Sample records for hot mix asphalt

  1. SOURCE ASSESSMENT: ASPHALT HOT MIX

    EPA Science Inventory

    This report summarizes data on air emissions from the asphalt hot mix industry. A representative asphalt hot mix plant was defined, based on the results of an industrial survey, to assess the severity of emissions from this industry. Source severity was defined as the ratio of th...

  2. Mix design procedure for crumb rubber modified hot mix asphalt.

    DOT National Transportation Integrated Search

    2005-06-01

    To improve the performance of hot-mix asphalt concrete at high temperatures, crumb-rubber is typically used. Although hot-mix asphalt concrete consisting of crumb-rubber has been successfully placed and have performed well over the years, the laborat...

  3. Special Specification 3XXX, dense-graded hot-mix asphalt.

    DOT National Transportation Integrated Search

    2004-01-01

    Construct a hot-mix asphalt (HMA) pavement layer composed of a compacted, dense-graded mixture of aggregate and asphalt binder mixed hot in a mixing plant. Pay adjustments will apply to HMA placed under this specification unless the HMA is deemed exe...

  4. Hot Mix Asphalt for Intersections in Hot Climates

    DOT National Transportation Integrated Search

    1998-03-01

    Rutting of hot mix asphalt (HMA) pavement at or near intersections is very common both in cold and hot climates. Obviously, the problem is more acute in hot climates compared to cold climates because the stiffness of HMA decreases with increase in pa...

  5. Evaluation of crumb rubber in hot mix asphalt.

    DOT National Transportation Integrated Search

    2004-07-01

    An asphalt-rubber hot mix asphalt (AR-HMA) design was created using a Superpave 12.5mm gradation and a #30 (-) mesh : crumb rubber at 20% total weight of the asphalt binder. At this point in time, asphalt rubber has only been used with HMA : that con...

  6. Detection of stripping in hot mix asphalt.

    DOT National Transportation Integrated Search

    2005-03-11

    Stripping in hot mix asphalt (HMA) refers to the loss of adhesion between the asphalt cement and the aggregate surface primarily caused by the action of moisture and moisture vapor (Kandhal and Rickards 2001). Moisture damage begins with a reduction ...

  7. Incorporation of recycled asphalt shingles in hot-mixed asphalt pavement mixtures.

    DOT National Transportation Integrated Search

    2010-03-01

    Rises in construction and asphalt binder costs, as well as the growing pressures on landfills, have contributed to the : increased use of tear-off scrap shingles (TOSS) and manufacturer waste scrap shingles (MWSS) into hot-mixed : asphalt (HMA) pavem...

  8. Evaluation of hot mix asphalt moisture sensitivity using the Nottingham asphalt test equipment.

    DOT National Transportation Integrated Search

    2005-07-01

    Moisture sensitivity of Hot Mix Asphalt (HMA) mixtures, generally called stripping, is a major form of distress in asphalt concrete pavement. It is characterized by the loss of adhesive bond between the asphalt binder and the aggregate (a failure of ...

  9. Workability of hot mix asphalt

    DOT National Transportation Integrated Search

    2003-04-01

    Workability in the field can be defined as a property that describes the ease with which hot mix asphalt (HMA) can be placed, worked by hand and compacted. Use of polymer-modified binders has increase in the U.S. due to the resultant performance bene...

  10. Hot mix asphalt tender zone

    DOT National Transportation Integrated Search

    2000-04-01

    Approximately 500 million tons of hot mix asphalt (HMA) are placed in the United States each year. With this large quantity of HMA, it is expected that some construction problems will occur from time to time. One problem that has been observed for ye...

  11. Field Management of Hot Mix Asphalt Volumetric Properties

    DOT National Transportation Integrated Search

    1995-12-01

    The Federal Highway Administration (FHWA) Demonstration Project No. 74 has clearly shown that significant differences exist between the volumetric properties of the laboratory designed and plant produced hot mix asphalt (HMA) mixes. The volumetric pr...

  12. 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

  13. 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.

  14. Performance Testing of Hot-Mix Asphalt Aggregates

    DOT National Transportation Integrated Search

    1999-12-01

    Hot mix asphalt (HMA) pavements are subject to thermal cracking, fatigue cracking, rutting, stripping, raveling, and freeze-thaw damage. Some of these distresses are directly affected by the choice of aggregates. Particle shape, surface texture, part...

  15. Use of NDT equipment for construction quality control of hot mix asphalt pavements

    DOT National Transportation Integrated Search

    2006-08-01

    The focus of the study has been to evaluate the utility of seismic methods in the quality management of the hot mix asphalt layers. Procedures are presented to measure the target field moduli of hot mix asphalt (HMA) with laboratory seismic methods, ...

  16. 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

  17. 77 FR 50608 - Approval and Promulgation of Air Quality Implementation Plans; New Hampshire; Hot Mix Asphalt Plants

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-22

    ... and Promulgation of Air Quality Implementation Plans; New Hampshire; Hot Mix Asphalt Plants AGENCY... is approving a revision to New Hampshire's regulation Env-A 2703.02 for hot mix asphalt plants. This rule establishes and requires limitations on visible emissions from all hot mix asphalt plants. This...

  18. Laboratory accelerated stripping simulator for hot mix asphalt.

    DOT National Transportation Integrated Search

    2005-01-18

    Moisture susceptibility of hot mix asphalt (HMA) pavements continues to be a major pavement distress. Past research : has primarily focused on HMA stripping prevention through material component evaluation/testing and addition of : preventative addit...

  19. Evaluation of Superpave Gyratory Compaction of Hot Mix Asphalt

    DOT National Transportation Integrated Search

    1988-01-01

    About 85 percent of hot mix asphalt (HMA) by volume consist of mineral aggregate. One of the most important properties of the aggregate in a HMA mix is the gradation. This study was carried out to evaluate the effect of restricted zone on volumetric ...

  20. Material acceptance risk analysis : superpave hot mix asphalt.

    DOT National Transportation Integrated Search

    2010-09-01

    The objective of this study is to review Superpave Hot Mix asphalt used by other state DOTs and make recommendation to Idaho Transportation Department (ITD) in using this product in its roadways and in particular in low-traffic roadways. Based on the...

  1. Investigation of using steel slag in hot mix asphalt for the surface course of flexible pavements

    NASA Astrophysics Data System (ADS)

    Nguyen, Hien Q.; Lu, Dai X.; Le, Son D.

    2018-04-01

    The rapid development of heavy industry in Vietnam leads to the establishments of steel industry. Steel slag, a by-product of steelwork industry, under Vietnamese’s law, was considered as a deleterious solid waste which needed to be processed and landfilled. However, this has changed recently, and steel slag is now seen as a normal or non-deleterious solid waste, and has been studied for reuse in the construction industry. In this study, steel slag was used, as a replacement for mineral aggregate, in hot mix asphalt. Two hot mix asphalt mixtures with an equivalent nominal aggregate size of 12.5 (C12.5) and 19 mm (C19) were produced using steel slag. In addition, one conventional hot mix asphalt mixture of C19 was produced using mineral aggregate for comparison purpose. Investigation in laboratory condition and trial sections was carried out on Marshall tests, surface roughness, skid resistance, and modulus of the pavement before and after applying a new surface course of hot mix asphalt. The study showed that all steel slag asphalt mixtures passed the Marshall stability and flow test requirements. The skid resistance of steel slag hot mix asphalt mixtures for the surface course satisfied the Vietnamese specification for asphalt. Moreover, the pavement sections with the surface course of steel slag hot mix asphalt showed a considerable higher modulus than that of the conventional one. Only the roughness of the surface course paved with C19 did not pass the requirement of the specification.

  2. Effect of end-point compaction on superpave hot mix asphalt (HMA) mix designs.

    DOT National Transportation Integrated Search

    2004-01-09

    In the Superpave hot mix asphalt (HMA) mix design system, gyratory specime ns are compacted to varying levels of initial (Ninitial), : design (Ndesign) and maximum (Nmaximum) gyrations. Initially, in the Superpave system, specimens were compacted to ...

  3. Performance of polymer modified hot mix asphalt pavements : an extended evaluation.

    DOT National Transportation Integrated Search

    2004-03-01

    In the summer of 1996, the Mississippi Department of Transportation (MDOT) initiated a field trial (MDOT : State Study No. 111) and a laboratory study (MDOT State Study No. 123) to evaluate the use of polymer : modified asphalts in hot mix asphalt pa...

  4. 77 FR 50651 - Approval and Promulgation of Air Quality Implementation Plans; New Hampshire; Hot Mix Asphalt Plants

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-22

    ... and Promulgation of Air Quality Implementation Plans; New Hampshire; Hot Mix Asphalt Plants AGENCY.... Specifically, EPA is proposing to approve amendments to the New Hampshire Hot Mix Asphalt Plant Rule at Env-A 2703.02(a). This rule establishes and requires limitations on visible emissions from all hot mix...

  5. Field trials of asphalt rubber hot mix in Virginia.

    DOT National Transportation Integrated Search

    1995-01-01

    Four test sections using asphalt rubber hot mix were placed in Virginia during the period of 1990 through 1993. The purpose of these installations was to familiarize both contractors and Virginia Department of Transportation (VDOT) personnel with the...

  6. Performance of Hot Mix Asphalt Mixture Incorporating Kenaf Fibre

    NASA Astrophysics Data System (ADS)

    Hainin, M. R.; Idham, M. K.; Yaro, N. S. A.; Hussein, S. O. A. E.; Warid, M. N. M.; Mohamed, A.; Naqibah, S. N.; Ramadhansyah, P. J.

    2018-04-01

    Kenaf fibre has been recognised to increase the strength of concrete, but its application in asphalt concrete is still unanswered. This research investigated the performance of Hot Mix Asphalt (HMA) incorporated with different percentages of kenaf fibre (0.1 %, 0.2% and 0.3% by weight of dry aggregate) in term of resilient modulus, rutting performance using Asphalt Pavement analyser (APA) and moisture damage using the Modified Lottman test (AASHTO-T283). The fibre was interweaved to a diameter of about 5-10 mm and length of 30 mm which is three times the nominal maximum aggregate size used in the mix. Asphaltic mixtures of asphalt concrete (AC) 10 were prepared and compacted using Marshall compactor which were subsequently tested to evaluate the resilient modulus and moisture susceptibility. Twelve cylindrical specimens (150mm diameter) from AC10, two control samples with two modified ones for each percentage of kenaf fibres compacted using Gyratory compactor were used for rutting test using APA. The laboratory results reveal that the addition of kenaf fibres slightly reduce the resilient modulus of the mixes and that asphaltic mix with 0.3% kenaf fibre can mitigate both rutting and moisture damage which makes the pavement more sustain to the loads applied even in the presence of water. 0.3% kenaf fibre content is considered to be the optimal content which had the least rut depth and the highest TSR of 81.07%. Based on grid analysis, addition of 0.3% kenaf fibre in asphaltic concrete was recommended in modifying the samples.

  7. Performance Evaluation of Hot Mix Asphalt with Different Proportions of RAP Content

    NASA Astrophysics Data System (ADS)

    Kamil Arshad, Ahmad; Awang, Haryati; Shaffie, Ekarizan; Hashim, Wardati; Rahman, Zanariah Abd

    2018-03-01

    Reclaimed Asphalt Pavement (RAP) is old asphalt pavement that has been removed from a road by milling or full depth removal. The use of RAP in hot mix asphalt (HMA) eliminates the need to dispose old asphalt pavements and conserves asphalt binders and aggregates, resulting in significant cost savings and benefits to society. This paper presents a study on HMA with different RAP proportions carried out to evaluate the volumetric properties and performance of asphalt mixes containing different proportions of RAP. Marshall Mix Design Method was used to produce control mix (0% RAP) and asphalt mixes containing 15% RAP, 25% RAP and 35% RAP in accordance with Specifications for Road Works of Public Works Department, Malaysia for AC14 dense graded asphalt gradation. Volumetric analysis was performed to ensure that the result is compliance with specification requirements. The resilient modulus test was performed to measure the stiffness of the mixes while the Modified Lottman test was conducted to evaluate the moisture susceptibility of these mixes. The Hamburg wheel tracking test was used to evaluate the rutting performance of these mixes. The results obtained showed that there were no substantial difference in Marshall Properties, moisture susceptibility, resilient modulus and rutting resistance between asphalt mixes with RAP and the control mix. The test results indicated that recycled mixes performed as good as the performance of conventional HMA in terms of moisture susceptibility and resilient modulus. It is recommended that further research be carried out for asphalt mixes containing more than 35% RAP material.

  8. Field Monitoring of Experimental Hot Mix Asphalt Projects Placed in Massachusetts

    DOT National Transportation Integrated Search

    2017-06-30

    Since 2000, Massachusetts has been involved with numerous field trials of experimental hot mix asphalt mixtures. These experimental mixtures included several pilot projects using the Superpave mixture design methodology, utilization of warm mix aspha...

  9. Resilient modulus and the fatigue properties of Kansas hot mix asphalt mixes

    DOT National Transportation Integrated Search

    2006-08-01

    This research study aimed to determine the dynamic modulus, bending stiffness and fatigue properties of four representative Superpave Hot Mix Asphalt (HMA) mixtures used in the construction of base layers of Kansas flexible pavements and to compare t...

  10. Steel slag in hot mix asphalt concrete : final report

    DOT National Transportation Integrated Search

    2000-04-01

    In September 1994, steel slag test and control sections were constructed in Oregon to evaluate the use of steel slag in hot mix asphalt concrete (HMAC). This report covers the construction and five-year performance of a pavement constructed with 30% ...

  11. A cost-comparison methodology for selecting appropriate hot-mix asphalt materials.

    DOT National Transportation Integrated Search

    2007-01-01

    The Virginia Department of Transportation's (VDOT) Road and Bridge Specifications lists 9 dense-graded hot-mix asphalt (HMA) surface mixes (three aggregate gradations x three binder types) that could be used on Virginia's highways. VDOT's Special Pro...

  12. Performance comparison of PG 64-22 versus PG 64-28 asphalt in hot mix asphalt placed in Connecticut.

    DOT National Transportation Integrated Search

    2012-11-01

    This research was conducted to determine if switching from a low-temperature asphalt performance grade : (PG) of -28C to -22C would be detrimental to the performance of Hot Mix Asphalt (HMA) pavements in : Connecticut. Test sections were placed o...

  13. Comparative performance of rubber modified hot mix asphalt under ALF loading.

    DOT National Transportation Integrated Search

    2003-08-01

    Experiment 2 at the Louisiana ALF site involved determining the engineering benefits of using powdered rubber (PRM) in hot mix asphalt mixes. Three full scale test sections were constructed and subjected to increasing loads from the ALF. Lane 2-1 inc...

  14. Density measurement verification for hot mixed asphalt concrete pavement construction.

    DOT National Transportation Integrated Search

    2010-06-01

    Oregon Department of Transportation (ODOT) requires a minimum density for the construction of dense-graded hot mix asphalt concrete (HMAC) pavements to ensure the likelihood that the pavement will not experience distresses that reduce the expected se...

  15. Density measurement verification for hot mix asphalt concrete pavement construction.

    DOT National Transportation Integrated Search

    2010-06-01

    Oregon Department of Transportation (ODOT) requires a minimum density for the construction of dense-graded hot mix asphalt concrete (HMAC) pavements to ensure the likelihood that the pavement will not experience distresses that reduce the expected se...

  16. Tolerable strains for hot mix asphalt overlays over concrete pavements.

    DOT National Transportation Integrated Search

    2013-01-01

    Due to change of temperature and/or moisture, freezing-thaw cycles, loss of subgrade support by erosion, and traffic loading, concrete : pavements can develop different types of distresses during service life. Hot mix asphalt (HMA) overlays are commo...

  17. Critical review of ADOT's hot mix asphalt specifications : final report 630.

    DOT National Transportation Integrated Search

    2008-12-01

    The Arizona Department of Transportation (ADOT) has developed specifications and procedures to : ensure the quality of the hot mix asphalt materials purchased by the Department. The document : recording these specifications and procedures is the Stan...

  18. Construction and testing of crumb rubber modified hot mix asphalt pavement.

    DOT National Transportation Integrated Search

    1999-12-01

    This research project was structured toward addressing that portion of ISTEA which directs the individual states to conduct studies on the recyclability of crumb rubber modified : (CRM) hot mix asphalt (HMA) and the technical performance of CRMHMA pa...

  19. Warm mix asphalt : final report.

    DOT National Transportation Integrated Search

    2014-11-01

    The performance of pavements constructed using warm mix asphalt (WMA) technology were : compared to the performance of conventional hot mix asphalt (HMA) pavements placed on the : same project. Measurements of friction resistance, rutting/wear, ride ...

  20. Particulate measurement and control devices for hot mix asphalt plants.

    DOT National Transportation Integrated Search

    1973-01-01

    The emission of particulates is the main form of air pollution from hot mix asphalt plants. The measurement of these emissions in the ambient air may be used by the state and the plant personnel to monitor the quality of air in the area of a plant. S...

  1. The use of phosphoric acid to stiffen hot mix asphalt binders

    DOT National Transportation Integrated Search

    2014-11-01

    This document offers guidelines for the use of phosphoric acid to stiffen asphalt binders for hot mix paving applications. Data are presented on the likely effect on pavement life, moisture resistance, and use with limestone aggregates and liquid ami...

  2. Alabama warm mix asphalt field study : final report.

    DOT National Transportation Integrated Search

    2010-05-01

    The Alabama Department of Transportation hosted a warm mix asphalt field demonstration in August 2007. The warm mix asphalt technology demonstrated was Evotherm Dispersed Asphalt Technology. The WMA and hot mix asphalt produced for the demonstration ...

  3. Analysis of the usage of rubberized asphalt in hot mix asphalt using Reclaimed Asphalt Pavement (RAP)

    NASA Astrophysics Data System (ADS)

    Dwidarma Nataadmadja, Adelia; Prahara, Eduardi; Sumbung, Pierre Christian

    2017-12-01

    There has been an increasing demand in using more environmentally friendly materials in pavement construction. One of the alternative materials that have been widely used is the Reclaimed Asphalt Pavement (RAP) aggregates. The RAP aggregates are derived from the crushed and screened pavement materials that contain asphalt and aggregates. This material is usually combined with natural aggregates and virgin asphalt binder to construct a new pavement. There have been numerous positive feedbacks in using this material although RAP aggregates also have certain weaknesses, such as questionable interaction between virgin and recycled materials and increased stiffness of RAP binder. Moreover, there has been a push on using rubber as an additive to asphalt binder to improve the welfare of rubber farmers. This research combines the usage of both latex and RAP as the ingredients to design hot mix asphalt (HMA) as latex could help in improving the flexibility of HMA and the interaction between the virgin and recycled materials. The main objective of this research is to find a suitable percentage of RAP aggregates to be used in HMA with certain percentage of latex as the binder additive.

  4. Texture, ride quality, and the uniformity of hot-mix asphalt pavements.

    DOT National Transportation Integrated Search

    2005-01-01

    Two years ago, the author completed a study with researchers at Virginia Tech that was designed to develop a tool to measure and control segregation of hot-mix asphalt pavements. This earlier work focused on the application of high-speed texture meas...

  5. Comparative performance of rubber modified hot mix asphalt under ALF loading : technical summary.

    DOT National Transportation Integrated Search

    2004-07-01

    The objectives of this study were to evaluate the overall performance under accelerated loading of hot mix asphalt mixtures containing powdered rubber modifier (PRM) as compared to similar mixes with conventional HMA and to optimize the use of these ...

  6. Mechanical Properties of Warm Mix Asphalt Prepared Using Foamed Asphalt Binders : Executive Summary Report

    DOT National Transportation Integrated Search

    2011-03-01

    Hot mix asphalt (HMA) is a mixture containing aggregates and asphalt binders prepared at specified : proportions. The aggregates and asphalt binder proportions are determined through a mix design : procedure such as the Marshall Mix Design or the Sup...

  7. Mechanical properties of warm mix asphalt prepared using foamed asphalt binders : executive summary report.

    DOT National Transportation Integrated Search

    2011-03-01

    Hot mix asphalt (HMA) is a mixture containing aggregates and asphalt binders prepared at specified : proportions. The aggregates and asphalt binder proportions are determined through a mix design : procedure such as the Marshall Mix Design or the Sup...

  8. 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.

  9. Infrared thermography-driven flaw detection and evaluation of hot mix asphalt pavements.

    DOT National Transportation Integrated Search

    2010-01-01

    This research was conducted to study more realistic explanations of how variables are created and : dealt with during hot mix asphalt (HMA) paving construction. Several paving projects across the : state of Nebraska have been visited where sensory de...

  10. Tolerable strains for hot mix asphalt overlays over concrete pavements : [technical summary].

    DOT National Transportation Integrated Search

    2013-01-01

    Due to change of temperature and/or moisture, freezing-thaw cycles, loss of subgrade support by erosion, and traffic loading, concrete pavements can develop different types of distresses during service life. Hot mix asphalt (HMA) overlays are commonl...

  11. Modeling of hot-mix asphalt compaction : a thermodynamics-based compressible viscoelastic model

    DOT National Transportation Integrated Search

    2010-12-01

    Compaction is the process of reducing the volume of hot-mix asphalt (HMA) by the application of external forces. As a result of compaction, the volume of air voids decreases, aggregate interlock increases, and interparticle friction increases. The qu...

