, Liguang; Jiang, Dawei

    2017-09-01

    The purpose of this paper is to solve the shortcoming of the mix proportion of pervious concrete. So we have done the research on the measurement of the specific surface area of aggregate, and the research on the volume change of cement after hydration, and the research on the best water-binder ratio and thickness of gelled material package. The experimental results show that the equivalent method is more accurate for measuring the specific surface area of aggregate. It can better reflect the specific surface area of aggregate. Moreover, the calculation method of the mix proportion of the cementing material can improve the utilization ratio of material and the quality of pervious concrete.

  16. Biodegradation of Asphalt Cement-20 by Aerobic Bacteria

    PubMed Central

    Pendrys, John P.

    1989-01-01

    Seven gram-negative, aerobic bacteria were isolated from a mixed culture enriched for asphalt-degrading bacteria. The predominant genera of these isolates were Pseudomonas, Acinetobacter, Alcaligenes, Flavimonas, and Flavobacterium. The mixed culture preferentially degraded the saturate and naphthene aromatic fractions of asphalt cement-20. A residue remained on the surface which was resistant to biodegradation and protected the underlying asphalt from biodegradation. The most potent asphalt-degrading bacterium, Acinetobacter calcoaceticus NAV2, excretes an emulsifier which is capable of emulsifying the saturate and naphthene aromatic fractions of asphalt cement-20. This emulsifier is not denatured by phenol. PMID:16347928

  17. Mix design and pollution control potential of pervious concrete with non-compliant waste fly ash.

    PubMed

    Soto-Pérez, Linoshka; Hwang, Sangchul

    2016-07-01

    Pervious concrete mix was optimized for the maximum compressive strength and the desired permeability at 7 mm/s with varying percentages of water-to-binder (W/B), fly ash-to-binder (FA/B), nano-iron oxide-to-binder (NI/B) and water reducer-to-binder (WR/B). The mass ratio of coarse aggregates in sizes of 4.75-9.5 mm to the binder was fixed at 4:1. Waste FA used in the study was not compliant with a standard specification for use as a mineral admixture in concrete. One optimum pervious concrete (Opt A) targeting high volume FA utilization had a 28-day compressive strength of 22.8 MPa and a permeability of 5.6 mm/s with a mix design at 36% W/B, 35% FA/B, 6% NI/B and 1.2% WR/B. The other (Opt B) targeting a less use of admixtures had a 28-day compressive strength and a permeability of 21.4 MPa and 7.6 mm/s, respectively, at 32% W/B, 10% FA/B, 0.5% NI/B and 0.8% WR/B. During 10 loads at a 2-h contact time each, the Opt A and Opt B achieved the average fecal coliform removals of 72.4% and 77.9% and phosphorus removals of 49.8% and 40.5%, respectively. Therefore, non-compliant waste FA could be utilized for a cleaner production of pervious concrete possessing a greater structural strength and compatible hydrological property and pollution control potential, compared to the ordinary pervious concrete.

  18. Characterization of steel fiber and/or polymer concrete mixes and applications to slender rectangular and I-beams

    NASA Astrophysics Data System (ADS)

    Ahmed, Ashraf Ibrahim

    This dissertation presents results from experimental studies related to polymer modified concrete, steel fiber reinforced concrete, and steel fiber/polymer modified concrete. As a first stage of this research, the properties of different concrete mixes were characterized. These mixes were: plain concrete, steel fiber concrete with fiber volume fraction of 1%, polymer modified concrete with 1% to 7.5% solids of polymer, and steel fiber/polymer modified concrete with 1% to 7.5% polymer solids and I% steel fiber fraction. Concrete cylinders and 4 x 4 inches beams were tested under compressive, tensile, flexural, and bar pull-out loadings. In the second phase of this research, slender beams with a depth to width ratio of three were tested under four point loading for shear and flexure. Half I-beams, with gross aspect ratio of four and web aspect ratio of three were tested under the combined loading of bending, shear, and torsion. Lateral eccentric loads were applied transversely in the shallow direction to the 3 x 9 inches beams and the half I-beams. Dog bone shaped reinforced and un-reinforced specimens with 3 x 3 inches square sections were tested under pure torsional loading. The addition of 1% steel fibers alone or with 5% solids of polymers to concrete mixes improved their toughness and ductility. The contribution of steel fibers to bending, shear, and torsion in slender and half I-beams is presented. The ACI code methods for calculating the torsional, shear, and flexural resistance of beams are compared to the experimental results. Post crack analysis performed on the slender beams and half I-beams indicated that the tested specimens could carry 70% of the maximum applied loads after initial concrete cracking and failure. The reduction in the tensile stresses of stirrups and longitudinal reinforcing bars, due to the steel fibers and polymer, are presented. Fibers and polymers increase bending and toughness in concrete.

  19. Asphalt cement poisoning

    MedlinePlus

    ... petroleum material that hardens when it cools. Asphalt cement poisoning occurs when someone swallows asphalt. If hot ... found in: Road paving materials Roofing materials Tile cements Asphalt may also be used for other purposes.

  20. Use of POTW biosolids in bituminous concrete

    SciTech Connect

    Smith, R.C.; Angelbeck, D.I.

    1995-11-01

    Although wastewater treatment helps alleviate water pollution, it creates residual by-products that can pose a disposal dilemma. Four main practices are presently employed to dispose of wastewater treatment plant sludge: land application, composting, incineration, and landfilling. A fifth disposal method that may help to alleviate the sludge disposal problem in future years is the incorporation of sludge into useful end products such as fertilizer or construction materials. This research was designed to evaluate the properties of bituminous concrete mixes that had anaerobically digested sewage sludge incorporated into their design. In doing so, it was desired to verify the work of Wells concerning sludge incorporation into bituminous concrete mixes using today`s asphalts. Hot mix and cold mix designs were studied.

  1. [Skin burns, necrosis and ulcers caused by wet cement, ready-mixed concrete and lime. 8 cases].

    PubMed

    Koch, P

    1996-01-01

    Skin burns and caustic ulcers caused by wet cement, due to calcium hydroxyde, are rarely reported in the literature. They occur mostly among amateur cement users. We report seven cases of skin burns, necrosis and ulcerations after use of wet cement and ready-mixed concrete, and one case of caustic ulcers induced by wet lime. Even short skin contacts to wet cement or concrete may induce extensive lesions in some cases. However, we were not able to incriminate with certainty any special concrete additives which could increase skin penetration of calcium hydroxyde. Warning notices about the danger of skin contact should be prominent on sacked cement. When ready-mixed concrete is delivered, the purchaser should be handed a note explaining the risk of kneeling in wet concrete and the importance of protective measures. This may probably contribute to reduce the frequency of those accidents.

  2. Long-Term Performance Evaluation of Asphalt Surface Treatments: Product Placement

    DTIC Science & Technology

    2010-02-01

    Polymer Modified MasterSeal (PMM). .................................... 27 Figure 24. Application of Pass QB...yards 0.8361274 square meters yards 0.9144 meters ERDC/GSL SR-10-1 1 1 Introduction Background Environmental degradation of asphalt concrete ...significant damage. Techniques for maintaining asphalt concrete airfield pavements are typi- cally performed in response to the formation of environmental

  3. The exposure to coarse, fine and ultrafine particle emissions from concrete mixing, drilling and cutting activities.

    PubMed

    Azarmi, Farhad; Kumar, Prashant; Mulheron, Mike

    2014-08-30

    Building activities generate coarse (PM10≤10μm), fine (PM2.5≤2.5μm) and ultrafine particles (<100nm) making it necessary to understand both the exposure levels of operatives on site and the dispersion of ultrafine particles into the surrounding environment. This study investigates the release of particulate matter, including ultrafine particles, during the mixing of fresh concrete (incorporating Portland cement with Ground Granulated Blastfurnace Slag, GGBS or Pulverised Fuel Ash, PFA) and the subsequent drilling and cutting of hardened concrete. Particles were measured in the 5-10,000nm size range using a GRIMM particle spectrometer and a fast response differential mobility spectrometer (DMS50). The mass concentrations of PM2.5-10 fraction contributed ∼52-64% of total mass released. The ultrafine particles dominated the total particle number concentrations (PNCs); being 74, 82, 95 and 97% for mixing with GGBS, mixing with PFA, drilling and cutting, respectively. Peak values measured during the drilling and cutting activities were 4 and 14 times the background. Equivalent emission factors were calculated and the total respiratory deposition dose rates for PNCs for drilling and cutting were 32.97±9.41×10(8)min(-1) and 88.25±58.82×10(8)min(-1). These are a step towards establishing number and mass emission inventories for particle exposure during construction activities. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. Linking asphalt binder fatigue to asphalt mixture fatigue performance using viscoelastic continuum damage modeling

    NASA Astrophysics Data System (ADS)

    Safaei, Farinaz; Castorena, Cassie; Kim, Y. Richard

    2016-08-01

    Fatigue cracking is a major form of distress in asphalt pavements. Asphalt binder is the weakest asphalt concrete constituent and, thus, plays a critical role in determining the fatigue resistance of pavements. Therefore, the ability to characterize and model the inherent fatigue performance of an asphalt binder is a necessary first step to design mixtures and pavements that are not susceptible to premature fatigue failure. The simplified viscoelastic continuum damage (S-VECD) model has been used successfully by researchers to predict the damage evolution in asphalt mixtures for various traffic and climatic conditions using limited uniaxial test data. In this study, the S-VECD model, developed for asphalt mixtures, is adapted for asphalt binders tested under cyclic torsion in a dynamic shear rheometer. Derivation of the model framework is presented. The model is verified by producing damage characteristic curves that are both temperature- and loading history-independent based on time sweep tests, given that the effects of plasticity and adhesion loss on the material behavior are minimal. The applicability of the S-VECD model to the accelerated loading that is inherent of the linear amplitude sweep test is demonstrated, which reveals reasonable performance predictions, but with some loss in accuracy compared to time sweep tests due to the confounding effects of nonlinearity imposed by the high strain amplitudes included in the test. The asphalt binder S-VECD model is validated through comparisons to asphalt mixture S-VECD model results derived from cyclic direct tension tests and Accelerated Loading Facility performance tests. The results demonstrate good agreement between the asphalt binder and mixture test results and pavement performance, indicating that the developed model framework is able to capture the asphalt binder's contribution to mixture fatigue and pavement fatigue cracking performance.

  5. Simulation Model for Scenario Optimization of the Ready-Mix Concrete Delivery Problem

    NASA Astrophysics Data System (ADS)

    Galić, Mario; Kraus, Ivan

    2016-12-01

    This paper introduces a discrete simulation model for solving routing and network material flow problems in construction projects. Before the description of the model a detailed literature review is provided. The model is verified using a case study of solving the ready-mix concrete network flow and routing problem in metropolitan area in Croatia. Within this study real-time input parameters were taken into account. Simulation model is structured in Enterprise Dynamics simulation software and Microsoft Excel linked with Google Maps. The model is dynamic, easily managed and adjustable, but also provides good estimation for minimization of costs and realization time in solving discrete routing and material network flow problems.

  6. Evaluation of energies of interaction correlated with observed stabilities and rheological properties of asphalt-aggregate mixtures of western shale-oil residue as a modifier to petroleum asphalt

    SciTech Connect

    Tauer, J.E.; Ensley, E.K.; Harnsberger, P.M.; Robertson, R.E.

    1993-02-01

    The objective of this study was to perform a preliminary evaluation of improving bonding and aging characteristics using a distillation residue from the Green River Formation (western) shale oil as a modifier to a petroleum asphalt for use as a crack and joint filler material in portland cement concrete and asphaltic pavements. This study was to examine the differences in moisture damage resistance and adhesion properties, as measured by bonding energy, of shale-oil modified asphalts compared with non-modified asphalts. The shale-oil modified asphalts mechanical properties were not expected to match those of the rubberized asphalt. A commercially available rubberized asphalt crack and joint filler material was also tested only for comparison of mechanical properties. Portland cement concrete briquets prepared with an asphalt material sandwiched between two concrete wafers were tested in a stress-relaxation type of experiment to evaluate the relaxation and recovery properties of the sealant materials. Energy of interaction (bonding energy) measurements were performed on asphalt materials with portland cement concrete, two silicate aggregates, and a limestone aggregate to evaluate the compatibility of the asphalt materials with various aggregates. The results show that the shale-oil modified petroleum asphalt improved the relaxation time, percent recovery, and bonding energy compared with the petroleum asphalt.

  7. Concrete disposal vaults: An alternative to Hazardous Waste/Mixed Waste earthen landfills

    SciTech Connect

    Freitag, A.A.; Stewart, D.E.; Peterson, S.L.

    1992-01-01

    The Hazardous Waste/Mixed Waste (HW/MW) Disposal Facility is a new facility planned for on site processing and disposal of existing and future solid hazardous and/or mixed wastes generated at Savannah River Site (SRS). The first phase of the project is the completion of engineered above grade concrete disposal vaults which are to be permitted as hazardous waste disposal facilities and designed in accordance with the Resource Conservation and Recovery Act (RCRA) and appropriate US Department of Energy (DOE) Orders. The RCRA minimum performance standards promulgated in 40 CFR 264 and 265 are based on double lined earthen landfills. The regulations allow for alternative design and operational practices provided that the alternative design and operating practices, together with location characteristics, will prevent the migration of any hazardous constituents into the groundwater or surface water at least as effectively as the specified double lined earthen system. The engineered concrete vault structure for SRS is designed to comply and/or exceed the performance standards of the RCRA regulations and the associated RCRA technical guidance documents issued by the US Environmental Protection Agency (EPA).

  8. Concrete disposal vaults: An alternative to Hazardous Waste/Mixed Waste earthen landfills

    SciTech Connect

    Freitag, A.A.; Stewart, D.E.; Peterson, S.L.

    1992-04-01

    The Hazardous Waste/Mixed Waste (HW/MW) Disposal Facility is a new facility planned for on site processing and disposal of existing and future solid hazardous and/or mixed wastes generated at Savannah River Site (SRS). The first phase of the project is the completion of engineered above grade concrete disposal vaults which are to be permitted as hazardous waste disposal facilities and designed in accordance with the Resource Conservation and Recovery Act (RCRA) and appropriate US Department of Energy (DOE) Orders. The RCRA minimum performance standards promulgated in 40 CFR 264 and 265 are based on double lined earthen landfills. The regulations allow for alternative design and operational practices provided that the alternative design and operating practices, together with location characteristics, will prevent the migration of any hazardous constituents into the groundwater or surface water at least as effectively as the specified double lined earthen system. The engineered concrete vault structure for SRS is designed to comply and/or exceed the performance standards of the RCRA regulations and the associated RCRA technical guidance documents issued by the US Environmental Protection Agency (EPA).

  9. Road pavers' occupational exposure to asphalt containing waste plastic and tall oil pitch.

    PubMed

    Väänänen, Virpi; Elovaara, Eivor; Nykyri, Erkki; Santonen, Tiina; Heikkilä, Pirjo

    2006-01-01

    Waste plastic (WP) and tall oil pitch (T), which are organic recycled industrial by-products, have been used as a binder with bitumen in stone mastic asphalt (SMA) and asphalt concrete (AC). We compared the exposure over one workday in 16 road pavers participating in a survey at four paving sites, using mixes of conventional asphalt (SMA, AC) or mixes containing waste material (SMA-WPT, AC-WPT). The concentrations of 11 aldehydes in air were 515 and 902 microg m(-3) at the SMA-WPT and AC-WPT worksites, being 3 and 13 times greater than at the corresponding worksites laying conventional asphalt. Resin acids (2-42 microg m(-3)), which are known sensitizers, were detected only during laying of AC-WPT. The emission levels (microg m(-3)) of total particulates (300-500), bitumen fumes (60-160), bitumen vapour (80-1120), naphthalene (0.59-1.2), phenanthrene (0.21-0.32), pyrene (<0.015-0.20), benzo(a)pyrene (<0.01) and the sum of 16 PAHs (polycyclic aromatic hydrocarbons, 1.28-2.00) were similar for conventional and WPT asphalts. The dermal deposition of 16 PAHs on exposure pads (on workers' wrist) was low in all pavers (0.7-3.5 ng cm(-2)). Eight OH-PAH biomarkers of naphthalene, phenanthrene and pyrene exposures were quantified in pre- and post-shift urine specimens. The post-shift concentrations (mean +/- SD, micromol mol(-1) creatinine) of 1- plus 2-naphthol; 1-,2-,3-,4- plus 9-phenanthrol; and 1-hydroxypyrene were, respectively, for asphalt workers: 18.1+/- 8.0, 2.41 +/- 0.71 and 0.66+/- 0.58 (smokers); 6.0+/- 2.3, 1.70+/- 0.72 and 0.27+/- 0.15 (non-smokers); WPT asphalt workers: 22.0+/- 9.2, 2.82+/- 1.11 and 0.76+/- 0.18 (smokers); 6.8+/- 2.6, 2.35+/- 0.69 and 0.46+/- 0.13 (non-smokers). The work-related uptake of PAHs was low in all pavers, although it was significantly greater in smokers than in non-smokers. The WPT asphalt workers complained of eye irritation and sore throat more than the pavers who had a much lower exposure to aldehydes and resin acids.

  10. Diagnosis of moisture damage in asphalt pavements

    NASA Astrophysics Data System (ADS)

    Canning, Jacqueline S.; Niezrecki, Christopher; Birgisson, Bjorn

    2004-07-01

    One of the most common modes of premature failure of asphalt pavements is water damage. Moisture damage in hot-mix asphalt (HMA) pavements occurs when water infiltrates the pavement system, causing premature failure of hot-mix asphalt pavements, primarily through loss of adhesion between the asphalt binder and the aggregates. Loss of adhesion can lead to stripping of the asphalt film from the aggregate and raveling, where aggregates are dislodged from the pavement. The laboratory testing procedures currently available for testing HMA moisture susceptibility were primarily developed to determine the degree of resistance to moisture damage by a particular combination of asphalt and aggregate as well as compare mixes composed of different types and quantities of aggregate. These methods are all based on destructive testing. There is currently a need for innovative nondestructive testing technologies that can be used to identify and isolate the effects of water damage in mixtures. As a first step in the development of a non-destructive method to test HMA pavements, modal hammer tests were conducted on several test specimens of fine and coarse grained granite-based mixes commonly used by the Florida Department of Transportation (FDOT). The results of the testing indicate that there is a large frequency shift in the transfer function measurements for the damaged samples compared to the undamaged samples. The results imply that modal hammer testing may be used as a method to characterize the health of HMA pavements.

  11. Rubberized asphalt emulsion

    SciTech Connect

    Wilkes, E.

    1986-09-02

    A method is described of making a rubberized asphalt composition which comprises the steps of: (a) combining asphalt with a hydrocarbon oil having a flash point of 300/sup 0/F. or more to provide a homogenous asphalt-oil mixture or solution, (b) then combining the asphalt-oil mixture with a particulate rubber at a temperature sufficient to provide a homogenous asphalt-rubber-oil gel, and (c) emulsifying the asphalt-rubber-oil gel by passing the gel, water, and an emulsifying agent through a colloid mill to provide an emulsion.

  12. Mutagenicity of bitumen and asphalt fumes.

    PubMed

    Heikkilä, P R; Väänänen, V; Hämeilä, M; Linnainmaa, K

    2003-08-01

    The mutagenicity of asphalt fumes was tested with the Salmonella bioassays. The aim was to investigate if recycled additives modify the genotoxicity of emissions. Recycling of old asphalt is increasing, and we studied also the mutagenicity of emissions sampled during the re-use of asphalt. The composition of vapours and fumes were analysed by gas chromatography and by liquid chromatography. Bitumens containing coal fly ash (CFA) or waste plastics were heated to the paving temperatures in the laboratory. In the field, bitumen fumes were collected during paving of stone mastic asphalts (lime or CFA as a filler), remixing of stone mastic asphalt (lime or CFA as a filler), and of asphalt concrete. All the lab-generated vapour fractions were non-mutagenic. The particulate fractions were mutagenic with TA98 in the presence of the S9 activation. In addition, the lab-fumes from bitumen containing waste plastics were positive with both strains without S9. Only particulate fractions sampled in the field were tested. They were mutagenic with and without metabolic activation with both strains. The mutagenic potency of the field samples was higher than that of the lab-generated fumes without S9, and the remixing fumes were more mutagenic than the normal paving and lab-generated fumes with S9. The use of inorganic additive, CFA, did not change the mutagenicity of the fumes, whereas the organic additive, waste plastics, increased the mutagenicity of the laboratory emissions significantly.

  13. Safety in ready mixed concrete industry: descriptive analysis of injuries and development of preventive measures.

    PubMed

    Akboğa, Özge; Baradan, Selim

    2017-02-07

    Ready mixed concrete (RMC) industry, one of the barebones of construction sector, has its distinctive occupational safety and health (OSH) risks. Employees experience risks that emerge during the fabrication of concrete, as well as its delivery to the construction site. Statistics show that usage and demand of RMC have been increasing along with the number of producers and workers. Unfortunately, adequate OSH measures to meet this rapid growth are not in place even in top RMC producing countries, such as Turkey. Moreover, lack of statistical data and academic research in this sector exacerbates this problem. This study aims to fill this gap by conducting data mining in Turkish Social Security Institution archives and performing univariate frequency and cross tabulation analysis on 71 incidents that RMC truck drivers were involved. Also, investigations and interviews were conducted in seven RMC plants in Turkey and Netherlands with OSH point of view. Based on the results of this research, problem areas were determined such as; cleaning truck mixer/pump is a hazardous activity where operators get injured frequently, and struck by falling objects is a major hazard at RMC industry. Finally, Job Safety Analyses were performed on these areas to suggest mitigation methods.

  14. Safety in ready mixed concrete industry: descriptive analysis of injuries and development of preventive measures

    PubMed Central

    AKBOĞA, Özge; BARADAN, Selim

    2016-01-01

    Ready mixed concrete (RMC) industry, one of the barebones of construction sector, has its distinctive occupational safety and health (OSH) risks. Employees experience risks that emerge during the fabrication of concrete, as well as its delivery to the construction site. Statistics show that usage and demand of RMC have been increasing along with the number of producers and workers. Unfortunately, adequate OSH measures to meet this rapid growth are not in place even in top RMC producing countries, such as Turkey. Moreover, lack of statistical data and academic research in this sector exacerbates this problem. This study aims to fill this gap by conducting data mining in Turkish Social Security Institution archives and performing univariate frequency and cross tabulation analysis on 71 incidents that RMC truck drivers were involved. Also, investigations and interviews were conducted in seven RMC plants in Turkey and Netherlands with OSH point of view. Based on the results of this research, problem areas were determined such as; cleaning truck mixer/pump is a hazardous activity where operators get injured frequently, and struck by falling objects is a major hazard at RMC industry. Finally, Job Safety Analyses were performed on these areas to suggest mitigation methods. PMID:27524105

  15. Polypropylene - asphalt mixtures for waterproofing membranes

    SciTech Connect

    Italia, P.; Brandolese, E.

    1996-12-31

    In any field of polymer-asphalt mixtures application is extremely important to achieve a very good compatibility between the components in order to improve as much as possible the performances due to the polymer content. In the case of waterproofing membranes application this compatibility reduce, moreover, the amount of polymer required to obtain the best performances. Using the Colloidal Instability Index Ic, as measured by the Iatroscan device, we propose a correlation between asphalt`s chemical characteristics and the polymer minimum amount sufficient to disperse in a stable way the asphalt itself in the polymeric matrix. As a result, through the proposed correlation, with a simple asphalt composition analysis it is possible to predict its performance when mixed with polypropilene. In the paper, beside the description of the Iatroscan analytical technique, we also present a method for determining phase inversion based on optical fluorescence microscopy performed on about 30 different samples of asphalt. We also present the experimental correlation laws between the polymer amount at phase inversion and the asphalt single components content.

  16. Rehabilitating asphalt highways

    SciTech Connect

    Butalia, T.S.

    2007-07-01

    Coal fly ash has been used on two Ohio full-depth reclamation projects in Delaware and Warren. The object of the project carried out with the Department of Civil and Environmental Engineering and Geodetic Science at Ohio State University is to demonstrate the effective use of Class fly ash in combination with lime or lime kiln dust in the full depth reclamation of asphalt pavements. The article describes the mixes used for the highway reconstruction of part of Section Line Road Delaware County and of a road in Warren County. During construction the pavement sections were instrumented with several structural and environmental monitoring devices and data is being collected on a quarterly basis. Falling Weight Deflectometer (FWD) tests to measure load defection behaviour, resilient of pavement layers and soil and base structural layer coefficient are being carried out twice a year. It was shown that use of fly ash increased the elastic modulus of base layers. This article first appeared in the Feb/May 2007 issue of Asphalt Contractor. 4 photos.

  17. A Study on the Rheological Properties of Recycled Rubber-Modified Asphalt Mixtures

    PubMed Central

    Karacasu, Murat; Er, Arzu

    2015-01-01

    Using waste rubber in asphalt mixes has become a common practice in road construction. This paper presents the results of a study on the rheological characteristics of rubber-modified asphalt (RMA) concrete under static and dynamic loading conditions. A number of static and dynamic creep tests were conducted on RMA mix specimens with different rubber sizes and contents, and a series of resonant column tests were conducted to evaluate the shear modulus and damping values. To simulate the stress-strain response of traffic-induced loading, the measurements were taken for different confining pressures and strain levels. The results of the study indicated that rubber modification increases stiffness and damping ratio, making it a very attractive material for use in road construction. However the grain size of the rubber is very important. Although RMA may cost up to 100% more than regular asphalt, the advantages it brings, such as an increased service life of the road and proper waste utilization contributing to a more sustainable infrastructure, may justify the added cost. PMID:25695096

  18. A study on the rheological properties of recycled rubber-modified asphalt mixtures.

    PubMed

    Karacasu, Murat; Okur, Volkan; Er, Arzu

    2015-01-01

    Using waste rubber in asphalt mixes has become a common practice in road construction. This paper presents the results of a study on the rheological characteristics of rubber-modified asphalt (RMA) concrete under static and dynamic loading conditions. A number of static and dynamic creep tests were conducted on RMA mix specimens with different rubber sizes and contents, and a series of resonant column tests were conducted to evaluate the shear modulus and damping values. To simulate the stress-strain response of traffic-induced loading, the measurements were taken for different confining pressures and strain levels. The results of the study indicated that rubber modification increases stiffness and damping ratio, making it a very attractive material for use in road construction. However the grain size of the rubber is very important. Although RMA may cost up to 100% more than regular asphalt, the advantages it brings, such as an increased service life of the road and proper waste utilization contributing to a more sustainable infrastructure, may justify the added cost.

  19. The Study of the Improvement of Mechanical Performance of Asphalt Modified by the Optimization of Mixing Time of EVA Bitumen

    NASA Astrophysics Data System (ADS)

    Saoula, Samia; Haddadi, Smail; Mokhtar, Khedidja Ait

    2011-12-01

    To improve the performances of a bitumen, the mixing time of bitumen-EVA is studied using two contents of EVA (3 and 5%). For the study analytical and chemical tests are carried out such as penetrability, softening point, ductility, FTIR, DSC, MEB and the storage stability. The aim of this work is to change and optimize the formula of the sample of EVA, which are not conform with the Algerian standards. This work showed that the mixing time is function of the content polymer. The mixing time has a strong effect on the properties; in fact it has improved the mechanical characteristics of the bituminous. Also, the mechanical tests showed that the permanent deformations and the indirect tensile strength at the temperatures of service resistances are improved.

  20. Evaluation of Cement, Lime, and Asphalt Amended Municipal Solid Waste Incinerator Residues

    DTIC Science & Technology

    1989-09-01

    waste does not contain sufficient pozzolans for lime solidification, or if organics in the cement residue mixes are excessive, a low 3 strength material...occur due to insufficient coverage of the residue by the asphalt binder . This defeats the asphalt’s primary metal immobilization mechanism...stabilized waste form direct contact with an cidic environment (Cote, 1986). Asphalt Amended Wastes. As with most thermoplastic agent, asphalt binder

  1. Concrete Block Pavements

    DTIC Science & Technology

    1983-03-01

    Calif. 42 1 •1 90 NEW LEGEND 80 A VIBORG, DENMARK, BLOCKS A VIBORG, DENMARK, ASPHALTIC CONCRETE AFTER 00 MELBOURNE, AUSTRALIA, BLOCKS VIBRATION MEAN ...the load-distributing characteristics of the Mlock pavements. *. 45 -, , - t 171 LEGENDT 0 CONCRETE BASE, MEAN OF 8 TESTS,9 KNAPTON (1978) I RANGE OF...45 to 60 min. 90. Table 11 summarizes the results of these tests. The mean penetration of water through the block pavements with a slope of I per

  2. Elimination chemistry in asphalt

    SciTech Connect

    Boucher, J.L.; Ihsiung Wang; Martinez, D.F. )

    1990-07-01

    Elimination chemistry provides important information, not only about the chemical properties of asphalt, but also the chemical modification method of asphalt. The chemical reactions which use the natural abundance of radicals are important for free-radical halogenation reaction. Spectral data demonstrates the formation of halogenated asphalt. The utility of dehydrohalogenation modified asphalt is limited. However, the resulting dehydrohalogenation modified asphalt does produce a significant unsaturated intermediate, which can incorporate elastomeric polymers (and monomers) via condensation or addition process. The second chemical modification method is the Hofmann elimination reaction, which was performed by reaction of methyl iodide with asphalt, followed by treatment of base. Spectroscopic data shows that a methyl group attached to nitrogen or sulfur in asphalt after Hofmann elimination reaction. Physical data shows that the Hofmann elimination modification improved the quality of asphalt, such as low temperature susceptibility measured by PVN. The modified asphalt also studied by HP-GPC in order to correlate their physical properties. The result shows that the molecular size distribution has changed and reduced the amount of LMS. The amount of decreasing LMS is also dependent on the content of nitrogen and sulfur in asphalts.

  3. Recycled materials in asphalt pavements. (Latest citations from the NTIS bibliographic database). Published Search

    SciTech Connect

    1995-03-01

    The bibliography contains citations concerning the recycling of asphalt pavement materials for road construction. Citations discuss asphalt concrete mixtures and recycling, recycled materials testing and evaluation, and pavement bases. Engineering and environmental aspects of recycled materials are examined. (Contains a minimum of 78 citations and includes a subject term index and title list.)

  4. Asphalt Pavement Aging and Temperature Dependent Properties Using Functionally Graded Viscoelastic Model

    ERIC Educational Resources Information Center

    Dave, Eshan V.

    2009-01-01

    Asphalt concrete pavements are inherently graded viscoelastic structures. Oxidative aging of asphalt binder and temperature cycling due to climatic conditions being the major cause of non-homogeneity. Current pavement analysis and simulation procedures dwell on the use of layered approach to account for these non-homogeneities. The conventional…

  5. Asphalt Pavement Aging and Temperature Dependent Properties Using Functionally Graded Viscoelastic Model

    ERIC Educational Resources Information Center

    Dave, Eshan V.