  12. Cost-benefit evaluation of short-term warranties for hot mix asphalt pavements.

    DOT National Transportation Integrated Search

    2012-03-01

    The purpose of this report is to provide the reader with the ten-year analysis for the cost-benefit of hot mix asphalt projects : constructed using the three and five-year warranty specifications developed by CDOT. There were eight projects evaluated...

  13. 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.

  14. Cost benefit analysis of anti-strip additives in hot mix asphalt with various aggregates.

    DOT National Transportation Integrated Search

    2015-05-01

    This report documents research on moisture sensitivity testing of hot-mix asphalt (HMA) mixes in Pennsylvania and the : associated use of antistrip. The primary objective of the research was to evaluate and compare benefit/cost ratios of mandatory us...

  15. Laboratory evaluation of warm mix asphalt.

    DOT National Transportation Integrated Search

    2011-09-14

    "Hot Mix Asphalt (HMA) has been traditionally produced at a discharge temperature of between : 280F (138C) and 320 F (160C), resulting in high energy (fuel) costs and generation of greenhouse : gases. The goal for Warm Mix Asphalt (WMA) is to...

  16. Using high-speed texture measurements to improve the uniformity of hot-mix asphalt.

    DOT National Transportation Integrated Search

    2003-01-01

    This study introduces Virginia's efforts to apply high-speed texture measurement as a tool to improve the uniformity of hot-mix asphalt (HMA) pavements. Three approaches for detecting and quantifying HMA segregation through measuring pavement surface...

  17. Hot mix asphalt research investigation for Connecticut : part A - reduction in the number Of superpave mix design levels.

    DOT National Transportation Integrated Search

    2009-07-01

    This research is the first in a series of investigated topics surrounding hot mix asphalt in Connecticut. : Currently there are at least 12 different mix designs that need to be developed by producers of HMA with : four traffic levels and three nomin...

  18. Hot mix asphalt research investigation for Connecticut : part E - comparison of field performance of superpave and traditional marshall mixes.

    DOT National Transportation Integrated Search

    2014-07-01

    This research is part of the series of investigated topics surrounding hot mix asphalt in Connecticut. : This research investigates the performance of sections of pavements designed using both the Marshall : and Superpave mix design methods. Sixteen ...

  19. Hot mix asphalt voids acceptance review of QC/QA data 2000 through 2004.

    DOT National Transportation Integrated Search

    2006-07-01

    This report analyzes the Quality Control/Quality Assurance (QC/QA) data for hot mix asphalt using voids acceptance as : the testing criteria for the years 2000 through 2004. Analysis of the overall quality of the HMA is accomplished by : reviewing th...

  20. Hot mix asphalt voids acceptance review of QC/QA data 2000 through 2010.

    DOT National Transportation Integrated Search

    2011-10-01

    This report analyzes the quality control/quality assurance (QC/QA) data for hot mix asphalt (HMA) using : voids acceptance as the testing criteria awarded in the years 2000 through 2010. Analysis of the overall : performance of the projects is accomp...

  1. Investigation of Warm Mix Asphalt (WMA) Technologies and Increased Percentages of Reclaimed Asphalt Pavement (RAP) in Asphalt Mixtures

    DOT National Transportation Integrated Search

    2011-04-01

    The implementation of warm-mix asphalt (WMA) is becoming more widespread with a growing number of contractors utilizing various WMA technologies. Early research suggests WMA may be more susceptible to moisture damage than traditional hot-mix asphalt ...

  2. Development of a test to measure the tendency for a hot-mix asphalt to segregate

    DOT National Transportation Integrated Search

    2000-02-01

    Hot Mix Asphalt tends to segregate during handling and placement. The use of a test to determine the tendency to segregate would assist the user in determining when a mix gradation needs adjustment to avoid construction of a segregated pavement or wh...

  3. Installation of warm mix asphalt projects in Virginia.

    DOT National Transportation Integrated Search

    2007-01-01

    Several processes have been developed to reduce the mixing and compaction temperatures of hot mix asphalt (HMA) without sacrificing the quality of the resulting pavement. The purpose of this study was to evaluate the installation of warm mix asphalt ...

  4. Colorado Department of Transportation hot-mix asphalt crack sealing and filling best practices guidelines.

    DOT National Transportation Integrated Search

    2014-10-01

    Crack sealing and filling on hot mix asphalt (HMA) pavements are cost-effective pavement preservation techniques that improve pavement performance and : extend the life of existing pavements. If performed in a timely and effective manner, crack seali...

  5. The next step toward end-result specifications for hot-mix asphalt materials and construction.

    DOT National Transportation Integrated Search

    2007-01-01

    In 2000, the Virginia Department of Transportation's (VDOT) Chief Engineer asked the Virginia Transportation Research Council to develop a vision of how and when VDOT would have a working end-result specification for hot-mix asphalt. The response to ...

  6. Evaluating the impacts of reducing the number of hot mix asphalt plant testing acceptance criteria on mix variability.

    DOT National Transportation Integrated Search

    2012-11-01

    The acceptance testing of Hot Mix Asphalt (HMA) conducted at the HMA production facility is an : important portion of the overall acceptance process used by the Connecticut Department of : Transportation (ConnDOT) for paving projects. In 2004, ConnDO...

  7. Investigation of warm-mix asphalt using Iowa aggregates.

    DOT National Transportation Integrated Search

    2011-04-01

    The implementation of warm-mix asphalt (WMA) is becoming more widespread with a growing number of contractors utilizing various WMA technologies. Early research suggests WMA may be more susceptible to moisture damage than traditional hot-mix asphalt ...

  8. Designing Recycled Hot Mix Asphalt Mixtures Using Superpave Technology

    DOT National Transportation Integrated Search

    1997-01-01

    Mix design procedures for recycled asphalt pavements require the selection of : virgin asphalt binder or recycling agent. This research project was undertaken : to develop a procedure for selecting the performance grade (PG) of virgin : asphalt binde...

  9. Field verification of asphalt aging in hot mix plants.

    DOT National Transportation Integrated Search

    1986-02-01

    As a measure of the aging of asphalt concrete mixes in the mixing and placement process, a formula was developed to determine the percentage of expected change in asphalt viscosity at the time of paving (Lund and Wilson, 1984). A value of 30 or highe...

  10. Early age rutting potential of warm mix asphalt (WMA).

    DOT National Transportation Integrated Search

    2012-12-01

    Various plant produced Warm Mix Asphalt (WMA) mixtures were evaluated and compared to identical : plant produced Hot Mix Asphalt to assess their early life rutting potential. Along with laboratory permanent : deformation testing, fatigue and moisture...

  11. Wetting characteristics of asphalt binders at mixing temperatures.

    DOT National Transportation Integrated Search

    2013-10-01

    Conventional hot mix asphalt (HMA) is produced by heating the aggregate and the asphalt binder to elevated : temperatures that are typically in the range of 150C to 160C. These temperatures ensure that the viscosity of the : asphalt binder is low eno...

  12. Use of moisture induced stress testing to evaluate stripping potential of hot mix asphalt (HMA).

    DOT National Transportation Integrated Search

    2012-07-01

    Stripping of hot mix asphalt (HMA) in the field is an ongoing issue for many Departments of Transportation : (DOTs). A leading cause of stripping is hydraulic scouring. The Moisture Induced Stress Tester (MIST) is a recently : developed technology th...

  13. Early age rutting potential of warm mix asphalt (WMA).

    DOT National Transportation Integrated Search

    2012-12-01

    Various plant produced Warm Mix Asphalt (WMA) mixtures were evaluated and compared to identical plant produced Hot Mix Asphalt to assess their early life rutting potential. Along with laboratory permanent deformation testing, fatigue and moisture dam...

  14. Comparison of fundamental and simulative test methods for evaluating permanent deformation of hot mix asphalt

    DOT National Transportation Integrated Search

    2002-10-01

    Rutting has long been a problem in hot mix asphalt (HMA) pavement. Through the years, researchers have used different kinds of fundamental and simulative test methods to estimate the rutting performance of HMA. It has been recognized that most fundam...

  15. Evaluation of the Performance of Warm Mix Asphalt in Washington State

    DOT National Transportation Integrated Search

    2012-10-01

    Warm mix asphalt (WMA) is a relatively new and emerging technology for the asphalt industry. : It offers potential construction and environmental advantages over traditional hot mix asphalt : (HMA). However, WMA must perform at least as well as HMA b...

  16. Evaluation of the benefits of adding waste fiberglass asphalt roofing shingles to hot mix asphalt

    DOT National Transportation Integrated Search

    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 proje...

  17. Evaluation of using higher percentages of recycled asphalt pavement in asphalt mixes in Virginia.

    DOT National Transportation Integrated Search

    2008-01-01

    In 2007, the Virginia Department of Transportation (VDOT) decided to allow higher percentages of recycled asphalt pavement (RAP), i.e., more than 20 percent, in hot-mix asphalt with no change in binder grade. Because of this increase, one section of ...

  18. Comparison of fatigue analysis approaches for hot-mix asphalt to ensure a state of good repair.

    DOT National Transportation Integrated Search

    2013-10-01

    Fatigue cracking is a primary form of distress in hot-mix asphalt. The long-term nature of fatigue due to repeated : loading and aging and its required tie to pavement structure present challenges in terms of evaluating mixture : resistance. This pro...

  19. Laboratory evaluation of influence of operational tolerance (acceptance criterion) on performance of hot-mix asphalt concrete.

    DOT National Transportation Integrated Search

    2010-06-01

    The performance of flexible pavements relies heavily on the final quality of the hot-mix asphalt concrete (HMAC) as it : is produced and placed in the field. To account for production and construction variability while ensuring the quality of the : H...

  20. Analysis of load-induced strains in a hot mix asphalt perpetual pavement : final report, April 2009.

    DOT National Transportation Integrated Search

    2009-04-01

    This report presents the findings of a research study conducted to investigate the structural performance of a 275 mm hot : mix asphalt perpetual pavement constructed as part of the WIM bypass lane at the Kenosha Safety & Weigh Station : Facility. Tw...

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

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wong, Yiik Diew; Sun, Darren Delai; 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, whilemore » 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.« less

  2. 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.

  3. Experimental demonstration of warm mix asphalt pavement on Rt. 4.

    DOT National Transportation Integrated Search

    2012-04-01

    A number of new technologies have been developed to lower the production and placement temperatures : of hot-mix asphalt (HMA). Generically, these technologies are referred to as warm-mix asphalt (WMA). : In Europe and to a lesser extent in North Ame...

  4. Diffusibility Enhancement of Rejuvenator by Epoxidized Soybean Oil and Its Influence on the Performance of Recycled Hot Mix Asphalt Mixtures

    PubMed Central

    Kuang, Dongliang; Jiao, Yuan; Ye, Zhou; Lu, Zaihong; Chen, Huaxin; Yu, Jianying; liu, Ning

    2018-01-01

    Epoxidized soybean oil (ESO) was employed as a novel penetrant cooperating with a conventional rejuvenator (CR) for the recycling of reclaimed asphalt pavement (RAP). The influence of ESO on the diffusibility and the regenerating effects of CR on RAP were investigated. The diffusibility testing result shows that the diffusibility of CR is enhanced by the addition of ESO because the epoxy group in ESO can facilitate asphaltene dispersion due to its high polarity, which simultaneously reduces the viscosity and improves the fluidity of aged bitumen so as to allow diffusion of the rejuvenator into the aged bitumen. Road performance testing of a recycled hot mix asphalt mixture (RHMA) indicates that the fatigue and cracking resistance properties as well as the water stability of RHMA containing CR can be improved by the addition of ESO due to the diffusibility enhancement of CR, which boosts the regenerating effect of CR on aged bitumen in RAP. The fatigue and cracking resistance properties as well as the water stability of the recycled hot mix asphalt mixture containing CR with 7 wt % ESO approximate those of the hot mix asphalt mixture composed of the same virgin aggregates and bitumen. Taking into account the rutting resistance decline versus the addition of ESO, the content of ESO should not exceed 7 wt % of the conventional rejuvenator. PMID:29783675

  5. Diffusibility Enhancement of Rejuvenator by Epoxidized Soybean Oil and Its Influence on the Performance of Recycled Hot Mix Asphalt Mixtures.

    PubMed

    Kuang, Dongliang; Jiao, Yuan; Ye, Zhou; Lu, Zaihong; Chen, Huaxin; Yu, Jianying; Liu, Ning

    2018-05-18

    Epoxidized soybean oil (ESO) was employed as a novel penetrant cooperating with a conventional rejuvenator (CR) for the recycling of reclaimed asphalt pavement (RAP). The influence of ESO on the diffusibility and the regenerating effects of CR on RAP were investigated. The diffusibility testing result shows that the diffusibility of CR is enhanced by the addition of ESO because the epoxy group in ESO can facilitate asphaltene dispersion due to its high polarity, which simultaneously reduces the viscosity and improves the fluidity of aged bitumen so as to allow diffusion of the rejuvenator into the aged bitumen. Road performance testing of a recycled hot mix asphalt mixture (RHMA) indicates that the fatigue and cracking resistance properties as well as the water stability of RHMA containing CR can be improved by the addition of ESO due to the diffusibility enhancement of CR, which boosts the regenerating effect of CR on aged bitumen in RAP. The fatigue and cracking resistance properties as well as the water stability of the recycled hot mix asphalt mixture containing CR with 7 wt % ESO approximate those of the hot mix asphalt mixture composed of the same virgin aggregates and bitumen. Taking into account the rutting resistance decline versus the addition of ESO, the content of ESO should not exceed 7 wt % of the conventional rejuvenator.

  6. Evaluation of the specification for flat and elongated particles for use in hot mix asphalt in Connecticut.

    DOT National Transportation Integrated Search

    2014-04-01

    This research was conducted to determine if the specification for flat and elongated aggregates : for use in Hot-Mix Asphalt (HMA) in Connecticut can be reasonably achieved. Currently, the : ConnDOT specification allows for no more than 10 percent fl...

  7. Development of Guidelines for Reduction of Temperature Differential Damage (TDD) for Hot Mix Asphalt Pavement Projects in Connecticut

    DOT National Transportation Integrated Search

    1999-11-01

    Connecticut Department of Transportation personnel used an infrared camera to observe thermal segregation of hot mix asphalt during pavement construction. Several sites were selected for study from ongoing paving projects. During paving operations, t...

  8. Determination of the in-place hot-mix asphalt layer modulus for rehabilitation projects using a mechanistic-empirical procedure.

    DOT National Transportation Integrated Search

    2006-01-01

    This project evaluated the procedures proposed by the Mechanistic-Empirical Pavement Design Guide (MEPDG) to characterize existing hot-mix asphalt (HMA) layers for rehabilitation purposes. Thirty-three cores were extracted from nine sites in Virginia...

  9. Design of Large Stone Asphalt Mixes to Minimize Rutting

    DOT National Transportation Integrated Search

    1990-01-01

    Rutting of heavy duty asphalt pavements has been increasingly experienced in recent years. This phenomenon is primarily resulting from high tire pressures and increased wheel loads. The design of Hot Mix Asphalt (HMA) which served reasonably well in ...

  10. The use of atomic force microscopy to evaluate warm mix asphalt.

    DOT National Transportation Integrated Search

    2013-01-01

    The main objective of this study was to use the Atomic Force Microscopy (AFM) to examine the moisture susceptibility : and healing characteristics of Warm Mix Asphalt (WMA) and compare it with those of conventional Hot Mix Asphalt (HMA). To : this en...

  11. Use of warm mix asphalt pavement on Route 9, in Durham.

    DOT National Transportation Integrated Search

    2012-06-01

    A number of new technologies have been developed to lower the production and placement temperatures : of hot-mix asphalt (HMA). Generically, these technologies are referred to as warm-mix asphalt (WMA). : In Europe and to a lesser extent in North Ame...

  12. Investigation of warm-mix asphalt using Iowa aggregates.

    DOT National Transportation Integrated Search

    2011-04-01

    The implementation of warm-mix asphalt (WMA) is becoming more widespread with a growing number of contractors utilizing various : WMA technologies. Early research suggests WMA may be more susceptible to moisture damage than traditional hot-mix asphal...

  13. 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.

  14. Hot plant recycling of asphaltic concrete : final report.

    DOT National Transportation Integrated Search

    1980-05-01

    This report covers the design, construction and evaluation of two hot mix recycling projects. One project recycled two inches of existing dense-asphaltic concrete through a modified batch plant. The second project recycled a total of five inches of e...

  15. Use of warm mix asphalt pavement on Interstate 95, Carmel to Hampden, northbound.

    DOT National Transportation Integrated Search

    2012-06-01

    A number of new technologies have been developed to lower the production and placement temperatures : of hot-mix asphalt (HMA). Generically, these technologies are referred to as warm-mix asphalt (WMA). : In Europe and to a lesser extent in North Ame...

  16. Use of a double chip seal to correct a flushing hot mix asphalt pavement in Washington state - final report.

    DOT National Transportation Integrated Search

    2016-09-01

    A double chip seal was applied to an existing hot mix asphalt (HMA) pavement to mitigate severe flushing that existed throughout the project. Special care was taken to adjust the amount of binder used to account for the degree of flushing in the exis...

  17. Development of guidelines for usage of high percent RAP in warm-mix asphalt pavements.

    DOT National Transportation Integrated Search

    2011-12-15

    Road construction using warm-mix asphalt has been rapidly gaining popularity in the United States, in part because : WMA is believed to be friendlier to the environment as compared to hot-mix asphalt. Parallel to this rapid growth in : WMA constructi...

  18. Evaluation of recycled hot mix asphalt concrete on Route 220 : final report.

    DOT National Transportation Integrated Search

    1985-01-01

    This report describes the performance of an approximately 8-mi section of roadway on which the rod two layers of asphalt concrete were milled, recycled through a conventional asphalt batch plant, and relaid. The recycled mix consisted of about 40% re...

  19. FNF Construction, Inc. Coverage under General Air Quality Permit for New or Modified Minor Source Hot Mix Asphalt Plants in Indian Country

    EPA Pesticide Factsheets

    Documents related to the FNF Construction, Inc. Request for Coverage under the General Air Quality Permit for New or Modified Minor Source Hot Mix Asphalt Plants in Indian Country to be Located near Ganado, Arizona on the Navajo Nation.

  20. Development of a non-solvent based test method for evaluating reclaimed asphalt pavement mixes.

    DOT National Transportation Integrated Search

    2004-09-01

    The percent of reclaimed asphalt pavement (RAP) used in hot mix asphalt (HMA) is currently established either by arbitrarily setting maximum percent limits, or alternatively, by evaluating both the virgin and recovered binder properties. The first ap...

  1. Use of warm mix asphalt pavement along Rt. 27 in the towns of Farmington and New Portland.

    DOT National Transportation Integrated Search

    2012-05-01

    A number of new technologies have been developed to lower the production and placement temperatures : of hot-mix asphalt (HMA). Generically, these technologies are referred to as warm-mix asphalt (WMA). : In Europe and to a lesser extent in North Ame...

  2. Warm-mix asphalt : European practice.

    DOT National Transportation Integrated Search

    2008-02-01

    Warm-mix asphalt (WMA) is a group of technologies that allow a reduction in the temperatures at which : asphalt mixes are produced and placed. These technologies tend to reduce the viscosity of the asphalt and : provide for the complete coating of ag...

  3. Characterization and best use of recycled asphalt shingles in hot-mix asphalt.

    DOT National Transportation Integrated Search

    2012-10-01

    Recycled asphalt shingles (RAS) often containing more than 20 percent asphalt binder has become another black gold in the asphalt industry. There are two basic types of RAS scraps in the market: tear-off asphalt shingles (TOAS) and manufacture waste ...

  4. Hot in-Place Recycling of Asphalt Pavements.

    DTIC Science & Technology

    1987-08-04

    WEARING SPECIFIED THICKNESS SURFACE • b. With ’Tew Aggregate, Modifier, And Asphalt ," ..’ . ,,, /f",’"" 4.. Figure 8. Typical Cold In-Place...34. .. .; ’-. , .?-. . ; ,....",.’.". ’. .- +-;-?,..- . .-’. , .. ’.,,..-, . ..- ?.,,,..-N ....-, ..,-. -".,,’." - HOT IN-PLACE RECYCLING OF ASPHALT PAVEMENTS An Engineering Report by0 Michael Lawrence Dowdy Submitted...for asphalt pavements. This type of asphalt pavement recycling process is becoming

  5. 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.

  6. 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

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

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    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 differentmore » 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« less

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

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    NONE

    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 ofmore » 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.« less

  9. Nondestructive evaluation of warm mix asphalt through resonant column testing.

    DOT National Transportation Integrated Search

    2014-02-01

    Non-destructive testing has been used for decades to characterize engineering properties of hot-mix asphalt. Among such tests is the resonant column (RC) test, which is commonly used to characterize soil materials. The resonant column device at Penn ...

  10. 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.

  11. Investigation of aged hot-mix asphalt pavements.

    DOT National Transportation Integrated Search

    2013-09-01

    Over the lifetime of an asphalt concrete (AC) pavement, the roadway requires periodic resurfacing and rehabilitation to provide : acceptable performance. The most popular resurfacing method is an asphalt overlay over the existing roadway. In the desi...

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

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Button, J.W.; Prapnnachari, S.

    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 includingmore » 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.« less

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

    DOE Office of Scientific and Technical Information (OSTI.GOV)

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

    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. Notmore » 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.« less

  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. 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

  16. Comprehensive evaluation of the long-term performance of rubberized pavement, phase I : laboratory study of rubberized asphalt mix performance.

    DOT National Transportation Integrated Search

    2012-12-01

    Crumb rubber, made from scrap tires, has been introduced into the production of different types of hot : mix asphalt (HMA) in either a wet or dry process. In the wet process, the crumb rubber and binder are : completely mixed to form asphalt rubber (...

  17. Use of the asphalt pavement analyzer to study in-service asphalt mixture performance.

    DOT National Transportation Integrated Search

    2004-12-30

    Permanent deformation or rutting is a major hot mix asphalt (HMA) performance distress. Implementation of the : Superior Performing Asphalt Pavement (Superpave) HMA mix design system was due, in part, to limit HMA rutting. : Along with the Superpave ...

  18. Use of the Asphalt Pavement Analyzer to study in-service asphalt mixture performance

    DOT National Transportation Integrated Search

    2004-12-30

    Permanent deformation or rutting is a major hot mix asphalt (HMA) performance distress. Implementation of the Superior Performing Asphalt Pavement (Superpave) HMA mix design system was due, in part, to limit HMA rutting. Along with the Superpave syst...

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

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    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 andmore » 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.« less

  20. 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

  1. 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.

  2. Limited Round Robin Asphalt Content Test Using Troxler Furnace

    DOT National Transportation Integrated Search

    1999-11-01

    The Asphalt Content by Ignition test can be used to determine the asphalt content of a hot mix asphalt (HMA). This test, developed by the National Center for Asphalt Technology (NCAT), burns the asphalt binder from a mix and thus allows the determina...

  3. Installation report : rubber modified asphalt mix.

    DOT National Transportation Integrated Search

    1983-01-01

    This report describes the design of an asphalt mix containing up to 3.0% closed cell waste rubber and a field installation of the mix. The Marshall design procedure was used to determine the asphalt content for the mix containing 3.0% rubber as well ...

  4. An investigation of the effects of elevated mixing temperatures on the properties of asphalt cement.

    DOT National Transportation Integrated Search

    1972-01-01

    This laboratory investigation was instituted to determine the feasibility of increasing the design mixing temperature for hot-mix asphaltic concrete. Based on data obtained from modified thin film oven tests, it appears that the upper design limit co...

  5. Designing, producing, and constructing fine-graded hot mix asphalt on Illinois roadways.

    DOT National Transportation Integrated Search

    2015-04-01

    Fine-graded (F-G) asphalt concrete mixtures are composed of an aggregate structure in which the fine fraction controls the : load-carrying capacity of the mix. Other states have reported benefits in using F-G mixtures, including improved compaction, ...

  6. A review of warm mix asphalt.

    DOT National Transportation Integrated Search

    2008-12-01

    Warm Mix Asphalt (WMA) technology, recently developed in Europe, is gaining strong interest in the US. By : lowering the viscosity of asphalt binder and/or increasing the workability of mixture using minimal heat, WMA : technology allows the mixing, ...

  7. Mechanical properties of warm mix asphalt prepared using foamed asphalt binders.

    DOT National Transportation Integrated Search

    2011-03-01

    Warm mix asphalt (WMA) is a name given to a group of technologies that have the common purpose of reducing the viscosity : of the asphalt binders. This reduction in viscosity offers the advantage of producing asphalt-aggregate mixtures at lower mixin...

  8. Mechanical Properties of Warm Mix Asphalt Prepared Using Foamed Asphalt Binders

    DOT National Transportation Integrated Search

    2011-03-01

    Warm mix asphalt (WMA) is a name given to a group of technologies that have the common purpose of reducing the viscosity : of the asphalt binders. This reduction in viscosity offers the advantage of producing asphalt-aggregate mixtures at lower mixin...

  9. Hot asphalt burns: a review of injuries and management options.

    PubMed

    Bosse, George M; Wadia, Shernaz A; Padmanabhan, Pradeep

    2014-07-01

    Hot asphalt burns to human tissue can increase the likelihood of infection and potential conversion of partial thickness to full-thickness injuries. Successful intervention for hot asphalt burns requires immediate and effective cooling of the asphalt on the tissue followed by subsequent gradual removal of the cooled asphalt. A review of the literature reveals that multiple substances have been used to remove asphalt, including topical antibiotics, petroleum jelly, a commercial product known as De-Solv-It (ORANGE-SOL, Chandler, AZ), sunflower oil, baby oil, liquid paraffin, butter, mayonnaise, and moist-exposed burn ointment (MEBO). Although many of these products may be effective in the removal of asphalt, they may not be readily available in an emergency department setting. Topical antibiotics are readily available, are more commonly described in the medical literature, and would be expected to be effective in the removal of asphalt. We developed guidelines for on scene (first-aid) management and the initial care of such patients upon presentation to a health care facility. These guidelines emphasize the principles of early cooling, gradual removal of adherent asphalt using topical antibiotics, and avoidance of the use of topical agents, which are likely to result in tissue toxicity.

  10. Properties of asphalt mixtures containing RAP.

    DOT National Transportation Integrated Search

    2009-12-01

    A typical NHDOT Hot Mix Asphalt (HMA) concrete mixture contains at least 15% Reclaimed Asphalt Pavement (RAP). The increasing cost of virgin asphalt and aggregate has increased the interest in using higher percentages of RAP in HMA mixtures. The purp...

  11. Impact of Various Compaction Equipment on Hot-Mix Asphalt (HMA) Design in Ohio.

    DOT National Transportation Integrated Search

    1998-09-01

    The study was initiated to examine the effect of different laboratory compaction devices on density, air voids, and optimum asphalt binder content for mixes designed for heavy volume traffic that are currently used in Ohio. A total of six and twelve ...

  12. Rubber modified asphalt mix.

    DOT National Transportation Integrated Search

    1985-01-01

    This report summarizes the design and field installation of an asphalt mix containing up to 3.0% closed cell rubber by weight of the mix. The performance is discussed as well as possible reasons for the early failure of the mix. Suggestions are made ...

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

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    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 includingmore » 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.« less

  14. Implementation of MEPDG for asphalt pavement with RAP.

    DOT National Transportation Integrated Search

    2013-06-01

    This study explored the potential of using high reclaimed asphalt pavement (RAP) content with hot mix asphalt (HMA) in base and surface courses for conditions prevailing in Oklahoma. A total of eight Superpave mixes (four mixes for each of two field ...

  15. Mix Proportion Design of Asphalt Concrete

    NASA Astrophysics Data System (ADS)

    Wu, Xianhu; Gao, Lingling; Du, Shoujun

    2017-12-01

    Based on the gradation of AC and SMA, this paper designs a new type of anti slide mixture with two types of advantages. Chapter introduces the material selection, ratio of ore mixture ratio design calculation, and determine the optimal asphalt content test and proportioning design of asphalt concrete mix. This paper introduces the new technology of mix proportion.

  16. QC/QA differences between hot mix asphalt (HMA) and warm mix asphalt (WMA).

    DOT National Transportation Integrated Search

    2013-01-01

    WMA represents a group of technologies which allow a reduction in temperatures at which asphalt mixtures are produced and placed on the road. ODOT Materials Division has conducted preliminary inquiries into QC/QA testing for WMA. Some respondents ind...

  17. Evaluation of Asphalt Pavement Analyzer for HMA Design

    DOT National Transportation Integrated Search

    1999-06-01

    Rutting is a common problem in hot mix asphalt pavements, particularly in hot climates and at intersections. The Asphalt Pavement Analyzer (APA) is a laboratory accelerated loading equipment that can be used to evaluate rutting potential of HMA. This...

  18. Investigation of aged hot-mix asphalt pavements : technical summary.

    DOT National Transportation Integrated Search

    2013-09-01

    Over the lifetime of an asphalt concrete (AC) pavement, the roadway requires periodic resurfacing and rehabilitation to provide acceptable performance. The most popular resurfacing method is an asphalt overlay over the existing roadway. In the design...

  19. Evaluation of binder aging and its influence in aging of hot mix asphalt concrete : technical report.

    DOT National Transportation Integrated Search

    2014-04-01

    Warm mix asphalt (WMA) technologies, through reduced mixing and placement temperatures, have : reduced fuel consumption, enhanced compaction, increased haul distances and an extended paving season. : Issues of concern in WMA are binder oxidation and ...

  20. Determination of usable residual asphalt binder in RAP.

    DOT National Transportation Integrated Search

    2009-01-01

    For current recycled mix designs, the Illinois Department of Transportation (IDOT) assumes 100% contribution of : working binder from Recycled Asphalt Pavement (RAP) materials when added to Hot Mix Asphalt (HMA). However, it is : unclear if this assu...

  1. Evaluation of Asphalt Absorption by Mineral Aggregates

    DOT National Transportation Integrated Search

    1991-01-01

    All mineral aggregates used in the hot mix asphalt (HMA) mixtures have some porosity and as such tend to absorb some amount of asphalt. Different test methods are used by the agencies to determine the amount of asphalt absorbed by the mineral aggrega...

  2. Experience with The Use of Warm Mix Asphalt Additives in Bitumen Binders

    NASA Astrophysics Data System (ADS)

    Cápayová, Silvia; Unčík, Stanislav; Cihlářová, Denisa

    2018-03-01

    In most European countries, Hot Mix Asphalt (HMA) technology is still being used as the standard for the production and processing of bituminous mixtures. However, from the perspective of environmental acceptability, global warming and greenhouse gas production, Slovakia is making an effort to put into practice modern technology, which is characterized by lower energy consumption and reducing negative impacts on the environment. Warm mix asphalt technologies (WMA), which have been verified at the Department of Transportation Engineering laboratory, Faculty of Civil Engineering, Slovak University of Technology (FCE, SUT) can provide the required mixture properties and can be used not only for the construction of new roads, but also for their renovation and reconstruction. The paper was created in cooperation with the Technical University of Ostrava, Czech Republic, which also deals with the addition of additives to asphalt mixtures and binders. It describes a comparison of the impact of some organic and chemical additives on the properties of commonly used bitumen binders in accordance with valid standards and technical regulations.

  3. Performance of Recycled Hot Mix Asphalt Mixtures

    DOT National Transportation Integrated Search

    1995-05-01

    This research project was undertaken to evaluate the performance of recycled pavements in comparison to virgin (control) asphalt pavements. Five projects, each consisting of a recycled section and a control section, were subjected to detailed evaluat...

  4. Asphalt Content by Ignition Round Robin Study

    DOT National Transportation Integrated Search

    1996-01-01

    The National Center for Asphalt Technology (NCAT) has developed a test method to : determine the asphalt content of hot mix asphalt (HMA) mixtures by ignition. In : the ignition method, a HMA sample is subjected to 5380C (lOOO0F) in a furnace to : ig...

  5. Polymer modified hot mix asphalt field trial.

    DOT National Transportation Integrated Search

    1999-12-01

    A problem plaguing HMA pavements is rutting, which develops because of the high summer temperatures and heavy trucks. Many different : polymer modifiers for asphalt cement have been developed to help improve both the rutting and thermal cracking prob...

  6. Development of mix design procedures for gap-graded asphalt-rubber asphalt concrete

    DOT National Transportation Integrated Search

    2007-11-01

    A research project was conducted to identify and document current modifications to ARIZONA 815c (75-blow Marshall method) used to develop gap-graded asphalt rubber asphalt concrete (GG AR AC) mix designs, and to develop and test improvements to provi...

  7. 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).

  8. 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.

  9. Improving Mechanical Properties of Hot Mix Asphalt Using Fibres and Polymers in Developing Countries

    NASA Astrophysics Data System (ADS)

    Preciado, Jaime; Martínez Arguelles, Gilberto; Dugarte, Margareth; Bonicelli, Alessandra; Cantero, Julio; Vega, Daniela; Barros, Yennis

    2017-10-01

    The enhancement of mechanical properties and long term performance of hot mix asphalt (HMA) should be considered as a goal in order to achieve a transport infrastructure really sustainable. However, this issue becomes a difficult task, if conventional HMA are used. In fact, performance of conventional HMA, usually presents poor long term performance and functional distresses related to high and low temperatures, which in turn implies higher maintenance costs and superior carbon footprints. To overcome this weaken, bitumen industry has been developing new polymer modifiers, additives to improve HMA behaviour. One of the techniques most used in developed countries to enhance HMA behaviour is the use of modified bitumen. Modifying the bitumen, and then producing modified HMA requires specific equipment and facilities that may be time-consuming, expensive and hard to manage. For instance, to warranty a successful modifying process, storage and handling of the modified bitumen are issues very complex to handle. On the other hand, producing a polymer modified HMA by adding polymers and additives directly during the bitumen/aggregate mixing process may offer very interesting advantages since the economical, production and sustainability standpoint. This paper aimed to determine the feasibility of the incorporation of fibres and plastomeric polymers into different types of HMA by means of the “dry process” (to add polymers during the mixing of aggregate and bitumen in the HMA plant) to produce polymer modified mixes. Thus, laboratory tests including Marshall Stability, Indirect Tensile Stiffness Modulus, repeated load test and Indirect Tensile Strength test were performed to assess the effect of the inclusion of fibres and plastomeric polymers on mechanical and volumetric properties of selected mixes. Results showed that the modification of bituminous mixtures following the “dry process” could be used to improve the performance and long term properties of HMA.

  10. Characteristics Buton Natural Asphalt-Rubber (BNA-R) on the Performance Improvement of Warm Mix Asphalt Using Natural Zeolite

    NASA Astrophysics Data System (ADS)

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

    2018-03-01

    The decrease in the ability of service of pavement can be caused by the durability factor in the pavement layer in receiving heavy traffic load and the temperature of the pavement. Permanent deformation is one of the criteria of failure of asphalt mixture. Performance assessment of the asphalt mixture can be observed from the rheological properties of asphalt binder. The use of BNA-R in this study is intended to modify the characteristics of bitumen penetration grade 60 / 70 used in warm mix asphalt. Warm mix asphalt with lower temperatures of mixing and compaction than conventional asphalt mixtures was chosen because it is more environmentally friendly. To reduce the temperature in this warm asphalt technology is achieved by using natural zeolite. Both of these materials are local materials that are widely available in Indonesia. The rheology of asphalt 60/70 modified with BNA-R indicates that the addition of BNA-R in the base asphalt increase the complex modulus value and decrease the phase angle value. These values were related to the performance of mixture in the permanent deformation criteria. Reducing the temperature of mixing and compaction should be balanced with modifying the asphalt binder used. Rutting due to permanent deformation can resulted in inconvenience to the passengers and can lead to high costs of road maintenance. To determine the permanent deformation of asphalt mix with material combinations was performed through the wheel tracking test machine with 3,780 cycles for 3 hours. The results shows that after test track over 7 thousand passes have seen permanent deformation characteristics of asphalt concrete mixture with a variation of the characteristics of bitumen.

  11. Selection and evaluation of performance-graded asphalt binders for Virginia.

    DOT National Transportation Integrated Search

    1999-06-01

    This study recommended performance-graded (PG) binders to be used in hot-mix asphalt in Virginia. Ten conventional viscosity-graded asphalt cements, representing the asphalt typically available in Virginia, were graded under the PG system to develop ...

  12. Installation report : experimental mix using foamed asphalt.

    DOT National Transportation Integrated Search

    1982-01-01

    This report describes the first foam asphalt mix produced and used in a highway pavement in Virginia. The aggregate used was a local Eastern Shore sand modified with 5% fly ash to improve the gradation. A foam asphalt chamber on a portable pug-mixer ...

  13. Investigation of the Asphalt Pavement Analyzer (APA) testing program in Nebraska.

    DOT National Transportation Integrated Search

    2008-03-01

    The asphalt pavement analyzer (APA) has been widely used to evaluate hot-mix asphalt (HMA) rutting potential in mix : design and quality control-quality assurance (QC-QA) applications, because the APA testing and its data analyses are : relatively si...

  14. 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

    DOE Office of Scientific and Technical Information (OSTI.GOV)

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

    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) Testmore » method for determining the amount of rubber in an asphalt-rubber concrete for quality control purposes.« less

  15. Performance Assessment of Warm Mix Asphalt (WMA) Pavements

    DOT National Transportation Integrated Search

    2009-09-01

    Abstract : Warm Mix Asphalt (WMA) is a new technology that was introduced in Europe in 1995. WMA offers several advantages over : conventional asphalt concrete mixtures, including: reduced energy consumption, reduced emissions, improved or more unifo...

  16. Performance assessment of warm mix asphalt (WMA) pavements.

    DOT National Transportation Integrated Search

    2009-09-01

    Warm Mix Asphalt (WMA) is a new technology that was introduced in Europe in 1995. WMA offers several advantages over : conventional asphalt concrete mixtures, including: reduced energy consumption, reduced emissions, improved or more uniform : binder...

  17. Improving the properties of reclaimed asphalt pavement for roadway base applications [summary].

    DOT National Transportation Integrated Search

    2012-01-01

    Over 90 percent of : U.S. roads are paved : with asphalt, which : must be periodically : resurfaced. Milling : produces reclaimed : asphalt pavement (RAP), : which can be recycled : in hot-mix asphalt, : but at no more than : 25%. Therefore, much : R...

  18. Detection of recycled asphalt pavement (RAP) in bituminous mixtures

    DOT National Transportation Integrated Search

    2004-06-01

    The overall goal of this study was to assist the Illinois Department of Transportation (IDOT) in identifying and developing methods for quality assurance of hot-mix asphalt (HMA) containing recycled asphalt pavement (RAP). Although the use of RAP can...

  19. Performance of warm mix asphalt with Buton natural asphalt-rubber and zeolite as an additives

    NASA Astrophysics Data System (ADS)

    Wahjuningsih, N.; Hadiwardoyo, S. P.; Sumabrata, R. J.; Anis, M.

    2018-01-01

    The aim of this research is improving of asphalt industry to decrease the fuel consumption by lowering the temperature of mixing and compacting of asphalt mixture. This technology known as Warm Mix Asphalt (WMA). Buton Natural Asphalt Rubber (BNA-R) as a function of the additive has been able to improve the performance of HMA. Zeolit has a function as an additive to lowering the mixing temperature. Aggregate composition using the composition of aggregate grading specifications for airport pavement, with the composition of BNA-R 5% and 10% and Zeolite content of 2%. The mixture have produced Resilient Modulus value by using the Universal Material Testing Apparatus (UMATTA) on optimum bitumen content each of which has been obtained from the Marshall test. Furthermore, the value of permanent deformation of asphalt mixtures tested using Wheel Tracking Machine (WTM). The result shows that BNA-R modified binder for WMA can decrease the rutting potential. The additive of local materials has improved the performance of the WMA for airport pavement with certain restrictions. From this research it is known there have been changes in the characteristics of resilient modulus and permanent deformation due to the addition of BNA-R for type of aggregate composition.

  20. Annual asphalt pavement industry survey on recycled materials and warm-mix asphalt usage : 2009-2012.

    DOT National Transportation Integrated Search

    2013-12-01

    One of the shared goals of the Federal Highway Administration (FHWA) and the National Asphalt Pavement Association : (NAPA) is to support and promote sustainable practices such as pavement recycling and warm-mix asphalt (WMA). The use of : recycled m...

  1. Field test of a polyphosphoric acid (PPA) modified asphalt binder on Rt. 1 in Perry.

    DOT National Transportation Integrated Search

    2013-04-01

    The Maine Department of Transportation (MaineDOT) uses the Superpave hot mix asphalt process and : specifies asphalt binder grades using the Performance Grade criteria. The Department mainly uses asphalt : binder grade PG 64-28. This is an asphalt bi...

  2. 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

  3. Asphalt mix characterization using dynamic modulus and APA testing.

    DOT National Transportation Integrated Search

    2005-11-01

    final report summarizes two research efforts related to asphalt mix characterization: dynamic modulus and Asphalt Pavement Analyzer testing. One phase of the research consisted of a laboratory-based evaluation of dynamic modulus of Oregon dense-grade...

  4. Asphalt binder grade selection and ignition oven calibration factors for HMAC with recycled asphalt products.

    DOT National Transportation Integrated Search

    2013-02-01

    This study investigated several characteristics of laboratory-fabricated and plant-produced hot-mix asphalt mixtures containing : various proportions of RAP and RAS with the principal objectives of developing a procedure for selecting the virgin bind...

  5. Performance assessment of warm mix asphalt (WMA) pavements : executive summary report.

    DOT National Transportation Integrated Search

    2009-09-01

    Warm Mix Asphalt (WMA) is a new technology which was : introduced in 1995 in Europe. WMA is gaining attention all : over the world because it offers several advantages over : conventional asphalt concrete mixes. The benefits include: : (1) Reduced en...

  6. Performance Assessment of Warm Mix Asphalt (WMA) Pavements : Executive Summary Report

    DOT National Transportation Integrated Search

    2009-09-01

    Warm Mix Asphalt (WMA) is a new technology which was : introduced in 1995 in Europe. WMA is gaining attention all : over the world because it offers several advantages over : conventional asphalt concrete mixes. The benefits include: : (1) Reduced en...

  7. 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.

  8. Characterization of Alaskan hot-mix asphalt containing reclaimed asphalt pavement material : final report.

    DOT National Transportation Integrated Search

    2016-06-01

    In order to properly characterize Alaskan HMA materials containing RAP, this study evaluated properties of 3 asphalt binders typically : used in Alaska, PG 52-28, PG 52-40, and PG 58-34, and 11 HMA mixtures containing up to 35% RAP that were either p...

  9. Durable Recycled Superpave Mixes in Kansas

    DOT National Transportation Integrated Search

    2018-04-01

    The use of economical and environment-friendly recycled asphalt materials has become increasingly popular for asphalt pavement construction. In general, reclaimed asphalt pavement (RAP) and recycled asphalt shingles (RAS) are used in hot-mix asphalt ...