    2009-01-01

    Asphalt concrete pavements are inherently graded viscoelastic structures. Oxidative aging of asphalt binder and temperature cycling due to climatic conditions being the major cause of non-homogeneity. Current pavement analysis and simulation procedures dwell on the use of layered approach to account for these non-homogeneities. The conventional…

  6. HPLC and NMR spectroscopy to characterize asphaltic materials

    SciTech Connect

    Jennings, P.W.; Pribanic, J.A.S.; Dawson, K.R.; Bricca, C.E.

    1981-09-01

    High performance liquid chromatography (HPLC) using gel permeation columns seems to offer a practical alternative for asphalt characterization because analyses can be performed quickly. The technique shows a unique molecular size distribution for each asphalt and this profile have been correlated with results of performance of pavement from which asphalt was extracted. Conclusions have shown that a larger quantity of larger molecular size materials are present in asphalts from roadways which exhibit cracking than in those from old, uncracked pavements. The effects on asphalt of a variety of treatments have been initiated. One method includes heating asphalt for 1 h at 163/sup 0/C in the presence of oxygen or nitrogen. The asphalt is mixed with lime and various aggregates and/or fly ash, as well. The mixture is then cooled and extracted with benzene. Once the solvent has been removed, the sample is redissolved in tetrahydrofuran and analyzed by HPLC. Results show that heating this particular asphalt with an aggregate with or without lime results in a 20% increase of large-sized molecules. Use of both fly ash and aggregate increases the total effect to 34%. The HPLC method can be used to substantiate new asphalt blends. 5 figures, 1 table.

  7. Stabilization/solidification of munition destruction waste by asphalt emulsion.

    PubMed

    Cervinkova, Marketa; Vondruska, Milan; Bednarik, Vratislav; Pazdera, Antonin

    2007-04-02

    Destruction of discarded military munitions in an explosion chamber produces two fractions of hazardous solid waste. The first one is scrap waste that remains in the chamber after explosion; the second one is fine dust waste, which is trapped on filters of gas products that are exhausted from the chamber after explosion. The technique of stabilization/solidification of the scrap waste by asphalt emulsion is described in this paper. The technique consists of simple mixing of the waste with anionic asphalt emulsion, or two-step mixing of the waste with cationic asphalt emulsion. These techniques are easy to use and the stabilized scrap waste proves low leachability of contained heavy metals assessed by TCLP test. Hence, it is possible to landfill the scrap waste stabilized by asphalt emulsion. If the dust waste, which has large specific surface, is stabilized by asphalt emulsion, it is not fully encapsulated; the results of the leaching tests do not meet the regulatory levels. However, the dust waste solidified by asphalt emulsion can be deposited into an asphalted disposal site of the landfill. The asphalt walls of the disposal site represent an efficient secondary barrier against pollutant release.

  8. International State-of-the-Art Colloquium on Low-Temperature Asphalt Pavement Cracking Held in Hanover, New Hampshire on 6-8 May 1987

    DTIC Science & Technology

    1991-02-01

    tem- perature susceptibility of the asphalt cement appear to General discussion be worse than it actually is. Further, air- blown asphalt The first...the fracture temperature was calculc’, ,where point for waxy and air- blown asphalt cements, and the the stress in the mix exceeded the strength of...of sured using a two-point bending apparatus and trapezoi- air- blown asphalts to reduce thermal cracking of asphalt dal-shaped spc.,inens. Twelve

  9. Characterization of asphalt materials containing bio oil from michigan wood

    NASA Astrophysics Data System (ADS)

    Mills-Beale, Julian

    The objective of this research is to develop sustainable wood-blend bioasphalt and characterize the atomic, molecular and bulk-scale behavior necessary to produce advanced asphalt paving mixtures. Bioasphalt was manufactured from Aspen, Basswood, Red Maple, Balsam, Maple, Pine, Beech and Magnolia wood via a 25 KWt fast-pyrolysis plant at 500 °C and refined into two distinct end forms - non-treated (5.54% moisture) and treated bioasphalt (1% moisture). Michigan petroleum-based asphalt, Performance Grade (PG) 58-28 was modified with 2, 5 and 10% of the bioasphalt by weight of base asphalt and characterized with the gas chromatography-mass spectroscopy (GC-MS), Fourier Transform Infra-red (FTIR) spectroscopy and the automated flocculation titrimetry techniques. The GC-MS method was used to characterize the Carbon-Hydrogen-Nitrogen (CHN) elemental ratio whiles the FTIR and the AFT were used to characterize the oxidative aging performance and the solubility parameters, respectively. For rheological characterization, the rotational viscosity, dynamic shear modulus and flexural bending methods are used in evaluating the low, intermediate and high temperature performance of the bio-modified asphalt materials. 54 5E3 (maximum of 3 million expected equivalent standard axle traffic loads) asphalt paving mixes were then prepared and characterized to investigate their laboratory permanent deformation, dynamic mix stiffness, moisture susceptibility, workability and constructability performance. From the research investigations, it was concluded that: 1) levo, 2, 6 dimethoxyphenol, 2 methoxy 4 vinylphenol, 2 methyl 1-2 cyclopentandione and 4-allyl-2, 6 dimetoxyphenol are the dominant chemical functional groups; 2) bioasphalt increases the viscosity and dynamic shear modulus of traditional asphalt binders; 3) Bio-modified petroleum asphalt can provide low-temperature cracking resistance benefits at -18 °C but is susceptible to cracking at -24 °C; 3) Carbonyl and sulphoxide

  10. Dependence of Expansion of a Salt-Saturated Concrete on Temperature and Mixing and Handling Procedures.

    DTIC Science & Technology

    1987-07-01

    surface; (3) shrinkage compensation, such that the volume of concrete after it has set is never less than the original volume. This was desired to...permanent sealing. 2. Intended field use of this concrete required that it be placeable by either free -fall through a tremie into dry boreholes of 100...mm to 1 m in diam- eter, or pumping into horizontal holes of the larger size; and that it be self-levelling and cohesive, with no aggregate segregation

  11. Asphalt in Pavement Maintenance.

    ERIC Educational Resources Information Center

    Asphalt Inst., College Park, MD.

    Maintenance methods that can be used equally well in all regions of the country have been developed for the use of asphalt in pavement maintenance. Specific information covering methods, equipment and terminology that applies to the use of asphalt in the maintenance of all types of pavement structures, including shoulders, is provided. In many…

  12. Recycling of excavated asphalt from gas-pipeline installations to Gas Research Institute. Final report - Phase 1

    SciTech Connect

    Lucido, J.; Tobin, A.

    1988-12-01

    Recent estimates indicate that over 11,500 miles of gas distribution piping is installed under existing asphalt pavement annually. This estimate includes 25% of all new installations and 60% of all replacement work. As gas distribution systems grow to meet demands, more projects will involve restoration of asphalt pavements. Because gas distribution piping installed and/or replaced under asphalt pavement can be significantly more expensive than an installation in unpaved soil--it is cause for major concern to the gas industry. The Phase I study addressed the concept of on-site recycling of excavated asphalt for gas utility trenching applications. Commercialization of this concept will eliminate the need for disposal of existing asphalt concrete and the importing of new asphalt concrete, creating potentially significant advantages to the industry.

  13. Bone Glue Modified Asphalt: A Step towards Energy Conservation and Environment Friendly Modified Asphalts.

    PubMed

    Rizvi, Hashim Raza; Khattak, Mohammad Jamal; Gallo, August A

    2014-01-01

    Asphalt has been modified for the past several decades using various additives, including synthetic polymers. Polymer modification improves structural and engineering characteristics of the binder, which is a result of improvement in rheological characteristics of binder as well as its adhesion capability with the aggregate. Such enhancement inevitably enhances the performance characteristics of hot mix asphalts (HMA) such as fatigue life, resistance to rutting, and thermal cracking. Even though polymer-modified HMA is popular in North America and European countries, its use is still limited in developing countries of Southeast Asia due to high costs associated with its manufacturing, processing, and energy consumption. In this study, a new kind of asphalt modifier derived from animal wastes, such as bones, hides, and flesh commonly known as Bone Glue, is studied. This biomaterial which is a by-product of food and cattle industries is cheap, conveniently available, and produced locally in developing countries. The results of the research study showed that the bone glue can easily be mixed with asphalt without significantly altering the asphalt binder's viscosity and mixing and compaction temperatures of HMA. Additionally, improvements in complex shear modulus for a range of temperatures were also determined and it was found that complex shear modulus was improved by bone glue modification.

  14. Bone Glue Modified Asphalt: A Step towards Energy Conservation and Environment Friendly Modified Asphalts

    PubMed Central

    Rizvi, Hashim Raza; Gallo, August A.

    2014-01-01

    Asphalt has been modified for the past several decades using various additives, including synthetic polymers. Polymer modification improves structural and engineering characteristics of the binder, which is a result of improvement in rheological characteristics of binder as well as its adhesion capability with the aggregate. Such enhancement inevitably enhances the performance characteristics of hot mix asphalts (HMA) such as fatigue life, resistance to rutting, and thermal cracking. Even though polymer-modified HMA is popular in North America and European countries, its use is still limited in developing countries of Southeast Asia due to high costs associated with its manufacturing, processing, and energy consumption. In this study, a new kind of asphalt modifier derived from animal wastes, such as bones, hides, and flesh commonly known as Bone Glue, is studied. This biomaterial which is a by-product of food and cattle industries is cheap, conveniently available, and produced locally in developing countries. The results of the research study showed that the bone glue can easily be mixed with asphalt without significantly altering the asphalt binder's viscosity and mixing and compaction temperatures of HMA. Additionally, improvements in complex shear modulus for a range of temperatures were also determined and it was found that complex shear modulus was improved by bone glue modification. PMID:27437456

  15. Coal-based synthetic asphalt. Final report

    SciTech Connect

    Guin, J.A.; Curtis, C.W.; Tarrer, A.R.

    1986-02-01

    The objective of the work was to investigate in the laboratory the technical and economic aspects of the production of a synthetic asphalt from U.S. bituminous and subbituminous coals. Bench-scale autoclave hydrogenation experiments were used to produce coal-based asphalt cements from Illinois No. 6 bituminous coal and a Wyoming subbituminous coal. A factorially designed experiment showed that VTS of coal-based asphalts was insensitive to process conditions. Hydrated lime treatment lowered VTS slightly, but the polymer additive was required to achieve specification VTS values. Age hardening was primarily due to oxidation with a minor contribution from volatiles loss. Marshall stability testing shhowed the coal-based compacted mixes to have excellent resistance to plastic flow. Immersion compression testing showed high stability and retained strengths.

  16. Development of lightweight concrete mixes for construction industry at the state of Arkansas

    NASA Astrophysics Data System (ADS)

    Almansouri, Mohammed Abdulwahab

    As the construction industry evolved, the need for more durable, long lasting infrastructure increased. Therefore, more efforts have been put to find new methods to improve the properties of the concrete to prolong the service life of the structural elements. One of these methods is the use of lightweight aggregate as an internal curing agent to help reducing self-desiccation and shrinkage. This research studied the effects of using locally available lightweight aggregate (expanded clay), as a partial replacement of normal weight aggregate in the concrete matrix. The concrete mixtures contained lightweight aggregate with a replacement percentage of 12.5, 25, 37.5, and 50 percent by volume. Fresh properties as well as compressive strength, modulus of rupture, and drying shrinkage were measured. While was effective in reducing drying shrinkage, the use of lightweight aggregate resulted in slightly reducing both the compressive strength and modulus of rupture.

  17. Evaluation of western shale-oil residue as an additive to petroleum asphalt for use as a pavement crack and joint sealant material

    SciTech Connect

    Harnsberger, P.M.; Wolf, J.M.; Robertson, R.E.

    1992-11-01

    The objective of this study was to perform a preliminary evaluation of using a distillation residue from Green River Formation (western) shale oil as an additive to a petroleum asphalt for use as a crack and joint filler material in portland cement concrete and asphaltic pavements. A commercially available rubberized asphalt crack and joint filler material was also tested for comparison. ASTM specification tests for sealant materials used in concrete and asphalt pavements were performed on the sealant materials. Portland cement concrete briquets prepared with an asphalt material sandwiched between two concrete wafers were tested in a stress-relaxation experiment to evaluate the relaxation and recovery properties of the sealant materials. The results show that the shale-oil modified petroleum asphalts and the neat petroleum asphalt do not pass the extension portion of the ASTM test; however, there is indication of improvement in the adhesive properties of the shale-oil modified asphalts. There is also evidence that the addition of shale-oil residue to the petroleum asphalt, especially at the 20% level, improves the relaxation and recovery properties compared with the petroleum asphalt.

  18. Investigation of porous asphalt microstructure using optical and electron microscopy.

    PubMed

    Poulikakos, L D; Partl, M N

    2010-11-01

    Direct observations of porous asphalt concrete samples in their natural state using optical and electron microscopy techniques led to useful information regarding the microstructure of two mixes and indicated a relationship between microstructure and in situ performance. This paper presents evidence that suboptimal microstructure can lead to premature failure thus making a first step in defining well or suboptimal performing pavements with a bottom-up approach (microstructure). Laboratory and field compaction produce different samples in terms of the microstructure. Laboratory compaction using the gyratory method has produced more microcracks in mineral aggregates after the binder had cooled. Well-performing mixes used polymer-modified binders, had a more homogeneous void structure with fewer elongated voids and better interlocking of the aggregates. Furthermore, well-performing mixes showed better distribution of the mastic and better coverage of the aggregates with bitumen. Low vacuum scanning electron microscopy showed that styrene butadiene styrene polymer modification in binder exists in the form of discontinuous globules and not continuous networks. A reduction in the polymer phase was observed as a result of aging and in-service use. © 2010 The Authors Journal compilation © 2010 The Royal Microscopical Society.

  19. Performance of Granite Asphalt Mixture Modified by Silane Coupling Agent

    NASA Astrophysics Data System (ADS)

    Liu, Zhihang; Li, Xia; Wang, Li; Kang, Rongling

    2017-06-01

    In order to improve pavement performance of granite asphalt mixture, the surface of granite mineral powder was organic modified by silane coupling agent. The water stability and high temperature stability of the asphalt mixture were analyzed by Marshall tests, immersion Marshall test, freeze-thaw splitting test and rutting test. The results show that the mixing amount of silane coupling agent in the range from 0.5% to 2.5% can significantly improve the high temperature stability and water stability of the asphalt mixture. Taking into account the performance and economic factors, 2.0% silane coupling agent on the surface of granite filler was recommended.

  20. Application of Common Mid-Point Method to Estimate Asphalt

    NASA Astrophysics Data System (ADS)

    Zhao, Shan; Al-Aadi, Imad

    2015-04-01

    3-D radar is a multi-array stepped-frequency ground penetration radar (GPR) that can measure at a very close sampling interval in both in-line and cross-line directions. Constructing asphalt layers in accordance with specified thicknesses is crucial for pavement structure capacity and pavement performance. Common mid-point method (CMP) is a multi-offset measurement method that can improve the accuracy of the asphalt layer thickness estimation. In this study, the viability of using 3-D radar to predict asphalt concrete pavement thickness with an extended CMP method was investigated. GPR signals were collected on asphalt pavements with various thicknesses. Time domain resolution of the 3-D radar was improved by applying zero-padding technique in the frequency domain. The performance of the 3-D radar was then compared to that of the air-coupled horn antenna. The study concluded that 3-D radar can be used to predict asphalt layer thickness using CMP method accurately when the layer thickness is larger than 0.13m. The lack of time domain resolution of 3-D radar can be solved by frequency zero-padding. Keywords: asphalt pavement thickness, 3-D Radar, stepped-frequency, common mid-point method, zero padding.

  1. Petroleum bitumens in asphalt concrete (review)

    SciTech Connect

    Rozental, D.A.

    1995-12-20

    Modern views on the chemical structure of the main components of heavy petroleum residues and principles of formation of the bitumen disperse systems are presented. Changes in the bitumen disperse structure upon contact with mineral fillers at 160-200{degrees}C for 1-5 h and the role of adsorption of bitumen surfactants on filler grains in these changes are discussed in terms of these views.

  2. Evaluation Criteria for Aged Asphalt Concrete Surfaces

    DTIC Science & Technology

    2007-06-01

    extraction / recovery process, and Table 3 pre- sents the results for conventional properties of the AC samples. ERDC/GSL TR-07-18 13 Figure 11...Figure 7, cores were extracted on site and the beams were sawn in the laboratory. Once the in situ modulus was obtained with the PSPA and the cores...were extracted , the sample was sawed and removed, and the hole was patched. Portable seismic pavement analyzer tests The PSPA (Figure 10), developed

  3. Evaluation of Minimum Asphalt Concrete Thickness Criteria

    DTIC Science & Technology

    2008-10-01

    characterized the actual material used for the pavement structure. The tests included CBR , dynamic cone penetrometer (DCP), nuclear density, nuclear...13 Dynamic cone penetrometer ... Dynamic cone penetrometer A dual mass DCP soil test device was used to obtain subsurface soil data at representative locations. The DCP has a steel cone

  4. Supercritical refining of asphalt to produce asphalt recycling agents

    SciTech Connect

    Chaffin, J.M.; Davison, R.R.; Glover, C.J.; Bullin, J.A.

    1995-12-31

    Several asphalts were fractionated using supercritical pentane. These fractions were analyzed and Gel Permeation Chromatography and High Performance Liquid Chromatography and their viscosities were measured. The properties of these fractions vary not only among the fractions of a given asphalt, but also for the same fraction produced from different asphalts. These widely varied fractions previously have been shown to have potential for reblending to produce superior asphalts. This study investigates the potential for using some of the fractions as asphalt recycling agents. A modified SHRP PAV test was conducted on nine recycled asphalts. The aging indices of eight of the recycled asphalts are superior to the aging index of the original asphalt. In addition, two of the blends using industrial supercritical fractions and the three blends using laboratory supercritical fractions have lower aging indices than blends using commercial recycling agents.

  5. Potential application of ultra-high performance fiber-reinforced concrete with wet-mix shotcrete system in tunneling

    NASA Astrophysics Data System (ADS)

    Goblet, Valentine Pascale

    In the tunneling industry, shotcrete has been used for several decades. The use of shotcrete or wet-mix spray-on methods allows the application of this method in complex underground profiles and shapes. The need for time efficient spraying methods and constructability for lining coverage opens the door for technologies like steel and synthetic fiber reinforced shotcrete to achieve a uniform and a good quality product. An important advantage of the application of fiber reinforced concrete in shotcrete systems for tunneling is that almost no steel fixing is required. This leads to several other advantages including safer working conditions during excavation, less cost, and higher quality achieved through the use of this new technology. However, there are still some limitations. This research presents an analysis and evaluation of the potential application of a new R&D product, ultra-high-performance fiber-reinforced concrete (UHP-FRC), developed by UTA associate professor Shih-Ho (Simon) Chao. This research will focus on its application to tunnel lining using a wet-mix shotcrete system. The objectives of this study are to evaluate the potential application of UHP-FRC with wet-mix shotcrete equipment. This is the first time UHP-FRC has been used for this purpose; hence, this thesis also presents a preliminary evaluation of the compressive and tensile strength of UHP-FRC after application with shotcrete equipment, and to identify proper shotcrete procedures for mixing and application of UHP-FRC. A test sample was created with the wet-mix shotcrete system for further compressive and tensile strength analysis and a proposed plan was developed on the best way to use the UHP-FRC in lining systems for the tunneling industry. As a result of this study, the viscosity for pumpability was achieved for UHP-FRC. However, the mixer was not fast enough to efficiently mix this material. After 2 days, material strength showed 7,200 psi, however, vertical shotcrete was not achieved

  6. Delamination detection in reinforced concrete using thermal inertia

    SciTech Connect

    Del Grande, N K; Durbin, P F

    1998-11-30

    We investigated the feasibility of thermal inertia mapping for bridge deck inspections. Using pulsed thermal imaging, we heat-stimulated surrogate delaminations in reinforced concrete and asphalt-concrete slabs. Using a dual-band infrared camera system, we measured thermal inertia responses of Styrofoam implants under 5 cm of asphalt, 5 cm of concrete, and 10 cm of asphalt and concrete. We compared thermal maps from solar-heated concrete and asphalt-concrete slabs with thermal inertia maps from flash-heated concrete and asphalt-concrete slabs. Thermal inertia mapping is a tool for visualizing and quantifying subsurface defects. Physically, thermal inertia is a measure of the resistance of the bridge deck to temperature change. Experimentally, it is determined from the inverse slope of the surface temperature versus the inverse square root of time. Mathematically, thermal inertia is the square root of the product of thermal conductivity, density, and heat capacity. Thermal inertia mapping distinguishes delaminated decks which have below-average thermal inertias from normal or shaded decks. Key Words: Pulsed Thermal Imaging, Thermal Inertia, Detection Of Concrete Bridgedeck Delaminations

  7. PREPACKED CONCRETE.

    DTIC Science & Technology

    Twenty four hardened plain concrete wallettes , each 31 in. high by 25 in. wide by 6 in. thick, were sawed into various rectangular parallelepipeds...The wallettes represented three groups of prepacked concrete: reference aggregate intruded with fresh-water grout, coral aggregate with fresh-water...prismatic test specimens were involved in the program for determining the effectsof: type of mixing water, type of wiremesh cover atop the wallette form

  8. 23. Surrender interview site, showing Pemberton Avenue concrete slab road ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    23. Surrender interview site, showing Pemberton Avenue concrete slab road type with gutter (asphalt construction typical on Union and Confederate Avenues), view to the sw. - Vicksburg National Military Park Roads & Bridges, Vicksburg, Warren County, MS

  9. Feasibility of using 100% Recycled Asphalt Pavement mixtures for road construction

    NASA Astrophysics Data System (ADS)

    Carlson, Russell Edgar, IV

    Recycled Asphalt Pavement (RAP) is the largest recycled good in the United States and 80 million tons are recycled yearly, saving taxpayers about $1.5 billion dollars. This paper explores the possibility of utilizing 100% RAP materials in asphalt pavement. Asphalt mixtures are produced at 135°C in a typical asphalt plant. However, at 135°C, not all binder from RAP materials may not become effective for coating aggregates. The main objective of the study is to determine the amount of effective binder available from RAP in the asphalt plant. The 100% RAP mixes have aged binder that can alter mix designs and interaction with virgin binder. In this study, to determine low temperature cracking resistance and fatigue performance, samples were prepared using a 100% RAP mix with no virgin binder and a 100% RAP mix with virgin asphalt binder to achieve the optimum binder content of the mix. Second, to determine the effectiveness of binder from RAP materials, compaction tests were performed by heating RAP materials at various temperatures. It was found that 100% RAP mixes cannot be feasible for field use if additional virgin binder is added to reach the optimum asphalt content. Based on limited test results, the low temperature grade was not within proper limits but the beam fatigue testing results were acceptable. Based on compaction test results, additional heating is needed to increase the effectiveness of asphalt binder from RAP materials.

  10. Rutting Performance of Cold-Applied Asphalt Repair Materials for Airfield Pavements

    DTIC Science & Technology

    2017-06-23

    ER D C/ G SL T R- 17 -1 0 Rutting Performance of Cold-Applied Asphalt Repair Materials for Airfield Pavements G eo te ch ni ca l a nd S...of Cold-Applied Asphalt Repair Materials for Airfield Pavements Ben C. Cox, John F. Rushing, and Web Floyd Geotechnical and Structures Laboratory...at ambient tempera- tures. This study primarily evaluated the rutting performance of nine commercial cold mix asphalt repair materials . Both

  11. The reinforcement and healing of asphalt mastic mixtures by rejuvenator encapsulation in alginate compartmented fibres

    NASA Astrophysics Data System (ADS)

    Tabaković, A.; Post, W.; Cantero, D.; Copuroglu, O.; Garcia, S. J.; Schlangen, E.

    2016-08-01

    This paper explores the potential use of compartmented alginate fibres as a new method of incorporating rejuvenators into asphalt pavement mixtures. The compartmented fibres are employed to locally distribute the rejuvenator and to overcome the problems associated with spherical capsules and hollow fibres. The work presents proof of concept of the encapsulation process which involved embedding the fibres into the asphalt mastic mixture and the survival rate of fibres in the asphalt mixture. To prove the effectiveness of the alginate as a rejuvenator encapsulating material and to demonstrate its ability survive asphalt production process, the fibres containing the rejuvenator were prepared and subjected to thermogravimetric analysis and uniaxial tensile test. The test results demonstrated that fibres have suitable thermal and mechanical strength to survive the asphalt mixing and compaction process. The CT scan of an asphalt mortar mix containing fibres demonstrated that fibres are present in the mix in their full length, undamaged, providing confirmation that the fibres survived the asphalt production process. In order to investigate the fibres physiological properties and ability to release the rejuvenator into cracks in the asphalt mastic, the environmental scanning electron microscope and optical microscope analysis were employed. To prove its success as an asphalt healing system, compartmented alginate fibres containing rejuvenator were embedded in asphalt mastic mix. The three point bend tests were performed on the asphalt mastic test samples and the degree to which the samples began to self-heal in response was measured and quantified. The research findings indicate that alginate fibres present a promising new approach for the development of self-healing asphalt pavement systems.

  12. Properties of concrete with tire derived aggregate and crumb rubber as a lighthweight substitute for mineral aggregates in the concrete mix

    NASA Astrophysics Data System (ADS)

    Siringi, Gideon Momanyi

    Scrap tires continue to be a nuisance to the environment and this research proposes one way of recycling them as a lightweight aggregate which can substitute for mineral aggregates in concrete. Aggregates derived from scrap tires are often referred to as Tire Derived Aggregate (TDA). First, the focus is how much mineral aggregate can be replaced by these waste tires and how the properties of concrete are affected with the introduction of rubber. This is being mindful of the fact that for a new material to be acceptable as an engineering material, its properties and behavior has to be well understood, the materials must perform properly and be acceptable to the regulating agencies. The role played by the quantity of TDA and Crumb Rubber replacing coarse aggregate and fine aggregate respectively as well as different treatment and additives in concrete on its properties are examined. Conventional concrete (without TDA) and concrete containing TDA are compared by examining their compressive strength based on ASTM C39, workability based on ASTM C143, Splitting Tensile Strength based on ASTM C496, Modulus of Rupture (flexural strength) based on ASTM C78 and Bond strength of concrete developed with reinforcing steel based on ASTM C234.Through stress-strain plots, the rubberized concrete is compared in terms of change in ductility, toughness and Elastic Modulus. Results indicate that while replacement of mineral aggregates with TDA results in reduction in compressive strength, this may be mitigated by addition of silica fume or using a smaller size of TDA to obtain the desired strength. The greatest benefit of using TDA is in the development of a higher ductile product with lower density while utilizing recycled TDA. From the results, it is observed that 7-10% of weight of mineral aggregates can be replaced by an equal volume of TDA to produce concrete with compressive strength of up to 4000 psi (27.5 MPa). Rubberized concrete would have higher ductility and toughness with

  13. Microbial Degradation of Asphalt1

    PubMed Central

    Phillips, U. A.; Traxler, R. W.

    1963-01-01

    Organisms of the genera Pseudomonas, Chromobacterium, and Bacillus capable of degrading asphalt were isolated by enrichment cultures. The asphalt degradation by these organisms varied from 3 to 25% after incubation for 1 week. The effects of temperature, pH, and atmosphere of incubation on asphalt degradation were investigated and were shown to vary with different organisms on the same substrate. PMID:16349633

  14. HP-GPC characterization of asphalt and modified asphalts from gulf countries and their relation to performance based properties

    SciTech Connect

    Wahhab, H.I.A.; Ali, M.F.; Asi, I.M.; Dubabe, I.A.

    1996-12-31

    Asphalt producing refineries in the Gulf countries include Ras Tanura and Riyadh (Saudi Arabia), Al-Ahmadi (Kuwait), and BAPCO (Bahrain). Riyadh and Ras Tanura refineries are located in the central and eastern Saudi Arabia respectively. Arabian light crude oil is used to produce 2000 to 3000 tons of asphalt per day using vacuum distillation, air blowing and grade blending techniques to produce 60/70 penetration grade asphalts in each of these two Saudi refineries. All of the asphalt cement used in Saudi Arabia, Qatar and parts of the United Arab Emirates is supplied by Riyadh and Ras Tanura refineries. Al-Ahmadi refinery supplies all of the asphalt cement needed for construction in the state of Kuwait. Ratwi-Burgan crude off mix is used to produce 750 to 1000 tons of asphalt per day using vacuum distillation and air blowing processes. This study was initiated to evaluate different locally available polymers in order to identify potential polymers to modify asphalts to satisfy the performance requirements in the Gulf countries environmental conditions.

  15. Microbial life in a liquid asphalt desert.

    PubMed

    Schulze-Makuch, Dirk; Haque, Shirin; de Sousa Antonio, Marina Resendes; Ali, Denzil; Hosein, Riad; Song, Young C; Yang, Jinshu; Zaikova, Elena; Beckles, Denise M; Guinan, Edward; Lehto, Harry J; Hallam, Steven J

    2011-04-01

    Pitch Lake in Trinidad and Tobago is a natural asphalt reservoir nourished by pitch seepage, a form of petroleum that consists of mostly asphaltines, from the surrounding oil-rich region. During upward seepage, pitch mixes with mud and gases under high pressure, and the lighter portion evaporates or is volatilized, which produces a liquid asphalt residue characterized by low water activity, recalcitrant carbon substrates, and noxious chemical compounds. An active microbial community of archaea and bacteria, many of them novel strains (particularly from the new Tar ARC groups), totaling a biomass of up to 10(7) cells per gram, was found to inhabit the liquid hydrocarbon matrix of Pitch Lake. Geochemical and molecular taxonomic approaches revealed diverse, novel, and deeply branching microbial lineages with the potential to mediate anaerobic hydrocarbon degradation processes in different parts of the asphalt column. In addition, we found markers for archaeal methane metabolism and specific gene sequences affiliated with facultative and obligate anaerobic sulfur- and nitrite-oxidizing bacteria. The microbial diversity at Pitch Lake was found to be unique when compared to microbial communities analyzed at other hydrocarbon-rich environments, which included Rancho Le Brea, a natural asphalt environment in California, USA, and an oil well and a mud volcano in Trinidad and Tobago, among other sites. These results open a window into the microbial ecology and biogeochemistry of recalcitrant hydrocarbon matrices and establish the site as a terrestrial analogue for modeling the biotic potential of hydrocarbon lakes such as those found on Saturn's largest moon Titan.

  16. Microbial Life in a Liquid Asphalt Desert

    NASA Astrophysics Data System (ADS)

    Schulze-Makuch, Dirk; Haque, Shirin; de Sousa Antonio, Marina Resendes; Ali, Denzil; Hosein, Riad; Song, Young C.; Yang, Jinshu; Zaikova, Elena; Beckles, Denise M.; Guinan, Edward; Lehto, Harry J.; Hallam, Steven J.