  10. Thermodynamics between RAP/RAS and virgin aggregates during asphalt concrete production : a literature review.

    DOT National Transportation Integrated Search

    2015-09-01

    In hot-mix asphalt (HMA) plants, virgin aggregates are heated and dried separately before being mixed with : RAP/RAS and virgin asphalt binder. RAP/RAS materials are not heated or dried directly by a burner to avoid : burning of aged binder coating o...

  11. Basic Performance of Fibre Reinforced Asphalt Concrete with Reclaimed Asphalt Pavement Produced In Low Temperatures with Foamed Bitumen

    NASA Astrophysics Data System (ADS)

    Chomicz-Kowalska, Anna; Iwański, Mateusz M.; Mrugała, Justyna

    2017-10-01

    During the reconstruction of road pavements, the reclaimed asphalt pavement (RAP), which is obtained through milling of the worn out existing asphalt, is commonly used for producing new base courses in cold recycling processes. Two of these techniques are most popular: one using mineral-cement-emulsion mixes and one utilizing mineral cement mixes with foamed bitumen. Additionally, some amounts of RAP can be incorporated into traditional hot mix asphalt. The demand for energy efficient and environmentally friendly solutions however, results in a need for development of new techniques that would result in cheaper and more reliable solutions with smaller carbon footprint. The reduction of processing temperatures with simultaneous incorporation of reclaimed material is the most efficient way of obtaining these objectives, but it often results in the overall decrease of bituminous mix quality. The paper presents the possibility of using RAP for producing asphalt concrete in warm mix asphalt (WMA) production process by the use of foamed bitumen modified with Fischer-Tropsch synthetic wax and polymer-basalt fibers. Additionally, a series of reference mixtures were produced to investigate the effects of the additives and of the warm process. The carried out analyses and tests shown that the experimental warm mix asphalt produced with RAP and foamed bitumen returned satisfactory performance. The introduction of synthetic F-T wax in the warm foam bitumen mixes resulted in a significantly improved compaction levels and moisture and frost resistance and the addition of polymer-basalt fibers has further improved the permanent deformation resistance of the mixes. All of the designed and tested mixes have fulfilled the requirements for binding course asphalt concrete with medium traffic loads.

  12. Wordburn hot in-plant asphalt pavement recycling project : final report.

    DOT National Transportation Integrated Search

    1992-05-01

    In 1977, the Oregon Department of Transportation constructed a demonstration project using approximately 47,000 tons of stockpiled asphalt concrete (AC) material to overlay a section of pavement in Oregon. The stockpiled AC material was hot in-plant ...

  13. The Rejuvenating Effect in Hot Asphalt Recycling by Mortar Transfer Ratio and Image Analysis

    PubMed Central

    Wang, Fusong; Wang, Zipeng; Li, Chao; Xiao, Yue; Wu, Shaopeng; Pan, Pan

    2017-01-01

    Using a rejuvenator to improve the performance of asphalt pavement is an effective and economic way of hot asphalt recycling. This research analyzes the rejuvenating effect on aged asphalt by means of a Mortar Transfer Ratio (MTR) test, which concerns the ratio of asphalt mortar that moves from recycled aggregates (RAP aggregates) to fresh added aggregates when aged asphalt is treated with a regenerating agent and comes into contact with fresh aggregates. The proposed MTR test analyzes the regeneration in terms of the softening degree on aged asphalt when the rejuvenator is applied. The covered area ratio is studied with an image analyzing tool to understand the possibility of mortar transferring from RAP aggregates to fresh aggregates. Additionally, a micro-crack closure test is conducted and observed through a microscope. The repairing ability and diffusion characteristics of micro-cracks can therefore be analyzed. The test results demonstrate that the proposed mortar transfer ratio is a feasible way to evaluate rejuvenator diffusion during hot recycling. The mortar transfer ratio and uncovered area ratio on fresh aggregates are compatible, and can be used to quantify the contribution of the rejuvenator. Within a certain temperature range, the diffusing effect of the rejuvenator is better when the diffusing temperature is higher. The diffusion time of the rejuvenator is optimum when diffusion occurs for 4–8 h. When the rejuvenator is properly applied, the rough and cracking surface can be repaired, resulting in better covered aggregates. The micro-closure analysis visually indicates that rejuvenators can be used to repair the RAP aggregates during hot recycling. PMID:28772935

  14. The Rejuvenating Effect in Hot Asphalt Recycling by Mortar Transfer Ratio and Image Analysis.

    PubMed

    Wang, Fusong; Wang, Zipeng; Li, Chao; Xiao, Yue; Wu, Shaopeng; Pan, Pan

    2017-05-24

    Using a rejuvenator to improve the performance of asphalt pavement is an effective and economic way of hot asphalt recycling. This research analyzes the rejuvenating effect on aged asphalt by means of a Mortar Transfer Ratio (MTR) test, which concerns the ratio of asphalt mortar that moves from recycled aggregates (RAP aggregates) to fresh added aggregates when aged asphalt is treated with a regenerating agent and comes into contact with fresh aggregates. The proposed MTR test analyzes the regeneration in terms of the softening degree on aged asphalt when the rejuvenator is applied. The covered area ratio is studied with an image analyzing tool to understand the possibility of mortar transferring from RAP aggregates to fresh aggregates. Additionally, a micro-crack closure test is conducted and observed through a microscope. The repairing ability and diffusion characteristics of micro-cracks can therefore be analyzed. The test results demonstrate that the proposed mortar transfer ratio is a feasible way to evaluate rejuvenator diffusion during hot recycling. The mortar transfer ratio and uncovered area ratio on fresh aggregates are compatible, and can be used to quantify the contribution of the rejuvenator. Within a certain temperature range, the diffusing effect of the rejuvenator is better when the diffusing temperature is higher. The diffusion time of the rejuvenator is optimum when diffusion occurs for 4-8 h. When the rejuvenator is properly applied, the rough and cracking surface can be repaired, resulting in better covered aggregates. The micro-closure analysis visually indicates that rejuvenators can be used to repair the RAP aggregates during hot recycling.

  15. Premature asphalt concrete pavement cracking.

    DOT National Transportation Integrated Search

    2015-06-01

    Recently, the Oregon Department of Transportation (ODOT) has identified hot mix asphalt concrete : (HMAC) pavements that have displayed top-down cracking within three years of construction. The objective of : the study was to evaluate the top-down cr...

  16. Quality control of recycled asphaltic concrete : final report.

    DOT National Transportation Integrated Search

    1982-07-01

    This study examined the variations found in recycled asphaltic concrete mix based upon plant quality control data and verification testing. The data was collected from four recycled hot-mix projects constructed in 1981. All plant control and acceptan...

  17. Evaluation of lignin as an antioxidant in asphalt binders and bituminous mixtures.

    DOT National Transportation Integrated Search

    2017-01-01

    The chemical process of oxidative age-hardening in asphalt pavements is one of the major distresses : leading to hot mix asphalt (HMA) pavement failure as evidenced by fatigue and thermal (low temperature) : cracking. : Research investigations at the...

  18. 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.

  19. 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.

  20. Hot mix asphalt research investigation for Connecticut : part C - permeability/porosity testing of HMA mix designs.

    DOT National Transportation Integrated Search

    2014-07-01

    The presence of water in asphalt pavements is detrimental to the life of the pavement. Most construction specifications require the pavement to be compacted to a specific air void content. As an asphalt pavement's air void contents increase, the perm...

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

    DTIC Science & Technology

    2017-06-23

    susceptibility of hot mix asphalt (HMA) using the asphalt pavement analyzer (APA). Designation T340- 10. Washington, DC: American Association of State...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

  2. Investigation of warm-mix asphalt for Iowa roadways.

    DOT National Transportation Integrated Search

    2013-09-01

    Phase II of this study further evaluated the performance of plant-produced warm-mix asphalt (WMA) mixes by conducting : additional mixture performance tests at a broader range of temperatures, adding additional pavements to the study, comparing : vir...

  3. Evaluation of lignin as an antioxidant in asphalt binders and bituminous mixtures : technical summary.

    DOT National Transportation Integrated Search

    2017-01-01

    The chemical process of oxidative age-hardening in asphalt pavements is one of the major distresses leading to hot mix asphalt (HMA) pavement failure as evidenced by fatigue and thermal (low temperature) cracking.

  4. Longitudinal Joint Construction Techniques for Asphalt Pavements

    DOT National Transportation Integrated Search

    1997-08-01

    Thirty hot mix asphalt (HMA) test sections were constructed in Michigan (1992), Wisconsin (1992), Colorado (1994), and Pennsylvania (1995) to evaluate the effectiveness of twelve different longitudinal joint construction techniques. The performance o...

  5. Alternative acceptance procedures for asphalt mixes.

    DOT National Transportation Integrated Search

    1992-01-01

    By the year 2005, the use of chlorinated solvents is to be eliminated. Faced with this eventuality, VDOT formed a task force to look at alternatives for the acceptance of asphalt mixes. One alternative is to use biodegradable solvents in the extracti...

  6. New generation mix-designs : laboratory-field testing and modifications to Texas HMA mix-design procedures.

    DOT National Transportation Integrated Search

    2012-10-01

    Recent changes to the Texas hot mix asphalt (HMA) mix-design procedures such as adaption of the higher-stiffer PG asphalt-binder grades and the Hamburg test have ensured that the mixes that are routinely used on the Texas highways are not prone to ru...

  7. A Factorial Design Approach to Analyse the Effect of Coarse Recycled Concrete Aggregates on the Properties of Hot Mix Asphalt

    NASA Astrophysics Data System (ADS)

    Tanty, Kiranbala; Mukharjee, Bibhuti Bhusan; Das, Sudhanshu Shekhar

    2018-06-01

    The present study investigates the effect of replacement of coarse fraction of natural aggregates by recycled concrete aggregates on the properties of hot mix asphalt (HMA) using general factorial design approach. For this two factors i.e. recycled coarse aggregates percentage [RCA (%)] and bitumen content percentage [BC (%)] are considered. Tests have been carried out on the HMA type bituminous concrete, prepared with varying RCA (%) and BC (%). Analysis of variance has been performed on the experimental data to determine the effect of the chosen factors on various parameters such as stability, flow, air void, void mineral aggregate, void filled with bitumen and bulk density. The study depicts that RCA (%) and BC (%) have significant effect on the selected responses as p value is less than the chosen significance level. In addition to above, the outcomes of the statistical analysis indicate that interaction between factors have significant effects on void mineral aggregate and bulk density of bituminous concrete.

  8. A Factorial Design Approach to Analyse the Effect of Coarse Recycled Concrete Aggregates on the Properties of Hot Mix Asphalt

    NASA Astrophysics Data System (ADS)

    Tanty, Kiranbala; Mukharjee, Bibhuti Bhusan; Das, Sudhanshu Shekhar

    2018-02-01

    The present study investigates the effect of replacement of coarse fraction of natural aggregates by recycled concrete aggregates on the properties of hot mix asphalt (HMA) using general factorial design approach. For this two factors i.e. recycled coarse aggregates percentage [RCA (%)] and bitumen content percentage [BC (%)] are considered. Tests have been carried out on the HMA type bituminous concrete, prepared with varying RCA (%) and BC (%). Analysis of variance has been performed on the experimental data to determine the effect of the chosen factors on various parameters such as stability, flow, air void, void mineral aggregate, void filled with bitumen and bulk density. The study depicts that RCA (%) and BC (%) have significant effect on the selected responses as p value is less than the chosen significance level. In addition to above, the outcomes of the statistical analysis indicate that interaction between factors have significant effects on void mineral aggregate and bulk density of bituminous concrete.

  9. Laboratory Study on the Fatigue Resistance of Asphaltic Concrete Containing Titanium Dioxide

    NASA Astrophysics Data System (ADS)

    Buhari, Rosnawati; Ezree Abdullah, Mohd; Khairul Ahmad, Mohd; Azhar Tajudin, Saiful; Khatijah Abu Bakar, Siti

    2018-03-01

    This study aims to evaluate the fatigue performance of modified asphalt mixture using Indirect Tensile Fatigue Test. Titanium Dioxide (TiO2) powder in a form of rutile was used for producing asphalt concrete with lower mixing and compaction temperature compared to conventional hot mix asphalt without reducing its physical and mechanical also resistance to fatigue. The characteristic of the asphalt and modified asphalt was evaluated using penetration test, softening test and rotational viscosity test. Titanium dioxide of 2%, 4%, 6%, 8% and 10% by weight of asphalt has been incorporated into unaged 80/100 asphalt mix in order to improvise its performance and to fulfill the objectives of this experimental study. As a result, TiO2 as an additive is potential to decrease the penetration and increasing the softening point of the asphalt. In terms of fatigue performance testing, addition TiO2 additive does help in improving the fatigue properties as it shows greater result than the control asphalt. In conclusion, TiO2 is great in improving fatigue properties.

  10. Field test of a polyphosphoric acid (PPA) modified asphalt binder on Rt. 1 in Perry : [second interim report, April 2012].

    DOT National Transportation Integrated Search

    2012-04-01

    The Maine Department of Transportation (MaineDOT) uses the Superpave hot mix asphalt process and : specifies asphalt binder grades using the Performance Grade criteria. The Department mainly uses asphalt : binder grade PG64-28. This is an asphalt bin...

  11. New generation HMA mix designs : accelerated pavement testing of a type C mix with the ALF machine.

    DOT National Transportation Integrated Search

    2012-09-01

    Recent changes to the Texas hot-mix asphalt (HMA) mix-design procedures, such as the adaption of the higher-stiffer performance-grade asphalt-binder grades and the Hamburg test, have ensured that the mixes that are routinely used on Texas highways ar...

  12. Performance life of HMA mixes : final report.

    DOT National Transportation Integrated Search

    2016-01-01

    A number of hot mix asphalt (HMA) types, such as permeable friction course (PFC), stone mastic asphalts : (SMA), performance design mixes and conventional dense graded mixes are currently used to construct or overlay : roads. One of the important inp...

  13. Recommendations for extending asphalt pavement surface life within Washington State.

    DOT National Transportation Integrated Search

    2016-10-01

    This study identifies and evaluates hot mix asphalt (HMA) mix design and construction techniques with potential for improving WSDOT pavement surface life. WSDOT pavement failure mechanisms are found to be predominantly cracking. Rutting may reach a f...

  14. Development of TTI's asphalt compaction monitoring system.

    DOT National Transportation Integrated Search

    2012-07-01

    In recent years, the Texas Department of Transportation has made significant progress with the : development and implementation of new technologies to measure the uniformity of new hot mix asphalt : layer construction. Early studies focused on the de...

  15. 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.

  16. Research notes : exploratory study of hot-in-place recycling of asphalt pavements.

    DOT National Transportation Integrated Search

    1995-06-01

    In 1992, the Oregon Department of Transportation (ODOT) contracted for six hot in-place recycling (HIR) projects for rehabilitation of asphalt concrete pavements. Five projects were constructed in 1992; the sixth was constructed in 1993.

  17. Validity of multiple stress creep recovery (MSCR) test for DOTD asphalt binder specification : technical summary.

    DOT National Transportation Integrated Search

    2017-09-01

    Higher traffic coupled with heavier loads led the asphalt industry to introduce polymer-modified binders to enhance the durability and strength of hot mix asphalt (HMA) pavements. When the Superpave Performance Graded (PG) binder specification (AASHT...

  18. Segregation of asphalt mixes caused by surge silos : final report.

    DOT National Transportation Integrated Search

    1982-01-01

    Segregation of asphalt mixes continues to be a problem in Virginia, particularly with base mixes and coarse surface mixes. Although the problem is encountered primarily on jobs using surge silos, it has been related to other factors such as mix desig...

  19. Variation in temperature and mechanical properties of asphaltic concrete due to storage in surge bins.

    DOT National Transportation Integrated Search

    1973-03-01

    The Louisiana Department of Highways specifications on asphaltic concrete allow the contractors to use silos or surge bins for storage of asphaltic concrete mixtures. However, the maximum allowable storage time of the hot mix, if the contractor elect...

  20. Evaluation of cement and fly ash treated recycled asphalt pavement and aggregates for base construction.

    DOT National Transportation Integrated Search

    2011-12-01

    Many entities currently use recycled asphalt pavement (RAP) and other aggregates as base material, temporary haul roads, : and, in the case of RAP, hot mix asphalt construction. Several states currently allow the use of RAP combined with cement : for...

  1. Evaluating Georgia DOT's compaction requirements for stone matrix asphalt mixes.

    DOT National Transportation Integrated Search

    2006-06-01

    This study determined a compactive effort for Stone Mastic Asphalt (SMA) mixes with the Superpave gyratory compactor (SGC) that would match a 50-blow Marshall compactive effort using aggregates and mix designs common in Georgia. SMA mix designs were ...

  2. Assessment of asphalt interlayer designed on jointed concrete.

    DOT National Transportation Integrated Search

    2014-11-01

    Reflective cracking in hot mix asphalt (HMA) overlays has been a common cause of poor pavement performance in Iowa for : many years. Reflective cracks commonly occur in HMA overlays when deteriorated portland cement concrete is paved over with : HMA....

  3. Asphalt pavement analyzer equipment acquisition : final report.

    DOT National Transportation Integrated Search

    2008-05-19

    In the design of Hot Mix Asphalt (HMA) there are tests performed on the aggregates such as resistance to abrasion, specific gravity and sieve/gradation analysis to ensure the aggregates are of sound quality prior to use in HMA. There are also tests p...

  4. High RAP mixes design methodology with balanced performance.

    DOT National Transportation Integrated Search

    2011-11-01

    "The use of reclaimed asphalt pavement (RAP) and recycled asphalt shingles (RAS) can significantly reduce the increasing cost of hot-mix asphalt paving, conserve energy, and protect the environment. This report presents a comprehensive study focusing...

  5. Comprehensive evaluation of the long-term performance of rubberized pavement, phase II : the influence of rubber and asphalt interaction on mixture durability.

    DOT National Transportation Integrated Search

    2014-12-01

    This project investigated the long-term performance of hot asphalt mixes containing crumb rubber : modifiers (CRM) added in dry or wet processes. A total of eight asphalt mixturesfour Porous : European Mixtures (PEMs) and four Stone Matrix Asphalt...

  6. Evaluation of warm mix technologies for use in asphalt rubber - asphaltic concrete friction courses (AR\\0x2010ACFC) : final report.

    DOT National Transportation Integrated Search

    2016-07-01

    The objective of this research project was to determine whether warm mix asphalt (WMA) technologies can be : used by the Arizona Department of Transportation (ADOT) for the production of an asphalt rubberasphaltic : concrete friction course (AR...

  7. Shoulder rehabilitation using portland cement and recycled asphalt pavement.

    DOT National Transportation Integrated Search

    2007-04-01

    Maine has hundreds of miles of roadway originally constructed with Portland Cement Concrete that now : are covered with Hot Mix Asphalt overlays. In 2001 the Maine Department of Transportation utilized an : experimental construction technique on one ...

  8. Evaluation of cement and fly ash treated recycled asphalt pavement and aggregates for base construction : tech summary.

    DOT National Transportation Integrated Search

    2011-12-01

    INTRODUCTION: Many entities currently use recycled asphalt pavement (RAP) and other aggregates as base materials, temporary haul roads, and, in the case of RAP, hot mix asphalt construction. Several : states currently allow the use of RAP combined wi...

  9. Performance of Virginia's warm-mix asphalt trial sections.

    DOT National Transportation Integrated Search

    2010-02-01

    Three trial sections using two warm-mix asphalt (WMA) technologies were constructed in various locations in Virginia in 2006, and experiences with these trial sections were used in the development of the Virginia Department of Transportation's specia...

  10. Asphalt Roofing Shingles Into Energy Project Summary Report

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    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 ofmore » 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.« less

  11. Evaluation of field-produced hot mix asphalt (HMA) mixtures with fractionated recycled asphalt pavement (RAP) : 2007 Illinois tollway field mix trials.

    DOT National Transportation Integrated Search

    2008-10-01

    To test the fractionated recycled asphalt pavement (FRAP) materials, the Illinois Tollway, working through its : contractors and consultants, developed and conducted a project on the applicability and feasibility of using : increased RAP contents thr...

  12. Polymer modified asphalt in hot mix pavement : interim report, executive summary.

    DOT National Transportation Integrated Search

    1988-11-01

    This report presents a summary of a literature review to determine the most appropriate testing procedures for use with polymer modified asphalts. In examining testing procedures, it was necessary to study the effects of polymer modifiers on both bin...

  13. 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.

  14. Recycling of asphalt concrete : Oregon's first hot mix project : interim report.

    DOT National Transportation Integrated Search

    1977-11-01

    The need to reduce fuel consumption and conserve natural resources have been items of ever-increasing importance during recent years. This report discusses a project in which almost 50,000 tons of asphalt concrete placed to carry detour traffic durin...

  15. Investigation and Evaluation of Ground Tire Rubber in Hot Mix Asphalt

    DOT National Transportation Integrated Search

    1989-08-01

    The purpose of this study, which is published in five volumes, was to identify and verify using all available state-of-the-art sources, how ground tire rubber can be utilized in asphalt concrete mixtures for pavement construction meeting standard qua...

  16. Exploratory study of hot-in-place recycling of asphalt pavements, volume II : appendices.

    DOT National Transportation Integrated Search

    1994-11-01

    Hot-in-place recycling (HIR) is a method for rehabilitation of asphalt pavements. Potential for cost savings and resource preservation are high because existing pavement materials are processed on-site, with only the addition of small amounts of recy...