    2011-04-01

    Pitch Lake in Trinidad and Tobago is a natural asphalt reservoir nourished by pitch seepage, a form of petroleum that consists of mostly asphaltines, from the surrounding oil-rich region. During upward seepage, pitch mixes with mud and gases under high pressure, and the lighter portion evaporates or is volatilized, which produces a liquid asphalt residue characterized by low water activity, recalcitrant carbon substrates, and noxious chemical compounds. An active microbial community of archaea and bacteria, many of them novel strains (particularly from the new Tar ARC groups), totaling a biomass of up to 107 cells per gram, was found to inhabit the liquid hydrocarbon matrix of Pitch Lake. Geochemical and molecular taxonomic approaches revealed diverse, novel, and deeply branching microbial lineages with the potential to mediate anaerobic hydrocarbon degradation processes in different parts of the asphalt column. In addition, we found markers for archaeal methane metabolism and specific gene sequences affiliated with facultative and obligate anaerobic sulfur- and nitrite-oxidizing bacteria. The microbial diversity at Pitch Lake was found to be unique when compared to microbial communities analyzed at other hydrocarbon-rich environments, which included Rancho Le Brea, a natural asphalt environment in California, USA, and an oil well and a mud volcano in Trinidad and Tobago, among other sites. These results open a window into the microbial ecology and biogeochemistry of recalcitrant hydrocarbon matrices and establish the site as a terrestrial analogue for modeling the biotic potential of hydrocarbon lakes such as those found on Saturn's largest moon Titan.

  17. Predicting rheological parameters of reclaimed asphalt cement with wave propagation techniques. Research report, 1 September 1993-31 August 1995

    SciTech Connect

    Nazarian, S.; Pezo, R.; Nori, S.R.G.; Picornell, M.

    1996-07-01

    A methodology to predict the rheological of asphalt cement from elastic modulus or from the indirect tensile (IDT) strength of the mix is presented. Wave propagation techniques were used to determine the modulus of the mix. Numerous specimens, prepared from four different mixtures with different asphalt contents and voids in the total mixes (VTM`s), were-oven aged for different periods. The elastic modulus and IDT strength of each specimen were determined, and its asphalt cement was recovered to evalutate its rheological properties. The effects of different parameters, such as asphalt content and VTM, on relationships between elastic modulus or IDT strength with rheological properties were determined.

  18. Abrasive blast material utilization in asphalt roadbed material

    SciTech Connect

    Means, J.L.; Nehring, K.W.; Heath, J.C.

    1996-12-31

    The State of California has promulgated rules on California-only hazardous wastes that offer the potential for some of these wastes to be recycled or reused. Abrasive blast material (ABM) from military and commercial operations such as sandblasting may fall into the category of waste that can be reused. Experiments were conducted on spent sandblasting grit to determine whether the grit could be incorporated into asphalt concrete for use as roadbed material, and a test roadbed was laid to evaluate the long-term stability of the metals found in the grit. Incorporation of the ABM in asphalt helps reduce the mobility of metal contaminants making the material suitable for reuse. The results of the initial characterization, treatability testing, and follow-up measurements of core samples taken from the test roadbed are presented to show that the use of abrasive blast material in asphalt roadbed material is a viable option under the proposed California regulatory standards.

  19. Performance modeling of Arabian asphalt using HP-GPC

    NASA Astrophysics Data System (ADS)

    Asi, I. M.; Wahhab, H. I. Al-Abdul; Al-Dubabi, I. A.; Ali, M. F.

    1997-08-01

    In this study, Arabian neat asphalt samples were collected from different asphalt producing refineries in the Gulf countries. Another set of polymer modified samples was also included in this study. In the polymer modification process, 5,10, and 15% crumb rubber (CRT) and 3,6, and 9% styrene-butadiene-styrene (SBS) were used. All asphalt samples were subjected to two aging processes to simulate heating, mixing, compaction, and in-service aging. The asphalt samples at the different aging stages were subjected to performance-based tests that were adapted and/or modified by the Strategic Highway Research Program (SHRP) team. High pressure gel permeation chromatography (HP-GPC) was used to chemically analyze the test samples by generating profiles of their molecular size distribution. Models were built to predict the performance-based properties from the produced HP-GPC profiles.

  20. An Innovative Concept for Testing Rutting Susceptibility of Asphalt Mixture

    NASA Astrophysics Data System (ADS)

    Mohseni, Alaeddin; Azari, Haleh

    Currently, flow number (FN) is being used for measuring permanent deformation resistance of asphalt mixtures. The provisional AASHTO TP 79-10 test method specifies the requirements of the FN test; however, there are undefined levels of test variables, such as temperature, axial stress, and confinement. Therefore, agreeable FN criteria that can reliably discriminate between various mixtures have not been established yet. As the asphalt industry continues to develop more sophisticated mixtures (Warm Mix, RAP and RAS), the FN value has failed to capture the true complexity of the asphalt mixtures. These shortcomings and the unpredictable testing time of the FN test have affected its usefulness for evaluating high temperature performance of asphalt mixtures. A new test procedure for evaluation of rutting susceptibility of asphalt mixtures is being proposed. The new procedure is conducted at one temperature and multiple stresses on the same replicate in three increments of 500 cycles, which only takes 33 minutes to complete. The property of the test is the permanent strain due to the last cycle of each test increment (Minimum Strain Rate, or MSR). A master curve is developed by plotting the MSR values versus parameter TP, which is a product of Temperature and Pressure. The MSR master curve represents the unit rutting damage (rut per axle) of asphalt mixtures at any stress and temperature and can be used in laboratory for material characterization, mix design verification, ranking of the mixtures, or for pavement design applications to predict rut depth for project climate and design traffic.

  1. Slow mechanical relaxation in asphalt

    SciTech Connect

    Stastna, J.; Zanzotto, L.

    1996-12-31

    Asphalt (or bitumen) is one of the earliest construction materials used by mankind. However, despite the long history of its use and the important role it plays at the present time, in the construction of pavements, the composition and especially the structure of asphalt is still not fully understood. It is generally believed that asphalt is a multiphase system in which the large and polar molecules called asphaltenes, or their agglomerates are dispersed in the medium consisting of the smaller molecules with low or no polarity. Opinions on how the asphalt structure is arranged vary. The study of asphalt structure is made extremely difficult by the nature of this material. Non-invasive methods such as dynamic mechanical or electric testing, which investigate the asphalt in its original state may greatly contribute to our knowledge of the asphalt internal structure.

  2. APPLICATION OF LOW TEMPERATU RE PROPERTIES IMPROVEMENT ASPHALT TO REPAIRE WORK OF RO CK FILL DAM WITH ASPHALT FACING

    NASA Astrophysics Data System (ADS)

    Shimazaki, Masaru; Tsunoo, Takashi; Kasahara, Atsushi

    The low temperature properties improvement asphalt that is no decreasing the transformation follow and the stress relaxation properties at the low temperature was developed. It aimed at properties of PG64-28 (lowest temperature 28 degree C and maximum temperature 64 degree C that was able to be used) from PG (Performance Grade) of mix design method SUPERPAVE (Superior Performance Pavement) of new road-building plan SHRP (Strategic Highway Research Program) in the United States when developing. When the repair work of the rock fill dam with asphalt facing located in Kyogoku-cho Abuta-gun Hokkaido was planned, the applicability of the developed asphalt was verified. As for the verification outcome and the developed asphalt, it was proven that it was applied to the repair construction, and there was no problem in manufacturing and construction.

  3. Evaluation of western and eastern shale oil residua as asphalt pavement recycling agents

    SciTech Connect

    Harnsberger, P.M.; Robertson, R.E.

    1990-03-01

    The objective of this investigation was to perform a preliminary evaluation of the utility of residual materials prepared from Green River Formation (western) and New Albany Shale (eastern) shale oils as recycling agents for aged asphalt pavement. Four petroleum asphalts were first aged by a thin-film accelerated-aging test, which simulates long service life of asphalt in pavement. The aged asphalts were mixed (recycled) with Green River Formation shale oil distillation residua to restore the original viscosities. Separately, for comparison, a commercial recycling agent was used to recycle the aged asphalts under the same circumstances. The recycled asphalts were reaged and the properties of both binder and asphalt-aggregate mixtures studied. Originally, the same study was intended for an eastern shale residua. However, the eastern shale oil distillation residua with the required flash point specification also had the properties of a viscosity builder; therefore, it was studied as such with asphalts that do not achieve sufficient viscosity during processing to serve as usable binders. Results show that Green River Formation shale oil residuum can be used to restore the original asphalt properties with favorable rheological properties, the shale oil residuum has a beneficial effect on resistance to moisture damage, the low-temperature properties of the shale oil residuum recycled asphalts are not adversely affected, and the low-temperature properties of the shale oil residuum recycled asphalts are dependent upon the chemistry of the mixture. The eastern shale oil residua was blended with soft petroleum asphalts. Results show the products have higher viscosities than the starting materials, the rheological properties of the soft asphalt-eastern shale oil residue blends are acceptable, and the eastern shale oil residue has dispersant properties despite its high viscosity. 11 refs., 3 figs., 9 tabs.

  4. Hanford Protective Barriers Program asphalt barrier studies -- FY 1988

    SciTech Connect

    Freeman, H.D.; Gee, G.W.

    1989-05-01

    The Hanford Protective Barrier (HPB) Program is evaluating alternative barriers to provide a means of meeting stringent water infiltration requirements. One type of alternative barrier being considered is an asphalt-based layer, 1.3 to 15 cm thick, which has been shown to be very effective as a barrier for radon gas and, hence, should be equally effective as a barrier for the larger molecules of water. Fiscal Year 1988 studies focused on the selection and formulation of the most promising asphalt materials for further testing in small-tube lysimeters. Results of laboratory-scale formulation and hydraulic conductivity tests led to the selection of a rubberized asphalt material and an admixture of 24 wt% asphalt emulsion and concrete sand as the two barriers for lysimeter testing. Eight lysimeters, four each containing the two asphalt treatments, were installed in the Small Tube Lysimeter Facility on the Hanford Site. The lysimeter tests allow the performance of these barrier formulations to be evaluated under more natural environmental conditions.

  5. Network morphology of straight and polymer modified asphalt cements.

    PubMed

    Rozeveld, S J; Shin, E E; Bhurke, A; France, L; Drzal, L T

    1997-09-01

    Asphalt cements are often regarded as a colloidal system containing several hydrocarbon constituents: asphaltenes, resins, and oils. The high molecular weight asphaltene particles are considered to be covered in a sheath of resins and dispersed in the lower molecular weight oily medium [Whiteoak (1990) The Shell Bitumen Handbook (Shell Bitumen UK, Riversdell House, Surrey, UK)]. However, the exact arrangement of the asphaltene particles within the oily phase will vary depending on the relative amounts of resin, asphaltene, and oils. It is this arrangement and the degree of association between asphaltene particles that govern the rheological properties of the cement [Simpson et al. (1961) J. Chem. Eng. Data 6:426-429; Whiteoak (1990)]. Here we report for the first time the observation of a three-dimensional network of asphaltene strands within straight, polymer-modified, and aged asphalt cements. While the existence of a asphaltene/resin micelle network has been proposed in previous studies [Whiteoak (1990)], direct observation has not been reported. The network is expected to greatly influence the rheological properties of the asphalt binder and ultimately the properties of asphalt concretes. In situ fracture studies of asphalt cement/aggregate composites indicate a possible correlation between the network structure and adhesion between the cement binder and aggregate.

  6. A review of the fundamentals of polymer-modified asphalts: Asphalt/polymer interactions and principles of compatibility.

    PubMed

    Polacco, Giovanni; Filippi, Sara; Merusi, Filippo; Stastna, George

    2015-10-01

    During the last decades, the number of vehicles per citizen as well as the traffic speed and load has dramatically increased. This sudden and somehow unplanned overloading has strongly shortened the life of pavements and increased its cost of maintenance and risks to users. In order to limit the deterioration of road networks, it is necessary to improve the quality and performance of pavements, which was achieved through the addition of a polymer to the bituminous binder. Since their introduction, polymer-modified asphalts have gained in importance during the second half of the twentieth century, and they now play a fundamental role in the field of road paving. With high-temperature and high-shear mixing with asphalt, the polymer incorporates asphalt molecules, thereby forming a swallowed network that involves the entire binder and results in a significant improvement of the viscoelastic properties in comparison with those of the unmodified binder. Such a process encounters the well-known difficulties related to the poor solubility of polymers, which limits the number of macromolecules able to not only form such a structure but also maintain it during high-temperature storage in static conditions, which may be necessary before laying the binder. Therefore, polymer-modified asphalts have been the subject of numerous studies aimed to understand and optimize their structure and storage stability, which gradually attracted polymer scientists into this field that was initially explored by civil engineers. The analytical techniques of polymer science have been applied to polymer-modified asphalts, which resulted in a good understanding of their internal structure. Nevertheless, the complexity and variability of asphalt composition rendered it nearly impossible to generalize the results and univocally predict the properties of a given polymer/asphalt pair. The aim of this paper is to review these aspects of polymer-modified asphalts. Together with a brief description of

  7. Properties of Sulfur Concrete.

    DTIC Science & Technology

    1979-07-06

    This report summarizes the state of the art of sulfur concrete . Sulfur concrete is created by mixing molten sulfur with aggregate and allowing the...and many organic compounds. It works well as a rapid runway repair material. Sulfur concrete also has unfavorable properties. It has poor durability

  8. Laboratory evaluation of selected tar sand asphalts

    SciTech Connect

    Button, J.W.; Epps, J.A.; Gallaway, B.M.

    1980-12-01

    Three tar sand asphalts of similar grades prepared from one syncrude by three different refining methods were characterized by tests commonly used to specify paving asphalts together with certain special tests. Asphalt-aggregate mixtures were prepared using these asphalts and tested in the laboratory to determine strength stiffness stability, tensile properties, temperature effects and water susceptibility. Comparison of the tar sand asphalt properties to conventional petroleum asphalt properties reveal no striking differences.

  9. Use of Scrap Rubber in Asphalt Pavement Surfaces

    DTIC Science & Technology

    1991-12-01

    DEVELOPMENT OF method is conducted by applying compressive loads RUBBER -AGGREGATE with a prescribed sinusoidal waveform and can be used ASPHALT CONCRETE...evaluation program of rubber -aggregate as- 104 phalt surfaces with rubber contents from I to 3% rubber by weight is currently being conducted by the California...Transportation reports using as- men. However, no relationship between the modulus of phalt containing up to 25% crumb rubber (Civil Engi- resiliency and the

  10. Feasibility of the use of ultrasound measurements for grade verification of the performance grade asphalt binders

    NASA Astrophysics Data System (ADS)

    Khalili, Mehdi

    This research investigates the feasibility of application of high frequency immersion ultrasonic measurement (UM) to discriminate different performance grade (PG) asphalt binders. PG asphalt binder is one of the main components of hot mix asphalt used for roadway construction. UT may provide an inexpensive alternative to sophisticated tests currently used for quality control of PG asphalt binders. Nine different PG asphalt binders used were selected for this investigation. Velocity (V) and integrated response (IR) of the ultrasonic wave were measured. The IR is a measure of the ratio of ultrasonic energy transmitted into the material to the ultrasonic energy reflected from the surface of material, in decibels. The physical properties of PG asphalt binders are temperature sensitive. Accordingly, the UM was performed at five temperatures. The results indicate that velocity decrease with increase in temperature of the asphalt binder. UT could distinguish between modified and non-modified asphalt binders. Discriminant Function Analysis was used to predict the grade of the performance grade asphalt binders using the UM.

  11. Acoustic Properties of Absorbent Asphalts

    NASA Astrophysics Data System (ADS)

    Trematerra, Amelia; Lombardi, Ilaria

    2017-08-01

    Road traffic is one of the greater cause of noise pollution in urban centers; a prolonged exposure to this source of noise disturbs populations subjected to it. In this paper is reported a study on the absorbent coefficients of asphalt. The acoustic measurements are carried out with a impedance tube (tube of Kundt). The sample are measured in three conditions: with dry material (traditional), “wet” asphalt and “dirty” asphalt.

  12. Asphalt Roofing Shingles Into Energy Project Summary Report

    SciTech Connect

    Jameson, Rex, PE

    2008-04-28

    Based on a widely cited September, 1999 report by the Vermont Agency of Natural Resources, nearly 11 million tons of asphalt roofing shingle wastes are produced in the United States each year. Recent data suggests that the total is made up of about 9.4 million tons from roofing tear-offs and about 1.6 million tons from manufacturing scrap. Developing beneficial uses for these materials would conserve natural resources, promote protection of the environment and strengthen the economy. This project explored the feasibility of using chipped asphalt shingle materials in cement manufacturing kilns and circulating fluidized bed (CFB) boilers. A method of enhancing the value of chipped shingle materials for use as fuel by removing certain fractions for use as substitute raw materials for the manufacture of new shingles was also explored. Procedures were developed to prevent asbestos containing materials from being processed at the chipping facilities, and the frequency of the occurrence of asbestos in residential roofing tear-off materials was evaluated. The economic feasibility of each potential use was evaluated based on experience gained during the project and on a review of the well established use of shingle materials in hot mix asphalt. This project demonstrated that chipped asphalt shingle materials can be suitable for use as fuel in circulating fluidized boilers and cement kilns. More experience would be necessary to determine the full benefits that could be derived and to discover long term effects, but no technical barriers to full scale commercial use of chipped asphalt shingle materials in these applications were discovered. While the technical feasibility of various options was demonstrated, only the use of asphalt shingle materials in hot mix asphalt applications is currently viable economically.

  13. Nuclear method for determination of asphalt content corrected for moisture in bituminous mixture. Final report, March 1988-February 1989

    SciTech Connect

    Christensen, D.W.; Tarris, J.P.

    1989-05-01

    This report presents results of research on the development of a method for determination of asphalt content corrected for moisture using the nuclear-gauge method. The researchers selected an approach that involved rapid drying of the asphalt concrete samples in a microwave oven prior to the determination of asphalt content using a Troxler Model 3241-C nuclear asphalt-content gauge. As a reference, asphalt contents were also measured using quantitative extraction. In general, good agreement was found between asphalt contents measured by the Troxler Model 3241-C nuclear gauge and asphalt contents measured by quantitative extraction. In extended sampling for Plant 1, no significant increase in nuclear gauge error was seen over a 10-day sampling period, which indicates that daily calibration of the nuclear gauge is probably unnecessary to maintain satisfactory performance. The field demonstration of the procedure of drying the bituminous mixture in a microwave oven and then determining its asphalt content by the nuclear method indicated asphalt-content results were obtained approximately 1 hour faster than results obtained by quantitative extraction.

  14. Integrated model for assessing the cost and CO2 emission (IMACC) for sustainable structural design in ready-mix concrete.

    PubMed

    Hong, Taehoon; Ji, Changyoon; Park, Hyoseon

    2012-07-30

    Cost has traditionally been considered the most important factor in the decision-making process. Recently, along with the consistent interest in environmental problems, environmental impact has also become a key factor. Accordingly, there is a need to develop a method that simultaneously reflects the cost and environmental impact in the decision-making process. This study proposed an integrated model for assessing the cost and CO(2) emission (IMACC) at the same time. IMACC is a model that assesses the cost and CO(2) emission of the various structural-design alternatives proposed in the structural-design process. To develop the IMACC, a standard on assessing the cost and CO(2) emission generated in the construction stage was proposed, along with the CO(2) emission factors in the structural materials, based on such materials' strengths. Moreover, using the economic and environmental scores that signify the cost and CO(2) emission reduction ratios, respectively, a method of selecting the best design alternative was proposed. To verify the applicability of IMACC, practical application was carried out. Structural designs were assessed, each of which used 21, 24, 27, and 30 MPa ready-mix concrete (RMC). The use of IMACC makes it easy to verify what the best design is. Results show the one that used 27 MPa RMC was the best design. Therefore, the proposed IMACC can be used as a tool for supporting the decision-making process in selecting the best design alternative. Copyright © 2012 Elsevier Ltd. All rights reserved.

  15. Hierarchical order of influence of mix variables affecting compressive strength of sustainable concrete containing fly ash, copper slag, silica fume, and fibres.

    PubMed

    Natarajan, Sakthieswaran; Karuppiah, Ganesan

    2014-01-01

    Experiments have been conducted to study the effect of addition of fly ash, copper slag, and steel and polypropylene fibres on compressive strength of concrete and to determine the hierarchical order of influence of the mix variables in affecting the strength using cluster analysis experimentally. While fly ash and copper slag are used for partial replacement of cement and fine aggregate, respectively, defined quantities of steel and polypropylene fibres were added to the mixes. It is found from the experimental study that, in general, irrespective of the presence or absence of fibres, (i) for a given copper slag-fine aggregate ratio, increase in fly ash-cement ratio the concrete strength decreases and with the increase in copper slag-sand ratio also the rate of strength decrease and (ii) for a given fly ash-cement ratio, increase in copper slag-fine aggregate ratio increases the strength of the concrete. From the cluster analysis, it is found that the quantities of coarse and fine aggregate present have high influence in affecting the strength. It is also observed that the quantities of fly ash and copper slag used as substitutes have equal "influence" in affecting the strength. Marginal effect of addition of fibres in the compression strength of concrete is also revealed by the cluster analysis.

  16. Hierarchical Order of Influence of Mix Variables Affecting Compressive Strength of Sustainable Concrete Containing Fly Ash, Copper Slag, Silica Fume, and Fibres

    PubMed Central

    Natarajan, Sakthieswaran; Karuppiah, Ganesan

    2014-01-01

    Experiments have been conducted to study the effect of addition of fly ash, copper slag, and steel and polypropylene fibres on compressive strength of concrete and to determine the hierarchical order of influence of the mix variables in affecting the strength using cluster analysis experimentally. While fly ash and copper slag are used for partial replacement of cement and fine aggregate, respectively, defined quantities of steel and polypropylene fibres were added to the mixes. It is found from the experimental study that, in general, irrespective of the presence or absence of fibres, (i) for a given copper slag-fine aggregate ratio, increase in fly ash-cement ratio the concrete strength decreases and with the increase in copper slag-sand ratio also the rate of strength decrease and (ii) for a given fly ash-cement ratio, increase in copper slag-fine aggregate ratio increases the strength of the concrete. From the cluster analysis, it is found that the quantities of coarse and fine aggregate present have high influence in affecting the strength. It is also observed that the quantities of fly ash and copper slag used as substitutes have equal “influence” in affecting the strength. Marginal effect of addition of fibres in the compression strength of concrete is also revealed by the cluster analysis. PMID:24707213

  17. Material Performance and Animal Clinical Studies on Performance-Optimized Hwangtoh Mixed Mortar and Concrete to Evaluate Their Mechanical Properties and Health Benefits.

    PubMed

    Koo, Bon-Min; Kim, Jang-Ho Jay; Kim, Tae-Kyun; Kim, Byung-Yun

    2015-09-17

    In this study, the amount of cement used in a concrete mix is minimized to reduce the toxic effects on users by adjusting the concrete mixture contents. The reduction of cement is achieved by using various admixtures (ground granulated blast-furnace slag, flyash, ordinary Portland cement, and activated Hwangtoh powder). To apply the mix to construction, material property tests such as compressive strength, slump, and pH are performed. Preliminary experimental results showed that the Hwangtoh concrete could be used as a healthy construction material. Also, the health issues and effects of Hwangtoh mortar are quantitatively evaluated through an animal clinical test. Mice are placed in Hwangtoh mortar and cement mortar cages to record their activity. For the test, five cages are made with Hwangtoh and ordinary Portland cement mortar floors, using Hwangtoh powder replacement ratios of 20%, 40%, 60%, and 80% of the normal cement mortar mixing ratio, and two cages are made with Hwangtoh mortar living quarters. The activity parameter measurements included weight, food intake, water intake, residential space selection, breeding activity, and aggression. The study results can be used to evaluate the benefits of using Hwangtoh as a cement replacing admixture for lifestyle, health and sustainability.

  18. Quality Assessment of Mixed and Ceramic Recycled Aggregates from Construction and Demolition Wastes in the Concrete Manufacture According to the Spanish Standard.

    PubMed

    Rodríguez-Robles, Desirée; García-González, Julia; Juan-Valdés, Andrés; Morán-Del Pozo, Julia Mª; Guerra-Romero, Manuel I

    2014-08-13

    Construction and demolition waste (CDW) constitutes an increasingly significant problem in society due to the volume generated, rendering sustainable management and disposal problematic. The aim of this study is to identify a possible reuse option in the concrete manufacturing for recycled aggregates with a significant ceramic content: mixed recycled aggregates (MixRA) and ceramic recycled aggregates (CerRA). In order to do so, several tests are conducted in accordance with the Spanish Code on Structural Concrete (EHE-08) to determine the composition in weight and physic-mechanical characteristics (particle size distributions, fine content, sand equivalent, density, water absorption, flakiness index, and resistance to fragmentation) of the samples for the partial inclusion of the recycled aggregates in concrete mixes. The results of these tests clearly support the hypothesis that this type of material may be suitable for such partial replacements if simple pretreatment is carried out. Furthermore, this measure of reuse is in line with European, national, and regional policies on sustainable development, and presents a solution to the environmental problem caused by the generation of CDW.

  19. Quality Assessment of Mixed and Ceramic Recycled Aggregates from Construction and Demolition Wastes in the Concrete Manufacture According to the Spanish Standard †

    PubMed Central

    Rodríguez-Robles, Desirée; García-González, Julia; Juan-Valdés, Andrés; Pozo, Julia Mª Morán-del; Guerra-Romero, Manuel I

    2014-01-01

    Construction and demolition waste (CDW) constitutes an increasingly significant problem in society due to the volume generated, rendering sustainable management and disposal problematic. The aim of this study is to identify a possible reuse option in the concrete manufacturing for recycled aggregates with a significant ceramic content: mixed recycled aggregates (MixRA) and ceramic recycled aggregates (CerRA). In order to do so, several tests are conducted in accordance with the Spanish Code on Structural Concrete (EHE-08) to determine the composition in weight and physic-mechanical characteristics (particle size distributions, fine content, sand equivalent, density, water absorption, flakiness index, and resistance to fragmentation) of the samples for the partial inclusion of the recycled aggregates in concrete mixes. The results of these tests clearly support the hypothesis that this type of material may be suitable for such partial replacements if simple pretreatment is carried out. Furthermore, this measure of reuse is in line with European, national, and regional policies on sustainable development, and presents a solution to the environmental problem caused by the generation of CDW. PMID:28788164

  20. Material Performance and Animal Clinical Studies on Performance-Optimized Hwangtoh Mixed Mortar and Concrete to Evaluate Their Mechanical Properties and Health Benefits

    PubMed Central

    Koo, Bon-Min; Kim, Jang-Ho Jay; Kim, Tae-Kyun; Kim, Byung-Yun

    2015-01-01

    In this study, the amount of cement used in a concrete mix is minimized to reduce the toxic effects on users by adjusting the concrete mixture contents. The reduction of cement is achieved by using various admixtures (ground granulated blast-furnace slag, flyash, ordinary Portland cement, and activated Hwangtoh powder). To apply the mix to construction, material property tests such as compressive strength, slump, and pH are performed. Preliminary experimental results showed that the Hwangtoh concrete could be used as a healthy construction material. Also, the health issues and effects of Hwangtoh mortar are quantitatively evaluated through an animal clinical test. Mice are placed in Hwangtoh mortar and cement mortar cages to record their activity. For the test, five cages are made with Hwangtoh and ordinary Portland cement mortar floors, using Hwangtoh powder replacement ratios of 20%, 40%, 60%, and 80% of the normal cement mortar mixing ratio, and two cages are made with Hwangtoh mortar living quarters. The activity parameter measurements included weight, food intake, water intake, residential space selection, breeding activity, and aggression. The study results can be used to evaluate the benefits of using Hwangtoh as a cement replacing admixture for lifestyle, health and sustainability. PMID:28793563

  1. Effect of asphalt rejuvenating agent on aged reclaimed asphalt pavement and binder properties

    NASA Astrophysics Data System (ADS)

    Sabahfar, Nassim

    Hot in-place recycling (HIR) preserves distressed asphalt pavements while minimizing use of virgin binder and aggregates. The final quality of an HIR mixture depends on characteristics of the original binder, aging of the pavement surface during service, and whether or not new binder or rejuvenator was added to the mixture. An HIR mixture should maintain desired properties for additional service periods, making asphalt binder modification inevitable. Asphalt binder modifications in HIR are commonly done by adding an asphalt rejuvenating agent (ARA). However, ARA may adversely affect the qualities of new HIR and potentially fail to improve the quality of the final surface. The objective of this research was to investigate the effects of rejuvenation on HIR performance characteristics by assessing critical performance indicators such as stiffness, permanent deformation, moisture susceptibility, and cracking resistance. A two-step experimental program was designed that included mechanical property measurements of the HIR mixture and rheological properties of the extracted binder. The level of mixing occurring between new and aged binder with ARA was also investigated. HIR Samples were obtained from three Kansas Department of Transportation projects, and Hamburg wheel-tracking device, dynamic modulus, flow number, Texas overlay, thermal stress restrained specimen, and moisture susceptibility tests were conducted on mixtures with and without ARA. Rheological studies on the extracted binder included dynamic shear rheometer and bending beam rheometer tests. The miscibility of new and aged binder was investigated using scanning electron microscope (SEM) images, energy dispersive X-ray spectroscopy (EDXS), and the exudation droplet test (EDT). Study results showed significant variability in the mechanical performance of HIR mixtures, which was attributed to the variability of binders as observed in EDT, SEM and EDXS studies. Life cycle cost analysis (LCCA) showed that HIR

  2. Maintenance methods for continuously reinforced concrete pavements

    NASA Astrophysics Data System (ADS)

    Yoder, E. J.

    1980-05-01

    Test sections were constructed on a section of 1-65 south of Indianapolis, Indiana to evaluate various maintenance techniques that might be adopted for this type of pavement. The road was stratified into similar sections using deflection, cracking and breakup as selection criteria. Maintenance methods used included concrete shoulders, undersealing, asphalt concrete overlay, subdrains at the pavement edge and various combinations of these methods. In every case the pavement was patched prior to installation of the maintenance.

  3. Polyurethane synthesis reactions in asphalts

    SciTech Connect

    Bukowski, A.; Gretkiewicz, J.

    1982-04-01

    A series of asphalt-polyurethane composites was prepared by means of polyurethane synthesis in asphalt and carried out in melt. The applied materials were asphalts of differentiated group components content, polyester polyols of chain structure from linear to strongly branched, 2,4-tolylene diisocyanate, 4,4-methylenebis(phenyl isocyanate), and tinorganic catalyst. The asphalt components react with isocyanates to a minimal degree. The influence of the applied substrates, temperature, and polyurethane content in the system on the basic kinetic relations characterizing the process is presented. Polyurethane synthesis in asphalts does not differ in a fundamental way from the obtaining of polyurethanes, especially when their content in the composition is significant, 20 wt% and more.

  4. How Concrete Is Concrete?

    ERIC Educational Resources Information Center

    Gravemeijer, Koeno

    2011-01-01

    If we want to make something concrete in mathematics education, we are inclined introduce, what we call, "manipulatives", in the form of tactile objects or visual representations. If we want to make something concrete in a everyday-life conversation, we look for an example. In the former, we try to make a concrete model of our own,…

  5. Automated titration method for use on blended asphalts

    DOEpatents

    Pauli, Adam T [Cheyenne, WY; Robertson, Raymond E [Laramie, WY; Branthaver, Jan F [Chatham, IL; Schabron, John F [Laramie, WY

    2012-08-07

    A system for determining parameters and compatibility of a substance such as an asphalt or other petroleum substance uses titration to highly accurately determine one or more flocculation occurrences and is especially applicable to the determination or use of Heithaus parameters and optimal mixing of various asphalt stocks. In a preferred embodiment, automated titration in an oxygen gas exclusive system and further using spectrophotometric analysis (2-8) of solution turbidity is presented. A reversible titration technique enabling in-situ titration measurement of various solution concentrations is also presented.

  6. Performance-based asphalt mixture design methodology

    NASA Astrophysics Data System (ADS)

    Ali, Al-Hosain Mansour

    Today, several State D.O.T.s are being investigating the use of tire rubber with local conventional materials. Several of the ongoing investigations identified potential benefits from the use of these materials, including improvements in material properties and performance. One of the major problems is being associated with the transferability of asphalt rubber technology without appropriately considering the effects of the variety of conventional materials on mixture behavior and performance. Typically, the design of these mixtures is being adapted to the physical properties of the conventional materials by using the empirical Marshall mixture design and without considering fundamental mixture behavior and performance. Use of design criteria related to the most common modes of failure for asphalt mixtures, such as rutting, fatigue cracking, and low temperature thermal cracking have to be developed and used for identifying the "best mixture," in term of performance, for the specific local materials and loading conditions. The main objective of this study was the development of a mixture design methodology that considers mixture behavior and performance. In order to achieve this objective a laboratory investigation able to evaluate mixture properties that can be related to mixture performance, (in terms of rutting, low temperature cracking, moisture damage and fatigue), and simulating the actual field loading conditions that the material is being exposed to, was conducted. The results proved that the inclusion of rubber into asphalt mixtures improved physical characteristics such as elasticity, flexibility, rebound, aging properties, increased fatigue resistance, and reduced rutting potential. The possibility of coupling the traditional Marshall mix design method with parameters related to mixture behavior and performance was investigated. Also, the SHRP SUPERPAVE mix design methodology was reviewed and considered in this study for the development of an integrated

  7. Asphalt emulsion sealing of uranium mill tailings. 1980 annual report

    SciTech Connect

    Hartley, J.N.; Koehmstedt, P.L; Esterl, D.J.; Freeman, H.D.; Buelt, J.L.; Nelson, D.A.; Elmore, M.R.

    1981-05-01

    Studies of asphalt emulsion sealants conducted by the Pacific Northwest Laboratory have demonstrated that the sealants are effective in containing radon and other potentially hazardous material within uranium tailings. The laboratory and field studies have further demonstrated that radon exhalation from uranium tailings piles can be reduced by greater than 99% to near background levels. Field tests at the tailings pile in Grand Junction, Colorado, confirmed that an 8-cm admix seal containing 22 wt% asphalt could be effectively applied with a cold-mix paver. Other techniques were successfully tested, including a soil stabilizer and a hot, rubberized asphalt seal that was applied with a distributor truck. After the seals were applied and compacted, overburden was applied over the seal to protect the seal from ultraviolet degradation.

  8. Asphalt emulsion sealing of uranium mill tailings. 1979 annual report

    SciTech Connect

    Hartley, J.N.; Koehmstedt, P.L.; Esterl, D.J.; Freeman, H.D.

    1980-06-01

    Uranium mill tailings are a source of low-level radiation and radioactive materials that may be released into the environment. Stabilization or disposal of these tailings in a safe and environmentally sound way is necessary to minimize radon exhalation and other radioactive releases. One of the most promising concepts for stabilizing uranium tailings is being investigated at the Pacific Northwest Laboratory: the use of asphalt emulsion to contain radon and other potentially hazardous materials in uranium tailings. Results of these studies indicate that radon flux from uranium tailings can be reduced by greater than 99% by covering the tailings with an asphalt emulsion that is poured on or sprayed on (3.0 to 7.0 mm thick), or mixed with some of the tailings and compacted to form an admixture seal (2.5 to 15.2 cm) containing 18 wt % residual asphalt.

  9. Application of asphalt emulsion seals to uranium mill tailings

    SciTech Connect

    Hartley, J.N.; Koehmstedt, P.L.; Esterl, D.J.; Freeman, H.D.; Clark, R.L.

    1980-11-01

    Studies of asphalt emulsion sealants have demonstrated that the sealants are effective in containing radon and other potentially hazardous material within uranium tailings. The laboratory and field studies have further demonstrated that radon exhalation from uranium tailings piles can be reduced by greater than 99% to less than background levels. Field tests at the tailings pile in Grand Junction, Colorado confirmed that an 8-cm admix seal containing 22 wt % asphalt could be effectively applied with a cold-mix paver. Other techniques were successfully tested, including a soil stabilizer and a hot, rubberized asphalt seal that was applied with a distributor truck. After the seals were applied and conpacted, overburden was applied over the seal to protect the seal from ultraviolet degradation. 14 figures.

  10. Evaluation of asphalt-rubber interlayers. (Revised). Final research report, September 1986-September 1992

    SciTech Connect

    Estakhri, C.K.; Pendleton, O.; Lytton, R.L.

    1994-02-01

    The report presents the field performance results of three asphalt-rubber interlayer test roads in terms of the effectiveness of the interlayer at reducing the rate of reflection cracking. Several variables were included in the field experiments: concentration of rubber, binder application rate, type or source of rubber, and digestion (or mixing) time of asphalt and rubber. Control sections were made up of no interlayer and interlayer binders of polymer-modified asphalt and conventional asphalt cement. Results of the statistical analyses of the data indicated that, in general, asphalt-rubber interlayers are more effective at reducing reflection cracking than no interlayer at all. Asphalt-rubber also peerformed better than control sections composed of asphalt cement interlayers and polymer-modified interlayers except in one case where the interlyaer was composed of a double application of asphalt cement/aggregate. The data also indicated that higher binder application rates lead to imnproved cracking resistance; however, on many test sections, excessively high binder application rates caused flushing at the pavement surface.

  11. Investigation of the Microstructural Mechanism of Relaxation and Fracture Healing in Asphalt

    DTIC Science & Technology

    1993-04-12

    FOR THE AIR FORCE OFFICE OF SCIENTIFIC RESEARCH FINAL REPORT GRANT NO. AFOSR-89-0520 DTIC * APRIL 12, 1993 uN 2 a 1993 TEXAS TRANSPORTATION INSTITUTE...throuqh Vibration Analysis . 114 APPROACH TO FUTURE RESEARCH ....... ..... .................. 117 MICROSTRUCTURAL FATIGUE RELATIONSHIPS...microdamage healing. This report contains one appendix entitled "Characterization of Damage Growth in Asphalt Concrete ." This appendix supports the

  12. Recycling of plastic and rubber tire waste in asphalt pavements

    SciTech Connect

    Morrison, G.R.; Lee, N.K.; Hesp, S.A.M.

    1994-12-31

    This paper discusses some important issues related to the use of recycled thermoplastics and rubber tire waste in asphalt binders for hot-mix pavements. Both high temperature rheological and low temperature fracture studies are presented on recycled polyethylene, devulcanized and crumb rubber-modified asphalt binders. The results are compared to unmodified and commercially available modified binders. This research is especially timely in light of the US Intermodal Surface Transportation Efficiency Act of 1991, Section 1038 which, starting in 1995, will force state and local governments to use significant amounts of recycled rubber tire or plastic waste in federally funded highway projects. High temperature rheological measurements of the loss modulus, loss tangent and complex modulus show a significant improvement when only small quantities of crumb rubber, devulcanized crumb rubber or waste polyethylene are added to the asphalt binders. The low temperature fracture performance of the modified asphalts is greatly influenced by the interfacial strength between the dispersed and continuous phase. The fracture toughness increases dramatically, only when low molecular weight polymers are grafted in-situ onto the rubber and polymer dispersed phases in order to strength the interface. This points to a crack-pinning mechanism as being responsible for the dramatic increase in fracture toughness that is observed in this work. Single phase, devulcanized crumb rubber-asphalt systems perform quite poorly at low temperatures.

  13. The Utilization of Graphene Oxide in Traditional Construction Materials: Asphalt.

    PubMed

    Zeng, Wenbo; Wu, Shaopeng; Pang, Ling; Sun, Yihan; Chen, Zongwu

    2017-01-07

    In the advanced research fields of solar cell and energy storing materials, graphene and graphene oxide (GO) are two of the most promising materials due to their high specific surface area, and excellent electrical and physical properties. However, they was seldom studied in the traditional materials because of their high cost. Nowadays, graphene and GO are much cheaper than before with the development of production technologies, which provides the possibility of using these extraordinary materials in the traditional construction industry. In this paper, GO was selected as a nano-material to modify two different asphalts. Then a thin film oven test and a pressure aging vessel test were applied to simulate the aging of GO-modified asphalts. After thermal aging, basic physical properties (softening point and penetration) were tested for the samples which were introduced at different mass ratios of GO (1% and 3%) to asphalt. In addition, rheological properties were tested to investigate how GO could influence the asphalts by dynamic shearing rheometer tests. Finally, some interesting findings and potential utilization (warm mixing and flame retardants) of GO in asphalt pavement construction were explained.

  14. Macro- and Micro-Mechanics of Mixed-Mode Dynamic Fracture of Concrete. Part 1. Micro-Mechanic Analysis

    DTIC Science & Technology

    1993-02-14

    fracture energy density of concrete were discussed by Hillerborg and Mindess [55-57]. The total external energy needed to quasi-statically fracture a...Composites.: Strzin Rate Effects on Fracture, eds. S. Mindess and S.P Shah, Materials Research Society Symposia Proceeding Vol. 64, 1986 18 S. Mindess ...Nijhoff Publishers, 1985, pp. 617-636. I 1 9 A. Benton, S. Mindess , and N. Benthur, "The Behavior of Concrete Under Impact Loading: Experimental

  15. Corrosion-resistant sulfur concretes

    NASA Astrophysics Data System (ADS)

    McBee, W. C.; Sullivan, T. A.; Jong, B. W.

    1983-04-01

    Sulfur concretes have been developed by the Bureau of Mines as construction materials with physical and mechanical properties that suit them for use in acid and salt corrosive environments where conventional concretes fail. Mixture design methods were established for preparing sulfur concretes using different types of aggregates and recently developed mixed-modified sulfur cements. Bench-scale testing of the sulfur concretes has shown their potential value. Corrosion resistance, strength, and durability of sulfur concrete are superior to those of conventional materials. Field in situ evaluation tests of the sulfur concretes as replacement for conventional concrete materials are in progress in corrosive areas of 24 commercial chemical, fertilizer, and metallurgical plants.

  16. Application of the endochronic theory of viscoplasticity to solid propellants and sandasphalt concrete

    NASA Technical Reports Server (NTRS)

    Peng, S. T. J.; Valanis, K. C.

    1977-01-01

    Solid propellants, sand-asphalt concrete and hard plastics showed rate sensitive mechanical behavior which, in addition, indicated that these materials have a permanent memory of the strain (or loading) path by which their present state was attained. A constitutive equation was formulated in general three dimensional tensorial form by means of irreversible thermodynamics. By using a very simple analytical form, it was shown that the mechanical behavior of solid propellants and sand-asphalt concrete can be readily described.

  17. Application of the endochronic theory of viscoplasticity to solid propellants and sandasphalt concrete

    NASA Technical Reports Server (NTRS)

    Peng, S. T. J.; Valanis, K. C.

    1977-01-01

    Solid propellants, sand-asphalt concrete and hard plastics showed rate sensitive mechanical behavior which, in addition, indicated that these materials have a permanent memory of the strain (or loading) path by which their present state was attained. A constitutive equation was formulated in general three dimensional tensorial form by means of irreversible thermodynamics. By using a very simple analytical form, it was shown that the mechanical behavior of solid propellants and sand-asphalt concrete can be readily described.

  18. Interaction nonlinearity in asphalt binders

    NASA Astrophysics Data System (ADS)

    Motamed, Arash; Bhasin, Amit; Liechti, Kenneth M.

    2012-05-01

    Asphalt mixtures are complex composites that comprise aggregate, asphalt binder, and air. Several research studies have shown that the mechanical behavior of the asphalt mixture is strongly influenced by the matrix, i.e. the asphalt binder. Characterization and a thorough understanding of the binder behavior is the first and crucial step towards developing an accurate constitutive model for the composite. Accurate constitutive models for the constituent materials are critical to ensure accurate performance predictions at a material and structural level using micromechanics. This paper presents the findings from a systematic investigation into the nature of the linear and nonlinear response of asphalt binders subjected to different types of loading using the Dynamic Shear Rheometer (DSR). Laboratory test data show that a compressive normal force is generated in an axially constrained specimen subjected to torsional shear. This paper investigates the source of this normal force and demonstrates that the asphalt binder can dilate when subjected to shear loads. This paper also presents the findings from a study conducted to investigate the source of the nonlinearity in the asphalt binder. Test results demonstrate that the application of cyclic shear loads results in the development of a normal force and a concomitant reduction in the dynamic shear modulus. This form of nonlinear response is referred to as an "interaction nonlinearity". A combination of experimental and analytical tools is used to demonstrate and verify the presence of this interaction nonlinearity in asphalt binders. The findings from this study highlight the importance of modeling the mechanical behavior of asphalt binders based on the overall stress state of the material.

  19. 75 FR 12988 - National Emission Standards for Hazardous Air Pollutants for Area Sources: Asphalt Processing and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-18

    ... Sources: Asphalt Processing and Asphalt Roofing Manufacturing; Technical Correction AGENCY: Environmental... the asphalt processing and asphalt roofing manufacturing area source category (74 FR 63236). Following... the asphalt processing and asphalt roofing manufacturing area source category on December 2, 2009 (40...

  20. Using emissivity-corrected thermal maps to locate deep structural defects in concrete bridge decks

    NASA Astrophysics Data System (ADS)

    DelGrande, Nancy; Durbin, Philip F.

    1995-05-01

    Dual-band infrared (DBIR) thermal imaging is a promising, noncontact, nondestructive evaluation tool to evaluate the amount of deteriorated concrete on asphalt-covered bridge decks. We conducted proof-of-principle demonstrations to characterize defects in concrete structures which could be detected with DBIR thermal imaging. We constructed two identical concrete slabs with synthetic delaminations, e.g., 1.8-in. thick styrofoam squares, implanted just above the 2-in. deep steel reinforcement bars. We covered one of the slabs with a 2-in. layer of asphalt. We mounted the DBIR cameras on a tower platform, to simulate the optics needed to conduct bridge-deck inspections from a moving vehicle. We detected 4-in. implants embedded in concrete and 9-in. implants embedded in asphalt-cevered concrete. The midday (above ambient) and predawn (below ambient) delamination-site temperatures correlated with the implant sizes. Using DBIR image ratios, we enhanced thermal-constrast and removed emissivity-noise, e.g., from concrete compositional variations and clutter. Using the LLNL/VIEW code, we removed the asphalt thermal-gradient mask to depict the 4-in. deep, 9- in. square, concrete implant site. We plan to image bridge deck defects from a moving vehicle for accurate estimations of the amount of deteriorated concrete impairing the deck integrity. Potential longterm benefits are affordable and reliable rehabilitation for asphalt-covered decks.

  1. Using emissivity-corrected thermal maps to locate deep structural defects in concrete bridge decks

    SciTech Connect

    Del Grande, N.K.; Durbin, P.F.

    1995-04-05

    Dual-band infrared (DBIR) thermal imaging is a promising, non-contact, nondestructive evaluation tool to evaluate the amount of deteriorated concrete on asphalt-covered bridge decks. We conducted proof-of-principle demonstrations to characterize defects in concrete structures which could be detected with DBIR thermal imaging. We constructed two identical concrete slabs with synthetic delaminations, e.g., 1/8-in. thick styrofoam squares, implanted just above the 2-in.-deep steel reinforcement bars. We covered one of the slabs with a 2-in. layer of asphalt. We mounted the DBIR cameras on a tower platform, to simulate the optics needed to conduct bridge-deck inspections from a moving vehicle. We detected 4-in. implants embedded in concrete and 9-in. implants embedded in asphalt-covered concrete. The midday (above-ambient) and predawn (below-ambient) delamination-site temperatures correlated with the implant sizes. Using DBIR image ratios, we enhanced thermal-contrast and removed emissivity-noise, e.g., from concrete compositional variations and clutter. Using the LLNL/VIEW code, we removed the asphalt thermal-gradient mask, to depict the 4-in. deep, 9-in. square, concrete implant size. We plan to image bridge deck defects, from a moving vehicle, for accurate estimations of the amount of deteriorated concrete impairing the deck integrity. Potential longterm benefits are affordable and reliable rehabilitation for asphalt-covered decks.

  2. The Potential of Heat Collection from Solar Radiation in Asphalt Solar Collectors in Malaysia

    NASA Astrophysics Data System (ADS)

    Beddu, Salmia; Talib, Siti Hidayah Abdul; Itam, Zarina

    2016-03-01

    The implementation of asphalt solar collectors as a means of an energy source is being widely studied in recent years. Asphalt pavements are exposed to daily solar radiation, and are capable of reaching up to 70°C in temperature. The potential of harvesting energy from solar pavements as an alternative energy source in replace of non-renewable energy sources prone to depletion such as fuel is promising. In Malaysia, the sun intensity is quite high and for this reason, absorbing the heat from sun radiation, and then utilizing it in many other applications such as generating electricity could definitely be impressive. Previous researches on the different methods of studying the effect of heat absorption caused by solar radiation prove to be quite old and inaffective. More recent findings, on the otherhand, prove to be more informative. This paper focuses on determining the potential of heat collection from solar radiation in asphalt solar collectors using steel piping. The asphalt solar collector model constructed for this research was prepared in the civil engineering laboratory. The hot mixed asphalt (HMA) contains 10% bitumen mixed with 90% aggregates of the total size of asphalt. Three stainless steel pipes were embedded into the interior region of the model according to the design criteria, and then put to test. Results show that harvesting energy from asphalt solar collectors proves highly potential in Malaysia due its the hot climate.

  3. Greenhouse Gas Emissions from Asphalt Pavement Construction: A Case Study in China

    PubMed Central

    Ma, Feng; Sha, Aimin; Lin, Ruiyu; Huang, Yue; Wang, Chao

    2016-01-01

    In China, the construction of asphalt pavement has a significant impact on the environment, and energy use and greenhouse gas (GHG) emissions from asphalt pavement construction have been receiving increasing attention in recent years. At present, there is no universal criterion for the evaluation of GHG emissions in asphalt pavement construction. This paper proposes to define the system boundaries for GHG emissions from asphalt pavement by using a process-based life cycle assessment method. A method for evaluating GHG emissions from asphalt pavement construction is suggested. The paper reports a case study of GHG emissions from a typical asphalt pavement construction project in China. The results show that the greenhouse gas emissions from the mixture mixing phase are the highest, and account for about 54% of the total amount. The second highest GHG emission phase is the production of raw materials. For GHG emissions of cement stabilized base/subbase, the production of raw materials emits the most, about 98%. The GHG emission for cement production alone is about 92%. The results indicate that any measures to reduce GHG emissions from asphalt pavement construction should be focused on the raw materials manufacturing stage. If the raw materials production phase is excluded, the measures to reduce GHG emissions should be aimed at the mixture mixing phase. PMID:27011196

  4. Greenhouse Gas Emissions from Asphalt Pavement Construction: A Case Study in China.

    PubMed

    Ma, Feng; Sha, Aimin; Lin, Ruiyu; Huang, Yue; Wang, Chao

    2016-03-22

    In China, the construction of asphalt pavement has a significant impact on the environment, and energy use and greenhouse gas (GHG) emissions from asphalt pavement construction have been receiving increasing attention in recent years. At present, there is no universal criterion for the evaluation of GHG emissions in asphalt pavement construction. This paper proposes to define the system boundaries for GHG emissions from asphalt pavement by using a process-based life cycle assessment method. A method for evaluating GHG emissions from asphalt pavement construction is suggested. The paper reports a case study of GHG emissions from a typical asphalt pavement construction project in China. The results show that the greenhouse gas emissions from the mixture mixing phase are the highest, and account for about 54% of the total amount. The second highest GHG emission phase is the production of raw materials. For GHG emissions of cement stabilized base/subbase, the production of raw materials emits the most, about 98%. The GHG emission for cement production alone is about 92%. The results indicate that any measures to reduce GHG emissions from asphalt pavement construction should be focused on the raw materials manufacturing stage. If the raw materials production phase is excluded, the measures to reduce GHG emissions should be aimed at the mixture mixing phase.

  5. Ultrasound data for laboratory calibration of an analytical model to calculate crack depth on asphalt pavements.

    PubMed

    Franesqui, Miguel A; Yepes, Jorge; García-González, Cándida

    2017-08-01

    This article outlines the ultrasound data employed to calibrate in the laboratory an analytical model that permits the calculation of the depth of partial-depth surface-initiated cracks on bituminous pavements using this non-destructive technique. This initial calibration is required so that the model provides sufficient precision during practical application. The ultrasonic pulse transit times were measured on beam samples of different asphalt mixtures (semi-dense asphalt concrete AC-S; asphalt concrete for very thin layers BBTM; and porous asphalt PA). The cracks on the laboratory samples were simulated by means of notches of variable depths. With the data of ultrasound transmission time ratios, curve-fittings were carried out on the analytical model, thus determining the regression parameters and their statistical dispersion. The calibrated models obtained from laboratory datasets were subsequently applied to auscultate the evolution of the crack depth after microwaves exposure in the research article entitled "Top-down cracking self-healing of asphalt pavements with steel filler from industrial waste applying microwaves" (Franesqui et al., 2017) [1].

  6. Bettis Asphalt and Construction, Inc.

    EPA Pesticide Factsheets

    The EPA is providing notice of a proposed Administrative Penalty Assessment against Bettis Asphalt and Construction, Inc. for alleged violations at its facility located at 2350 Northwest Water Works Drive, Topeka, Kansas 66606.

  7. Airborne Exposures to Polycyclic Aromatic Compounds Among Workers in Asphalt Roofing Manufacturing Facilities.

    PubMed

    Trumbore, David C; Osborn, Linda V; Johnson, Kathleen A; Fayerweather, William E

    2015-01-01

    We studied exposure of 151 workers to polycyclic aromatic compounds and asphalt emissions during the manufacturing of asphalt roofing products-including 64 workers from 10 asphalt plants producing oxidized, straight-run, cutback, and wax- or polymer-modified asphalts, and 87 workers from 11 roofing plants producing asphalt shingles and granulated roll roofing. The facilities were located throughout the United States and used asphalt from many refiners and crude oils. This article helps fill a gap in exposure data for asphalt roofing manufacturing workers by using a fluorescence technique that targets biologically active 4-6 ring polycyclic aromatic compounds and is strongly correlated with carcinogenic activity in animal studies. Worker exposures to polycyclic aromatic compounds were compared between manufacturing plants, at different temperatures and using different raw materials, and to important external benchmarks. High levels of fine limestone particulate in the plant air during roofing manufacturing increased polycyclic aromatic compound exposure, resulting in the hypothesis that the particulate brought adsorbed polycyclic aromatic compounds to the worker breathing zone. Elevated asphalt temperatures increased exposures during the pouring of asphalt. Co-exposures in these workplaces which act as confounders for both the measurement of total organic matter and fluorescence were detected and their influence discussed. Exposures to polycyclic aromatic compounds in asphalt roofing manufacturing facilities were lower than or similar to those reported in hot-mix paving application studies, and much below those reported in studies of hot application of built-up roofing asphalt. These relatively low exposures in manufacturing are primarily attributed to air emission controls in the facilities, and the relatively moderate temperatures, compared to built-up roofing, used in these facilities for oxidized asphalt. The exposure to polycyclic aromatic compounds was a very

  8. Building a Concrete Foundation: A Mixed-Method Study of Teaching Styles and the Use of Concrete, Representational, and Abstract Mathematics Instruction

    ERIC Educational Resources Information Center

    Thigpen, L. Christine

    2012-01-01

    The purpose of this study was to explore teaching styles and how frequently teachers with a variety of teaching styles incorporate multiple representations, such as manipulatives, drawings, counters, etc., in the middle school mathematics classroom. Through this explanatory mixed methods study it was possible to collect the quantitative data in…

  9. Evaluation of a biomass-derived oil for use as additive in paving asphalt

    SciTech Connect

    Houde, J. Jr.; Clelland, I.; Sawatzky, H.

    1995-12-31

    A biomass derived oil referred to as sludge derived oil (SDO) has been evaluated to determine its potential use as an asphalt cement additive. The oil is derived from a relatively low temperature (450{degrees}C) atmospheric pressure thermoconversion process called Enersludge. The Enersludge process converts dried sewage sludge to a liquid hydrocarbon fraction. Relatively high concentrations of polar groups were identified in extensive characterization tests which indicated SDO could be utilized as an additive for asphalt. The oil`s unique properties make it a antistripping additive. Also, its strong affinity for heavy asphaltic material makes it an ideal rejuvenating agent for recycled asphalt. The SDO performed as well as the commercial antistripping asphalt additives tested in static immersion stripping tests. Laboratory-scale tests have shown that the strength of asphalt concrete produced using SDO is similar to that produced using commercial additives. In September 1994 SDO was used to pave a test strip in Quebec, Canada. This paper describes the work done at ERL/CANMET to develop SDO for antistripping applications.

  10. Feasibility of crumb rubber use for asphalt pavement construction in Rhode Island. Final research report

    SciTech Connect

    Lee, K.W.; Kovacs, W.D.; Marcus, A.S.; Madapati, R.R.

    1995-12-15

    This is the final report of the research project, entitled `Viable Use of Crumb Rubber for Highway Construction in Rhode Island.` This study dealt with the investigation of the means by which the State of Rhode Island can effectively comply with the mandate of the Section 1038 of the 1991 Intermodal Surface Transportation Efficiency Act (ISTEA) to use recycled rubber in asphalt pavements. More specifically, this laboratory investigation characterized Hot Mix Asphalt (HMA) with Crumb Rubber Modifiers (CRM).

  11. Stormwater quality of spring-summer-fall effluent from three partial-infiltration permeable pavement systems and conventional asphalt pavement.

    PubMed

    Drake, Jennifer; Bradford, Andrea; Van Seters, Tim

    2014-06-15

    This study examined the spring, summer and fall water quality performance of three partial-infiltration permeable pavement (PP) systems and a conventional asphalt pavement in Ontario. The study, conducted between 2010 and 2012, compared the water quality of effluent from two Interlocking Permeable Concrete Pavements (AquaPave(®) and Eco-Optiloc(®)) and a Hydromedia(®) Pervious Concrete pavement with runoff from an Asphalt control pavement. The usage of permeable pavements can mitigate the impact of urbanization on receiving surface water systems through quantity control and stormwater treatment. The PP systems provided excellent stormwater treatment for petroleum hydrocarbons, total suspended solids, metals (copper, iron, manganese and zinc) and nutrients (total-nitrogen and total-phosphorus) by reducing event mean concentrations (EMC) as well as total pollutant loadings. The PPs significantly reduced the concentration and loading of ammonia (NH4(+)+NH3), nitrite (NO2(-)) and organic-nitrogen (Org-N) but increased the concentration and loading of nitrate (NO3(-)). The PP systems had mixed performances for the treatment of phosphate (PO4(3-)). The PP systems increased the concentration of sodium (Na) and chloride (Cl) but EMCs remained well below recommended levels for drinking water quality. Relative to the observed runoff, winter road salt was released more slowly from the PP systems resulting in elevated spring and early-summer Cl and Na concentrations in effluent. PP materials were found to introduce dissolved solids into the infiltrating stormwater. The release of these pollutants was verified by additional laboratory scale testing of the individual pavement and aggregate materials at the University of Guelph. Pollutant concentrations were greatest during the first few months after construction and declined rapidly over the course of the study.

  12. Effect of new type of synthetic waxes on reduced production and compaction temperature of asphalt mixture with reclaimed asphalt

    NASA Astrophysics Data System (ADS)

    Valentová, Tereza; Benešová, Lucie; Mastný, Jan; Valentin, Jan

    2017-09-01

    Lower mixing and paving temperatures of asphalt mixtures, which are an important issue in recent years, with respect to increased energy demand of civil engineering structures during their processing, allow reduction of this demand and result in minimized greenhouse gas production. In present time, there are many possibilities how to achieve reduction of production temperature during the mixing and paving of an asphalt mixture. The existing solutions distinguish in target operating temperature behaviour which has to be achieved in terms of good workability. This paper is focused on technical solutions based on use of new types of selected synthetic and bio-based waxes. In case of bio-based additive sugar cane wax was used, which is free of paraffins and is reclaimed as waste product during processing of sugar cane. The used waxes are added to bituminous binder in form of free-flowing granules or fine-grained powder. Synthetic waxes are represented by new series of Fischer-Tropsch wax in form of fine granules as well as by polyethylene waxes in form of fine-grained powder or granules. Those waxes were used to modify a standard paving grade bitumen dosed into asphalt mixture of ACsurf type containing up to 30 % of reclaimed asphalt (RA).

  13. Mixing and compaction temperatures for Superpave mixes

    NASA Astrophysics Data System (ADS)

    Yildirim, Yetkin

    According to Superpave mixture design, gyratory specimens are mixed and compacted at equiviscous binder temperatures corresponding to viscosities of 0.17 and 0.28 Pa.s. respectively. These were the values previously used in the Marshal mix design method to determine optimal mixing and compaction temperatures. In order to estimate the appropriate mixing and compaction temperatures for Superpave mixture design, a temperature-viscosity relationship for the binder needs to be developed (ASTM D 2493, Calculation of Mixing and Compaction Temperatures). The current approach is simple and provides reasonable temperatures for unmodified binders. However, some modified binders have exhibited unreasonably high temperatures for mixing and compaction using this technique. These high temperatures can result in construction problems, damage of asphalt, and production of fumes. Heating asphalt binder to very high temperatures during construction oxidizes the binder and separates the polymer from asphalt binder. It is known that polymer modified asphalt binders have many benefits to the roads, such as; increasing rutting resistance, enhancing low temperature cracking resistance, improving traction, better adhesion and cohesion, elevating tensile strength which are directly related to the service life of the pavement. Therefore, oxidation and separation of the polymer from the asphalt binder results in reduction of the service life. ASTM D 2493 was established for unmodified asphalt binders which are Newtonian fluids at high temperatures. For these materials, viscosity does not depend on shear rate. However, most of the modified asphalt binders exhibit a phenomenon known as pseudoplasticity, where viscosity does depend on shear rate. Thus, at the high shear rates occurring during mixing and compaction, it is not necessary to go to very high temperatures. This research was undertaken to determine the shear rate during compaction such that the effect of this parameter could be

  14. Viscosity function in polymer-modified asphalts.

    PubMed

    Stastna, J; Zanzotto, L; Vacin, O J

    2003-03-01

    Asphalt is a multidisperse micellar system with rheological behavior resembling that of a low-molecular-weight polymer. Nowadays, asphalt is frequently modified by blending it with various polymers. Such modified asphalt has rheological properties that differ from the properties of the base asphalt. It is quite common to study asphalt in dynamic experiments. Such studies, however useful, cannot reveal all characteristic features of polymer-modified asphalts. Asphalt modification by polymers is strongly manifested in the region of transitions from a viscoelastic fluid to the Newtonian fluid. The viscosity study in this region can reveal behavior characteristic of the used polymer modifier, thus complementing the dynamic studies of these materials. The viscosity of base asphalt modified by styrene-butadiene-styrene and by ethylene-vinyl acetate polymers (in several concentrations) is studied and discussed in this note.