  17. Determination of proper mixing and compacting temperatures of laboratory fabricated asphalt concrete specimens.

    DOT National Transportation Integrated Search

    1995-04-01

    The Oregon Department of Transportation (ODOT) Materials Unit has historically used one temperature for the mixing and compacting of laboratory fabricated asphalt concrete specimens. Since switching to the performance based asphalt (PBA) specificatio...

  18. In-place voids monitoring of hot mix asphalt pavements : follow-up.

    DOT National Transportation Integrated Search

    2014-01-01

    In order to validate the policy of allowing the adjustment of the asphalt cement to reduce the laboratory : air voids up to one percent, cores were taken over a period of four years on 19 paving projects and : tested for air voids. After being compac...

  19. Verification of job mix formula for Alaskan HMA.

    DOT National Transportation Integrated Search

    2014-08-01

    Some asphalt pavement does not last as long as it should. Every year, a significant amount of money is spent by the state on : repairing and maintaining pavement, which raises the question: Are we getting the mix design we need? Since hot mix asphalt...

  20. 0-6613 : evaluate binder and mixture aging for warm mix asphalt.

    DOT National Transportation Integrated Search

    2013-08-01

    Warm mix asphalt (WMA) technologies employ reduced : mixing and placement temperatures, thereby allowing : reduced fuel consumption, enhanced compaction, : increased haul distances, and an extended paving : season. However, there have been issues of ...

  1. 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

  2. Mixing and compaction recommendations for warm mix asphalt (WMA) with recycled asphalt shingles (RAS) : final report.

    DOT National Transportation Integrated Search

    2017-05-01

    The use of recycled asphalt shingles (RAS) is an attractive option for asphalt mixture producers due to the : high amount of recycled asphalt binder available in RAS. By weight, RAS contains 10 to 25% asphalt by total : weight of the shingle. The asp...

  3. Construction and performance of ultra thin asphalt friction course

    DOT National Transportation Integrated Search

    1997-09-01

    The Novachip process, also known as ultrathin friction course, was developed in France in 1986. The process utilizes a single piece of equipment to place a thin, gap-graded hot mix asphalt (HMA) onto a relatively thick layer of polymer modified aspha...

  4. Quantify the energy and environmental effects of using recycled asphalt and recycled concrete for pavement construction phase I : final report.

    DOT National Transportation Integrated Search

    2009-08-01

    The objective of this study is to quantify the energy and environment impacts from using recycled materials : for highway construction. Specifically, when recycled asphalt pavement is re-used for producing hot mix : asphalt or when recycled concrete ...

  5. Additional asphalt to increase the durability of Virginia's superpave surface mixes.

    DOT National Transportation Integrated Search

    2003-01-01

    Although Superpave has been successful in preventing rutting, many believe that the design asphalt content needs fine-tuning to produce durable mixes. This investigation used various laboratory tests to test samples of field surface mixes (12.5 mm an...

  6. 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.

  7. Assessment of asphalt interlayer designed on jointed concrete : [tech transfer summary].

    DOT National Transportation Integrated Search

    2014-11-01

    Based on the substantial reduction in reflective cracking and only marginal : cost increases from using the interlayer on this research project, it is : recommended that future hot mix asphalt (HMA) overlay projects in Iowa : consider using the crack...

  8. Compatibility of aggregate, asphalt cement and antistrip materials : final report.

    DOT National Transportation Integrated Search

    1995-12-01

    Studies undertaken for the FHWA revealed a significant moisture damage problem in Louisiana hot mix pavements. At that time an antistrip additive from a qualified products list was required at the set rate of 0.5 percent weight of asphalt cement. The...

  9. Installation report : evaluation of recycled hot mix asphaltic concrete on Route 220.

    DOT National Transportation Integrated Search

    1982-01-01

    This report describes a project in which the bituminous pavement on an approximately 8-mi. (13-km) section of roadway was removed, recycled through a conventional asphalt batch plant, and relaid. The project was accomplished with little difficulty an...

  10. Use of manufactured waste shingles in a hot-mix asphalt field project.

    DOT National Transportation Integrated Search

    2008-01-01

    The Virginia Department of Transportation (VDOT) is faced with trying to maintain its roads with materials whose cost is increasing at an alarming rate. The significant cost increase for asphalt concrete, which is used to pave a majority of Virginia'...

  11. The use of atomic force microscopy to evaluate warm mix asphalt : [executive summary report].

    DOT National Transportation Integrated Search

    2013-01-01

    Warm Mix Asphalt (WMA) has received considerable attention in past few years due to its benefits in reducing energy consumption and pollutant emissions during production and placement of asphalt mixtures, as well as a compaction aid during the constr...

  12. 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…

  13. Sulphur extended asphalt : research report.

    DOT National Transportation Integrated Search

    1980-05-01

    Extensive research has been directed toward the addition of sulphur to asphaltic concrete mixes to function as either a quality aggregate or as an asphalt cement extender. By utilizing a high sulphur/asphalt ratio sulphur extended asphalt mix, it was...

  14. Determining asphalt content for recycled asphalt pavement (RAP) materials.

    DOT National Transportation Integrated Search

    2003-07-01

    The State of Oregon uses significant amounts of Recycled Asphalt Pavement (RAP) in dense-graded mixes on State : highways. The design process for these mixes relies on accurately knowing the amount of asphalt cement in the RAP : materials being used....

  15. Compaction at the longitudinal construction joint in asphalt pavements (KYSPR-00-208)

    DOT National Transportation Integrated Search

    2002-05-01

    Poor compaction practices at longitudinal construction joints in hot-mix asphalt (HMA) pavements lead to premature pavement failure. The hypothesis is that poorly constructed or compacted HMA joints tend to be more permeable and allow water to enter ...

  16. 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.

  17. Quality control analysis : part IV : field simulation of asphaltic concrete specifications.

    DOT National Transportation Integrated Search

    1969-02-01

    The report present some of the major findings, from a simulated study of statistical specifications, on three asphaltic concrete projects representing a total of approximately 30, 000 tons of hot mix. The major emphasis of the study has been on the a...

  18. Use of normal propyl bromide solvents for extraction and recovery of asphalt cements

    DOT National Transportation Integrated Search

    2000-11-01

    Four normal propyl bromide (nPB) solvents were evaluated for use as chlorinated solvent replacements in typical hot mix asphalt (HMA) extraction and recovery processes. The experimental design included one method of extraction (centrifuge), one metho...

  19. Investigation of asphalt content design for open-graded bituminous mixes.

    DOT National Transportation Integrated Search

    1974-01-01

    Several design procedures associated with determining the proper asphalt content for open-graded bituminous mixes were investigated. Also considered was the proper amount of tack coat that should be placed on the old surface prior to paving operation...

  20. Mixing and Compaction Temperatures for Hot Mix Asphalt Concrete

    DOT National Transportation Integrated Search

    2000-01-01

    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 met...

  1. Evaluation of a drainage blanket in an asphalt shoulder section : interim report.

    DOT National Transportation Integrated Search

    1974-02-01

    The aim of this research project was to develop a permeable, yet stable, hot mix asphaltic drainage system for a typical pavement section. Development of such systems should provide the Department with effective means of draining water from highway b...

  2. Balanced RAP/RAS mix design and performance evaluation system for project-specific service conditions.

    DOT National Transportation Integrated Search

    2012-11-01

    The use of reclaimed asphalt pavement (RAP) and recycled asphalt shingles (RAS) can significantly reduce the increasing cost of hot-mix asphalt paving, conserve energy, and protect the environment. However, the premature cracking problem has been a s...

  3. 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.

  4. Laboratory study of test methods for polymer modified asphalt in hot mix pavement.

    DOT National Transportation Integrated Search

    1989-11-01

    Increasing use of asphalt binders modified with elastomeric or plastic modifiers makes the specification of binders a difficult task. Ideally, a generic specification would allow various suppliers and additives to compete based on expected performanc...

  5. Tests for Plastic Fines in Aggregates Related to Stripping in Asphalt Paving Mixtures

    DOT National Transportation Integrated Search

    1988-03-01

    This study was undertaken for determining the best aggregate test method that indicates the presence of detrimental plastic fines in the fine aggregate, which may induce stripping in hot mix asphalt (HMA) mixtures. Ten fine aggregates representing a ...

  6. Evaluation of latex polymers to resist stripping in asphalt pavements in Oregon : final report.

    DOT National Transportation Integrated Search

    2005-03-01

    This study assessed the effectiveness of latex polymer anti-stripping treatment by inspecting and evaluating the : condition of pavements constructed in Oregon from 1997-2001. Ten hot mix asphalt concrete paving projects : were identified throughout ...

  7. Investigation of warm mix asphalt for Iowa roadways - phase II : tech transfer summary.

    DOT National Transportation Integrated Search

    2013-09-01

    The implementation of warm mix asphalt (WMA) is becoming more : widespread with a growing number of contractors utilizing WMA : technologies to take advantage of reduced mixing and compaction : temperatures, reduced fuel consumption, and improved com...

  8. 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

  9. 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

  10. 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

  11. Permanent deformation characteristics of Oregon mixes using the asphalt pavement analyzer : final report.

    DOT National Transportation Integrated Search

    2004-01-01

    The Asphalt Pavement Analyzer (APA) device was used to characterize the impacts of various mix factors on the development of permanent deformation dense-graded mixes. Factors investigated included: aggregate size of 12.5 and 19 mm (0.5 and 0.75 in), ...

  12. Construction and performance of a stone matrix asphalt mix test section in Virginia.

    DOT National Transportation Integrated Search

    1995-01-01

    SMA is a gap-graded mix filled with a rich asphalt-fines mastic developed in Europe. In 1991 five states constructed trial sections to determine if satisfactory mixes could be produced in the United States with current materials and high rates of pro...

  13. Characterization of asphalt treated base course material

    DOT National Transportation Integrated Search

    2010-06-01

    Asphalt-treated bases are often used in new pavements; the materials are available and low-cost, but there is little data on how these materials perform in cold regions. : This study investigated four ATB types (hot asphalt, emulsion, foamed asphalt,...

  14. Field and laboratory investigation of warm mix asphalt in Texas.

    DOT National Transportation Integrated Search

    2010-07-01

    During the first half of this research study, TxDOT had only placed 1000 tons of warm mix asphalt : (WMA) as part of a demonstration project. By the end of this three year study, TxDOT had placed more : than 1,000,000 tons of WMA and allowed its use ...

  15. Testing and analysis of LWT and SCB properties of asphaltic concrete mixtures : tech summary.

    DOT National Transportation Integrated Search

    2016-04-01

    For pavement to perform well in the fi eld, a balance of both rut and crack resistance in response to the traffi c loads : and environment conditions is required. Controlling volumetric properties of a hot mix asphalt (HMA) mixture is not : enough to...

  16. Characterization of HMA mixtures containing high reclaimed asphalt pavement content with crumb rubber additives : [technical summary].

    DOT National Transportation Integrated Search

    2013-03-01

    With the increase in hot mix asphalt (HMA) mixtures prices continuously climbing, highway agencies and owners are continually : searching for methods to decrease material costs and maximize their benefi ts with no compromise in performance. One su...

  17. Compaction and measurement of field density for Oregon open-graded (F-MIX) asphalt pavement

    DOT National Transportation Integrated Search

    1999-06-01

    A research project conducted by Oregon State University (OSU) and the Oregon Department of Transportation (ODOT) investigated compaction of Oregon F-mix asphalt pavement, an open-graded mix with 25-mm maximum size aggregate and air voids typically in...

  18. 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

  19. 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.

  20. Quality control/quality assurance testing for joint density and segregation of asphalt mixtures : tech transfer summary.

    DOT National Transportation Integrated Search

    2013-04-01

    A longitudinal joint is the interface between two adjacent and parallel hot-mix asphalt (HMA) mats. Inadequate joint construction can lead to a location where water can penetrate the pavement layers and reduce the structural support of the underlying...

  1. Determination of the PG binder grade to use in a RAP mix

    DOT National Transportation Integrated Search

    2001-04-01

    The use of Recycled Asphalt Pavement (RAP) in new Hot Mix Asphalt (HMA) has become routine in the part few years. This practice is spurred by the increased amounts of pavement being milled off prior to overlaying. Using RAP has economical and environ...

  2. Regional implementation of warm mix asphalt.

    DOT National Transportation Integrated Search

    2014-09-01

    Asphalt is used in over 94 percent of all paved roadways in the United States. The ability to reduce its cost and emissions : while improving its performance has benefits that could potentially change the direction the asphalt industry moves toward i...

  3. A laboratory investigation into the effects of aggregate-related factors of critical VMA in asphalt paving mixtures.

    DOT National Transportation Integrated Search

    2000-06-01

    This report summarizes research conducted at Iowa State University on behalf of the Iowa : Department of Transportation, focusing on the volumetric state of hot-mix asphalt (HMA) : mixtures as they transition from stable to unstable configurations. T...

  4. Investigation of the behavior of asphalt tack coat interface layer.

    DOT National Transportation Integrated Search

    2005-08-04

    Asphalt tack coat is a light application of asphalt, usually asphalt diluted with water. It ensures a bond between the surface being paved and the overlying course by providing increased shear strength between two interfaces. Normally hot asphalt cem...

  5. 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.

  6. 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.

  7. Asphalt overlay cost-effectiveness : Manitoba TGS and Minnesota SPS-5 projects 10-year ranking of treatments (1989-1999)

    DOT National Transportation Integrated Search

    2000-10-01

    This report reviews Manitoba's and Minnesota's Specific Pavement Studies (SPS-5) projects. The studies focus on investigating the performance of hot mix asphalt (HMA) overlays on HMA pavements and involve nine core test sections. The SPS-5 design var...

  8. The use of Crumb Rubber as Substitute of Fine Aggregate for Hot Asphalt Mixture using Polymer Modified Bitumen

    NASA Astrophysics Data System (ADS)

    Setyawan, A.; Nugroho, S. K.; Irsyad, A. M.; Mutaqo, H. F.; Ramadhan, P.; Sumarsono, A.; Pramesti, F. P.

    2018-03-01

    The development of road pavement to fulfilled the need of modern life is not only focused on heavy duty road, but also a light duty road for the convenience of road users according to its function. For example the use of pavement on the jogging track, rail crossing, playground and so on. Due to the need of an alternative and the innovation of a comfortable pavement layer, but sufficiently strong in holding the load on the layer. The alternative innovation that can be used for the respective requirement is the utilization of waste old tires as substitute material in pavement construction. In this case the use of crumb rubber made from old tire rubber as an 100% fine aggregate substitute on the asphalt mixtures is investigated. To improve the strength and durability of the mixtures, the addition of polymer modified bitumen was incorporated. The two types of asphalt mixture selected in this study by using a continuous gradation of asphalt concrete and a gap gradation of hot roll asphalt. Testing to be implemented in this research is volumetric characteristics, Marshall characteristics, resistance to abrasion and impact and permeability. Replacement of fine aggregate with crumb rubber on asphalt concrete mixture with 60/70 penetration grade bitumen and polymer modified asphalt SBS E-55 in this research are expected to be an alternative in improving the quality of pavement and overcoming the environmental problems by reuse the waste materials.

  9. Use of lime as antistrip additive for mitigating moisture susceptibility of asphalt mixes containing baghouse fines.

    DOT National Transportation Integrated Search

    2005-08-31

    This study investigated the effectiveness of hydrated lime as an antistrip additive for mixes : containing excess baghouse fines. Wet process of lime addition was used without marination. One percent : lime was added to asphalt mixes containing 5.5% ...

  10. Performance of foamed warm mix asphalt in Virginia over four to six years.

    DOT National Transportation Integrated Search

    2017-08-01

    The Virginia Department of Transportation (VDOT) began allowing the use of warm mix asphalt (WMA) in 2008 and has become a national leader in the use of WMA technologies. Several WMA technologies were investigated in research projects prior to implem...

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

    DTIC Science & Technology

    2013-12-01

    Manufacturer WMA Category Dosage Ratea (%) 1 PG 67-22 Ergon --- --- 2 Sasobit® SasolWax organic wax 1.5 3 Evotherm ™ 3G MeadWestvaco chemical...better performing than the HMA (Mix 1), while the Evotherm ™ (Mix 3) and foamed asphalt (Mix 4) WMAs did not perform quite as well as HMA. These...Sasobit®) 1 4.0 0.4301 0.4873 31 52 2 4.0 0.4788 0.4879 24 49 3 4.1 0.4049 0.464 29 60 Avg. 4.0 0.4379 0.4797 28 54 3 ( Evotherm ™) 1 4.0 0.0205 0.5793 20

  12. 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

    Justification January 1980 BY Distribution Availabilit CodesIAvail an~d/or Dist special Prepa red for DIRECTORATE OF MILITARY PROGRAMS OFFICE, CHIEF OF...of water on the resilient modulus of asphalt treated mixes. Proecedinfp 4. Asphalt concrete mixes using the Tilton aggregates Association of Asphalt

  13. Influence of hot asphalt mixture using asbuton on road composite pavement

    NASA Astrophysics Data System (ADS)

    Gaus, Abdul; Darwis, Muhammad; Imran

    2017-11-01

    Construction and rehabilitation of road infrastructure in Indonesia require about 1.2 million tons of asphalt per year, approximately 100% used of petroleum asphalt. Only a half of asphalt demand can be provided domestically, while about 600 thousand tons have to be imported from abroad. Indonesia has natural asphalt with a quite large deposit but has not been fully utilized. Lack of availability of asphalt and the increasing demand of the domestic market will give effect to an increase in bitumen cost in the domestic market. Somehow, this is not a sufficient condition due to the rising cost of road infrastructure. This study aims to determine the effect of using a layer of asphalt concrete pavement asbuton to rigid pavement (PR-modification). Stressing that occur in rigid pavement, asphalt concrete layer and base course measured by using LVDT and for the subgrade using soil pressure transducer. Using asbuton on asphalt concrete will have more benefit on improving the stability of the marshall. The maximum deflection occurring in the PR-modification at 5.19 mm with a maximum stress of 175.10 kN. Vertical and horizontal tension that occur at the base course at -20 cm row by 0.855 MPa and 0.00282 MPa. Addition of layers of asphalt concrete in rigid pavement using asbuton has increased power by 9.5%.

  14. Validation of source approval of HMA surface mix aggregate : final report.

    DOT National Transportation Integrated Search

    2016-04-01

    The main focus of this research project was to develop methodologies for the validation of source approval of hot : mix asphalt surface mix aggregate. In order to further enhance the validation process, a secondary focus was also to : create a spectr...

  15. Annual asphalt pavement industry survey on recycled materials and warm-mix asphalt usage : 2009-2012, [summary].

    DOT National Transportation Integrated Search

    2013-12-01

    The objective of this survey was to quantify the use of recycled materials, including RAP and RAS, and WMA produced by the asphalt pavement industry. The National Asphalt Pavement Association (NAPA) conducted a voluntary survey of asphalt mixture pro...

  16. 40 CFR 60.91 - Definitions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Hot Mix Asphalt Facilities § 60.91... Act and in subpart A of this part. (a) Hot mix asphalt facility means any facility, as described in § 60.90, used to manufacture hot mix asphalt by heating and drying aggregate and mixing with asphalt...

  17. 40 CFR 60.91 - Definitions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Hot Mix Asphalt Facilities § 60.91... Act and in subpart A of this part. (a) Hot mix asphalt facility means any facility, as described in § 60.90, used to manufacture hot mix asphalt by heating and drying aggregate and mixing with asphalt...

  18. 40 CFR 60.91 - Definitions.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Hot Mix Asphalt Facilities § 60.91... Act and in subpart A of this part. (a) Hot mix asphalt facility means any facility, as described in § 60.90, used to manufacture hot mix asphalt by heating and drying aggregate and mixing with asphalt...

  19. 40 CFR 60.91 - Definitions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Hot Mix Asphalt Facilities § 60.91... Act and in subpart A of this part. (a) Hot mix asphalt facility means any facility, as described in § 60.90, used to manufacture hot mix asphalt by heating and drying aggregate and mixing with asphalt...

  20. 40 CFR 60.91 - Definitions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Hot Mix Asphalt Facilities § 60.91... Act and in subpart A of this part. (a) Hot mix asphalt facility means any facility, as described in § 60.90, used to manufacture hot mix asphalt by heating and drying aggregate and mixing with asphalt...

  1. Asphalt cement chip seals in Oregon : construction report

    DOT National Transportation Integrated Search

    2000-06-01

    Most chip seals in Oregon have been constructed using an emulsified asphalt binder. However, chip seals using an asphalt cement (hot oil) binder have been tried in limited situations in Oregon. This report includes a literature review and summarizes ...

  2. 0-6744 : new HMA shear resistance and rutting test for Texas mixes.

    DOT National Transportation Integrated Search

    2014-08-01

    Traditionally run at one test temperature (122F), the : Hamburg wheel tracking test (HWTT) (Figure 1) has a : proven history of successfully identifying and screening : hot-mix asphalt (HMA) mixes that are prone to rutting : and/or susceptible to m...

  3. 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.

  4. Evaluation of binder aging and its influence in aging of hot mix asphalt concrete : technical report.

    DOT National Transportation Integrated Search

    2014-01-01

    TxDOT Project 0-6009 was a comprehensive interdisciplinary research effort that has developed the ability : to predict asphalt oxidative hardening over time and pavement depth, and the impact of this hardening on : mixture durability. The many interr...