  15. User’s Guide: Cracking and Seating of Portland Cement Concrete Pavements

    DTIC Science & Technology

    1992-08-01

    Concrete Pavements 6. AUTHOR(S) Randy C. Ahlrich 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) 8. PERFORMING ORGANIZATION REPORT NUMBER USAE...OF PAGES Asphalt concrete Maintenance 29 Concrete Repair 16. PRICE CODE Cracking Seating OF REPORT OF THIS PAGE d OF ABSTRACT Unclassified Unclassified...Seated Concrete ," Transportation Research Record 1215, Washington, DC. Ahlrich, R. C. and Godwin, L. N. 1991. "Cracking and Seating of PCC Pavements

  16. Comparison of the performances of several modified bituminous mix formulas

    NASA Astrophysics Data System (ADS)

    Saoula, Samia; Haddadi, Smail; Mokhtar, Khedidja Ait

    2012-09-01

    The mechanical behaviour of several formulas of bituminous concrete containing polymer (HDPE), polymer-bitumens (EVA) and waste of sole of shoes (containing copolymer butadiene-styrene-SBR noted DSBR and ethylene and vinyl acetate-EVA noted DEVA) were studied. The aim of this work is to improvement of the poor mechanicals performances of a bituminous concrete formula (0/14) which isn't conforming to the Algerian standards. Also, the mechanical tests showed that the permanent deformations and the indirect tensile strength at the temperatures of service resistances are improved. At high-temperature service, formulas of asphalt bitumen-EVA most resistant against the average temperature in service, it mixes made with waste are best resistant. All the formulas have a good behaviour with water.

  17. Incorporation de particules de bardeaux d'asphalte de postconsommation dans les enrobes bitumineux

    NASA Astrophysics Data System (ADS)

    Malo, Jean-Michel

    Every year, more than 200 000 tons of used residential roofing asphalt shingles are sent to landfills in Quebec. In order to reduce this amount, a research project funded by the 3RMCDQ and RECYC-QUÉBEC is ongoing at the LCMB at École de technologie supérieure (ÉTS) in Montreal. This project studies the feasibility of incorporating tear-off shingles particles in hot mix asphalt which could be used on Quebec roads. Currently, in Quebec, the ministry of Transportation (MTQ), allows the use of 5% of new asphalt shingles (factory reject) in the base course and 3% in the surface course, and tear-off shingles are not allowed. Incorporating new shingles particles is valued notably by the MTQ standardization for a reduction of binder in these mixes. As of now, the MTQ does not have a standard on the use of tear-off shingles, but the subject of experimental boards. The research done at ETS aim to characterize a standard base mix, GB20, and a standard surface mix, ESG-10, that contains tear-off shingles. Mixes containing different percentage of virgin binder were fabricated then tested on compaction capacity, on rutting resistance, on thermal cracking resistance (TSRST) and on complex modulus (E*). The amount of Virgin binder is calculated according to different percentage of effective binder from the shingles. This study has permitted to identify an optimal formula for both types of hot mix asphalt that were tested. Results show that for the standard ESG-10 surface mix, the possible contribution of tear-off asphalt shingles would be about 20%. For the standard GB-20 base mix, no reduction in the virgin binder may be considered for now when 5% of tear-off asphalt shingles are incorporated in the formula mix. In this case, further testing on complex modulus are recommended to obtain meaningful results that will determine if a reduction of the virgin binder would not be favorable.

  18. [PAH exposure in asphalt workers].

    PubMed

    Garattini, Siria; Sarnico, Michela; Benvenuti, Alessandra; Barbieri, P G

    2010-01-01

    There has been interest in evaluating the potential carcinogenicity of bitumen fumes in asphalt workers since the 1960's. The IARC classified air-refined bitumens as possible human carcinogens, while coal-tar fumes were classified as known carcinogens. Occupational/environmental PAH exposure can be measured by several urinary markers. Urinary 1-OHP has become the most commonly used biological marker of PAH exposure in asphalt workers. The aim of this study was to assess asphalt workers' exposure levels by monitoring 1-OHP urinary excretion and compare this data with those of non-occupationally exposed subjects. We investigated three groups of asphalt workers: 100 in summer 2007, 29 in winter 2007, and 148 during summer 2008 and compared 1-OHP urinary concentrations using Kruskall-Wallis test. Median 1-OHP urinary concentrations during the three biomonitoring sampling periods were 0.65, 0.17 and 0.53 microg/g creatinine respectively. There was a significant difference in 1-OHP values between the three groups (p < 0.001). our study showed that PAH exposure of asphalt workers' is higher than that observed in the general population and in workers in urban areas. Our results suggest that PAH exposure in the three groups studied is not sufficiently kept under control by the use of personal protective equipment and that biomonitoring is useful in evaluating PAH exposure and for risk assessment. Regulations need to be enforced for workers exposed to cancer risk, such as the register of workers exposed to carcinogens.

  19. Inherent Control - Hot-Mix Asphalt Industry

    EPA Pesticide Factsheets

    This document may be of assistance in applying the New Source Review (NSR) air permitting regulations including the Prevention of Significant Deterioration (PSD) requirements. This document is part of the NSR Policy and Guidance Database. Some documents in the database are a scanned or retyped version of a paper photocopy of the original. Although we have taken considerable effort to quality assure the documents, some may contain typographical errors. Contact the office that issued the document if you need a copy of the original.

  20. Research on the Technology Applying Anti-Rutting Additive to Asphalt Mixture

    NASA Astrophysics Data System (ADS)

    Sun, Jie; Huang, Liming; Li, Chun

    High-temperature problems like rutting, displacement and upheaval are the most serious ones for bituminous pavement of urban roads. Especially, such problems at crossroads and fixed places where buses stop, for instance, BRT, affect service ability and life of roads largely. Application of anti-rutting asphalt mixture mainly aims at reducing strain and deformation generated by bituminous concrete under effect of vehicle load, decreasing remainders that cannot be recovered in deformation, improving the ability of bituminous pavement to resist deformation under high temperature and delaying generation of rutting. Anti-rutting asphalt mixture in this thesis refers to the asphalt mixture where anti-rutting additive is added by dry method and high-temperature stability is improved.

  1. Field Performance of Asphalt Pavements with New Technologies in Northern Nevada

    NASA Astrophysics Data System (ADS)

    Faeth, Benjamin Michael

    The Regional Transportation Commission (RTC) of the Washoe Valley Area has been tasked to determine if three advanced asphalt pavement technologies and one modified aggregate gradation are suitable for implementation within Reno, Stead, and Sparks Nevada. This was accomplished through research and test roads and Intersections to determine if Recycled Asphalt Pavement (RAP), Warm Mix Asphalt (WMA), Polymer-Modified Asphalt Binder, and the Type 2-R aggregate gradation were succeeding in their design plans. Over the course of several years the streets being used by RTC to test the technologies are succeeding within their design lifespans, and the Intersections being used to test the Type 2-R aggregate gradation are showing significant resistance to rutting. Due to the roads and Intersections not being more than 10 years old, these conclusions are subject to change over time.

  2. Contributions of performance-graded asphalt to low temperature cracking resistance of pavements. Final report

    SciTech Connect

    Loh, S.W.; Olek, J.

    1999-05-01

    The purpose of this research was to study and evaluate the role that asphalt cracking. As part of the Strategic Highway Research Program (SHRP) new specifications for asphalt binders were developed that are based on the performance of the material. The asphalt binder graded and specified according to these new performance-based specifications is called PG binder. These new specifications are commonly referred to as Superpave (Superior Performing Asphalt Pavement) binder specifications. A section of Interstate 64 in southern Indiana was experiencing severe low temperature cracking before it was reconstructed over the summers of 1995 and 1996. The binder used in the new pavement mixes was PG material. Dynamic Shear Rheometer (DSR) tests, Bending Beam Rheometer (BBR) tests, and viscosity tests were performed on this binder. Comparisons were made between test results obtained from the binders in the old pavement and the new pavement. All tests and comparisons were based on the Superpave binder specifications.

  3. A review on using crumb rubber in reinforcement of asphalt pavement.

    PubMed

    Mashaan, Nuha Salim; Ali, Asim Hassan; Karim, Mohamed Rehan; Abdelaziz, Mahrez

    2014-01-01

    An immense problem affecting environmental pollution is the increase of waste tyre vehicles. In an attempt to decrease the magnitude of this issue, crumb rubber modifier (CRM) obtained from waste tyre rubber has gained interest in asphalt reinforcement. The use of crumb rubber in the reinforcement of asphalt is considered as a smart solution for sustainable development by reusing waste materials, and it is believed that crumb rubber modifier (CRM) could be an alternative polymer material in improving hot mix asphalt performance properties. In this paper, a critical review on the use of crumb rubber in reinforcement of asphalt pavement will be presented and discussed. It will also include a review on the effects of CRM on the stiffness, rutting, and fatigue resistance of road pavement construction.

  4. A Review on Using Crumb Rubber in Reinforcement of Asphalt Pavement

    PubMed Central

    Mashaan, Nuha Salim; Ali, Asim Hassan; Karim, Mohamed Rehan; Abdelaziz, Mahrez

    2014-01-01

    An immense problem affecting environmental pollution is the increase of waste tyre vehicles. In an attempt to decrease the magnitude of this issue, crumb rubber modifier (CRM) obtained from waste tyre rubber has gained interest in asphalt reinforcement. The use of crumb rubber in the reinforcement of asphalt is considered as a smart solution for sustainable development by reusing waste materials, and it is believed that crumb rubber modifier (CRM) could be an alternative polymer material in improving hot mix asphalt performance properties. In this paper, a critical review on the use of crumb rubber in reinforcement of asphalt pavement will be presented and discussed. It will also include a review on the effects of CRM on the stiffness, rutting, and fatigue resistance of road pavement construction. PMID:24688369

  5. Development of superior asphalt recycling agency: Phase 1, Technical feasibility. Technical progress report

    SciTech Connect

    Bullin, J.A.; Glover, C.J.; Davison, R.R.; Lin, Moon-Sun; Chaffin, J.; Liu, Meng; Eckhardt, C.

    1996-04-01

    About every 12 years, asphalt roads must be reworked, and this is usually done by placing thick layers (hot-mix overlays) of new material on top of failed material, resulting in considerable waste of material and use of new asphalt binder. A good recycling agent is needed, not only to reduce the viscosity of the aged material but also to restore compatibility. Objective is to establish the technical feasibility (Phase I) of determining the specifications and operating parameters for producing high quality recycling agents which will allow most/all the old asphalt-based road material to be recycled. It is expected that supercritical fractionation can be used. The advanced road aging simulation procedure will be used to study aging of blends of old asphalt and recycling agents.

  6. Construction of an experimental sulfur-extended-asphalt pavement

    NASA Astrophysics Data System (ADS)

    Dodge, K. S.

    1982-07-01

    The design, placement and collection of initial data from a sulfur extended asphalt (SEA) pavement and a conventional pavement used as a control is documented. The SEA pavement used 30 percent sulfur by total weight of the binder. Mix temperatures, hot bin gradations, and toxic emissions were monitored at the plant and the site throughout placement. Aggregates were collected from the hot bin during production of the control and SEA mixes for use in a Marshall mix design. Cores were extracted from both SEA and control pavements 1 month after placement for laboratory testing. Pavement surface properties were also examined after 1 month of service.

  7. Physical and environmental properties of asphalt mixtures containing incinerator bottom ash.

    PubMed

    Huang, Chin-Ming; Chiu, Chui-Te; Li, Kung-Cheh; Yang, Wan-Fa

    2006-10-11

    This paper presents parts of the results from a research project sponsored by Taiwan Environmental Protection Administration (TEPA), investigating both the physical and environmental properties of asphalt mixtures using different amount of incinerator bottom ash (IBA) as fine aggregate substitution. The Marshall mix design method was used to determine the design asphalt content and evaluate the potential performance of these IBA-asphalt mixtures. Water sensitivity and wheel track rutting were also performed on these mixtures. Leachates, from both laboratory and outdoor leaching tests, were performed to measure the concentration of selected heavy metals and the level of daphnia toxicity. While with adequate Marshall stability, the IBA-asphalt mixtures were shown to have excessively high Marshall flow and excessively low VMA (voids in the mineral aggregate). The results of the wheel tracking tests also indicated that the IBA-asphalt mixtures had low rutting resistance. The results of the water sensitivity test according to procedure of AASHTO T283 method showed that the IBA-asphalt mixtures had a higher tensile strength ratio (TSR) as compared with the conventional asphalt mixtures. Considering the environmental aspects, outdoor leaching tests showed that IBA had a high level of daphnia toxicity. From an ecological perspective, IBA could be identified as hazardous waste in Taiwan. However, after being mixed with asphalt binder, the concentration of heavy metals and the levels of daphnia toxicity were significantly reduced. The leachates of 10-day flat plate leaching tests on Marshall specimens containing IBA indicated that the heavy metal were undetectable and the daphnia toxicity was ineffective.

  8. Overlays for plain jointed concrete pavements

    NASA Astrophysics Data System (ADS)

    Gulden, W.; Brown, D.

    1984-09-01

    This report describes the construction and performance of 4 concrete and 16 asphalt overlay test sections after nine years of traffic. The test sections were placed on I-85 which carries a substantial number of heavy trucks to determine what treatments and overlay type and thickness would give acceptable performance. The concrete overlay sections were placed in 1975 and consisted of 3 inch, 4 1/2 inch, and 6 inch CRC and 6 inch jointed PCC with 15 ft. and 30 ft. joint spacing. The asphalt sections were placed in 1976 with the variables being overlay thickness of 2 inches, 4 inches, and 6 inches and the placement of two geotextiles and strips of a waterproofing membrane for each overlay thickness. An Arkansas base test section was also included in the experiment.

  9. Development of asphalts and pavements using recycled tire rubber. Phase 1, Technical feasibility. Technical progress report, September 1, 1994--August 31, 1995

    SciTech Connect

    Bullin, J.A.; Davison, R.R.; Glover, C.J.

    1996-06-01

    About 285 million tires are discarded every year; less than 100 million are currently being recycled, with the rest being placed in landfills and other waste sites. A solution to reduce the littering of the environment is to use ground tire rubber in road construction. Currently, about 27 million tons of asphalt are used each year in road construction and maintenance of the country`s 2 million miles of roads. If all of the waste tire rubber could be combined with asphalt in road construction, it would displace less than 6% of the total asphalt used each year, yet could save about 60 trillion Btus annually. Purpose of this project is to provide data needed to optimize the performance of rubber-asphalt concretes. The first phase is to develop asphalts and recycling agents tailored for compatibility with ground tire rubber. Chapter 2 presents results on Laboratory Testing and Evaluation: fractionate asphalt material, reblending for aromatic asphalts, verifying optimal curing parameters, aging of blends, and measuring ductilities of asphalt-rubber binders. Chapter 3 focuses on Evaluating Mixture Characteristics (modified binders). Chapter 4 covers Adhesion Test Development (water susceptibility is also covered). The final chapter focuses on the Performance/Economic Update and Commercialization Plan.

  10. Construction Productivity Advancement Research (CPAR) Program

    DTIC Science & Technology

    1992-12-01

    Friction Courses." 14. SUBJECT TERMS 15 NUMBIR OF PAGES Asphalt concrete Pavement cons t rluc ti ion 2: Asphalt modifiers Pavement design 16 PRICE...Binders MIX DESIGN 9 Comparison Of Mix Design Methods For Asphalt-Rubber Concrete Mixtures Asphalt-Rubber Open-Graded Friction Courses 0 DENSE GRADED...Asphalt And Asphalt-Rubber Concrete 16 CONCLUSIONS 17 List of Tables Table 1 Mix Binder Contents 13 List of Figures Figure 1 Absolute and Brookfield

  11. Flame retarded asphalt blend composition

    SciTech Connect

    Walters, R.B.

    1987-04-21

    This patent describes a flame retarded asphalt composition consisting essentially of a blend of: (a) thermoplastic elastomer modified bitumen; (b) 20-30 wt % inert filler; (c) 1-20 wt % of at least one halogenated flame retardant; and (d) 1-5 wt % of at least one inorganic phosphorus containing compound selected from the group consisting of ammonium phosphate compounds and red phosphorus.

  12. Determination of Specific Heat Capacity on Composite Shape-Stabilized Phase Change Materials and Asphalt Mixtures by Heat Exchange System.

    PubMed

    Ma, Biao; Zhou, Xue-Yan; Liu, Jiang; You, Zhanping; Wei, Kun; Huang, Xiao-Feng

    2016-05-19

    Previous research has shown that composite shape-stabilized phase change material (CPCM) has a remarkable capacity for thermal storage and stabilization, and it can be directly applied to highway construction without leakage. However, recent studies on temperature changing behaviors of CPCM and asphalt mixture cannot intuitively reflect the thermoregulation mechanism and efficiency of CPCM on asphalt mixture. The objective of this paper is to determine the specific heat capacity of CPCM and asphalt mixtures mixed with CPCM using the heat exchange system and the data acquisition system. Studies have shown that the temperature-rise curve of 5 °C CPCM has an obvious temperature plateau, while an asphalt mixture mixed with 5 °C CPCM does not; with increasing temperature, the specific heat capacities of both 5 °C CPCM and asphalt mixture first increase and then decrease, while the variation rate of 5 °C CPCM is larger than that of the asphalt mixture, and the maximum specific heat capacity of 5 °C CPCM appears around the initial phase change temperature. It is concluded that the temperature intervals of 5 °C CPCM are -18 °C-7 °C, 7 °C-25 °C and 25 °C-44 °C, respectively, and that of the asphalt mixture are -18 °C~10 °C, -10 °C~5 °C and 5 °C~28 °C. A low dosage of 5 °C CPCM has little influence on the specific heat capacity of asphalt mixture. Finally, the functions of specific heat capacities and temperature for CPCM and asphalt mixture mixed with CPCM were recommended by the sectional regression method.

  13. Determination of Specific Heat Capacity on Composite Shape-Stabilized Phase Change Materials and Asphalt Mixtures by Heat Exchange System

    PubMed Central

    Ma, Biao; Zhou, Xue-yan; Liu, Jiang; You, Zhanping; Wei, Kun; Huang, Xiao-feng

    2016-01-01

    Previous research has shown that composite shape-stabilized phase change material (CPCM) has a remarkable capacity for thermal storage and stabilization, and it can be directly applied to highway construction without leakage. However, recent studies on temperature changing behaviors of CPCM and asphalt mixture cannot intuitively reflect the thermoregulation mechanism and efficiency of CPCM on asphalt mixture. The objective of this paper is to determine the specific heat capacity of CPCM and asphalt mixtures mixed with CPCM using the heat exchange system and the data acquisition system. Studies have shown that the temperature-rise curve of 5 °C CPCM has an obvious temperature plateau, while an asphalt mixture mixed with 5 °C CPCM does not; with increasing temperature, the specific heat capacities of both 5 °C CPCM and asphalt mixture first increase and then decrease, while the variation rate of 5 °C CPCM is larger than that of the asphalt mixture, and the maximum specific heat capacity of 5 °C CPCM appears around the initial phase change temperature. It is concluded that the temperature intervals of 5 °C CPCM are −18 °C–7 °C, 7 °C–25 °C and 25 °C–44 °C, respectively, and that of the asphalt mixture are −18 °C~10 °C, −10 °C~5 °C and 5 °C~28 °C. A low dosage of 5 °C CPCM has little influence on the specific heat capacity of asphalt mixture. Finally, the functions of specific heat capacities and temperature for CPCM and asphalt mixture mixed with CPCM were recommended by the sectional regression method. PMID:28773510

  14. Performance of Waterless Concrete

    NASA Technical Reports Server (NTRS)

    Toutanji, Houssam; Evans, Steve; Grugel, Richard N.

    2010-01-01

    The development of permanent lunar bases is constrained by performance of construction materials and availability of in-situ resources. Concrete seems a suitable construction material for the lunar environment, but water, one of its major components, is an extremely scarce resource on the Moon. This study explores an alternative to hydraulic concrete by replacing the binding mix of concrete (cement and water) with sulfur. Sulfur is a volatile element on the lunar surface that can be extracted from lunar soils by heating. Sulfur concrete mixes were prepared to investigate the effect of extreme environmental conditions on the properties of sulfur concrete. A hypervelocity impact test was conducted, having as its target a 5-cm cubic sample of sulfur concrete. This item consisted of JSC-1 lunar regolith simulant (65%) and sulfur (35%). The sample was placed in the MSFC Impact Test Facility s Micro Light Gas Gun target chamber, and was struck by a 1-mm diameter (1.4e-03 g) aluminum projectile at 5.85 km/s. In addition, HZTERN code, provided by NASA was used to study the effectiveness of sulfur concrete when subjected to space radiation.

  15. A laboratory investigation on the use of framed asphalt for recycled bituminous pavements

    NASA Astrophysics Data System (ADS)

    Brennan, M.

    1981-03-01

    The foaming characteristics of a selection of asphalts commonly used in construction in Indiana were recorded in terms of expansion ratio and half life. The performance of three of these asphalts as binders for a recycled bituminous paving mixture was evaluated using: (1) the Gyratory and the Marshall Compactive methods; (2) the Marshall stability testing procedure; and (3) the Hveem stability testing procedure. The effect of curing time and moisture on the stability of a recycled mix was also determined. A foaming temperature of 160 C (325 F) and an added water content of 2% were selected as the best conditions for optimum foam volume and half life. Excellent Marshall stability values were obtained with 0.5% and 1.0% foamed asphalt added to the recycled mixtures. Curing time had a marked effect on the lower additions of foamed asphalt. The effect of water decreases with increased amounts of foamed asphalt. Comparison of the Marshall Stability values and the Hveem Stability values indicates that the same optimum percent of foamed asphalt was obtained.

  16. Investigation of Low Heat Accumulation Asphalt Mixture and Its Impact on Urban Heat Environment.

    PubMed

    Xie, Jianguang; Yang, Zhaoxu; Liang, Leilei

    2015-01-01

    This study is focused on investigating the effectiveness of low heat accumulation asphalt mixture and its impact on the urban heat environment. Infrared radiation experiments showed that the temperature of the asphalt mixture decreased with the increase in far-infrared radiant material. The results also revealed that, compared to asphalt with 0% far-infrared radiant content, the asphalt material with a certain ratio of far-infrared radiation material had higher stability at high and low temperatures as well as good water absorption capacity. The Marshall stability of the specimen mixed with 6% far-infrared radiant was higher by 12.2% and had a residual stability of up to 98.9%. Moreover, the low-temperature splitting tensile strength of the asphalt mixture with 6% far-infrared radiation material increased by 21.3%. The friction coefficient of the asphalt mixtures with 6% and 12% far-infrared radiation material increased by 17.7% and 26.9%, respectively.

  17. Investigation of Low Heat Accumulation Asphalt Mixture and Its Impact on Urban Heat Environment

    PubMed Central

    Xie, Jianguang; Yang, Zhaoxu; Liang, Leilei

    2015-01-01

    This study is focused on investigating the effectiveness of low heat accumulation asphalt mixture and its impact on the urban heat environment. Infrared radiation experiments showed that the temperature of the asphalt mixture decreased with the increase in far-infrared radiant material. The results also revealed that, compared to asphalt with 0% far-infrared radiant content, the asphalt material with a certain ratio of far-infrared radiation material had higher stability at high and low temperatures as well as good water absorption capacity. The Marshall stability of the specimen mixed with 6% far-infrared radiant was higher by 12.2% and had a residual stability of up to 98.9%. Moreover, the low-temperature splitting tensile strength of the asphalt mixture with 6% far-infrared radiation material increased by 21.3%. The friction coefficient of the asphalt mixtures with 6% and 12% far-infrared radiation material increased by 17.7% and 26.9%, respectively. PMID:26222762

  18. A feasibility study to use coal tar contaminated soil in asphalt cement mixture production

    SciTech Connect

    Dulam, C.S.; Hoag, G.E.; Dahmani, A.; Nadim, F.

    1996-11-01

    Coal tars are the residues produced during the gasification of coal. Traditionally, coal tars were buried onsite at the power plants or left as residuals in the bottom of gas holders. Currently, there are more than 1,500 such historic sites which will undergo site assessment in the near future. The use of coal tar residuals in asphalt-based products could result in greatly reduced disposal costs, in comparison to current methods of disposal. Present disposal practice of coal tar contaminated residuals includes disposal in hazardous waste landfills or incineration. Treatment and disposal costs are reported to be as much as $1,000/ton for current coal tar contaminated residuals disposal options. This feasibility study was performed to determine the use of coal tar contaminated soil (CTCS) in bituminous materials to produce hot asphalt mix. Mixtures of varying composition of CTCS and bituminous material were produced to perform TCLP. The air emissions during the mixing process were captured and analyzed. In this study, a bench scale investigation was performed to identify and quantify the emissions from heating the CTCS at the mixer temperature. The pilot scale investigations were performed by replacing reclaimable asphalt pavement (RAP) with CTCS during the hot asphalt mix production. The investigations were performed on two types of mixtures; using CTCS as the direct additive in the first type, and using SS-1 (slow setting asphalt emulsion) stabilized CTCS as an additive in the second type.

  19. Recycling asphalt pavements. January 1975-January 1990 (a Bibliography from the COMPENDEX data base). Report for January 1975-January 1990

    SciTech Connect

    Not Available

    1990-03-01

    This bibliography contains citations concerning the recycling of asphalt-containing pavement materials. Articles include examples of recycling asphalt pavements; performance testing of recycled paving; methods including cold in-place, cold off-site, and hot-mix recycling; additives in recycled pavement for better performance; use of scrap roofing asphalt in conjunction with recycled paving; economics of recycling; process design; and process variables. Recycling of other materials is considered in related bibliographies. (Contains 130 citations fully indexed and including a title list.)

  20. Microstructural and rheological analysis of fillers and asphalt mastics

    NASA Astrophysics Data System (ADS)

    Geber, R.; Simon, A.; Kocserha, I.; Buzimov, A.

    2017-01-01

    Pavements are made of different grades of mineral aggregates and organic binder. The aggregates are sorted in different sizes and different amount which are mixed together with bitumen. The finest mineral fraction (d<0.063 mm) is called filler. This component has an important role in asphalt mixture - it fills the gaps between the aggregates and if mixed with bitumen (which is called asphalt mastics) it sticks the larger particles together. Particle size, microstructure and surface properties of fillers highly affect the cohesion with bitumen, therefore the aim of our research was to investigate the microstructure of mineral fillers (limestone, dolomite) which are used in Hungarian road constructions with the use of different techniques (particle size distribution, scanning electronmicroscopy tests, mercury intrusion porosimetry, BET specific surface tests, determination of hydrophobicity). After the tests of fillers, asphalt mastics were prepared and rheological examinations were obtained. These examinations served to observe the interaction and the effect of fillers. The stiffening effect of fillers and the causes of rutting were also investigated. Based on our results, it can be stated that particle size, hydrophobic properties and the amount of fillers highly affect the rheological properties of mastics.

  1. Certification Tests on Cold Patch Asphalt Repair Materials for Use in Airfield Pavements

    DTIC Science & Technology

    2010-06-01

    the amount of bituminous material. The maximum specific gravity is used in calculating the percentage of air voids in compacted samples, in... gravity was calculated. Compaction For this work, a Pine Instruments Company model AFGC125X gyratory compactor with a 4-in.-diam mold was used to...produce cylindrical asphalt concrete specimens. Compaction was performed using a ram pressure of 87 psi and an internal angle of gyration of 1.16 deg

  2. Investigation of thermal properties of raw materials of asphalt mixtures

    NASA Astrophysics Data System (ADS)

    Géber, R.; Simon, A.; Kocserha, I.

    2017-02-01

    Asphalt mixtures are composite materials, which are made of different grades of mineral aggregates and bitumen. During the mixing process mineral materials were blended with bitumen at relatively high temperature (∼200 °C). As the binding process come off in these higher temperature range, thermal properties of asphaltic materials are important. The aim of this project is to reveal the thermal properties of raw materials. During our research two types of mineral aggregates were tested (limestone and dolomite) by different methods. Differential thermal analysis, thermal expansion and thermal conductivity were investigated at technologically important temperatures. The results showed that the structure of mineral materials did not change at elevated temperatures, expansion of samples was neglible, while thermal conductivity changed by temperature.

  3. Migrating corrosion inhibitor protection of concrete

    SciTech Connect

    Bjegovic, D.; Miksic, B.

    1999-11-01

    Migrating corrosion inhibitors (MCI) were developed to protect steel rebar from corrosion in concrete. They were designed to be incorporated as an admixture during concrete batching or used for surface impregnation of existing concrete structures. Two investigations are summarized. One studied the effectiveness of MCIs as a corrosion inhibitor for steel rebar when used as an admixture in fresh concrete mix. The other is a long-term study of MCI concrete impregnation that chronicles corrosion rates of rebar in concrete specimens. Based on data from each study, it was concluded that migrating corrosion inhibitors are compatible with concrete and effectively delay the onset of corrosion.

  4. Thermal stability analysis under embankment with asphalt pavement and cement pavement in permafrost regions.

    PubMed

    Junwei, Zhang; Jinping, Li; Xiaojuan, Quan

    2013-01-01

    The permafrost degradation is the fundamental cause generating embankment diseases and pavement diseases in permafrost region while the permafrost degradation is related with temperature. Based on the field monitoring results of ground temperature along G214 Highway in high temperature permafrost regions, both the ground temperatures in superficial layer and the annual average temperatures under the embankment were discussed, respectively, for concrete pavements and asphalt pavements. The maximum depth of temperature field under the embankment for concrete pavements and asphalt pavements was also studied by using the finite element method. The results of numerical analysis indicate that there were remarkable seasonal differences of the ground temperatures in superficial layer between asphalt pavement and concrete pavement. The maximum influencing depth of temperature field under the permafrost embankment for every pavement was under the depth of 8 m. The thawed cores under both embankments have close relation with the maximum thawed depth, the embankment height, and the service time. The effective measurements will be proposed to keep the thermal stabilities of highway embankment by the results.

  5. A Rayleigh-Wave Attenuation Method for Crack Depth Determination in Asphalt Beams

    NASA Astrophysics Data System (ADS)

    Gibson, Alex; Gallo, Gonzalo E.

    2004-02-01

    It has been established through research on concrete structures that the attenuation of surface waves is sensitive to the presence of a surface-breaking obstructing its path. This is the basis for a non-destructive crack depth measurement technique to quantitatively establish the extent of damage on a pavement subject to of top-down cracking. A previously developed self-compensating technique was applied to asphalt concrete beams constructed with a variety of crack and notch configurations. In the study different notch geometries and the effect of crack width, by comparing results from saw-cut notches to those of narrow cracks, were examined. Two types of impact sources were used and the results obtained were compared to each other. The frequency-dependent signal transmission coefficient was measured at 30 and 50 mm spacing for both undamaged and cracked beams. A single relationship between signal attenuation and crack depth can be attained by normalizing the crack depth with respect to the wavelength. Although the frequency response of a beam is different to that of a slab, the viability of Rayleigh wave attenuation measurements in asphalt pavement surfaces was proved if certain corrections are considered. The method may provide a non-destructive means to determine the depth of cracks in asphalt, such as it does in concrete, with the future understanding of certain phenomena encountered in this work.

  6. Thermal Stability Analysis under Embankment with Asphalt Pavement and Cement Pavement in Permafrost Regions

    PubMed Central

    Jinping, Li; Xiaojuan, Quan

    2013-01-01

    The permafrost degradation is the fundamental cause generating embankment diseases and pavement diseases in permafrost region while the permafrost degradation is related with temperature. Based on the field monitoring results of ground temperature along G214 Highway in high temperature permafrost regions, both the ground temperatures in superficial layer and the annual average temperatures under the embankment were discussed, respectively, for concrete pavements and asphalt pavements. The maximum depth of temperature field under the embankment for concrete pavements and asphalt pavements was also studied by using the finite element method. The results of numerical analysis indicate that there were remarkable seasonal differences of the ground temperatures in superficial layer between asphalt pavement and concrete pavement. The maximum influencing depth of temperature field under the permafrost embankment for every pavement was under the depth of 8 m. The thawed cores under both embankments have close relation with the maximum thawed depth, the embankment height, and the service time. The effective measurements will be proposed to keep the thermal stabilities of highway embankment by the results. PMID:24027444

  7. Final Rule to Reduce Toxic Air Emissions from Asphalt Processing and Asphalt Roofing Manufacturing Facilities Fact Sheet

    EPA Pesticide Factsheets

    This page contains a February 2003 fact sheet with information regarding the National Emissions Standards for Hazardous Air Pollutants (NESHAP) for Asphalt Processing and Asphalt Roofing Manufacturing.

  8. Method and apparatus for fragmenting asphalt

    SciTech Connect

    Eftefield, L. G.; Simmons, G. P.; Stone, G. L.

    1985-12-24

    A method and apparatus for laterally severing an asphalt layer to form a ribbon, separating the asphalt ribbon from an underlying base, elevating the separated asphalt ribbon, and fracturing the elevated asphalt ribbon by bending same. A cutting member having a leading edge which is insertable between the asphalt ribbon and base provides separation thereof along a lateral line. A ramp and elevating structure elevatingly guide the separated asphalt ribbon into a pair of breaker drums which are rotatable in opposite circumferential directions. Each breaker drum has protruding teeth which are arranged in laterally separated circumferential rows with the teeth in adjacent circumferential rows being preferably arcuately offset. Corresponding circumferential rows on the opposed breaker drums are laterally aligned and the teeth in those rows engage opposite surfaces of the asphalt ribbon during rotation of the breaker drums. The teeth in corresponding rows on the respective breaker drums alternately engage opposite surfaces of the asphalt ribbon at longitudinally spaced locations to bend and fracture the asphalt ribbon by displacing it in generally opposite transverse directions at the engaged locations.

  9. Pelletized Asphalt for Airfield Damage Repair

    DTIC Science & Technology

    2009-08-01

    test sections were built on an existing Portland cement concrete (PCC) runway at the Silver Flag Training Area at Tyndall Air Force Base (AFB...pavements is caused by the shrinkage induced stresses when air temperatures drop rapidly. During rapid contraction, the stresses accumulate and may...least 130°F and which can be poured as a free -flowing material from shipping containers into a continuous or batch mixing plant to produce HMA on

  10. Optimizing the durability of the coarse fraction of porous asphalt RAP for effective recycling

    NASA Astrophysics Data System (ADS)

    Holleran, Irina; Wilson, Douglas J.; Black, Philippa; Holleran, Glynn; Walubita, Lubinda F.

    2017-09-01

    Porous asphalt (PA) durability depends not only on the binder used to manufacture the mix, but also on the aggregates chosen, particularly the coarse fraction component. Aggregates for PA should be of the highest quality and highly durable to withstand the effects of weather and traffic. To recycle PA into a new PA mix, without compromising the long-term performance, the durability of the recovered aggregates from PA-derived reclaimed asphalt pavement (RAP) should be assessed alongside the aged binder properties. In this study, the Micro-Deval (MD) Abrasion test, combined with water absorption, was found to be a good predictor of asphalt mix performance for PA. Minerology of the aggregates is an important factor when setting limits for MD loss. New Zealand (NZ) aggregates are significantly younger in geological terms, and chemically and physically less stable compared to the aggregates used in many other countries. This is especially true for greywacke, the most used aggregate in NZ for road construction. If the MD limits reported in some literature are applied to NZ PA-derived RAP aggregates, poor performing material can be erroneously incorporated in asphalt mixes. Findings from this study contributes in understanding how PA-derived RAP can be recycled into new value PA mixes.

  11. Evaluation of Asphalt Binder Modifiers

    DTIC Science & Technology

    1990-01-01

    or SBS rubber described as an oil-extended polymer produced in pellet form. This type of rubber is available in other solid forms such as crumb or...is done to improve the performance characteristics of future pavements. Many research programs have been conducted on asphalt modifiers. Most of...tests were conducted during the second year of the study and resultant data were used to choose five materials to meet the test objectives of this

  12. Supercritical fractions as asphalt recycling agents and preliminary aging studies on recycled asphalts

    SciTech Connect

    Chaffin, J.M.; Liu, M.; Davison, R.R.; Glover, C.J.; Bullin, J.A.

    1997-03-01

    Several asphalts were fractionated using supercritical pentane. These fractions were analyzed by gel permeation chromatography and high-performance liquid chromatography, and their viscosities were measured. The properties of these fractions vary not only among the fractions of a given asphalt but also for the same fraction produced from different asphalts. These widely varied fractions previously have been shown to have potential for reblending to produce superior asphalts. This study investigates the potential for using some of the fractions as asphalt recycling agents. A modified strategic highway research program (SHRP) pressure aging vessel (PAV) test and kinetics studies were conducted on nine recycled asphalts and the original asphalt. The aging indexes of eight of the recycled asphalts are superior to the aging index of the original asphalt. Two of the blends using industrial supercritical fractions and the three blends using laboratory supercritical fractions have lower aging indexes than blends using commercial recycling agents. The kinetics investigation also indicates that at road conditions the recycled asphalts will harden more slowly than the original asphalt. The degree of hardening for a given amount of oxidation in the recycled binders was found to be a strong function of the total saturate content in the recycled binder.

  13. Experimental investigation of basic oxygen furnace slag used as aggregate in asphalt mixture.

    PubMed

    Xue, Yongjie; Wu, Shaopeng; Hou, Haobo; Zha, Jin

    2006-11-16

    Chinese researchers have commenced a great deal of researches on the development of application fields of basic oxygen steel making furnace slag (BOF slag) for many years. Lots of new applications and properties have been found, but few of them in asphalt mixture of road construction engineering. This paper discussed the feasibility of BOF steel slag used as aggregate in asphalt pavement by two points of view including BOF steel slag's physical and micro-properties as well as steel slag asphalt materials and pavement performances. For the former part, this paper mainly concerned the mechanochemistry and physical changes of the steel slag and studied it by performing XRD, SEM, TG and mercury porosimeter analysis and testing method. In the second part, this paper intended to use BOF steel slag as raw material, and design steel slag SMA mixture. By using traditional rutting test, soak wheel track and modified Lottman test, the high temperature stability and water resistance ability were tested. Single axes compression test and indirect tensile test were performed to evaluate the low temperature crack resistance performance and fatigue characteristic. Simultaneously, by observing steel slag SMA pavement which was paved successfully. A follow-up study to evaluate the performance of the experimental pavement confirmed that the experimental pavement was comparable with conventional asphalt pavement, even superior to the later in some aspects. All of above test results and analysis had only one main purpose that this paper validated the opinion that using BOF slag in asphalt concrete is feasible. So this paper suggested that treated and tested steel slag should be used in a more extensive range, especially in asphalt mixture paving projects in such an abundant steel slag resource region.

  14. Permeability of Clay Concretes

    NASA Astrophysics Data System (ADS)

    Solomon, F.; Ekolu, S. O.

    2015-11-01

    This paper presents an investigation on the effect of clay addition on water permeability and air permeability of concretes. Clay concrete mixes consisted of 0 to 40% clay content incorporated as cement replacement. Flow methods using triaxial cells and air permeameters were used for measuring the injected water and air flows under pressure. It was found that the higher the clay content in the mixture, the greater the permeability. At higher water-cement ratios (w/c), the paste matrix is less dense and easily allows water to ingress into concrete. But at high clay contents of 30 to 40% clay, the variation in permeability was significantly diminished among different concrete mixtures. It was confirmed that air permeability results were higher than the corresponding water permeability values when all permeability coefficients were converted to intrinsic permeability values.

  15. Assessment of Asphalt Concrete Reinforcement Grid in Flexible Pavements

    DTIC Science & Technology

    2016-05-01

    Flexible Pavements Lynette A. Barna, Charles E. Smith Jr., and Andrew Bernier U.S. Army Engineer Research and Development Center (ERDC) Cold Regions...Development Center (ERDC) Cold Regions Re- search and Engineering Laboratory (CRREL), and Aaron Smart and Ann Scholz, NHDOT Bureau of Materials and...Association of State Highway and Transportation Officials CBR California Bearing Ratio CRREL Cold Regions Research and Engineering Laboratory CRADA

  16. Determine Parameters Causing Water Damage to Asphalt Concrete.

    DTIC Science & Technology

    1986-09-01

    COMPACTED MIXTURES TEST AND SAMPLE TREATMENT % ASPHALTENES % SATURATES % AROMATICS % POLARS METHOD GAK-30-GI LTh-D 29.81 7.21 20.21 42.77 GAK-30-GI LTM-W...FROM DRY AND WET COMPACTED MIXTURES (CONTINUED). TEST AND SAMPLE TREATMENT % ASPHALTENES % SATURATES % AROMATICS % POLARS. .# METHOD GAN-30W-G2 IC-D...FROM DRY AND WET COMPACTED MIXTURES (CONCLUDED). TEST AND SAMPLE TREATMENT % ASPHALTENES % SATURATES % AROMATICS % POLARS METHOD MS2-20-C LTM-D 33.84

  17. Evaluation Criteria for Aged Asphalt Concrete Surfaces; Phase II

    DTIC Science & Technology

    2008-05-01

    Airfield ( Fort Polk, LA), Redstone Army Airfield (Huntsville, AL), Simmons Army Airfield ( Fort Bragg , NC), and Forney Army Airfield ( Fort Leonard Wood...Redstone Army Airfield in Huntsville, AL, Simmons Army Airfield in Fort Bragg , NC, and Forney Army Airfield in Fort Leonard Wood, MO, in addition to the...Polk, LA; Redstone Army Airfield in Huntsville, AL; Simmons Army Airfield in Fort Bragg , NC; and Forney Army Airfield in Fort Leonard Wood, MO. The in

  18. Effects of street tree shade on asphalt concrete pavement performance

    Treesearch

    E.G. McPherson; J. Muchnick

    2005-01-01

    Forty-eight street segments were paired into 24 high-and low-shade pairs in Modesto, California, U.S. Field data were collected to calculate a Pavement Condition Index (PCI) and Tree Shade Index (TSI) for each segment. Statistical analyses found that greater PCI was associated with greater TSI, indicating that tree shade was partially responsible for reduced pavement...

  19. Asphalt Rubber Concrete Pavement. User’s Guide

    DTIC Science & Technology

    1994-09-01

    Wor6’ ’ Alexandria, VA 22310-3860 ’%cooir 1 ... for she An Mah~~ n , W &piný Aetmf Aumy &AM Destroy this report when no longer needed. Do not return it...IIOUI𔄀IM5Mo M NCY AMu(S) AID AIS(S) N P/•ONITORINGAGIN"Y REPORIT NUMBRI| U.S. Amy Cm " for Public Works FE.AP.UG-9412 7701 Telhiqi Road AlexAria VA...CODE " CAM• CLASRCI I _10SC]’- CLASFiCATIN t. SECURITY €IA$SIICATI) N 20. LIMITATION OF ABSTRACT OF oM TiF s PA41 OF ABSTRACT UicA1111_"-1- Uwcl

  20. EVALUATION OF EMISSIONS FROM PAVING ASPHALTS

    EPA Science Inventory

    The report provides data from pilot-scale measurements of the emissions of specific air pollutants from paving asphalt both with and without recycled crumb rubber additives. The methods used in this work measured emissions from a static layer of asphalt maintained for several hou...

  1. Asphalt Raking. Instructor Manual. Trainee Manual.

    ERIC Educational Resources Information Center

    Laborers-AGC Education and Training Fund, Pomfret Center, CT.

    This packet consists of the instructor and trainee manuals for an asphalt raking course. The instructor manual contains a course schedule for 4 days of instruction, content outline, and instructor outline. The trainee manual is divided into five sections: safety, asphalt basics, placing methods, repair and patching, and clean-up and maintenance.…

  2. EVALUATION OF EMISSIONS FROM PAVING ASPHALTS

    EPA Science Inventory

    The report provides data from pilot-scale measurements of the emissions of specific air pollutants from paving asphalt both with and without recycled crumb rubber additives. The methods used in this work measured emissions from a static layer of asphalt maintained for several hou...

  3. Asphalt Raking. Instructor Manual. Trainee Manual.

    ERIC Educational Resources Information Center

    Laborers-AGC Education and Training Fund, Pomfret Center, CT.

    This packet consists of the instructor and trainee manuals for an asphalt raking course. The instructor manual contains a course schedule for 4 days of instruction, content outline, and instructor outline. The trainee manual is divided into five sections: safety, asphalt basics, placing methods, repair and patching, and clean-up and maintenance.…

  4. MATCON MODIFIED ASPHALT COVER CONTAINMENT SYSTEM DEMONSTRATION

    EPA Science Inventory

    In order to make improvements to conventional paving asphalt to make it more suitable for containment applications, Wilder Construction Co. of Everett, WA offers MatCon, a polymer modified asphalt system comprised of proprietary binder, when coupled with a selected aggregate type...

  5. Heating Techniques for Asphalt/Aggregate Mixtures.

    DTIC Science & Technology

    1979-12-01

    aggregate mixtures. Rec- ommendations are made for techniques to be developed which will meet the rapid repair time that is specified. Microwave ...Plants . . . . . . . . . . . . . . . . . . . . IV LITERATURE SEARCH . . . . . . . . . . . . . . . . . . . . . Microwave -Powered Units...33 iii 4 I - ’ .. .. LIST OF FIGURES Figure Title Page I Solar- Microwave Asphalt Storage Tank. .. ... ........ 22 2 Asphalt-Mobile

  6. Soil temperatures under urban trees and asphalt

    Treesearch

    Howard G. Halverson; Gordon M. Heisler

    1981-01-01

    Summer temperatures under trees planted in holes cut through an asphalt cover in a parking lot and in soil beneath the surrounding asphalt were higher than soil temperatures under trees at a control site. Winter minimums were not different, but maximum summer temperature exceeded the control by 3ºC beneath the parking lot trees and up to 10ºC beneath...

  7. MATCON MODIFIED ASPHALT COVER CONTAINMENT SYSTEM DEMONSTRATION

    EPA Science Inventory

    In order to make improvements to conventional paving asphalt to make it more suitable for containment applications, Wilder Construction Co. of Everett, WA offers MatCon, a polymer modified asphalt system comprised of proprietary binder, when coupled with a selected aggregate type...

  8. Recommendations and strategies for using reclaimed asphalt pavement in the Flemish Region based on a first life cycle assessment research

    NASA Astrophysics Data System (ADS)

    Van den bergh, Wim; Kara, Patricia; Anthonissen, Joke; Margaritis, Alexandros; Jacobs, Geert; Couscheir, Karolien

    2017-09-01

    In Flanders, using Reclaimed Asphalt Pavement (RAP) is allowed in asphalt mixes for base layers. Primary economic and secondary laboratory-measured mechanical properties are given as justification for higher amounts in specific mixes. However, one should evaluate the performance of these mixes on long-term by environmental impact of the production until end-of-life. In this paper recommendations and strategies for using RA, based on current research, are discussed in a broader perspective such as using a carbon-footprint tool and warm-mix asphalt production in the Flemish Region. The paper aims to a wide discussion by reporting several outcomes of laboratory research, statistics and practical application in order to set a general strategy for the road engineering sector in the Flemish Region.

  9. Mixture design and performance prediction of rubber-modified asphalt in Ohio. Final report

    SciTech Connect

    Liang, R.Y.

    1997-08-01

    Appropriate disposal of scrap tires has been a major environmental concern over the years, mainly due to potential fire and health hazards associated with uncontrolled stockpiling. Primarily driven by this environmental concern, the Intermodal Surface Transportation Efficiency Act (ISTEA) of 1991 has required each State to begin incorporating scrap tire rubber into its asphalt paving materials. Although in the revision of the original ISTEA, the mandate has been eliminated, there remains a language of encouraging the use of crumb rubbers in asphalt paving materials. Ohio Department of Transportation (ODOT) desires to develop the mix design procedure, construction practice, and performance specifications for crumb rubber modified asphalt paving materials. This research was conducted to develop the needed design and construction guidance for meeting the ODOT anticipated needs. Specifically, the objectives of this research encompass the following scope: (1) investigation of the rheological properties of asphalt-rubber binder to determine optimum content of crumb rubber, (2) development of optimum mix design for various applications, including both wet and dry mix processes, (3) characterization of mechanical properties of recommended paving mixtures, including resilient modulus, fatigue cracking behavior, low-temperature thermal cracking resistance, water sensitivity test, incremental creep test and loaded wheel track test, and (4) comparison of performance of selected paving mixes.

  10. Effect of Cement on Emulsified Asphalt Mixtures

    NASA Astrophysics Data System (ADS)

    Oruc, Seref; Celik, Fazil; Akpinar, M. Vefa

    2007-10-01

    Emulsified asphalt mixtures have environmental, economical, and logistical advantages over hot mixtures. However, they have attracted little attention as structural layers due to their inadequate performance and susceptibility to early life damage by rainfall. The objective of this article is to provide an improved insight into how the mechanical properties of emulsion mixtures may be improved and to determine the influence of cement on emulsified asphalt mixtures. Laboratory tests on strength, temperature susceptibility, water damage, creep and permanent deformation were implemented to evaluate the mechanical properties of emulsified asphalt mixtures. The test results showed that mechanical properties of emulsified asphalt mixtures have significantly improved with Portland cement addition. This experimental study suggested that cement modified asphalt emulsion mixtures might be an alternate way of a structural layer material in pavement.

  11. Softening agents for recycling asphalt pavement

    SciTech Connect

    Sawatzky, H.; Clelland, F.I.; Farnand, B.A.; Houde, J. Jr.

    1993-08-10

    An asphaltic composition is described consisting essentially of: comminuted aged asphaltic pavement material; an effective amount, from about 2% to about 15 % by weight of a blend of an agent selected from the group consisting of a soft asphalt cement, a conventional asphalt cement, and a cutback asphalt, with a nitrogen-containing, adhesion-improving, anti-stripping agent comprising a sewage sludge-derived oil, or a fraction thereof, said sewage sludge-derived oil comprising a mixture of saturated aliphatic hydrocarbons, monoaromatic hydrocarbons, diaromatic hydrocarbons, polyaromatic hydrocarbons, polar compounds and basic, pyridene-soluble compounds, having the following elemental chemical composition: nitrogen, about 3.4% to about 5% by weight; oxygen, about 5.8% to about 6.9% by weight; sulfur, about 0.3% to about 0.8% by weight; hydrogen, about 9.7% to about 10.4%, and carbon, about 76.9% to about 79.8%.

  12. Compatibilizer for crumb rubber modified asphalt

    SciTech Connect

    Labib, M.E.; Memon, G.M.; Chollar, B.H.

    1996-12-31

    The United States of America discards more than 300 million tires each year, and out of that a large fraction of the tires is dumped into stock piles. This large quantity of tires creates an environmental problem. The use of scrap tires is limited. There is a usage potential in such fields as fuel for combustion and Crumb Rubber-Modified Asphalt binder (CRMA). The use of crumb rubber in modifying asphalt is not a new technique; it is been used since early 1960 by pavement engineers. Crumb rubber is a composite of different blends of natural and synthetic rubber (natural rubber, processing oils, polybutadiene, polystyrene butadiene, and filler). Prior research had concluded that the performance of crumb rubber modified asphalt is asphalt dependent. In some cases it improves the Theological properties and in some cases it degrades the properties of modified asphalt.

  13. Test of cold asphalt storability based on alternative approaches

    NASA Astrophysics Data System (ADS)

    Abaffyová, Zora; Komačka, Jozef

    2017-09-01

    Cold asphalt products for potholes repairs should be workable (soft enough) for long time to ensure their applicability. Storability is assessed indirectly using various tests of workability. Therefore, simple test methods (self-compaction and disintegration test) was developed and verified to investigate changes of storability of this group of cold asphalts. Selfcompaction of the tested mixture in the upturned Abram’s cone for the cement concrete slump test and in the mould for the California Bearing Ratio test was assessed in first stage. After that the video record of disintegration test was taken. During this test, the mould was lifted up and the mixture fell off the mould (Abram’s cone) or disintegrate (CBR mould). The drop of surface after 10 min self-compaction and netto time related to falling out or disintegration of the mixture were used to evaluate the mixture from storability point of view. It was found out the self-compaction test has not a potential to reveal and prove changes of mixture properties. Based on the disintegration test results it can be stated this test at 5 °C using the upturned Abram’s cone could be a suitable approach to determine qualitative changes of a cold mixture from storability point of view.

  14. 9 CFR 91.26 - Concrete flooring.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 9 Animals and Animal Products 1 2011-01-01 2011-01-01 false Concrete flooring. 91.26 Section 91.26... LIVESTOCK FOR EXPORTATION Inspection of Vessels and Accommodations § 91.26 Concrete flooring. (a) Pens aboard an ocean vessel shall have a 3 inch concrete pavement, proportioned and mixed to give 2000...

  15. 9 CFR 91.26 - Concrete flooring.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Concrete flooring. 91.26 Section 91.26... LIVESTOCK FOR EXPORTATION Inspection of Vessels and Accommodations § 91.26 Concrete flooring. (a) Pens aboard an ocean vessel shall have a 3 inch concrete pavement, proportioned and mixed to give 2000...

  16. Strain transfer analysis of optical fiber based sensors embedded in an asphalt pavement structure

    NASA Astrophysics Data System (ADS)

    Wang, Huaping; Xiang, Ping

    2016-07-01

    Asphalt pavement is vulnerable to random damage, such as cracking and rutting, which can be proactively identified by distributed optical fiber sensing technology. However, due to the material nature of optical fibers, a bare fiber is apt to be damaged during the construction process of pavements. Thus, a protective layer is needed for this application. Unfortunately, part of the strain of the host material is absorbed by the protective layer when transferring the strain to the sensing fiber. To account for the strain transfer error, in this paper a theoretical analysis of the strain transfer of a three-layered general model has been carried out by introducing Goodman’s hypothesis to describe the interfacial shear stress relationship. The model considers the viscoelastic behavior of the host material and protective layer. The effects of one crack in the host material and the sensing length on strain transfer relationship are been discussed. To validate the effectiveness of the strain transfer analysis, a flexible asphalt-mastic packaged distributed optical fiber sensor was designed and tested in a laboratory environment to monitor the distributed strain and appearance of cracks in an asphalt concrete beam at two different temperatures. The experimental results indicated that the developed strain transfer formula can significantly reduce the strain transfer error, and that the asphalt-mastic packaged optical fiber sensor can successfully monitor the distributed strain and identify local cracks.

  17. Assessing the durability of North Buton Asphalt seal with Polymer Modified and Rejuvenation in warm mixture design

    NASA Astrophysics Data System (ADS)

    Zalman; Yulianto, B.; Setyawan, A.

    2017-02-01

    Utilization of Buton Asphalt has been expanded with various optimizations through modification of the base material so that it can be used either as an additive in granular form or as modified asphalt. While in North Buton using Asphalt Buton that uses a special material specification Buton Asphalt cold mixture of Butur Seal, a thin layer of Buton Asphalt B 50/30 above the base course or existing asphalt pavement layer, which has been prepared in accordance with the General Specifications. Technically utilization of Butur Seal is still very sensitive to human resource capacity in understanding the physical condition of Asbuton, and severely affects construction to failure. Buton asphalt cold mix in the field also showed some kind of damage caused by difficulties or not fitting rejuvenation materials used. Making the challenge to do research on the characteristic properties of Asphalt Buton B50 / 30 with modifications, to get Asbuton that has higher durability in use in the field. Quality performance of the Asbuton cold mixtures is observed through a series of tests in the laboratory. This test includes testing the stability and the compressive test. Tests conducted in the laboratory are expected to be directly applicable as it is done in the field. This research aimed to investigate the characteristics of Butur Seal in warm mixture that can be used in the construction and maintenance of roads in North Burton and to investigate the characteristics of Butur Seal with the addition of elastomeric polymers and rejuvenation materials in warm mixing temperature of 30, 40, 60 and 80° C.

  18. Mechanical Performance of Asphalt Mortar Containing Hydrated Lime and EAFSS at Low and High Temperatures

    PubMed Central

    Moon, Ki Hoon; Wang, Di; Riccardi, Chiara; Wistuba, Michael P.

    2017-01-01

    In this paper, the possibility of improving the global response of asphalt materials for pavement applications through the use of hydrated lime and Electric Arc-Furnace Steel Slag (EAFSS) was investigated. For this purpose, a set of asphalt mortars was prepared by mixing two different asphalt binders with fine granite aggregate together with hydrated lime or EAFSS at three different percentages. Bending Beam Rheometer (BBR) creep tests and Dynamic Shear Rheometer (DSR) complex modulus tests were performed to evaluate the material response both at low and high temperature. Then, the rheological Huet model was fitted to the BBR creep results for estimating the impact of filler content on the model parameters. It was found that an addition of hydrated lime and EAFSS up to 10% and 5%, respectively, results in satisfactory low-temperature performance with a substantial improvement of the high-temperature behavior. PMID:28773100

  19. Mechanical Performance of Asphalt Mortar Containing Hydrated Lime and EAFSS at Low and High Temperatures.

    PubMed

    Moon, Ki Hoon; Falchetto, Augusto Cannone; Wang, Di; Riccardi, Chiara; Wistuba, Michael P

    2017-07-03

    In this paper, the possibility of improving the global response of asphalt materials for pavement applications through the use of hydrated lime and Electric Arc-Furnace Steel Slag (EAFSS) was investigated. For this purpose, a set of asphalt mortars was prepared by mixing two different asphalt binders with fine granite aggregate together with hydrated lime or EAFSS at three different percentages. Bending Beam Rheometer (BBR) creep tests and Dynamic Shear Rheometer (DSR) complex modulus tests were performed to evaluate the material response both at low and high temperature. Then, the rheological Huet model was fitted to the BBR creep results for estimating the impact of filler content on the model parameters. It was found that an addition of hydrated lime and EAFSS up to 10% and 5%, respectively, results in satisfactory low-temperature performance with a substantial improvement of the high-temperature behavior.

  20. Application of pyrolized carbon black from scrap tires in asphalt pavement design and construction

    SciTech Connect

    Park, T.; Coree, B.J.; Lovell, C.W.

    1995-12-31

    According to EPA reports (1991) of the over 242 million waste generated each year in the United State, 5% are exported, 6% recycled, 11% incinerated, and 78% are landfilled, stockpiled, or illegally dumped. A variety of uses for these tires are being studied. Among these is pyrolysis which produces 5 5% of oil, 25% of carbon black, 9% of steel, 5% of fiber and 6% of gas. Pyrolized carbon black contains 9 % of ash, 4% of sulfur, 12% of butadine copolymer and 75% of carbon black. The objective of this research is to investigate the viability of using PCB as an additive in hot mix asphalt. The use of PCB in asphalt pavement is expected not only to improve the performance of conventional asphalt, but also to provide a means for the mass disposal of waste fires.

  1. Recycled tire rubber and other waste materials in asphalt mixtures. Transportation research record

    SciTech Connect

    1995-12-31

    The papers in this volume, dealing with various facets of recycled tire rubber and other waste materials in asphalt mixtures, should be of interest to state and local construction, design, materials, and research engineers as well as contractors and material producers. In the first papers, Rebala and Estakhri, Malpass and Khosla, and Baker and Connolly describe research related to crumb rubber modified mixtures that was done for the Texas, North Carolina, and New Jersey State Departments of Transportation. Ali et al. report on their research in Canada to determine the feasibility of sing reclaimed roofing materials in hot mix asphalt pavement. Emery discusses the evaluation of 11 Ontario rubber modified demonstration projects in terms of pavement performance, environmental impacts, and recyclability. In the last paper, Fwa and Aziz report on their work in Singapore related to the use of incinerator residue in asphalt mixtures.

  2. Use of asphalt emulsion sealants in disposal of uranium mill tailings

    SciTech Connect

    Hartley, J.N.; Freeman, H.D.; Elmore, M.R.

    1981-07-01

    Studies of asphalt emulsion sealants conducted by the Pacific Northwest Laboratory have demonstrated that the sealants are effective in containing radon within uranium tailings. The laboratory and field studies have further demonstrated that radon exhalation from uranium tailings piles can be reduced by greater than 99% to near background levels. Field tests at the tailings pile in Grand Junction, Colorado confirmed that an 8-cm admix seal containing 22 wt % asphalt could be effectively applied with a cold-mix paver. Other techniques were successfully tested, including a soil stabilizer and a hot, rubberized asphalt seal that was applied with a distributor truck. After the seals were applied and compacted, overburden was applied over the seal to protect the seal from ultraviolet degradation.