  5. Recommended use of reclaimed asphalt pavement in the Superpave mix design method: technician's manual.

    DOT National Transportation Integrated Search

    2001-01-01

    This manual is a reference guide for mix design and field testing technicians who deal with reclaimed asphalt pavement (RAP) in Superpave mixtures. It will provide detailed descriptions and examples of each step involved in designing and testing a Su...

  6. 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.

  7. Validation of source approval of HMA surface mix aggregate using spectrometer : final report.

    DOT National Transportation Integrated Search

    2016-04-01

    The main focus of this research project was to develop methodologies for the validation of source approval of hot : mix asphalt surface mix aggregate. In order to further enhance the validation process, a secondary focus was also to : create a spectr...

  8. Performance of Coarse-Graded Mixes at Westrack - Premature Rutting

    DOT National Transportation Integrated Search

    1998-06-01

    WesTrack is the Federal Highway Administration's (FHWA) test facility in Nevada for developing performance-related specifications for hot-mix asphalt pavement construction. It is also providing some of the earliest data on the performance of Superpav...

  9. Regional implementation of warm mix asphalt : [tech summary].

    DOT National Transportation Integrated Search

    2014-09-01

    Asphalt is used in over 94 percent of all paved roadways in the United States. The ability to reduce its cost and : emissions while improving its performance has bene ts that could potentially change the direction the asphalt : industry moves in t...

  10. HMA shear resistance, permanent deformation, and rutting tests for Texas mixes : year-1 report.

    DOT National Transportation Integrated Search

    2014-04-01

    Traditionally run at one test temperature (122F), the Hamburg Wheel Tracking Test (HWTT) has a proven : history of identifying hot-mix asphalt (HMA) mixes that are moisture susceptible and/or prone to rutting. However, : with the record summer temp...

  11. Ten year performance of asphalt additive test sections : Lave Butte - Fremont Highway Junction Section, The Dalles - California Highway (US#97), Deschutes County, Oregon.

    DOT National Transportation Integrated Search

    1998-09-01

    The durability of hot mix asphalt concrete (HMAC) overlays is important to the Oregon Department of Transportation (ODOT), as this is the most common form of surface rehabilitation on state roads. To see if several HMAC additives available in Oregon ...

  12. Laboratory and field performance measurements to support the implementation of warm mix asphalt in Texas.

    DOT National Transportation Integrated Search

    2012-07-01

    An objective of this study was to monitor the performance of more than 10 warm mix asphalt (WMA) : projects in the state. Several WMA technologies were included in the study (foaming, Advera, Evotherm, : Rediset, Sasobit) and it was determined that p...

  13. HMA shear resistance, permanent deformation, and rutting tests for Texas mixes : final year-2 report.

    DOT National Transportation Integrated Search

    2014-11-01

    Traditionally run at one test temperature (122F), the Hamburg wheel tracking test (HWTT) has a proven : history of identifying hot mix asphalt (HMA) mixes that are moisture susceptible and/or prone to rutting. However, : with the record summer temp...

  14. Moisture Sensitivity of Crumb Rubber Modified Modifier Warm Mix Asphalt Additive for Two Different Compaction Temperatures

    NASA Astrophysics Data System (ADS)

    Bilema, Munder A.; Aman, Mohamad Y.; Hassan, Norhidayah A.; Ahmad, Kabiru A.; Elghatas, Hamza M.; Radwan, Ashraf A.; Shyaa, Ahmed S.

    2018-04-01

    Crumb rubber obtained from scrap tires has been incorporated with asphalt binder to improve the performance of asphalt mixtures in the past decades. Pavements containing crumb-rubber modified (CRM) binders present one major drawback: larger amounts of greenhouse gas emissions are produced as there is rise in the energy consumption at the asphalt plant due to the higher viscosity of these type of binders compared with a conventional mixture. The objective of this paper is to calculate the optimum bitumen content for each percentage and evaluate the moisture sensitivity of crumb rubber modified asphalt at two different compacting temperatures. In this study, crumb rubber modified percentages was 0%, 5%, 10% and 15% from the binder weight, with adding 1.5% warm mix asphalt additive (Sasobit) and crush granite aggregate of 9.5mm Nominal maximum size was used after assessing its properties. Ordinary Portland Cement (OPC) used by 2% from fine aggregate. The wet method was using to mix the CRM with bitumen, the CRM conducted at 177°C for 30 min with 700rpm and Sasobit conducted at 120°C for 10 min with 1000rpm. As a result, from this study the optimum bitumen content (OBC) was increased with increased crumb rubber content. For performance test, it was conducted using the AASHTO T283 (2007): Resistance of Compacted Bituminous Mixture to Moisture-Induced Damage. The result was as expected and it was within the specification of the test, the result show that the moisture damage increased with increased the crumb rubber content but it is not exceeding the limit of specification 80% for indirect tension strength ratio (ITSR). For the temperature was with lowing the temperature the moisture damage increased.

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

    DOT National Transportation Integrated Search

    2016-11-01

    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 the characteristics of the original binder, aging of the : pavement surface dur...

  16. 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.

  17. Design of Large Stone Asphalt Mixes for Low-Volume Roads Using Six-Inch Diameter Marshall Specimens

    DOT National Transportation Integrated Search

    1991-01-01

    Premature rutting of road pavements constructed for hauling coal and logs is common. Although these roads carry low volumes of traffic, they are subjected to heavy and channelized wheel loads. Unfortunately, conventional asphalt mixes containing aggr...

  18. Validation of source approval of HMA surface mix aggregate : research summary.

    DOT National Transportation Integrated Search

    2016-04-01

    Pavement surfaces must maintain an adequate level of friction in order to provide a : safe surface for vehicles. The Maryland State Highway Administration (SHA) is : responsible for ensuring that flexible pavement construction, using hot mix asphalt ...

  19. Laboratory evaluation of Trinidad Lake Asphalt : final report.

    DOT National Transportation Integrated Search

    1985-05-01

    The Department has examined several asphalt cement additives over the last 6 - 8 years in an attempt to produce an increased strength dense graded asphaltic concrete or an acceptable mix using marginal sand aggregates. Trinidad Lake Asphalt, an natur...

  20. Performance of asphalt mixture incorporating recycled waste

    NASA Astrophysics Data System (ADS)

    Hamid, Nor Baizura; Abdullah, Mohd Ezree; Sanik, Mohd Erwan; Mokhtar, Mardiha; Kaamin, Masiri; Raduan, Rasyidah; Ramli, Mohd Zakwan

    2017-12-01

    Nowadays, the amount of premix waste was increased every year, especially at the batching plants. Normally, the waste materials will be discarded without doing any innovative and effective research about those materials. This situation has become one of the global concerns due to the increasing number of premix waste produced every year. Therefore, the aim of this study is to evaluate the performance of hot mix asphalt (HMA) using premix waste on improving asphalt mixture fatigue behaviour. The method used in this study was Superpave mix design method. The sample conducted in this study were 0%, 10%, 20%, 30%, and 100% of premix waste respectively. For a binder test, the laboratory test conducted were penetration test, softening test and thin film oven test while for the performance test were resilient modulus test and indirect tensile fatigue test. From the laboratory test, the resilient modulus test was conducted with two different temperature which was 25°C and 40°C. The result from that test was 20% of premix waste had higher resilient modulus at that two different temperatures compared to another samples. From that test also shown that the sample at the lower temperature which was 25°C has higher resilient modulus compared to the temperature of 40°C. Indirect tensile fatigue test showed that the 30% of premix waste sample was suitable for the modified asphalt mixture with referring to the maximum deformation and strain for comparison control, 10%,20%, and 100% of premix waste samples. So, it can be concluded that premix waste inhibits great potential as road construction material and suitable for repeated traffic loading.

  1. The potential use of tar sand bitumen as paving asphalt

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Petersen, J.C.

    1988-01-01

    In this paper several research reports describing the preparation of potential paving asphalts from tar sand bitumen are reviewed and the results of the studies compared. The tar sand asphalts described in the studies were prepared from 1) hot water-recovered bitumen from deposits near San Luis Obispo, California (Edna deposits), and deposits near Vernal and Sunnyside, Utah; and 2) bitumen recovered from the Northwest Asphalt Ridge deposits near Vernal, Utah, by both in situ steamflood and in situ combustion recovery processes. Important properties of the tar sand asphalts compare favorably with those of specification petroleum asphalts. Laboratory data suggest thatmore » some tar sand asphalts may have superior aging characteristics and produce more water-resistant paving mixtures than typical petroleum asphalts.« less

  2. 40 CFR 60.90 - Applicability and designation of affected facility.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... for Hot Mix Asphalt Facilities § 60.90 Applicability and designation of affected facility. (a) The affected facility to which the provisions of this subpart apply is each hot mix asphalt facility. For the purpose of this subpart, a hot mix asphalt facility is comprised only of any combination of the following...

  3. 40 CFR 60.90 - Applicability and designation of affected facility.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... for Hot Mix Asphalt Facilities § 60.90 Applicability and designation of affected facility. (a) The affected facility to which the provisions of this subpart apply is each hot mix asphalt facility. For the purpose of this subpart, a hot mix asphalt facility is comprised only of any combination of the following...

  4. 40 CFR 60.90 - Applicability and designation of affected facility.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... for Hot Mix Asphalt Facilities § 60.90 Applicability and designation of affected facility. (a) The affected facility to which the provisions of this subpart apply is each hot mix asphalt facility. For the purpose of this subpart, a hot mix asphalt facility is comprised only of any combination of the following...

  5. 40 CFR 60.90 - Applicability and designation of affected facility.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... for Hot Mix Asphalt Facilities § 60.90 Applicability and designation of affected facility. (a) The affected facility to which the provisions of this subpart apply is each hot mix asphalt facility. For the purpose of this subpart, a hot mix asphalt facility is comprised only of any combination of the following...

  6. 40 CFR 60.90 - Applicability and designation of affected facility.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... for Hot Mix Asphalt Facilities § 60.90 Applicability and designation of affected facility. (a) The affected facility to which the provisions of this subpart apply is each hot mix asphalt facility. For the purpose of this subpart, a hot mix asphalt facility is comprised only of any combination of the following...

  7. Evaluation of Different Mineral Filler Aggregates for Asphalt Mixtures

    NASA Astrophysics Data System (ADS)

    Wasilewska, Marta; Małaszkiewicz, Dorota; Ignatiuk, Natalia

    2017-10-01

    Mineral filler aggregates play an important role in asphalt mixtures because they fill voids in paving mix and improve the cohesion of asphalt binder. Limestone powder containing over 90% of CaCO3 is the most frequently used type of filler. Waste material from the production of coarse aggregate can be successfully used as a mineral filler aggregate for hot asphalt concrete mixtures as the limestone powder replacement. This paper presents the experimental results of selected properties of filler aggregates which were obtained from rocks with different mineral composition and origin. Five types of rocks were used as a source of the mineral filler aggregate: granite, gabbro, trachybasalt, quartz sandstone and rocks from postglacial deposits. Limestone filler was used in this study as the reference material. The following tests were performed: grading (air jet sieving), quality of fines according to methylene blue test, water content by drying in a ventilated oven, particle density using pyknometer method, Delta ring and ball test, Bitumen Number, fineness determined as Blaine specific surface area. Mineral filler aggregates showed significant differences when they were mixed with bitumen and stiffening effect in Delta ring and ball test was evaluated. The highest values were achieved when gabbro and granite fillers were used. Additionally, Scanning Electron Microscopy (SEM) analysis of grain shape and size was carried out. Significant differences in grain size and shape were observed. The highest non-homogeneity in size was determined for quartz sandstone, gabbro and granite filler. Their Blaine specific surface area was lower than 2800 cm2/g, while for limestone and postglacial fillers with regular and round grains it exceeded 3000 cm2/g. All examined mineral filler aggregates met requirements of Polish National Specification WT-1: 2014 and could be used in asphalt mixtures.

  8. 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.

  9. Effect of asphalt rejuvenating agent on aged reclaimed asphalt pavement and binder properties : technical summary.

    DOT National Transportation Integrated Search

    2016-11-01

    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 the characteristics of the original binder, aging of the pavement surface during ...

  10. Asphalt pavement performance-based specifications : research brief.

    DOT National Transportation Integrated Search

    2017-03-01

    The fundamental objective of asphalt mix design is to select an aggregate skeleton and asphalt binder content that balances constructability and performance. High performance mixtures that protect against rutting, cracking and moisture damage are dif...

  11. Environmental and functional benefits and trade-offs of hot in-place recycling treatment techniques : final project report.

    DOT National Transportation Integrated Search

    2016-12-01

    Surface recycling is suitable for pavements with minor cracks limited to 25-50 mm in depth. Hot-in-place recycling (HIR) process includes drying and heating the upper layers, scarifying the soft asphalt, mixing the scarified material with a rejuvenat...

  12. Hot recycling of asphaltic concrete pavement : IR-15-3(8)121, Wildcat to Pine Creek

    DOT National Transportation Integrated Search

    1981-02-01

    There are various methods of pavement material recycling. This report is devoted to hot-mix plant recycling considerations and procedures. The several phases of the hot-mix recycling process are discussed separately, including removal and size reduct...

  13. Laboratory tests for hot-mix asphalt characterization in Virginia.

    DOT National Transportation Integrated Search

    2005-01-01

    This project reviewed existing laboratory methods for accurately describing the constitutive behavior of the mixes used in the Commonwealth of Virginia. Indirect tensile (IDT) strength, resilient modulus, static creep in the IDT and uniaxial modes, f...

  14. Hot mix asphalt research investigation for Connecticut, part D : evaluate the feasibility of using permeability for in-place density dispute resolution on bridge decks.

    DOT National Transportation Integrated Search

    2014-07-01

    The presence of water in asphalt pavements is detrimental to the life of the pavement. Most : construction specifications require the pavement to be compacted to a specific air void content. As an asphalt : pavements air void content increases, th...

  15. Quantitative determination of asphalt antistripping additive.

    DOT National Transportation Integrated Search

    2004-01-01

    A small device (StripScan) has been developed by InstroTech, Inc., that uses litmus paper and a spectrophotometer to analyze vapors from hot liquid asphalt binders and mixtures to determine the percentage of antistripping additive present. Approximat...

  16. 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.

  17. Assessment of the performance of several roadway mixes under rain, snow, and winter maintenance activities.

    DOT National Transportation Integrated Search

    2004-01-01

    The purpose of this study was to assess the relative functional performance, including skid resistance and splash and spray, of five hot-mix-asphalt (HMA) surfaces and a tinned portland cement concrete highway surface during controlled wet and wintry...

  18. Laboratory evaluation of a warm asphalt technology for use in Virginia.

    DOT National Transportation Integrated Search

    2008-01-01

    Rising energy costs and increased environmental awareness have brought attention to the potential benefits of warm asphalt in the United States. Warm-mix asphalt (WMA) is produced by incorporating additives into asphalt mixtures to allow production a...

  19. Hot-spot mix in ignition-scale inertial confinement fusion targets.

    PubMed

    Regan, S P; Epstein, R; Hammel, B A; Suter, L J; Scott, H A; Barrios, M A; Bradley, D K; Callahan, D A; Cerjan, C; Collins, G W; Dixit, S N; Döppner, T; Edwards, M J; Farley, D R; Fournier, K B; Glenn, S; Glenzer, S H; Golovkin, I E; Haan, S W; Hamza, A; Hicks, D G; Izumi, N; Jones, O S; Kilkenny, J D; Kline, J L; Kyrala, G A; Landen, O L; Ma, T; MacFarlane, J J; MacKinnon, A J; Mancini, R C; McCrory, R L; Meezan, N B; Meyerhofer, D D; Nikroo, A; Park, H-S; Ralph, J; Remington, B A; Sangster, T C; Smalyuk, V A; Springer, P T; Town, R P J

    2013-07-26

    Mixing of plastic ablator material, doped with Cu and Ge dopants, deep into the hot spot of ignition-scale inertial confinement fusion implosions by hydrodynamic instabilities is diagnosed with x-ray spectroscopy on the National Ignition Facility. The amount of hot-spot mix mass is determined from the absolute brightness of the emergent Cu and Ge K-shell emission. The Cu and Ge dopants placed at different radial locations in the plastic ablator show the ablation-front hydrodynamic instability is primarily responsible for hot-spot mix. Low neutron yields and hot-spot mix mass between 34(-13,+50)  ng and 4000(-2970,+17 160)  ng are observed.

  20. Hot-spot mix in ignition-scale inertial confinement fusion targets

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Regan, S. P.; Epstein, R.; Hammel, B. A.

    Mixing of plastic ablator material, doped with Cu and Ge dopants, deep into the hot spot of ignition-scale inertial confinement fusion implosions by hydrodynamic instabilities is diagnosed with x-ray spectroscopy on the National Ignition Facility. The amount of hot-spot mix mass is determined from the absolute brightness of the emergent Cu and Ge K-shell emission. The Cu and Ge dopants placed at different radial locations in the plastic ablator show the ablation-front hydrodynamic instability is primarily responsible for hot-spot mix. As a result, low neutron yields and hot-spot mix mass between 34(–13,+50) ng and 4000(–2970,+17 160) ng are observed.

  1. Hot-spot mix in ignition-scale inertial confinement fusion targets

    DOE PAGES

    Regan, S. P.; Epstein, R.; Hammel, B. A.; ...

    2013-07-22

    Mixing of plastic ablator material, doped with Cu and Ge dopants, deep into the hot spot of ignition-scale inertial confinement fusion implosions by hydrodynamic instabilities is diagnosed with x-ray spectroscopy on the National Ignition Facility. The amount of hot-spot mix mass is determined from the absolute brightness of the emergent Cu and Ge K-shell emission. The Cu and Ge dopants placed at different radial locations in the plastic ablator show the ablation-front hydrodynamic instability is primarily responsible for hot-spot mix. As a result, low neutron yields and hot-spot mix mass between 34(–13,+50) ng and 4000(–2970,+17 160) ng are observed.

  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. 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".

  4. Fracture properties and fatigue cracking resistance of asphalt binders.

    DOT National Transportation Integrated Search

    2012-03-01

    Several different types of modifiers are increasingly bring used to improve the performance of asphalt binders or to : achieve desired mixture production characteristics (e.g., Warm Mix Asphalt). However, current Superpave : performance specification...

  5. Performance Measures of Warm Asphalt Mixtures for Safe and Reliable Freight Transportation

    DOT National Transportation Integrated Search

    2009-04-01

    Warm mix asphalt (WMA) is an emerging technology that can allow asphalt to flow at a lower temperature for mixing, placing and compaction. The advantages of WMA include reduced fuel consumption, less carbon dioxide emission, longer paving season, lon...

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

    DOE Office of Scientific and Technical Information (OSTI.GOV)

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

    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 suppliesmore » 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.« less

  7. Effects of Reclaimed Asphalt Pavement (RAP) Contents and Sources on Dynamic Modulus (|E*|) and Fatigue Performance of Asphalt Mixtures in Georgia

    DOT National Transportation Integrated Search

    2016-09-01

    This report presents the effect of RAP contents and sources on the dynamic modulus and the performance of Georgia asphalt concrete mixtures. Asphalt concrete mixtures were prepared based on two Job Mix Formulas from North and South with 12.5mm nomina...

  8. 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

  9. Impact of low asphalt binder for coarse HMA mixes : final report.

    DOT National Transportation Integrated Search

    2017-06-01

    Asphalt mixtures are commonly specified using volumetric controls in combination with aggregate gradation limits, like most transportation agencies, MnDOT also uses this approach. Since 2010 onward, several asphalt paving projects for MnDOT have been...

  10. Improved performance of reclaimed asphalt pavement mixes.

    DOT National Transportation Integrated Search

    2014-08-07

    Utilization of RAP in asphalt pavements has become an important strategy to help offset rising : raw material prices and to improve the sustainability of our transportation infrastructure. The : South Dakota DOT began to routinely use RAP in mainl...

  11. Evaluation of moisture-induced damage of dense graded and gap graded asphalt mixture with nanopolymer modified binder

    NASA Astrophysics Data System (ADS)

    Shaffie, E.; Arshad, A. K.; Ahmad, J.; Hashim, W.

    2018-04-01

    The purpose of this research is to study the moisture induce damage performance of dense graded (AC14) and stone mastic asphalt (SMA14) asphalt pavement using Nanolyacrylate polymer modified asphalt binder. The physical properties of aggregate, volumetric and performance of asphalt mixes were assessed and evaluated with the laboratory tests. The study investigates fourteenth different asphalt mixtures consisting of NP modified asphalt binder formulations at 2%, 4% and 6%. Two types of asphalt binder, penetration grade PEN 80-100 and performance grade PG 76 were added with Nanopolyacrylate as asphalt modifier. The modified asphalt binder was prepared by adding 6 percent of Nanopolyacrylate (NP) to the asphalt binder. Both AC14 and SMA14 mixtures passed the Marshall requirements which indicate that these mixtures were good with respect to durability and flexibility. In terms of moisture induce damage, it was observed that the strength of the asphalt mixes increased with the addition of NP polymer modified asphalt binder. Similar trend could also be seen for SMA14 mixes, where the ITS value of SMA14 showed a significant difference compared to AC14 and all the mixtures exceeded the minimum requirement value as specified in the specification. Thus, addition of nanopolyacrylate polymer to the asphalt binder has significantly improved the cohesion as well as adhesion properties of the asphalt binder, and hence the stripping performance. Therefore, it can be concluded that the nanopolyacylate is suitable to be used as a modifier to the modified asphalt binder in order to enhance the properties of the asphalt binder and thus improving the performance of asphalt in both AC14 and SMA14 mixes.