  3. Evaluation of the treatment of chromite ore processing residue by ferrous sulfate and asphalt.

    PubMed

    Moon, Deok Hyun; Wazne, Mahmoud; Koutsospyros, Agamemnon; Christodoulatos, Christos; Gevgilili, Halil; Malik, Moinuddin; Kalyon, Dilhan M

    2009-07-15

    The effectiveness of the treatment of chromite ore processing residue (COPR) with ferrous sulfate and encapsulation into asphalt were explored separately and in combination. The asphalt treatment was conducted by mixing COPR or ferrous sulfate pretreated COPR with varying amounts of asphalt. To assess the efficacy of the treatment, the leachability of toxicity characteristic leaching procedure (TCLP) total chromium (Cr) from all treated samples was determined for curing periods up to 16 months. X-ray absorption near edge structure (XANES) analyses were also performed to evaluate the Cr(6+) concentration in the selected samples. The combination treatment of ferrous sulfate and the encapsulation of the treated COPR into asphalt reduced the TCLP total Cr concentration to lower than the regulatory limit of 5mg/L for Cr contaminated soils, after 16 months. However, the Cr concentrations were still higher than the universal treatment standards (UTS) of 0.6 mg/L for hazardous waste. On the other hand, treatment with ferrous sulfate alone or the encapsulation of the COPR in asphalt failed to meet the TCLP total Cr concentration of 5mg/L, after 16 months. XANES analyses results showed that more than 75% Cr(6+) reduction was achieved upon pretreatment with ferrous sulfate.

  4. A review of air quality issues and compliance for the asphalt paving industry in Maryland

    SciTech Connect

    Courtright, B.F.; Caughlin, M.J.

    1999-07-01

    The Maryland Air and Radiation Management Administration (ARMA) conducted a Sector Initiative in order to achieve a compliance audit of the asphalt paving industry sector in Maryland. This sector is commonly referred to as the hot-mix asphalt (HMA) industry. There are 59 HMA production plants in Maryland. Each asphalt production facility was reviewed to determine their compliance status with federal NSPS requirements (stack particulate and visible emission requirements), as well as with Maryland's more comprehensive and generally more restrictive requirements including visible emission, particulate matter, air toxics, dust, nuisance, odor, and other criteria pollutant requirements. The study included reviewing past data (stack test reports, inspections, VE observations, complaint histories) and conducting new inspections and observations at all 59 of the plants. The study also included conducting new particulate stack tests (Summer of 1998) at nine HMA plants. The historic data demonstrated general compliance with stack-tested particulate emission rates. The new stack tests all demonstrated compliance with applicable particulate limits. Visible emissions observations revealed a lesser degree of compliance. Asphalt plants, if not carefully controlled, can be a major source of nuisance complaints. Complaint histories were also reviewed. This paper presents detailed results of ARMA's compliance review of the asphalt industry in Maryland. This includes test results, compliance determinations, and compliance rates. Other issues including impacts on surrounding communities, changing Department of Transportation requirements, and air toxics requirements are also reviewed.

  5. Effects of carboxylic acids on the rheological properties of crumb rubber modified asphalt

    SciTech Connect

    Tauer, J.E.; Robertson, R.E.

    1996-12-31

    The Federal mandate of 1991-1995 on the use of scrap tires in Federal roadway construction sparked a major interest in gaining a fundamental understanding of the behavior of rubber in asphalt. This study is a systematic elucidation of what chemistry controls the final crumb rubber modified asphalt (CRMA) product quality. We discovered that the type and total acid content in the asphalt are the most influential chemical factors that determine the changes in the important roadway properties of shear modulus (G*) and loss angle ({delta}) of CRMA. Low acid (<0.005 m/L) asphalts were modified with three types of carboxylic acid and each made into CRMA using typical field mixing conditions of 1 hour at 175{degrees}C. Rheological measurements were then made at various storage times up to 192 hours following storage at both 156 and 200{degrees}C. We found the changes in CRMA theological properties correspond to the acid type spiked into the asphalt.

  6. The use of a non-nuclear density gauge for monitoring the compaction process of asphalt pavement

    NASA Astrophysics Data System (ADS)

    Van den bergh, Wim; Vuye, Cedric; Kara, Patricia; Couscheir, Karolien; Blom, Johan; Van Bouwel, Philippe

    2017-09-01

    The mechanical performance of an asphalt pavement affects its durability – thus carbon footprint. Many parameters contribute to the success of a durable asphalt mix, e.g. material selection, an accurate mix and even the road design in which the asphalt mix quality is quantified. The quality of the asphalt mix, by its mechanical properties, is also related to the compaction degree. However, and specifically for high volume rates, the laying process at the construction site needs an effective method to monitor and adjust immediately the compaction quality before cooling and without damaging the layer, which is now absent. In this paper the use of a non-nuclear density gauge (PQI – Pavement Quality Indicator) is evaluated, based on a site at Brussels Airport. Considering the outcome of the present research, this PQI is advised as a unique tool for continuous density measurements and allow immediate adjustments during compaction, and decreases the number of core drilling for quality control, and as a posteriori asphalt pavement density test where cores are prohibited. The use of PQI could be recommended to be a part of the standard quality control process in the Flemish region.

  7. An Experimental Investigation on the Effect of Addition of Ternary Blend on the Mix Design Characteristics of High Strength Concrete using Steel Fibre

    NASA Astrophysics Data System (ADS)

    Sinha, Deepa A., Dr; Verma, A. K., Dr

    2017-08-01

    This paper presents the results of M60 grade of concrete. M60 grade of concrete is achieved by maximum density technique. Concrete is brittle and weak in tension and develops cracks during curing and due to thermal expansion / contraction over a period ot time. Thus the effect of addition of 1% steel fibre is studied. For ages, concrete has been one of the widely used materials for construction. When cement is manufactured, every one ton of cement produces around one ton of carbon dioxide leading to global warming and also as natural resources are finishing, so use of supplementary cementitious material like alccofine and flyash is used as partial replacement of cement is considered. The effect of binary and ternary blend on the strength characteristics is studied. The results indicate that the concrete made with alccofine and flyash generally show excellent fresh and hardened properties. The ternary system that is Portland cement-fly ash-Alccofine concrete was found to increase the strength of concrete when compared to concrete made with Portland cement or even from Portland cement and fly ash.

  8. Characteristics of Ceramic Fiber Modified Asphalt Mortar.

    PubMed

    Wan, Jiuming; Wu, Shaopeng; Xiao, Yue; Liu, Quantao; Schlangen, Erik

    2016-09-21

    Ceramic fiber, with a major composition of Al₂O₃ and SiO₂, has advantages of stability at relatively high temperature, big specific surface area and resistance to external mechanical vibration. It has the potential contribution of improving the rutting resistance and temperature sensitivity of modified asphalt binder by proper modification design. In this research, ceramic fiber was introduced into both pen 60/80 and pen 80/100 asphalt binder by different weight ratios. An asphalt penetration test, softening point test, ductility test and dynamic viscoelastic behavior were conducted to characterize and predict the ceramic fiber modified asphalt mortar (CFAM). Research results indicated that the ceramic fiber has a great effect on reinforcement of asphalt, which makes the asphalt stiffer so that the asphalt can only undertake less strain under the same stress. The heat insulation effect of the ceramic fiber will improve the temperature stability. Complex modulus and phase angle results indicate that the ceramic fiber can significantly enhance the high temperature resistance of soft binder.

  9. Characteristics of Ceramic Fiber Modified Asphalt Mortar

    PubMed Central

    Wan, Jiuming; Wu, Shaopeng; Xiao, Yue; Liu, Quantao; Schlangen, Erik

    2016-01-01

    Ceramic fiber, with a major composition of Al2O3 and SiO2, has advantages of stability at relatively high temperature, big specific surface area and resistance to external mechanical vibration. It has the potential contribution of improving the rutting resistance and temperature sensitivity of modified asphalt binder by proper modification design. In this research, ceramic fiber was introduced into both pen 60/80 and pen 80/100 asphalt binder by different weight ratios. An asphalt penetration test, softening point test, ductility test and dynamic viscoelastic behavior were conducted to characterize and predict the ceramic fiber modified asphalt mortar (CFAM). Research results indicated that the ceramic fiber has a great effect on reinforcement of asphalt, which makes the asphalt stiffer so that the asphalt can only undertake less strain under the same stress. The heat insulation effect of the ceramic fiber will improve the temperature stability. Complex modulus and phase angle results indicate that the ceramic fiber can significantly enhance the high temperature resistance of soft binder. PMID:28773908

  10. Studies of Composition and performance of mountain sand concrete powders

    NASA Astrophysics Data System (ADS)

    Tang, ZH; Li, XG; Nie, X. P.; Wang, J. C.; Shuai, S. X.

    2017-02-01

    We have designed experiments to study the effect of gravel and sand on different labels of concrete. The result show that the compressive strength can be improved by increasing the proportion of mortar in low-grade concrete and increasing the proportion of stone in high-grade concrete. Tests showed that the powder of gravel and sand can significantly improve the mixing performance of concrete. The correlation of performance indicators with the strength of fresh concrete was also analyzed. The results in this research have important guiding significance for the design of concrete mix ratio and the application of powder in concrete.

  11. A historical review of additives and modifiers used in paving asphalt refining processes in the United States.

    PubMed

    Mundt, Diane J; Adams, Robert C; Marano, Kristin M

    2009-11-01

    The U.S. asphalt paving industry has evolved over time to meet various performance specifications for liquid petroleum asphalt binder (known as bitumen outside the United States). Additives to liquid petroleum asphalt produced in the refinery may affect exposures to workers in the hot mix paving industry. This investigation documented the changes in the composition and distribution of the liquid petroleum asphalt products produced from petroleum refining in the United States since World War II. This assessment was accomplished by reviewing documents and interviewing individual experts in the industry to identify current and historical practices. Individuals from 18 facilities were surveyed; the number of facilities reporting use of any material within a particular class ranged from none to more than half the respondents. Materials such as products of the process stream, polymers, elastomers, and anti-strip compounds have been added to liquid petroleum asphalt in the United States over the past 50 years, but modification has not been generally consistent by geography or time. Modifications made to liquid petroleum asphalt were made generally to improve performance and were dictated by state specifications.

  12. Characterization of asphalt additive produced from hydroretorted Alabama shale

    SciTech Connect

    Rue, D.M.; Roberts, M.J.

    1992-12-31

    Shale oil, produced from beneficiated Alabama shale by pressurized fluidized-bed hydroretorting, was fractionated to produce shale oil asphalt additives (SOA). Three shale oil fractions boiling above 305{degrees}C were added to standard AC-20 asphalt to improve pavement properties. The physical properties and aging characteristics of AC-20 asphalt binder (cement) containing SOA are similar to those of unmodified AC-20 asphalt binder. Asphalt pavement briquettes made with AC-20 asphalt binder containing 5 to 10 percent SOA have superior resistance to freeze-thaw cracking and a greater retention of tensile strength when wet compared to pavement briquettes containing AC-20 binder alone.

  13. Assessments of low emission asphalt mixtures produced using combinations of foaming agents

    NASA Astrophysics Data System (ADS)

    Mohd Hasan, Mohd Rosli

    The asphalt foaming techniques have been used over the last couple of decades as an alternative to the traditional method of preparing asphalt mixtures. Based on positive feedback from the industry, this study was initiated to explore and evaluate the performance of the Warm Mix Asphalt (WMA) mixture produced through a foaming process using physical and chemical foaming agents, which are ethanol and sodium bicarbonate (NaHCO3), respectively. The success of this project may lead to new theories and provide an environmentally friendly technique to produce asphalt mixtures. This may advance the understanding of the foaming process and improve the performance of WMA to support sustainable development. Theoretically, ethanol can function in the same manner as water but requires less energy to foam due to its lower boiling point, 78°C. During the asphalt foaming process, numerous bubbles were generated by the vaporized ethanol, which significantly increased the volume of the asphalt binder, hence the coating potential of aggregates improves. The sodium bicarbonate was incorporated to enhance the quantity of bubbles and its stability. Therefore, understanding foaming agents, their solubility, chemical reactions, chemical function groups and rheological properties of the foamed binder are essential to help control the foam structure and final properties of the foamed WMA mixture. In order to understand the overall performance of newly developed foaming WMA, this material was evaluated for moisture susceptibility, rutting potential, and resistance to fracture and thermal cracking. The coatability, workability and compactability of foamed asphalt mixtures during production were also evaluated. Based on the results, it was found that the newly proposed foaming WMA has high potential to promote sustainable development by lowering the energy consumption and impacts on the environment. The ethanol is efficient in lowering the viscosity of asphalt binders, enhancing the

  14. Glass transition and physical hardening of asphalts

    NASA Astrophysics Data System (ADS)

    Kriz, Pavel

    Glass transition and physical hardening was studied in straight-run paving asphalt binders. Two methods, modulated differential scanning calorimetry and dynamic mechanical analysis, were utilized in this study. Kinetic nature of the glass transition was observed in studied asphalts. The glass transition temperature, which represents the transition, was found to be a quantity dependent on observation time and thus meaningless without observation time being specified. The glass transition of asphalts was found to be very broad on the temperature scale due to complexity of the chemical composition. Asphalts were found to be multiphase systems, with glassy amorphous, non-glassy amorphous and crystalline domains existing between approximately 10 and -45°C. Physical hardening was observed in asphalts at broad range of temperatures. Physical aging, i.e. structural relaxation of the glass, was identified as a major process contributing to physical hardening. Direct effect of crystallization was rather insignificant in the temperature range of glass transition. However, the presence of crystals was suggested to affect the molecular mobility of the amorphous phase and thus increase the hardening rate and also extent the phenomenon to higher temperatures outside the normal glass transition range. The concept of rigid amorphous phase was offered. The effect of the physical hardening could generally be reversed upon heating to higher temperature. Although for semi-crystalline asphalt, temperature higher by 50°C than the isothermal storage temperature, was found not to be sufficient to successfully reverse the hardening. Effect of thermal stress on the hardening rate was studied. It was found that the imposed stress was either not significant factor affecting the asphalt hardening or the imposed stress was too low to affect hardening rate significantly. Rheological model able to capture the dependence of relaxation times on the isothermal storage time, reference temperature

  15. Rheological properties of asphalts with particulate additives

    SciTech Connect

    Shashidhar, N.; Chollar, B.H.

    1996-12-31

    The Superpave asphalt binder specifications are performance-based specifications for purchasing asphalt binders for the construction of roads. This means that the asphalt is characterized by fundamental material (rheological) properties that relate to the distress modes of the pavements. The distress modes addressed are primarily rutting, fatigue cracking and low temperature cracking. For example, G*/sin({delta}) is designed to predict the rutting potential of pavements, where G* is the magnitude of the complex shear modulus and 6 is the phase angle. The binder for a road that is situated in a certain climatic zone requires the binder to have a minimum G*/sin({delta}) of 2200 Pa at the highest consecutive 7-day average pavement temperature the road had experienced. Implicit in such a performance based specification is that the fundamental property, G*/sin({delta}), of the binder correlates with rutting potential of the pavement regardless of the nature of the binder. In other words, the specification is transparent to the fact that the binder can simply be an asphalt, or an asphalt modified by polymers, particulates and other materials that can form a two-phase mixture. This paper discusses the asphalt-particulate system.

  16. Exposure to ultrafine particles in asphalt work.

    PubMed

    Elihn, Karine; Ulvestad, Bente; Hetland, Siri; Wallen, Anna; Randem, Britt Grethe

    2008-12-01

    An epidemiologic study has demonstrated that asphalt workers show increased loss of lung function and an increase of biomarkers of inflammation over the asphalt paving season. The aim of this study was to investigate which possible agent(s) causes the inflammatory reaction, with emphasis on ultrafine particles. The workers' exposure to total dust, polycyclic aromatic hydrocarbons, and NO(2) was determined by personal sampling. Exposure to ultrafine particles was measured by means of particle counters and scanning mobility particle sizer mounted on a van following the paving machine. The fractions of organic and elemental carbon were determined. Asphalt paving workers were exposed to ultrafine particles with medium concentration of about 3.4 x 10(4)/cm(3). Ultrafine particles at the paving site originated mainly from asphalt paving activities and traffic exhaust; most seemed to originate from asphalt fumes. Oil mist exceeded occupational limits on some occasions. Diesel particulate matter was measured as elemental carbon, which was low, around 3 microg/m(3). NO(2) and total dust did not exceed limits. Asphalt pavers were exposed to relatively high concentrations of ultrafine particles throughout their working day, with possible adverse health effects.

  17. Asphalt: paving the way to development

    SciTech Connect

    Not Available

    1984-02-22

    Synthetic asphalt (extracted from the residual-fuel output of refineries as opposed to naturally occurring Gilsonite) is priced below that of the original barrel of crude in many countries; in such circumstances, it is virtually a waste product. Energy planners recognize the illogic of allowing any vital, nonrenewable natural resource such as petroleum to generate any unnecessary waste. Coking units, such as the US $1.2-billion unit at Pascagoula, MS, convert the resid end of the barrel to gasoline, distillates, and coke, virtually eliminating the former waste. Although asphalt is an integral part of a country's national transportation system, and therefore of infrastructure and economic well-being, its constructive use still must surmount its traditional position as a mere by-product of refining. Asphalt's value also goes to motor-fuel efficiency, and the effects of highway conditions on vehicles. Poor roads waste fuel not only in driving, but in burning of fuel to heat and transport asphalt when repairs must be frequent. Since the finding cost alone of new oil in oil-producing countries is in the area of US $14 per barrel, it is probable that asphalt prices will eventually rise. Domestic asphalt prices in 23 nations are compared. Lowest prices are found in oil-exporting, developing countries; highest prices are usually found in oil-importing countries, whether industrialized or not. This issue presents the fuel price/tax series and the industrial fuel prices for February for countries of the Western Hemisphere.

  18. Rapid determination of actinides in asphalt samples

    DOE PAGES

    Maxwell, Sherrod L.; Culligan, Brian K.; Hutchison, Jay B.

    2014-01-12

    A new rapid method for the determination of actinides in asphalt samples has been developed that can be used in emergency response situations or for routine analysis If a radiological dispersive device (RDD), Improvised Nuclear Device (IND) or a nuclear accident such as the accident at the Fukushima Nuclear Power Plant in March, 2011 occurs, there will be an urgent need for rapid analyses of many different environmental matrices, including asphalt materials, to support dose mitigation and environmental clean up. The new method for the determination of actinides in asphalt utilizes a rapid furnace step to destroy bitumen and organicsmore » present in the asphalt and sodium hydroxide fusion to digest the remaining sample. Sample preconcentration steps are used to collect the actinides and a new stacked TRU Resin + DGA Resin column method is employed to separate the actinide isotopes in the asphalt samples. The TRU Resin plus DGA Resin separation approach, which allows sequential separation of plutonium, uranium, americium and curium isotopes in asphalt samples, can be applied to soil samples as well.« less

  19. Observation of asphalt binder microstructure with ESEM.

    PubMed

    Mikhailenko, P; Kadhim, H; Baaj, H; Tighe, S

    2017-09-01

    The observation of asphalt binder with the environmental scanning electron microscope (ESEM) has shown the potential to observe asphalt binder microstructure and its evolution with binder aging. A procedure for the induction and identification of the microstructure in asphalt binder was established in this study and included sample preparation and observation parameters. A suitable heat-sampling asphalt binder sample preparation method was determined for the test and several stainless steel and Teflon sample moulds developed, finding that stainless steel was the preferable material. The magnification and ESEM settings conducive to observing the 3D microstructure were determined through a number of observations to be 1000×, although other magnifications could be considered. Both straight run binder (PG 58-28) and an air blown oxidised binder were analysed; their structures being compared for their relative size, abundance and other characteristics, showing a clear evolution in the fibril microstructure. The microstructure took longer to appear for the oxidised binder. It was confirmed that the fibril microstructure corresponded to actual characteristics in the asphalt binder. Additionally, a 'bee' micelle structure was found as a transitional structure in ESEM observation. The test methods in this study will be used for more comprehensive analysis of asphalt binder microstructure. © 2017 The Authors Journal of Microscopy © 2017 Royal Microscopical Society.

  20. Rapid determination of actinides in asphalt samples

    SciTech Connect

    Maxwell, Sherrod L.; Culligan, Brian K.; Hutchison, Jay B.

    2014-01-12

    A new rapid method for the determination of actinides in asphalt samples has been developed that can be used in emergency response situations or for routine analysis If a radiological dispersive device (RDD), Improvised Nuclear Device (IND) or a nuclear accident such as the accident at the Fukushima Nuclear Power Plant in March, 2011 occurs, there will be an urgent need for rapid analyses of many different environmental matrices, including asphalt materials, to support dose mitigation and environmental clean up. The new method for the determination of actinides in asphalt utilizes a rapid furnace step to destroy bitumen and organics present in the asphalt and sodium hydroxide fusion to digest the remaining sample. Sample preconcentration steps are used to collect the actinides and a new stacked TRU Resin + DGA Resin column method is employed to separate the actinide isotopes in the asphalt samples. The TRU Resin plus DGA Resin separation approach, which allows sequential separation of plutonium, uranium, americium and curium isotopes in asphalt samples, can be applied to soil samples as well.

  1. Development of superior asphalt recycling agents. Phase 1, Technical feasibility. Technical progress report

    SciTech Connect

    Bullin, J.A.; Glover, C.J.; Davison, R.R.; Chaffin, J.; Lin, Moon-Sun

    1995-07-01

    About 27 million tons of asphalt and nearly twenty times this much aggregate are consumed each year to build and maintain over two million miles of roads in this country. Over a cycle of about 12 years on the average, these roads must be reworked and much of these millions of tons of rock and asphalt cannot be reused with present recycling technology. Instead, much of the maintenance is accomplished by placing thick layers (hot-mix overlays) of new material on top of the failed material. This results in considerable waste of material, both in terms of quality aggregate and in terms of asphalt binder. In addition, the new asphalt binder represents a significant source of potential energy. The main impediment to recycling asphalt binder is the poorly developed science of recycling agent composition and, as a result, optimum recycling agents are not available. An excellent recycling agent should not only be able to reduce the viscosity of the aged material, but it must also be able to restore compatibility. The properties of the old material and recycling agent must be compatible to give both good initial properties and aging characteristics, and this must be understood. The agent must also be inexpensive and easily manufactured. A large quantity of potential feedstock for the production of recycling agents is available and much of it is now fed to cokers. This material could be recovered by supercritical extraction which is an existing refinery technology. A supercritical pilot plant is available at Texas A&M and has been used to produce fractions for study. The objective of this research is to establish the technical feasibility of determining the specifications and operating parameters necessary to produce high quality recycling agents which will allow most old asphalt-based road material to be recycled.

  2. Hei-way general purpose recycled asphalt material (RHM). Final report

    SciTech Connect

    Dash, U.

    1993-02-01

    Utilization of Reclaimed Asphalt Pavement (RAP) in paving projects is a popular concept. It conserves material and can often provide an economical alternative to using virgin materials. The research summarizes the utilization of about 8000 tons of RAP in a project in Armstrong County (SR 3011 and SR 3013) using a proprietary process by Heilman Pavement Specialities. The mix is called Recycled Heilman Mix (RHM), which is prepared using a proprietary blend of asphalt cement (AC-5) and a rejuvenator mixed with equal weights of RAP and virgin aggregates in a batch-type pugmill. A control mix was produced by using 9.6 gallons per ton of E-5 emulsion and a blend of equal weights of RAP and coarse aggregates. The construction of the two sites were completed in September 1988 without any significant problems. A three-wheeled roller, ballasted rubber-tired roller and a second 1-ton tandem roller was used for compaction. There were no significant construction problems. RHM performed well on this project. The method of recycling asphalt pavements appears to be viable. RHM is stockpileable. Although RHM was 40 to 50 percent more expensive on the project, the life cycle costs on larger projects can be more competitive, especially when the cost of a seal coat is either avoided or delayed on RHM jobs when compared to E-5 mixes as control.

  3. Development of an Image-based Multi-Scale Finite Element Approach to Predict Fatigue Damage in Asphalt Mixtures

    NASA Astrophysics Data System (ADS)

    Arshadi, Amir

    compared. Indirect tensile fatigue tests were conducted on asphalt mixture samples. A comparison between experimental results and the results from simulation shows that the model developed in this study is capable of predicting the effect of asphalt binder properties and aggregate micro-structure on mechanical behavior of asphalt concrete under loading.

  4. Bond characteristics of reinforcing steel embedded in geopolymer concrete

    NASA Astrophysics Data System (ADS)

    Kathirvel, Parthiban; Thangavelu, Manju; Gopalan, Rashmi; Raja Mohan Kaliyaperumal, Saravana

    2017-07-01

    The force transferring between reinforcing steel and the surrounding concrete in reinforced concrete is influenced by several factors. Whereas, the study on bond behaviour of geopolymer concrete (GPC) is lagging. In this paper, an experimental attempt has been made to evaluate the geopolymer concrete bond with reinforcing steel of different diameter and embedded length using standard pull out test. The geopolymer concrete is made of ground granulated blast furnace slag (GGBFS) as geopolymer source material (GSM). The tests were conducted to evaluate the development of bond between steel and concrete of grade M40 and M50 with 12 and 16 mm diameter reinforcing steel for geopolymer and cement concrete mixes and to develop a relation between bond strength and compressive strength. From the experimental results, it has been observed that the bond strength of the geopolymer concrete mixes was more compared to the cement concrete mixes and increases with the reduction in the diameter of the bar.

  5. Dermal exposure and urinary 1-hydroxypyrene among asphalt roofing workers

    SciTech Connect

    McClean, M.D.; Rinehart, R.D.; Sapkota, A.; Cavallari, J.M.; Herrick, R.F.

    2007-07-01

    The primary objective of this study was to identify significant determinants of dermal exposure to polycyclic aromatic compounds (PACs) among asphalt roofing workers and use urinary 1-hydroxyprene (1-OHP) measurements to evaluate the effect of dermal exposure on total absorbed dose. The study population included 26 asphalt roofing workers who performed three primary tasks: tearing off old roofs, putting down new roofs, and operating the kettle at ground level. During multiple consecutive work shifts, dermal patch samples were collected from the underside of each worker's wrists and were analyzed for PACs, pyrene, and benzo(a)pyrene (BAP). During the same work week, urine samples were collected at pre-shift, post-shift, and bedtime each day and were analyzed for 1-OHP (205 urine samples). Linear mixed effects models were used to evaluate the dermal measurements for the purpose of identifying important determinants of exposure, and to evaluate urinary 1-OHP measurements for the purpose of identifying important determinants of total absorbed dose. Dermal exposures to PAC, pyrene, and BAP were found to vary significantly by roofing task and by the presence of an old coal tar pitch roof. For each of the three analytes, the adjusted mean dermal exposures associated with tear-off were approximately four times higher than exposures associated with operating the kettle. Exposure to coal tar pitch was associated with a 6-fold increase in PAC exposure, an 8-fold increase in pyrene exposure and a 35-fold increase in BAP exposure. The presence of coal tar pitch was the primary determinant of dermal exposure, particularly for exposure to BAP. However, the task-based differences that were observed while controlling for pitch suggest that exposure to asphalt also contributes to dermal exposures.

  6. Analysis of asphalt-based roof systems using thermal analysis

    SciTech Connect

    Paroli, R.M.; Delgado, A.H.

    1996-12-31

    Asphalt has been used in the construction of roads and houses for thousands of years. The properties of asphalt has rendered it quite useful in roofing and waterproofing applications. The most popular use of asphalt in industrial roofing is in the form of a built-up roof or modified-bituminous sheet. This type of roof consists of asphalt, reinforcement and aggregate which is used to protect the asphalt from ultraviolet rays. All materials have their weaknesses and asphalt is no exception. A good asphalt (e.g., low asphaltene content) must be used to ensure the quality and low-temperature performance of roofing asphalts. Polymer additives can be added. The objective of this work was to demonstrate the utility of termogravimetry and dynamic mechanical analysis in establishing the durability of modified bituminous membranes.

  7. Preparation and rheological behavior of polymer-modified asphalts

    NASA Astrophysics Data System (ADS)

    Yousefi, Ali Akbar

    1999-09-01

    Different materials and methods were used to prepare and stabilize polymer-modified asphalts. Addition of thermoplastic elastomers improved some technically important properties of asphalt. Due to inherent factors like large density difference between asphalt and polyethylene, many physical methods in which the structure of asphalt is unchanged, failed to stabilize this system. The effect of addition of copolymers and a pyrolytic oil residue derived from used tire rubber were also studied and found to be ineffective on the storage stability of the polymer-asphalt emulsions while high and moderate temperature properties of the asphalt were found to be improved. Finally, the technique of catalytic grafting of polymer on the surface of high-density particles (e.g. carbon black) was used to balance the large density difference between asphalt and polymer. The resulting polymer-asphalts were stable at high temperatures and showed enhanced properties at low and high temperatures.

  8. SITE DEMONSTRATION CAPSULE --MATCON MODIFIED ASPHALT FOR WASTE CONTAINMENT

    EPA Science Inventory

    MatCon is a polymer modified asphalt material designed specifically for waste contaminment applications. The modifications to the material differentiate it from conventional paving asphalt by minimizing the damaging effects of environmental exposure that could detract from the d...

  9. Investigation of fatigue failure in bituminous base mixes

    NASA Astrophysics Data System (ADS)

    Maupin, G. W., Jr.

    1980-02-01

    A correlation between the results obtained with the fatigue test and those from the indirect tensile test on two base mixes was attempted in anticipation of the possible use of the latter test to design base mixes for maximum fatigue life. Two base mixes at several asphalt contents were tested at two test temperatures. Flexural fatigue tests and indirect tensile tests were performed for each mix and temperature condition. The asphalt content corresponding to the maximum fatigue life agreed generally with the asphalt content corresponding to maximum work in the indirect tensile test. The work computed from the indirect tensile test is useful in selecting the asphalt content for the maximum fatigue life of base mixes.

  10. Effects of preparation process on performance of rubber modified asphalt

    NASA Astrophysics Data System (ADS)

    Liu, Hanbing; Luo, Guobao; Wang, Xianqiang; Jiao, Yubo

    2015-06-01

    The rational utilization of waste rubber tire is essential for the environmental protection. Utilizing rubber particles to modify asphalt can not only improve asphalt performance, but also help the recycling of waste materials. Considering the effect of different preparation process parameters on the performance of rubber modified asphalt, this paper analyzes the effects of the shear temperature, shear time and shear rate on the performance of rubber modified asphalt, and provided a reference for its preparation.

  11. Concrete Construction Using Slipform Techniques.

    DTIC Science & Technology

    1982-11-01

    is a type of extrusion process. Plastic concrete is placed or pumped into moving forms which shape and hold the concrete until it is self-supporting...Various methods of moving and lifting sectional forms were tried, but all had the same defect of leaving numerous horizontal and vertical joints in the...skid-mounted box equipped with a vibrator and extrusion e plate. This machine was pulled by the ready-mix trucks or transit 6 trucks which supplied the

  12. 40 CFR 52.2054 - Control of asphalt paving material.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 5 2013-07-01 2013-07-01 false Control of asphalt paving material. 52... asphalt paving material. (a) Notwithstanding any provisions to the contrary in the Pennsylvania Implementation Plan, the Pennsylvania Department of Transportation shall restrict the annual usage of asphalts to...