  12. Hot-spot mix in ignition-scale implosions on the NIF [Hot-spot mix in ignition-scale implosions on the National Ignition Facility (NIF)

    DOE PAGES

    Regan, S. P.; Epstein, R.; Hammel, B. A.; ...

    2012-03-30

    Ignition of an inertial confinement fusion (ICF) target depends on the formation of a central hot spot with sufficient temperature and areal density. Radiative and conductive losses from the hot spot can be enhanced by hydrodynamic instabilities. The concentric spherical layers of current National Ignition Facility (NIF) ignition targets consist of a plastic ablator surrounding 2 a thin shell of cryogenic thermonuclear fuel (i.e., hydrogen isotopes), with fuel vapor filling the interior volume. The Rev. 5 ablator is doped with Ge to minimize preheat of the ablator closest to the DT ice caused by Au M-band emission from the hohlraummore » x-ray drive. Richtmyer–Meshkov and Rayleigh–Taylor hydrodynamic instabilities seeded by high-mode (50 < t < 200) ablator-surface perturbations can cause Ge-doped ablator to mix into the interior of the shell at the end of the acceleration phase. As the shell decelerates, it compresses the fuel vapor, forming a hot spot. K-shell line emission from the ionized Ge that has penetrated into the hot spot provides an experimental signature of hot-spot mix. The Ge emission from tritium–hydrogen–deuterium (THD) and DT cryogenic targets and gas-filled plastic shell capsules, which replace the THD layer with a massequivalent CH layer, was examined. The inferred amount of hot-spot mix mass, estimated from the Ge K-shell line brightness using a detailed atomic physics code, is typically below the 75 ng allowance for hot-spot mix. Furthermore, predictions of a simple mix model, based on linear growth of the measured surface-mass modulations, are consistent with the experimental results.« less

  13. Hot-spot mix in ignition-scale implosions on the NIF [Hot-spot mix in ignition-scale implosions on the National Ignition Facility (NIF)

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Regan, S. P.; Epstein, R.; Hammel, B. A.

    Ignition of an inertial confinement fusion (ICF) target depends on the formation of a central hot spot with sufficient temperature and areal density. Radiative and conductive losses from the hot spot can be enhanced by hydrodynamic instabilities. The concentric spherical layers of current National Ignition Facility (NIF) ignition targets consist of a plastic ablator surrounding 2 a thin shell of cryogenic thermonuclear fuel (i.e., hydrogen isotopes), with fuel vapor filling the interior volume. The Rev. 5 ablator is doped with Ge to minimize preheat of the ablator closest to the DT ice caused by Au M-band emission from the hohlraummore » x-ray drive. Richtmyer–Meshkov and Rayleigh–Taylor hydrodynamic instabilities seeded by high-mode (50 < t < 200) ablator-surface perturbations can cause Ge-doped ablator to mix into the interior of the shell at the end of the acceleration phase. As the shell decelerates, it compresses the fuel vapor, forming a hot spot. K-shell line emission from the ionized Ge that has penetrated into the hot spot provides an experimental signature of hot-spot mix. The Ge emission from tritium–hydrogen–deuterium (THD) and DT cryogenic targets and gas-filled plastic shell capsules, which replace the THD layer with a massequivalent CH layer, was examined. The inferred amount of hot-spot mix mass, estimated from the Ge K-shell line brightness using a detailed atomic physics code, is typically below the 75 ng allowance for hot-spot mix. Furthermore, predictions of a simple mix model, based on linear growth of the measured surface-mass modulations, are consistent with the experimental results.« less

  14. Molecular Simulation Study on Modification Mechanism of Red Mud Modified Asphalt

    NASA Astrophysics Data System (ADS)

    Tao, FU; Hui-ming, BAO; xing-xing, Duan

    2017-12-01

    This article used red mud, the aluminum industrial wastes, as modified asphalt material, through the study of the routine test of modified asphalt properties, and the micro test of electron microscope scanning, infrared spectrum and differential scanning calorimetry analysis etc. to discuss its performance and modification mechanism . The test results show that after mixing red mud, asphalt’s penetration index and 15 °C ductility reduced, softening point enhanced, thus the temperature sensitivity and high temperature stability of asphalt improved; Red mud after mixing the matrix asphalt, can form a uniform, stable and matrix asphalt blending system, and improve the asphalt’s thermal stability. Using molecular simulation technology to analyze the asphalt with the temperature change of energy and find in the process of asphalt melting, the largest is the key to influence on bituminous, and van der waals energy is small. It concludes that red mud -modified asphalt material is mainly controlled by bond energy, in order to obtain its favorable property of modification mechanism, red mud of senior activation and molecular bond energy of asphalt is needed to be enhanced.The results of molecular simulation show that the main component of hematite in red mud is the most adsorbed in the asphalt, the asphaltene is the second, the colloid is the worst, but the adsorption capacity of the colloid is the highest.

  15. 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

  16. Occupational exposure to asphalt mixture during road paving is related to increased mitochondria DNA copy number: a cross-sectional study.

    PubMed

    Xu, Yiyi; Lindh, Christian H; Jönsson, Bo A G; Broberg, Karin; Albin, Maria

    2018-03-27

    Asphalt workers are exposed to polyaromatic hydrocarbons (PAHs) from hot mix asphalt via both inhalation and dermal absorption. The use of crumb rubber modified (CRM) asphalt may result in higher exposure to PAHs and more adverse effects. Our aim is to assess occupational exposure to PAHs from conventional and CRM asphalt paving by measuring PAH metabolites in urine, and to investigate the effects on mitochondrial DNA copy number (mtDNAcn) and telomere length. We recruited 116 workers paving conventional asphalt, 51 workers paving CRM asphalt and 100 controls in Sweden, all males. A repeated-measures analysis included 31 workers paving both types of asphalt. Urine and blood samples were collected pre-working on Monday morning and post-working on Thursday afternoon after 4 days working. PAH metabolites: 1-hydroxypyrene (1-OH-PYR) and 2-hydroxyphenanthrene (2-OH-PH) were measured in urine by LC-MS/MS. Relative mtDNAcn and telomere length were measured by quantitative PCR. Conventional and CRM asphalt workers showed higher 1-OH-PYR and 2-OH-PH than controls (p < 0.001 for all). Relative mtDNAcn were 0.21 units (p < 0.001) higher in conventional asphalt workers and 0.13 units (p = 0.010) higher in CRM asphalt workers compared to controls. Relative telomere length did not differ across occupational groups, but it was positively associated with increment of 2-OH-PH (β = 0.075, p = 0.037) in asphalt workers. The repeated-measures analysis showed no difference in either increment of 1-OH-PYP, or changes in effect biomarkers (mtDNAcn or telomere length) between paving with conventional and CRM asphalt. Increment of 2-OH-PH was smaller after paving with CRM asphalt. Road asphalt paving in open areas resulted in PAHs exposure, as shown by elevation of PAH metabolites in urine. Asphalt workers may experience oxidative stress, evidenced by alternation in mtDNAcn; however the effects could not be fully explained by exposure to PAHs from the asphalt

  17. 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.

  18. Comparison of several asphalt design methods.

    DOT National Transportation Integrated Search

    1998-01-01

    This laboratory study compared several methods of selecting the optimum asphalt content of surface mixes. Six surface mixes were tested using the 50-blow Marshall design, the 75-blow Marshall design, two brands of SHRP gyratory compactors, and the U....

  19. Testing protocols to ensure performance of high asphalt binder replacement mixes using RAP and RAS.

    DOT National Transportation Integrated Search

    2015-12-01

    The use of reclaimed asphalt pavement (RAP) and recycled asphalt shingles (RAS) in asphalt concrete (AC) mixtures can reduce demand for virgin aggregates and asphalt binder, bringing environmental and economic benefits. However, replacing virgin asph...

  20. Assessments of low emission asphalt mixtures produced using combinations of foaming agents

    NASA Astrophysics Data System (ADS)

    Mohd Hasan, Mohd Rosli

    workability, and having a higher expulsion rate from the foamed binder compared to water as a foaming agent. The addition of foaming agents to the asphalt binder has also lowered the activation energy of the asphalt binder, which has high potential in lowering the energy demand during production processes. The foamed WMA mixture prepared at 100°C was found to have behavior comparable with the control Hot Mix Asphalt (HMA) prepared at 155°C in terms of coatability, workability and compactability. Based on the mixture performance tests, the foamed WMA has a comparable or better performance than the HMA in terms of resistance to moisture damage, permanent deformation, fracture cracking and thermal cracking. The application of nano-hydrated lime is efficient in enhancing the aggregate coatability and improving the bearing capacity of asphalt pavement to lower the rutting potential and moisture susceptibility of foamed WMA mixtures. Limitations for each of the related parameters are also reported in this dissertation for the lab production of foamed WMA mixtures using ethanol and NaHCO 3 as foaming agents. The specified values were made based on the binder test, service characteristics and performance of foamed WMA mixtures in order to yield a comparable or better performance than the control HMA. Field validations should be carried out to understand the overall performance and durability of the proposed foaming WMA.

  1. Flexible overlays for rigid pavements : final report, February 2010.

    DOT National Transportation Integrated Search

    2010-02-01

    Approximately 45% of the New Jersey Department of Transportations (NJDOT) roadways are : composite (hot mix asphalt overlying Portland cement concrete). Hot mix asphalt (HMA) is used as : the overlying material because of its inexpensive nature wh...

  2. Field manual for crack sealing in asphalt pavements.

    DOT National Transportation Integrated Search

    2006-01-01

    This field manual was developed as a product of research project 4061 Comparison of Hot Poured Crack Sealant to Emulsified Asphalt Crack Sealant conducted by The University of Texas at Austin Center for Transportation Research (CTR). Organizati...

  3. Analysis on mechanics response of long-life asphalt pavement at moist hot heavy loading area

    NASA Astrophysics Data System (ADS)

    Xu, Xinquan; Li, Hao; Wu, Chuanhai; Li, Shanqiang

    2018-04-01

    Based on the durability of semi-rigid base asphalt pavement test road in Guangdong Yunluo expressway, by comparing the mechanics response of modified semi-rigid base, RCC base and inverted semi-rigid base with the state of continuous, using four unit five parameter model to evaluate rut depth of asphalt pavement structure, and through commonly used fatigue life prediction model to evaluate fatigue performance of three types of asphalt pavement structure. Theoretical calculation and four years tracking observation results of test road show that rut depth of modified semi-rigid base asphalt pavement is the minimum, the road performance is the best, and the fatigue performance is the optimal.

  4. Air pollution from hot mix plants.

    DOT National Transportation Integrated Search

    1970-10-01

    The Louisiana Air Control Commission adopted Regulation II, effective 1969, which sets stringent limits on suspended particulates. Because of the lack of knowledge concerning air pollution caused by hot mix plants within the Stake and because of the ...

  5. Estimates of air emissions from asphalt storage tanks and truck loading

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Trumbore, D.C.

    1999-12-31

    Title V of the 1990 Clean Air Act requires the accurate estimation of emissions from all US manufacturing processes, and places the burden of proof for that estimate on the process owner. This paper is published as a tool to assist in the estimation of air emission from hot asphalt storage tanks and asphalt truck loading operations. Data are presented on asphalt vapor pressure, vapor molecular weight, and the emission split between volatile organic compounds and particulate emissions that can be used with AP-42 calculation techniques to estimate air emissions from asphalt storage tanks and truck loading operations. Since currentmore » AP-42 techniques are not valid in asphalt tanks with active fume removal, a different technique for estimation of air emissions in those tanks, based on direct measurement of vapor space combustible gas content, is proposed. Likewise, since AP-42 does not address carbon monoxide or hydrogen sulfide emissions that are known to be present in asphalt operations, this paper proposes techniques for estimation of those emissions. Finally, data are presented on the effectiveness of fiber bed filters in reducing air emissions in asphalt operations.« less

  6. Research on High-RAP Asphalt Mixtures with Rejuvenators and WMA Additives.

    DOT National Transportation Integrated Search

    2016-09-27

    This study is to evaluate the mechanical and chemical properties of the asphalt concrete (AC) mixture, fine aggregate matrix (FAM), and binder modified by three different rejuvenators and warm mix asphalt (WMA) additive. In this regard, for testing o...

  7. 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).

  8. Modeling the performance properties of RAS and RAP blended asphalt mixes using chemical compositional information.

    DOT National Transportation Integrated Search

    2017-01-01

    Reclaimed asphalt pavement (RAP) and recycled asphalt shingles (RAS) can improve the sustainability of asphalt concrete (AC) due to cost savings and environmental factors, but it is necessary to ensure that pavement performance is not compromised. To...

  9. 40 CFR 63.11566 - What definitions apply to this subpart?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...) used to manufacture shingles and rolled roofing products. Coating mixer means the equipment used to mix... substrate. Hot-mix asphalt operation means operations involved in mixing asphalt cement and aggregates to... determined gravimetrically using EPA Method 5A—Determination of Particulate Matter Emissions From the Asphalt...

  10. Criteria for asphalt-rubber concrete in civil airport pavements: Mixture design

    NASA Astrophysics Data System (ADS)

    Roberts, F. L.; Lytton, R. L.; Hoyt, D.

    1986-07-01

    A mixture design procedure is developed to allow the use of asphalt-rubber binders in concrete for flexible airport pavement. The asphalt-rubber is produced by reacting asphalt with ground, scrap tire rubber to produce the binder for the asphalt-rubber concrete. Procedures for laboratory preparation of alsphalt-rubber binders using an equipment setup that was found by researchers to produce laboratory binders with similar properties to field processes are included. The rubber-asphalt concrete mixture design procedure includes adjustments to the aggregate gradation to permit space for the rubber particles in the asphalt-rubber binder as well as suggested mixing and compaction temperatures, and compaction efforts. While the procedure was used in the laboratory to successfully produce asphalt-rubber concrete mixtures, it should be evaluated in the field to ensure that consistent results can be achieved in a production environment.

  11. Best practice for using RAS in HMA.

    DOT National Transportation Integrated Search

    2012-04-01

    The use of recycled asphalt shingles (RAS) in hot-mix asphalt (HMA) mixtures has the potential to : significantly reduce the cost of asphalt paving mixes while conserving energy and preserving the : environment. This report documents the best practic...

  12. Marshall properties of asphalt concrete using crumb rubber modified of motorcycle tire waste

    NASA Astrophysics Data System (ADS)

    Siswanto, Henri; Supriyanto, Bambang; Pranoto, Chandra, Pria Rizky; Hakim, Arief Rahman

    2017-09-01

    The aim of this study is to explain the effect of Crumb Rubber Modified (CRM) of motorcycle tire waste on Marshall properties of asphalt mix. Two types of aggregate gradation, asphalt concrete wearing course (ACWC) and asphalt concrete base (ACB), and CRM passing #50 sieve size were used. Seven levels of CRM content were investigated in this study, namely 0%, 0.5%, 1%, 1.5%, 3%, 4.5%, and 6% by weight of aggregate. Marshall test is conducted on Marshall specimens. The specimens are tested in their optimum binder content (OBC). The results indicate that CRM addition of motorcycle tire waste increases the Marshall stability of the both mix, ACWC and ACB. In addition, 1% CRM addition of motorcycle tire waste of the total mix weight is the best mix.

  13. 76 FR 22817 - Approval and Promulgation of Air Quality Implementation Plans; South Carolina; Update to...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-25

    ... Manufacturing'' 5. ``Section VI--Hot Mix Asphalt Manufacturing'' 6. ``Section VII--Metal Refining;'' [[Page... Industries 1. ``Section III--Kraft Pulp and Paper Manufacturing Plants'' 2. ``Section VI--Hot Mix Asphalt... Manufacturing'' 3. ``Section XI--Total Reduced Sulfur Emissions of Kraft Pulp Mills;'' viii. Regulation 62.5...

  14. 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.

  15. Evaluation of retention factor and moisture correction for determining asphalt content in asphalt concrete mixtures.

    DOT National Transportation Integrated Search

    1985-05-01

    The purpose of this report is to compare the differences in asphalt contents determined after correction of mix and extracted aggregate weights for moisture when drying with the standard oven and microwave oven. It is also intended to determine if th...

  16. Construction and performance monitoring of various asphalt mixes in Illinois : 2016 interim report.

    DOT National Transportation Integrated Search

    2017-02-01

    A series of five experimental projects were constructed to better determine the life-cycle cost and performance of pavement overlays using various levels of asphalt binder replacement (ABR) from use of reclaimed asphalt pavement (RAP), recycled aspha...

  17. 77 FR 16833 - Agency Information Collection Activities; Submission to OMB for Review and Approval; Comment...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-22

    ... Activities; Submission to OMB for Review and Approval; Comment Request; NSPS for Hot Mix Asphalt Facilities... in paper, will be made available for public viewing at http://www.regulations.gov as EPA receives... information about the electronic docket, go to www.regulations.gov . Title: NSPS for Hot Mix Asphalt...

  18. Hot spot mix in ICF implosions on the NIF

    NASA Astrophysics Data System (ADS)

    Ma, Tammy

    2016-10-01

    In the quest to achieve ignition through the inertial confinement fusion scheme, one of the critical challenges is to drive a symmetric implosion at high velocity without hydrodynamic instabilities becoming detrimental. These instabilities, primarily at the ablation front and the fuel-ablator interface, can cause mix of the higher-Z shell into the hot spot, resulting in increased radiation loss and thus reduced temperature and neutron yield. To quantify the level of mix, we developed a model that infers the level of hot spot contamination using the ratio of the enhanced x-ray production relative to the neutron yield. Applying this methodology to the full ensemble of indirect-drive National Ignition Facility (NIF) cryogenically layered DT implosions provides insight on the sensitivity of performance to the level of ablator-hot spot mix. In particular, the improvement seen with the High Foot design can be primarily attributed to a reduction in ablation-front instability mix that enabled the implosions to be pushed to higher velocity and performance. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344, Lawrence Livermore National Security, LLC.

  19. 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

  20. Results from VDOT's pilot project using volumetric properties and asphalt content for acceptance of asphalt concrete.

    DOT National Transportation Integrated Search

    1995-01-01

    In 1994 the Virginia Department of Transportation (VDOT) developed a specification for the acceptance of asphalt concrete based largely on Marshall compacted volumetric properties of the mix. A copy of the Special Provision is shown in the Appendix. ...

  1. Performance of asphaltic concrete incorporating styrene butadiene rubber subjected to varying aging condition

    NASA Astrophysics Data System (ADS)

    Salah, Faisal Mohammed; Jaya, Ramadhansyah Putra; Mohamed, Azman; Hassan, Norhidayah Abdul; Rosni, Nurul Najihah Mad; Mohamed, Abdullahi Ali; Agussabti

    2017-12-01

    The influence of styrene butadiene rubber (SBR) on asphaltic concrete properties at different aging conditions was presented in this study. These aging conditions were named as un-aged, short-term, and long-term aging. The conventional asphalt binder of penetration grade 60/70 was used in this work. Four different levels of SBR addition were employed (i.e., 0 %, 1 %, 3 %, and 5 % by binder weight). Asphalt concrete mixes were prepared at selected optimum asphalt content (5 %). The performance was evaluated based on Marshall Stability, resilient modulus, and dynamic creep tests. Results indicated the improving stability and permanent deformation characteristics that the mixes modified with SBR polymer have under aging conditions. The result also showed that the stability, resilient modulus, and dynamic creep tests have the highest rates compared to the short-term aging and un-aged samples. Thus, the use of 5 % SBR can produce more durable asphalt concrete mixtures with better serviceability.

  2. Precision and accuracy of nuclear asphalt content gauges in determining asphalt content in asphaltic concrete pavement.

    DOT National Transportation Integrated Search

    1988-06-17

    Use of nuclear asphalt content gauges for determining asphalt content of asphaltic concrete pavement are gaining acceptance as an alternative method to the vacuum extraction process. The reasons nuclear asphalt content gauges are considered promising...

  3. Effect of Reclaimed Asphalt Pavement on Binder Properties Using the Superpave System

    DOT National Transportation Integrated Search

    1998-09-01

    While the use of reclaimed asphalt pavement (RAP) in asphalt mixes is common practice within many state departments of transportation, the evolution of the Superpave system has prompted a need for specific Superpave guidelines for the use of RAP. In ...

  4. Development of indirect ring tension test for fracture characterization of asphalt mixtures

    NASA Astrophysics Data System (ADS)

    Zeinali Siavashani, Alireza

    Low temperature cracking is a major distress in asphalt pavements. Several test configurations have been introduced to characterize the fracture properties of hot mix (HMA); however, most are considered to be research tools due to the complexity of the test methods or equipment. This dissertation describes the development of the indirect ring tension (IRT) fracture test for HMA, which was designed to be an effective and user-friendly test that could be deployed at the Department of Transportation level. The primary advantages of this innovative and yet practical test include: relatively large fracture surface test zone, simplicity of the specimen geometry, widespread availability of the required test equipment, and ability to test laboratory compacted specimens as well as field cores. Numerical modeling was utilized to calibrate the stress intensity factor formula of the IRT fracture test for various specimen dimensions. The results of this extensive analysis were encapsulated in a single equation. To develop the test procedure, a laboratory study was conducted to determine the optimal test parameters for HMA material. An experimental plan was then developed to evaluate the capability of the test in capturing the variations in the mix properties, asphalt pavement density, asphalt material aging, and test temperature. Five plant-produced HMA mixtures were used in this extensive study, and the results revealed that the IRT fracture test is highly repeatable, and capable of capturing the variations in the fracture properties of HMA. Furthermore, an analytical model was developed based on the viscoelastic properties of HMA to estimate the maximum allowable crack size for the pavements in the experimental study. This analysis indicated that the low-temperature cracking potential of the asphalt mixtures is highly sensitive to the fracture toughness and brittleness of the HMA material. Additionally, the IRT fracture test data seemed to correlate well with the data from

  5. New Hampshire binder and mix review.

    DOT National Transportation Integrated Search

    2012-08-01

    This review was initiated to compare relative rut testing and simple performance tests (now known as Asphalt Mix : Performance Tests) for the New Hampshire inch mix with 15% Recycled Asphalt Pavement (RAP). The tested mixes were : made from ...