  13. 7 CFR 3201.76 - Asphalt and tar removers.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 15 2014-01-01 2014-01-01 false Asphalt and tar removers. 3201.76 Section 3201.76... Designated Items § 3201.76 Asphalt and tar removers. (a) Definition. Cleaning agents designed to remove asphalt or tar from equipment, roads, or other surfaces. (b) Minimum biobased content. The Federal...

  14. 7 CFR 3201.76 - Asphalt and tar removers.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 15 2013-01-01 2013-01-01 false Asphalt and tar removers. 3201.76 Section 3201.76... Designated Items § 3201.76 Asphalt and tar removers. (a) Definition. Cleaning agents designed to remove asphalt or tar from equipment, roads, or other surfaces. (b) Minimum biobased content. The Federal...

  15. 40 CFR 52.2054 - Control of asphalt paving material.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 5 2012-07-01 2012-07-01 false Control of asphalt paving material. 52... asphalt paving material. (a) Notwithstanding any provisions to the contrary in the Pennsylvania Implementation Plan, the Pennsylvania Department of Transportation shall restrict the annual usage of asphalts to...

  16. 40 CFR 52.2054 - Control of asphalt paving material.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 5 2014-07-01 2014-07-01 false Control of asphalt paving material. 52... asphalt paving material. (a) Notwithstanding any provisions to the contrary in the Pennsylvania Implementation Plan, the Pennsylvania Department of Transportation shall restrict the annual usage of asphalts to...

  17. Full-Depth Asphalt Pavements for Parking Lots and Driveways.

    ERIC Educational Resources Information Center

    Asphalt Inst., College Park, MD.

    The latest information for designing full-depth asphalt pavements for parking lots and driveways is covered in relationship to the continued increase in vehicle registration. It is based on The Asphalt Institute's Thickness Design Manual, Series No. 1 (MS-1), Seventh Edition, which covers all aspects of asphalt pavement thickness design in detail,…

  18. 40 CFR 52.2054 - Control of asphalt paving material.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 4 2011-07-01 2011-07-01 false Control of asphalt paving material. 52... asphalt paving material. (a) Notwithstanding any provisions to the contrary in the Pennsylvania Implementation Plan, the Pennsylvania Department of Transportation shall restrict the annual usage of asphalts...

  19. 40 CFR 52.2054 - Control of asphalt paving material.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Control of asphalt paving material. 52... asphalt paving material. (a) Notwithstanding any provisions to the contrary in the Pennsylvania Implementation Plan, the Pennsylvania Department of Transportation shall restrict the annual usage of asphalts...

  20. Current practices for modification of paving asphalts

    SciTech Connect

    Bahia, H.U.; Perdomo, D.

    1996-12-31

    The Superpave binder specification, AASHTO MP1, has introduced new concepts for selecting paving asphalt binders. The specification, in addition to using rheological and failure measurements that are more related to performance, is based on the idea that the criteria to maintain a satisfactory contribution of asphalt binders to the resistance of pavement failures remains the same but have to be satisfied at critical application temperatures. The test procedures require that the material be characterized within certain ranges of strains or stresses to ensure that material and geometric non-linearities are not confounded in the measurements. These new specification concepts have resulted in re-evaluation of asphalt modification by the majority of modified asphalt suppliers. The philosophy of asphalt modification is expected to change, following these new concepts, from a general improvement of quality to more focus on using modifiers based on the most critical need as defined by two factors: (1) The application temperature domain and (2) the type of distress to be remedied. The new specification requirements should result in a more effective use of modifiers as the amount and type of modifier will be directly related to the application environment and the engineering requirements.

  1. Asphalt and risk of cancer in man.

    PubMed Central

    Chiazze, L; Watkins, D K; Amsel, J

    1991-01-01

    Epidemiological publications regarding the carcinogenic potential of asphalt (bitumen) are reviewed. In 1984 the International Agency for Research on Cancer (IARC) stated that there is "inadequate evidence that bitumens alone are carcinogenic to humans." They did, however, conclude that animal data provided sufficient evidence for the carcinogenicity of certain extracts of steam refined and air refined bitumens. In the absence of data on man, IARC considered it reasonable to regard chemicals with sufficient evidence of carcinogenicity in animals as if they presented a carcinogenic risk to man. Epidemiological data for man accumulated since the IARC report do not fulfil the criteria for showing a causal association between exposure to asphalt and development of cancer. The studies cited all suffer from a lack of data on exposure or potential confounders, which are necessary to establish whether or not such an association may or may not exist. In view of the evidence (or lack thereof) regarding asphalt today, an appropriate public health attitude suggests at least that action be taken to protect those working with asphalt by monitoring the workplace, taking whatever steps are possible to minimise exposures and to inform workers of potential hazards. At the same time, a need exists for well designed analytical epidemiological studies to determine whether a risk of cancer in man exists from exposure to asphalt. PMID:1878310

  2. Application of ultraviolet spectrophotometry to estimate occupational exposure to airborne polyaromatic compounds in asphalt pavers.

    PubMed

    Buratti, Marina; Campo, Laura; Fustinoni, Silvia; Valla, Carla; Martinotti, Irene; Cirla, Piero E; Cavallo, Domenico; Foà, Vito

    2007-06-01

    An ultraviolet (UV) spectrophotometric procedure was devised for the determination of polycyclic aromatic compound-oriented organic soluble matter in vapors and particulate collected from emissions of hot asphalt mix. Ultrasonic extraction was carried out with acetonitrile, followed by UV measurements at 254 nm. Polycyclic aromatic compounds (PACs) in volatile and particulate fraction were quantified as phenanthrene or benzo[k]fluoranthene equivalents. A comparison between UV and high-pressure liquid chromatography with fluorescence detection showed that PACs were one to three orders of magnitude higher than the sum of 15 priority polycyclic aromatic hydrocarbons (PAHs); still, significant correlations were found between volatile or particulate PACs and, respectively, total volatile or particulate PAHs. Moreover, in the particulate phase, PACs correlated with total particulate matter quantified by gravimetry. The proposed procedure was employed in a field study for monitoring personal exposure to asphalt emissions of workers engaged in road construction. Observed levels of acetonitrile-soluble PACs in air samples were very low (2-20 microg/m3); however, asphalt pavers were exposed to significantly higher concentrations of volatile PACs than construction workers (geometric mean, 5.9 microg/m3 vs. 4.1 microg/m3). This method for estimating the global content of volatile or particulate PACs in air samples satisfies our requirements of simplicity and is suitable for conducting an initial screening to assess exposure to airborne polyaromatic organics in asphalt pavers.

  3. Technical, financial, and geographic challenges in recycling asphalt composition roof shingles

    SciTech Connect

    Reith, C.C.; Carpenter, M.; Robertson, D.T.

    1999-07-01

    Eleven million tons of asphalt composition shingles are disposed of annually in US landfills. The wastes from roof removal or repair operations are a promising, but under-harvested feedstock for recycling. This waste stream generally arrives by truck at local landfills, where it is relatively unmixed and ready for recycling. However, in most cases the shingles are landfilled at the local tipping fee. The authors analyzed impediments and opportunities in recycling asphalt shingles and elected to commence operations in the east San Francisco Bay area, where tipping fees as high as $50 per ton provide an economic incentive to intercept and recycle this waste stream. Their approach has been to use a 60 inch x 38 inch rotating-head grinder propelled by a 400 horsepower diesel engine. Roofing waste is introduced to the grinder, which processes up to 50 tons per hour. The product is half-inch minus granular asphalt with co-mingled sand that may be used as a feedstock (approximately 5%) in the production of hot-mix asphalt, as used for road construction. A potentially more profitable reuse of recycled product is in the production of a cold patch for road repair which, when fully commercialized, will further improve the economics of shingles recycling. Other reuse scenarios are being explored. The authors are carefully chronicling and optimizing the Bay Area recycling campaign with the intent of promoting similar activities nationwide as soon as the economics become favorable.

  4. Effects on the Physical and Mechanical Properties of Porous Concrete for Plant Growth of Blast Furnace Slag, Natural Jute Fiber, and Styrene Butadiene Latex Using a Dry Mixing Manufacturing Process.

    PubMed

    Kim, Hwang-Hee; Kim, Chun-Soo; Jeon, Ji-Hong; Park, Chan-Gi

    2016-01-29

    To evaluate the effects of industrial by-products materials on the performance of porous concrete for plant growth, this study investigated the physical, strength, and freeze/thaw resistances of porous concrete for plant growth, prepared by replacing cement with blast furnace slag powder at 60% by weight, and replacing natural stone aggregates with coarse blast furnace slag aggregates at rates of 0%, 20%, 40%, 60% and 100% by weight. In addition, the effects of adding natural jute fiber and styrene butadiene (SB) latex to these concrete mixtures were evaluated. The void ratio, compressive strength, and freeze/thaw resistance of the samples were measured. With increasing replacement rate of blast furnace aggregates, addition of latex, and mixing of natural jute fiber the void ratio of the concrete was increased. Compressive strength decreased as the replacement rate of blast-furnace slag aggregates increased. The compressive strength decreased after 100 freeze/thaw cycles, regardless of the replacement rate of blast furnace slag aggregates or of the addition of natural jute fiber and latex. The addition of natural jute fiber and latex decreased the compressive strength after 100 freeze/thaw cycles. The test results indicate that the control mixture satisfied the target compressive strength of 10 MPa and the target void ratio of 25% at replacement rates of 0% and 20% for blast furnace aggregates, and that the mixtures containing latex satisfied the criteria up to an aggregate replacement rate of 60%. However, the mixtures containing natural jute fiber did not satisfy these criteria. The relationship between void ratio and residual compressive strength after 100 freeze/thaw cycles indicates that the control mixture and the mixtures containing jute fiber at aggregate replacement rates of 20% and 40% satisfied the target void ratio of 25% and the target residual compressive strength of over 80% after 100 freeze/thaw cycles. The mixtures containing latex and aggregate

  5. Effects on the Physical and Mechanical Properties of Porous Concrete for Plant Growth of Blast Furnace Slag, Natural Jute Fiber, and Styrene Butadiene Latex Using a Dry Mixing Manufacturing Process

    PubMed Central

    Kim, Hwang-Hee; Kim, Chun-Soo; Jeon, Ji-Hong; Park, Chan-Gi

    2016-01-01

    To evaluate the effects of industrial by-products materials on the performance of porous concrete for plant growth, this study investigated the physical, strength, and freeze/thaw resistances of porous concrete for plant growth, prepared by replacing cement with blast furnace slag powder at 60% by weight, and replacing natural stone aggregates with coarse blast furnace slag aggregates at rates of 0%, 20%, 40%, 60% and 100% by weight. In addition, the effects of adding natural jute fiber and styrene butadiene (SB) latex to these concrete mixtures were evaluated. The void ratio, compressive strength, and freeze/thaw resistance of the samples were measured. With increasing replacement rate of blast furnace aggregates, addition of latex, and mixing of natural jute fiber the void ratio of the concrete was increased. Compressive strength decreased as the replacement rate of blast-furnace slag aggregates increased. The compressive strength decreased after 100 freeze/thaw cycles, regardless of the replacement rate of blast furnace slag aggregates or of the addition of natural jute fiber and latex. The addition of natural jute fiber and latex decreased the compressive strength after 100 freeze/thaw cycles. The test results indicate that the control mixture satisfied the target compressive strength of 10 MPa and the target void ratio of 25% at replacement rates of 0% and 20% for blast furnace aggregates, and that the mixtures containing latex satisfied the criteria up to an aggregate replacement rate of 60%. However, the mixtures containing natural jute fiber did not satisfy these criteria. The relationship between void ratio and residual compressive strength after 100 freeze/thaw cycles indicates that the control mixture and the mixtures containing jute fiber at aggregate replacement rates of 20% and 40% satisfied the target void ratio of 25% and the target residual compressive strength of over 80% after 100 freeze/thaw cycles. The mixtures containing latex and aggregate

  6. Effect of Warm Asphalt Additive on the Creep and Recovery Behaviour of Aged Binder Containing Waste Engine Oil

    NASA Astrophysics Data System (ADS)

    Hassan, Norhidayah Abdul; Kamaruddin, Nurul Hidayah Mohd; Rosli Hainin, Mohd; Ezree Abdullah, Mohd

    2017-08-01

    The use of waste engine oil as an additive in asphalt mixture has been reported to be able to offset the stiffening effect caused by the recycled asphalt mixture. Additionally, the fumes and odor of the waste engine oil has caused an uncomfortable condition for the workers during road construction particularly at higher production temperature. Therefore, this problem was addressed by integrating chemical warm asphalt additive into the mixture which functions to reduce the mixing and compaction temperature. This study was initiated by blending the additive in the asphalt binder of bitumen penetration grade 80/100 prior to the addition of pavement mixture. The effect of chemical warm asphalt additive, Rediset WMX was investigated by modifying the aged binder containing waste engine oil with 0%, 1%, 2% and 3% by weight of the binder. The samples were then tested for determining the rutting behaviour under different loading stress levels of 3Pa (low), 10Pa (medium) and 50Pa (high) using Dynamic Shear Rheometer (DSR). A reference temperature of 60 °C was fixed to reflect the maximum temperature of the pavement. The results found that the addition of Rediset did not affect the creep and recovery behavior of the modified binder under different loading. On the other hand, 2% Rediset resulted a slight decrease in its rutting resistance as shown by the reduction of non-recoverable compliance under high load stress. However, overall, the inclusion of chemical warm asphalt additive to the modified binder did not adversely affect the rutting resistance which could be beneficial in lowering the temperature of asphalt production and simultaneously not compromising the binder properties.

  7. Thiol/disulfide homeostasis in asphalt workers.

    PubMed

    Yilmaz, Ömer Hınç; Bal, Ceylan; Neşelioglu, Salim; Büyükşekerci, Murat; Gündüzöz, Meşide; Eren, Funda; Tutkun, Lutfiye; Yilmaz, Fatma Meric

    2016-09-02

    The aim of this study was to investigate thiol/disulfide homeostasis in asphalt workers who are exposed to polycyclic aromatic hydrocarbons occupationally. The study was carried out in 34 nonsmoker asphalt workers. Additionally, 35 healthy nonsmoker volunteers were recruited as control group. Thiol and disulfide concentrations were determined using the novel automated measurement method. Levels of urinary 1-OH-pyrene were analyzed by liquid chromatography. Disulfide/thiol ratio was significantly higher in exposed group (p = .034). Also, a positive correlation was detected between disulfide/thiol ratio and 1-OH-pyrene values (r = .249, p = .036). Thiol/disulfide homeostasis was found to be disturbed in asphalt workers. The novel test used in this study may be useful for evaluating the oxidative status in polycyclic aromatic hydrocarbon (PAH) exposure.

  8. Pneumoproteins and inflammatory biomarkers in asphalt pavers.

    PubMed

    Ellingsen, Dag G; Ulvestad, Bente; Andersson, Lena; Barregard, Lars

    2010-09-01

    Pneumoproteins, biomarkers of systemic inflammation and endothelial activation were studied across a season in 72 asphalt pavers, 32 asphalt plant operators and 19 asphalt engineers. Smokers had lower concentrations of Clara cell protein (CC-16) and surfactant protein A, but higher concentrations of surfactant protein D, interleukin 6, C-reactive protein, fibrinogen and intercellular adhesion molecule (ICAM)-1 than non-smokers. Smokers reporting wheezing had lower mean CC-16 concentration than smokers not reporting wheezing (5.7 vs 8.6 microg l(-1); p = 0.05). Cholesterol, P-selectin and ICAM-1 were lower in pavers and operators at the end compared with the start of the season. This may be related to increased physical activity during the season.

  9. Minimum Thickness Requirements for Asphalt Surface Course and Base Layer in Airfield Pavements

    DTIC Science & Technology

    2011-08-01

    shear stress, and therefore, to rutting, some minimum thickness of hot- mix asphalt (HMA) is needed to protect this strong base course from the...pavements with different thicknesses of bituminous materials, and base and subbase quality materials. The analysis indicated that at elevated...temperatures, the bituminous bound pavement layers were not superior in load distributing capability to excellent quality (100 CBR) base materials. A 100-CBR

  10. Genotoxic effects of fumes from asphalt modified with waste plastic and tall oil pitch.

    PubMed

    Lindberg, Hanna K; Väänänen, Virpi; Järventaus, Hilkka; Suhonen, Satu; Nygren, Jonas; Hämeilä, Mervi; Valtonen, Jarkko; Heikkilä, Pirjo; Norppa, Hannu

    2008-05-31

    As the use of recycled materials and industrial by-products in asphalt mixtures is increasing, we investigated if recycled additives modify the genotoxicity of fumes emitted from asphalt. Fumes were generated in the laboratory at paving temperature from stone-mastic asphalt (SMA) and from SMA modified with waste plastic (90% polyethylene, 10% polypropylene) and tall oil pitch (SMA-WPT). In addition, fumes from SMA, SMA-WPT, asphalt concrete (AC), and AC modified with waste plastic and tall oil pitch (AC-WPT) were collected at paving sites. The genotoxicity of the fumes was studied by analysis of DNA damage (measured in the comet assay) and micronucleus formation in human bronchial epithelial BEAS 2B cells in vitro and by counting mutations in Salmonella typhimurium strains TA98 and YG1024. DNA damage was also assessed in buccal leukocytes from road pavers before and after working with SMA, SMA-WPT, AC, and AC-WPT. The chemical composition of the emissions was analysed by gas chromatography/mass spectrometry. The SMA-WPT fume generated in the laboratory induced a clear increase in DNA damage in BEAS 2B cells without metabolic activation. The laboratory-generated SMA fume increased the frequency of micronucleated BEAS 2B cells without metabolic activation. None of the asphalt fumes collected at the paving sites produced DNA damage with or without metabolic activation. Fumes from SMA and SMA-WPT from the paving sites increased micronucleus frequency without metabolic activation. None of the asphalt fumes studied showed mutagenic activity in Salmonella. No statistically significant differences in DNA damage in buccal leukocytes were detected between the pre- and post-shift samples collected from the road pavers. However, a positive correlation was found between DNA damage and the urinary metabolites of polycyclic aromatic hydrocarbons (PAHs) after work shift, which suggested an association between occupational exposures during road paving and genotoxic effects. Our

  11. Practical experiences with new types of highly modified asphalt binders

    NASA Astrophysics Data System (ADS)

    Špaček, Petr; Hegr, Zdeněk; Beneš, Jan

    2017-09-01

    As a result of steadily increasing traffic load on the roads in the Czech Republic, we should be focused on the innovative technical solutions, which will lead to extending the life time of asphalt pavements. One of these ways could be the future use of bitumen with a higher degree of polymer modification. This paper discusses experience with comparison of new highly polymer modified asphalt binder type with conventional polymer modified asphalt binder and unmodified binder with penetration grade 50/70. There are compared the results of various types laboratory tests of asphalt binders, as well as the results of asphalt mixtures laboratory tests. The paper also mentions the experience with workability and compactability of asphalt mixture with highly polymer modified asphalt binder during the realization of the experimental reference road section by the Skanska company in the Czech Republic.

  12. Examination of Behavior of Fresh Concrete Under Pressure

    NASA Astrophysics Data System (ADS)

    Yücel, K. T.

    2012-05-01

    Transporting fresh concrete constitutes a significant part of the production process. Transferring ready-mixed concrete on-site is done using concrete pumps. Recent developments in concrete technology, and in mineral and chemical additives, have resulted in new developments in pumping techniques and the use of different concrete mixtures and equipment. These developments required further knowledge of the behavior of fresh concrete under pressure. Two criteria were determined for the pumpability of concrete: the power required to move the concrete or of the repulsive force; and the cohesion of the fresh concrete. It would be insufficient to relate pumpability to these two criteria; the values of segregation pressure, diffusion ability, water retention capacity, and side friction of the mixture are significant parameters in ensuring that concrete is pumped freely along the pipe. To solve the pumpability problem, friction stresses should be determined as a function of the linear pressure gradient, the pressure leading to segregation of the fresh concrete should be determined, and tests for the bleeding of concrete under pressure should be examined. The scope of the research is the examination of the behavior of fresh concrete under pressure. To determine the segregation pressures, a test apparatus was designed for the bleeding of concrete under pressure. The main purpose of the study is to determine whether the concrete can be pumped easily and whether it will lose its cohesion during the pumping, based on tests of concrete workability and bleeding of concrete under pressure.

  13. Evaluation of Fatigue Performance of Asphalt Based on Constant Strain DSR Test

    NASA Astrophysics Data System (ADS)

    Zhu, H. Z.; Yan, E. H.; Lu, Z. T.

    2017-02-01

    Asphalt performance has important effect on the fatigue resistance performance of asphalt mixture. This research based on the DSR time scanning mode, investigated the constant strain performance of 70 # matrix asphalt and SBS modified asphalt. Based on 50% G* 0 to simulate the fatigue performance of two kinds of the asphalt.

  14. Quick-setting concrete and a method for making quick-setting concrete

    DOEpatents

    Wagh, A.S.; Singh, D.; Pullockaran, J.D.; Knox, L.

    1997-04-29

    A method for producing quick setting concrete is provided comprising mixing a concrete dry mixture with carbonate solution to create a slurry, and allowing the slurry to cure. The invention also provides for a quick setting concrete having a predetermined proportion of CaCO{sub 3} of between 5 and 23 weight percent of the entire concrete mixture, and whereby the concrete has a compression strength of approximately 4,000 pounds per square inch (psi) within 24 hours after pouring. 2 figs.

  15. Investigation of PAH Biomarkers in the Urine of Workers Exposed to Hot Asphalt

    PubMed Central

    Sobus, Jon R.; Mcclean, Michael D.; Herrick, Robert F.; Waidyanatha, Suramya; Onyemauwa, Frank; Kupper, Lawrence L.; Rappaport, Stephen M.

    2009-01-01

    Airborne emissions from hot asphalt contain mixtures of polycyclic aromatic hydrocarbons (PAHs), including several carcinogens. We investigated urinary biomarkers of three PAHs, namely naphthalene (Nap), phenanthrene (Phe), and pyrene (Pyr) in 20 road-paving workers exposed to hot asphalt and in 6 road milling workers who were not using hot asphalt (reference group). Our analysis included baseline urine samples as well as postshift, bedtime, and morning samples collected over three consecutive days. We measured unmetabolized Nap (U-Nap) and Phe (U-Phe) as well as the monohydroxylated metabolites of Nap (OH-Nap), Phe (OH-Phe), and Pyr (OH-Pyr) in each urine sample. In baseline samples, no significant differences in biomarker levels were observed between pavers and millers, suggesting similar background exposures. In postshift, bedtime, and morning urine samples, the high pairwise correlations observed between levels of all biomarkers suggest common exposure sources. Among pavers, levels of all biomarkers were significantly elevated in postshift samples, indicating rapid uptake and elimination of PAHs following exposure to hot asphalt (biomarker levels were not elevated among millers). Results from linear mixed-effects models of levels of U-Nap, U-Phe, OH-Phe, and OH-Pyr across pavers showed significant effects of work assignments with roller operators having lower biomarker levels than the other workers. However, no work-related effect was observed for levels of OH-Nap, apparently due to the influence of cigarette smoking. Biological half-lives, estimated from regression coefficients for time among pavers, were 8 h for U-Phe, 10 h for U-Nap, 13 h for OH-Phe and OH-Pyr, and 26 h for OH-Nap. These results support the use of U-Nap, U-Phe, OH-Phe, and OH-Pyr, but probably not OH-Nap, as short-term biomarkers of exposure to PAHs emanating from hot asphalt. PMID:19602500

  16. Investigation of PAH biomarkers in the urine of workers exposed to hot asphalt.

    PubMed

    Sobus, Jon R; McClean, Michael D; Herrick, Robert F; Waidyanatha, Suramya; Onyemauwa, Frank; Kupper, Lawrence L; Rappaport, Stephen M

    2009-08-01

    Airborne emissions from hot asphalt contain mixtures of polycyclic aromatic hydrocarbons (PAHs), including several carcinogens. We investigated urinary biomarkers of three PAHs, namely naphthalene (Nap), phenanthrene (Phe), and pyrene (Pyr) in 20 road-paving workers exposed to hot asphalt and in 6 road milling workers who were not using hot asphalt (reference group). Our analysis included baseline urine samples as well as postshift, bedtime, and morning samples collected over three consecutive days. We measured unmetabolized Nap (U-Nap) and Phe (U-Phe) as well as the monohydroxylated metabolites of Nap (OH-Nap), Phe (OH-Phe), and Pyr (OH-Pyr) in each urine sample. In baseline samples, no significant differences in biomarker levels were observed between pavers and millers, suggesting similar background exposures. In postshift, bedtime, and morning urine samples, the high pairwise correlations observed between levels of all biomarkers suggest common exposure sources. Among pavers, levels of all biomarkers were significantly elevated in postshift samples, indicating rapid uptake and elimination of PAHs following exposure to hot asphalt (biomarker levels were not elevated among millers). Results from linear mixed-effects models of levels of U-Nap, U-Phe, OH-Phe, and OH-Pyr across pavers showed significant effects of work assignments with roller operators having lower biomarker levels than the other workers. However, no work-related effect was observed for levels of OH-Nap, apparently due to the influence of cigarette smoking. Biological half-lives, estimated from regression coefficients for time among pavers, were 8 h for U-Phe, 10 h for U-Nap, 13 h for OH-Phe and OH-Pyr, and 26 h for OH-Nap. These results support the use of U-Nap, U-Phe, OH-Phe, and OH-Pyr, but probably not OH-Nap, as short-term biomarkers of exposure to PAHs emanating from hot asphalt.

  17. Petroleum degradation and associated microbial signatures at the Chapopote asphalt volcano, Southern Gulf of Mexico

    NASA Astrophysics Data System (ADS)

    Schubotz, Florence; Lipp, Julius S.; Elvert, Marcus; Kasten, Sabine; Mollar, Xavier Prieto; Zabel, Matthias; Bohrmann, Gerhard; Hinrichs, Kai-Uwe

    2011-08-01

    At the Chapopote Knoll in the Southern Gulf of Mexico, deposits of asphalt provide the substrate for a prolific cold seep ecosystem extensively colonized by chemosynthetic communities. This study investigates microbial life and associated biological processes within the asphalts and surrounding oil-impregnated sediments by analysis of intact polar membrane lipids (IPLs), petroleum hydrocarbons and stable carbon isotopic compositions (δ 13C) of hydrocarbon gases. Asphalt samples are lightly to heavily biodegraded suggesting that petroleum-derived hydrocarbons serve as substrates for the chemosynthetic communities. Accordingly, detection of bacterial diester and diether phospholipids in asphalt samples containing finely dispersed gas hydrate suggests the presence of hydrocarbon-degrading bacteria. Biological methanogenesis contributes a substantial fraction to the methane captured as hydrate in the shallow asphalt deposits evidenced by significant depletion in 13C relative to background thermogenic methane. In sediments, petroleum migrating from the subsurface stimulates both methanogenesis and methanotrophy at a sulfate-methane transition zone 6-7 m below the seafloor. In this zone, microbial IPLs are dominated by archaeal phosphohydroxyarchaeols and archaeal diglycosidic diethers and tetraethers. Bacterial IPLs dominate surface sediments that are impregnated by severely biodegraded oil. In the sulfate-reduction zone, diagnostic IPLs indicate that sulfate-reducing bacteria (SRB) play an important role in petroleum degradation. A diverse mixture of phosphohydroxyarchaeols and mixed phospho- and diglycosidic archaeal tetraethers in shallow oil-impregnated sediments point to the presence of anaerobic methane-oxidizing ANME-2 and ANME-1 archaea, respectively, or methanogens. Archaeal IPLs increase in relative abundance with increasing sediment depth and decreasing sulfate concentrations, accompanied by a shift of archaeol-based to tetraether-based archaeal IPLs. The

  18. Microstructural investigations on aerated concrete

    SciTech Connect

    Narayanan, N.; Ramamurthy, K.

    2000-03-01

    Aerated concrete is characterized by the presence of large voids deliberately included in its matrix to reduce the density. This study reports the investigations conducted on the structure of cement-based autoclaved aerated concrete (AAC) and non-AAC with sand or fly ash as the filler. The reasons for changes in compressive strength and drying shrinkage are explained with reference to the changes in the microstructure. Compositional analysis was carried out using XRD. It was observed that fly ash responds poorly to autoclaving. The process of pore refinement in fly ash mixes is discussed with reference to the formation of Hadley grains as well as fly ash hydration. The paste-void interface in aerated concrete investigated in relation to the paste-aggregate interface in normal concrete revealed the existence of an interfacial transition zone.

  19. Lignite slime as activator in production of oxidized asphalts

    SciTech Connect

    Gureev, A.A.; Gorlov, E.G.; Leont'eva, O.B.; Zotova, O.V.

    1988-03-01

    The possibility of activation of the oxidation of straight-run resids to asphalts by the addition of lignite slimes obtained in the liquefaction of coals of the Kansk-Achinsk basin was studied on the basis of a hypothesis formulated with due regard for the principles of physicochemical mechanics of petroleum disperse systems. A reduction of the air bubble size in the oxidizing vessel should lead to an increase in the total surface of oxidation and hence to a shortening of the time required for oxidation of the feed. A straight-run vacuum resid from mixed West Siberian and Ukhta crudes was used. The resid was oxidized with and without the addition of slime.

  20. Microstructural Analysis and Rheological Modeling of Asphalt Mixtures Containing Recycled Asphalt Materials

    PubMed Central

    Cannone Falchetto, Augusto; Moon, Ki Hoon; Wistuba, Michael P.

    2014-01-01

    The use of recycled materials in pavement construction has seen, over the years, a significant increase closely associated with substantial economic and environmental benefits. During the past decades, many transportation agencies have evaluated the effect of adding Reclaimed Asphalt Pavement (RAP), and, more recently, Recycled Asphalt Shingles (RAS) on the performance of asphalt pavement, while limits were proposed on the amount of recycled materials which can be used. In this paper, the effect of adding RAP and RAS on the microstructural and low temperature properties of asphalt mixtures is investigated using digital image processing (DIP) and modeling of rheological data obtained with the Bending Beam Rheometer (BBR). Detailed information on the internal microstructure of asphalt mixtures is acquired based on digital images of small beam specimens and numerical estimations of spatial correlation functions. It is found that RAP increases the autocorrelation length (ACL) of the spatial distribution of aggregates, asphalt mastic and air voids phases, while an opposite trend is observed when RAS is included. Analogical and semi empirical models are used to back-calculate binder creep stiffness from mixture experimental data. Differences between back-calculated results and experimental data suggest limited or partial blending between new and aged binder. PMID:28788190