  6. 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

  7. Research notes : asphalt cement chip seals - how have they done?

    DOT National Transportation Integrated Search

    2002-05-01

    In 1999, the Oregon Department of Transportation (ODOT) joined with Lane, Clackamas, Deschutes and Lincoln Counties to find out if asphalt cement (hot oil) chip seals would perform better and reduce the time required for traffic control after the tre...

  8. Rutting resistance of asphalt mixture with cup lumps modified binder

    NASA Astrophysics Data System (ADS)

    Shaffie, E.; Hanif, W. M. M. Wan; Arshad, A. K.; Hashim, W.

    2017-11-01

    Rutting is the most common pavement distress in pavement structures which occurs mainly due to several factors such as increasing of traffic volume, climatic conditions and also due to construction design errors. This failure reduced the service life of the pavement, reduced driver safety and increase cost of maintenance. Polymer Modified Binder has been observed for a long time in improving asphalt pavement performance. Research shows that the use of polymer in bituminous mix not only improve the resistance to rutting but also increase the life span of the pavement. This research evaluates the physical properties and rutting performance of dense graded Superpave-designed HMA mix. Two different types of dense graded Superpave HMA mix were developed consists of unmodified binder mix (UMB) and cup lumps rubber (liquid form) modified binder mix (CLMB). Natural rubber polymer modified binder was prepared from addition of 8 percent of cup lumps into binder. Results showed that all the mixes passed the Superpave volumetric properties criteria which indicate that these mixtures were good with respect to durability and flexibility. Furthermore, rutting results from APA rutting test was determined to evaluate the performance of these mixtures. The rutting result of CLMB demonstrates better resistance to rutting than those prepared using UMB mix. Addition of cup lumps rubber in asphalt mixture was found to be significant, where the cup lumps rubber has certainly improves the binder properties and enhanced its rutting resistance due to greater elasticity offered by the cup lumps rubber particles. It shows that the use of cup lumps rubber can significantly reduce the rut depth of asphalt mixture by 41% compared to the minimum rut depth obtained for the UMB mix. Therefore, it can be concluded that the cup lumps rubber is suitable to be used as a modifier to modified binder in order to enhance the properties of the binder and thus improves the performance of asphalt mixes.

  9. Performance of Asphalt Concrete Wearing Course (AC-WC) Utilizing Reclaimed Asphalt Pavement from Cold Milling Bound with 80/100 Pen Asphalt

    NASA Astrophysics Data System (ADS)

    Thanya, I. N. A.; Suweda, I. W.; Putra, G. K.

    2018-03-01

    Demands on natural aggregate materials for road pavement can be reduced by utilizing reclaimed asphalt pavement (RAP). This research was aimed at evaluating the performance of AC-WC mixture using RAP materials from cold milling, bound with 80/100 pen asphalt. The RAP aggregate gradation was adjusted by adding the required amount of natural aggregates to meet the specification in Indonesia. The RAP and added aggregates were hotmixed and compacted with Marshall hummer at 2×75 blows. The asphalt content were varied. It was found that the optimum asphalt content was 6.05 % with the following Marshall characteristics: stability 1237.08 kg; flow 3.36 mm; Marshall quotient 324,73kg/mm; void in mix (VIM) 3,360%; void in mineral aggregate (VMA) 15.103; and void filled with bitumen (VFB) 77.759% and residual stability 91.04; all met the Indonesian specification. The cantabro abration loss (CAL) at 30°C was 9,02%. The indirect tensile stiffness modulus (ITSM) at 20 °C was 7961.4 MPa; dynamic creep with 100 kPa pressure at 40°C gave slope 0.0112 microsstrain/pulse which is suitable for heavy load traffic. The fatigue test results was obtained at increased stress level, i.e. at 900, 1100, and 1300 kPa. Based on the equation derived from the fatigue strain and repeated loading relationship, at 100 microstrain (με) the repeated load was 434,661.58 times, and at one million (106) repeated loading, the samples could withstand strain of 92,38 microstrain. The performance of the samples were overall better than AC-WC mixture using virgin aggregates bound with 60/70 pen asphalt.

  10. 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.

  11. Implementation of warm-mix asphalt mixtures in Nebraska pavements.

    DOT National Transportation Integrated Search

    2012-07-01

    The primary objective of this research is to evaluate the feasibility of several WMA mixtures as potential asphalt paving : mixtures for Nebraska pavements. To that end, three well-known WMA additives (i.e., Sasobit, Evotherm, and Advera : synthetic ...

  12. 75 FR 6309 - Approval and Promulgation of Implementation Plans Georgia: State Implementation Plan Revision

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-09

    ... subparagraph (4)(b)4, relating to sulfur dioxide, to correct an error in the standard condition for temperature... subparagraph (b)5(i) to clarify the specific equipment covered by permit-by-rule for hot mix asphalt plants... million BtU per hour'' is replaced by ``hot mix asphalt facilities,'' to best describe the facilities...

  13. 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

  14. Fatigue and fracture properties of aged binders in the context of reclaimed asphalt mixes.

    DOT National Transportation Integrated Search

    2014-08-01

    Evidence in the literature indicates that the stiffness of the asphalt binder increases and ductility of the binder decreases : with oxidative aging. Typically for unmodified asphalt binders, increase in stiffness or decrease in ductility is regarded...

  15. Validation of the mix design process for cold in-place rehabilitation using foamed asphalt.

    DOT National Transportation Integrated Search

    2007-06-01

    Asphalt pavement recycling has grown dramatically over the last few years as a viable : technology to rehabilitate existing asphalt pavements. Iowa's current Cold In-place : Recycling (CIR) practice utilizes a generic recipe specification to define t...

  16. 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.

  17. 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…

  18. Strength and deformation characteristics of pavements

    NASA Astrophysics Data System (ADS)

    Shook, J. F.; Kallas, B. F.; McCullough, B. F.; Taute, A.; Rada, G.; Witczak, M. W.; Heisey, J. S.; Stokoe, K. H.; Meyer, A. H.; Huffman, M. S.

    The Colorado experimental base project was a full-scale field experment constructed with various thicknesses of two full depth hot mix sand asphalt beans, one full depth asphalt concrete base, and one thickness of a standard design with untreated base and subbase layers. Relative thicknesses of one asphalt concrete base, two hot mix sand asphalt bases, and one standard design with untreated base and subbase required to give an equal level of pavement performance were determined. Certain measured properties of the pavement and the pavement components were related to observed levels of performance by using both empirical and theoretical models for pavement behavior.

  19. 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.

  20. Revealing the Location of the Mixing Layer in a Hot Bubble

    NASA Astrophysics Data System (ADS)

    Guerrero, M. A.; Fang, X.; Chu, Y.-H.; Toalá, J. A.; Gruendl, R. A.

    2017-10-01

    The fast stellar winds can blow bubbles in the circumstellar material ejected from previous phases of stellar evolution. These are found at different scales, from planetary nebulae (PNe) around stars evolving to the white dwarf stage, to Wolf-Rayet (WR) bubbles and up to large-scale bubbles around massive star clusters. In all cases, the fast stellar wind is shock-heated and a hot bubble is produced. Processes of mass evaporation and mixing of nebular material and heat conduction occurring at the mixing layer between the hot bubble and the optical nebula are key to determine the thermal structure of these bubbles and their evolution. In this contribution we review our current understanding of the X-ray observations of hot bubbles in PNe and present the first spatially-resolved study of a mixing layer in a PN.

  1. Field test method to determine presence and quantity of modifiers in liquid asphalt : [summary].

    DOT National Transportation Integrated Search

    2015-05-01

    Approximately five million tons of asphalt mix are produced each year for the Florida : Department of Transportation (FDOT), of which 60% is modified with styrene butadiene : styrene (SBS) polymer and/or ground tire rubber (GTR). Asphalt binders are ...

  2. Temperature-viscosity relationships of selected asphalt cements.

    DOT National Transportation Integrated Search

    1970-06-01

    To gain information on the appropriate temperature to obtain a given desirable viscosity for the various asphalt cements commonly used in Oregon, viscosities were determined at three or more temperatures near the mixing temperature. From the values d...

  3. A Study of Moisture Induced Material Loss of Hot Mix Asphalt (HMA)

    DOT National Transportation Integrated Search

    2017-10-31

    Maine Department of Transportation has noticed the partial or complete loss of material within 2-3 years of construction in the traffic wheel path in the presence of moisture in few of their mixes. Regularly used moisture susceptibility tests are una...

  4. Connecticut warm mix asphalt (WMA) pilot projects 2010 and 2011.

    DOT National Transportation Integrated Search

    2014-06-01

    WMA overlays were placed in several pilot projects in Connecticut during the 2010 and 2011 construction : seasons. These technologies included Sasobit, Evotherm, Advera, Double-Barrel Green foamed : asphalt as well as SonneWarmix. The res...

  5. Evaluation of stone-matrix asphalt mixtures containing recycled asphalt shingles(RAS).

    DOT National Transportation Integrated Search

    2017-05-01

    In recent years, there has been increased interest in the use of reclaimed material in asphalt : mixtures. The use of recycled asphalt shingles (RAS) has been of interest because of the high asphalt : content, although this asphalt is considerably st...

  6. Preliminary investigation of RAP and RAS in HMAC.

    DOT National Transportation Integrated Search

    2010-02-01

    laboratory study was undertaken to investigate how various proportions of reclaimed asphalt pavement (RAP) and reclaimed asphalt shingles (RAS) added to hot mixed asphalt concrete (HMAC) mixtures affect the Superpave performance grade of the blended ...

  7. Warm Mix Asphalt

    DOT National Transportation Integrated Search

    2009-04-17

    State of Alaska State of Alaska - Warm Mix Project Warm Mix Project: Location - Petersburg, Alaska which is Petersburg, Alaska which is located in the heart of Southeast Alaska located in the heart of Southeast Alaska's Inside Passage at the tip of M...

  8. 9. Tower building. Hot water tap floor shown. Mixing vat ...

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

    9. Tower building. Hot water tap floor shown. Mixing vat at center level. Juices mix and flow and left lower level. Copper kettles are down below view level. Looking toward front of building. - Tivoli-Union Brewery, 1320-1348 Tenth Street, Denver, Denver County, CO

  9. Preliminary investigation of RAP and RAS in HMAC : final report, February 2010.

    DOT National Transportation Integrated Search

    2010-02-01

    A laboratory study was undertaken to investigate how various proportions of reclaimed asphalt pavement (RAP) and reclaimed asphalt shingles (RAS) added to hot mixed asphalt concrete (HMAC) mixtures affect the Superpave performance grade of the blende...

  10. Short-term markers of DNA damage among roofers who work with hot asphalt.

    PubMed

    Serdar, Berrin; Brindley, Stephen; Dooley, Greg; Volckens, John; Juarez-Colunga, Elizabeth; Gan, Ryan

    2016-10-20

    Roofers are at increased risk for various malignancies and their occupational exposures to polycyclic aromatic hydrocarbons (PAHs) have been considered as important risk factors. The overall goal of this project was to investigate the usefulness of phosphorylated histone H2AX (γH2AX) as a short-term biomarker of DNA damage among roofers. Blood, urine, and dermal wipe samples were collected from 20 roofers who work with hot asphalt before and after 6 h of work on Monday and Thursday of the same week (4 sampling periods). Particle-bound and gas-phase PAHs were collected using personal monitors during work hours. γH2AX was quantified in peripheral lymphocytes using flow cytometry and 8-hydroxy-2-deoxyguanosine (8-OHdG) was assessed in urine using ELISA. General linear mixed models were used to evaluate associations between DNA damage and possible predictors (such as sampling period, exposure levels, work- and life-style factors). Differences in mean biomarker and DNA damage levels were tested via ANOVA contrasts. Exposure measurements did not show an association with any of the urinary biomarkers or the measures of DNA damage. Naphthalene was the most abundant PAH in gas-phase, while benzo(e)pyrene was the most abundant particle-bound PAH. Post-shift levels of γH2AX and 8-OHdG were higher on both study days, when compared to pre-shift levels. Cigarette smoking was a predictor of γH2AX and urinary creatinine was a predictor of urinary 8-OHdG. Between-subject variance to total variance ratio was 35.3 % for γH2ax and 4.8 % for 8-OHdG. γH2AX is a promising biomarker of DNA damage in occupational epidemiology studies. It has a lower within-subject variation than urinary 8-OHdG and can easily be detected in large scale groups. Future studies that explore the kinetics of H2AX phosphorylation in relation to chemical exposures may reveal the transient and persistent nature of this sensitive biomarker of early DNA damage.

  11. Analyzing the influence of manufacturing conditions of reclaimed asphalt concrete on the characteristics of the asphalt binder: development of a gradual binder extraction method

    NASA Astrophysics Data System (ADS)

    Navaro, J.; Bruneau, D.; Drouadaine, I.; Pouteau, B.; Colin, J.; Dony, A.

    2012-05-01

    When asphalt concrete is manufactured incorporating a high percentage (almost 70%) of reclaimed materials from the deconstruction of road surfaces under renovation, and when the corresponding production device is designed specifically to reduce the energy input need (lowering the production temperature), the resulting manufacturing process contributes to the protection of the environment and reduces production costs. However, to meet the quality requirements of the finished product, virgin materials of appropriate quality and quantity must also be added (mineral aggregates and new asphalt binder) and control systems set up to quantify and optimize the parameters involved (thus avoiding the guess work which still often prevails today). It was for this reason that a new experimental technique described here was devised, which will ultimately be used in asphalt concrete production plants. The technique involves lixiviating reclaimed asphalt concrete using a chlorinated solvent; the resulting solute is collected gradually, then the mixture of binders (virgin and reclaimed asphalt concrete) can be characterized and their mass fractions quantified using a combination of UV and IR spectrometry. With this experimental technique we were able to assess the extent to which the reclaimed asphalt pavement binder participates in the agglomeration and cohesion of the reclaimed asphalt concrete. This assessment was made in terms of the main parameters in the production process, temperature of the materials and mixing time.

  12. Specifications for use of WMA technology in delivering HMA and non-conventional mixtures : [brief].

    DOT National Transportation Integrated Search

    2015-03-01

    Recent national research efforts have focused on the development and evaluation of warm mix : asphalt (WMA) technologies as a means to reduce the environmental impact and enhance : the performance of conventional hot mix asphalt (HMA). As a result, d...

  13. Deliverable P1 study 0-6132.

    DOT National Transportation Integrated Search

    2012-09-01

    Study 0-6132 has promoted the development and implementation of the balanced mix design (BMD) approach for selecting the optimal asphalt content for all of TxDOTs hot mix asphalts (HMA), including Item 341. In this approach the engineering propert...

  14. Adjusting Asphalt Mixes for Increased Durability and Implementation of a Performance Tester to Evaluate Fatigue Cracking of Asphalt

    DOT National Transportation Integrated Search

    2018-01-17

    Cracking is a common failure mechanism in asphalt concrete pavement structures. It is one of the main reasons for large road maintenance and rehabilitation expenditures, as well as reduced user comfort and increased fuel consumption due to high road ...

  15. Airport manager's guide for the maintenance of asphalt pavements of general aviation airports.

    DOT National Transportation Integrated Search

    2009-01-01

    Hot asphalt pavement (HAP) is used as a surface material on many General Aviation : (GA) airports in California. Currently there are 251 public use airports in California. An : understanding of the proper design, construction and maintenance of the h...

  16. Performance characterizations of asphalt binders and mixtures incorporating silane additive ZycoTherm

    NASA Astrophysics Data System (ADS)

    Hasan, Mohd Rosli Mohd; Hamzah, Meor Othman; Yee, Teh Sek

    2017-10-01

    Experimental works were conducted to evaluate the properties of asphalt binders and mixtures produced using a relatively new silane additive, named ZycoTherm. In this study, 0.1wt% ZycoTherm was blended with asphalt binder to enable production of asphalt mixture at lower than normal temperatures, as well as improve mix workability and compactability. Asphalt mixture performances towards pavement distresses in tropical climate region were also investigated. The properties of control asphalt binders (60/70 and 80/10 penetration grade) and asphalt binders incorporating 0.1% ZycoTherm were reported based on the penetration, softening point, rotational viscosity, complex modulus and phase angle. Subsequently, to compare the performance of asphalt mixture incorporating ZycoTherm with the control asphalt mixture, cylindrical samples were prepared at recommended temperatures and air voids depending on the binder types and test requirements. The samples were tested for indirect tensile strength (ITS), resilient modulus, dynamic creep, Hamburg wheel tracking and moisture induced damage. From compaction data using the Servopak gyratory compactor, specimen prepared using ZycoTherm exhibit higher workability and compactability compared to the conventional mixture. From the mixture performance test results, mixtures prepared with ZycoTherm showed comparable if not better performance than the control sample in terms of the resistance to moisture damage, permanent deformation and cracking.

  17. Validation of RAP and/or RAS in hydraulic cement concrete : project summary.

    DOT National Transportation Integrated Search

    2017-01-31

    Reclaimed or recycled asphalt pavement (RAP) : and recycled asphalt shingles (RAS) have been : widely used in hot-mix asphalt (HMA) in Texas. : However, a high volume of RAP is still available : in stockpiles along the Texas Department of : Transport...

  18. Investigation of nuclear asphalt content gauge : final report.

    DOT National Transportation Integrated Search

    1995-07-01

    The introduction of new aggregate sources to Louisiana in the mid 1980s has presented problems in asphalt concrete mix design and construction. Absorptive aggregates such as reclaimed portland cement concrete and some stones now being supplied have m...

  19. 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

  20. 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.

  1. Rehabilitating asphalt highways

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    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 andmore » 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.« less

  2. The Variation Test and Extraction Equipment to Optimum Asphalt by Using Gasoline Solvent

    NASA Astrophysics Data System (ADS)

    Soehardi, Fitridawati

    2017-12-01

    Based on the Binamarga Specification 2010 at third revision, the extraction test should be carried out using the specimen from the loose asphalt mixture extracted from the back of the finisher bitumen machine. The purpose of this research is to find out the result of pretest and posttest extraction asphalt content. The Extraction test using two equipment, they are Soklet and Centrifuge. The specimens was used AMP, Asphalt Finisher and Core, which involved gasoline solvent. Based on the asphalt level extraction test results, the appropriate equipment was used centrifuge with the level accuracy as requirement of Binamarga Specification 2010 at third revision and the level of ease used as equipment in the field study. The asphalt content obtained for AMP 5,51%, Asphalt Finisher5,46% and Core 5.34%. As for the socket asphalt content obtained is AMP 5.55%, Asphalt Finisher 5.50% and Core core 5. 41%. The extract test value of asphalt content decreased, so it can be formulated KA JMF Asphalt Finisher mix used was 5.56% with the tolerance given according to Binamarga Specification 2010 at third revision is ± 0.30%. In accordance with the results obtained then the results of a centrifuge tool that matches and meets the requirements of time, accuracy of results and economic value.

  3. 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.

  4. 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.

  5. Characteristic Asphalt Concrete Wearing Course (ACWC) Using Variation Lime Filler

    NASA Astrophysics Data System (ADS)

    Permana, R. A.; Pramesti, F. P.; Setyawan, A.

    2018-03-01

    This research use of lime filler Sukaraja expected add durability layers of concrete pavement is asphalt damage caused by the weather and load traffic. This study attempts to know how much value characteristic Marshall on a mixture of concrete asphalt using lime filler. This research uses experimental methods that is with a pilot to get results, thus will look filler utilization lime on construction concrete asphalt variation in filler levels 2 %, 3 %, 4 %.The results showed that the use of lime filler will affect characteristic a mixture of concrete asphalt. The more filler chalk used to increase the value of stability. On the cretaceous filler 2 % value of stability is 1067,04 kg. When lime filler levels added to the levels of filler 4 %, the value of stability increased to 1213,92 kg. The flexibility increased the number of filler as levels lime 2 % to 4 % suggests that are conducted more stiff mix.

  6. Comparative Evaluation of 4-Inch and 6-Inch Diameter Specimens for Testing Large Stone Asphalt Mixes

    DOT National Transportation Integrated Search

    1990-01-01

    Increased incidence of premature rutting of heavy duty asphalt pavements has : been experienced in recent years. There is a general agreement among most : asphalt paving technologists that the use of large size stone in the binder and : base courses ...

  7. Development of binder test to determine fracture energy [summary].

    DOT National Transportation Integrated Search

    2012-04-01

    Asphalt binder makes up a relatively small percentage 4% to 8% of the hot mix asphalt used in pavements, but its performance as a binder is critical to the longevity of road surfaces. Asphalt is : a material whose flexibility changes with : t...

  8. Literature review : performance of RAP/RAS mixes and new direction.

    DOT National Transportation Integrated Search

    2014-04-01

    In the last several years reclaimed asphalt pavement (RAP) and recycled asphalt shingles (RAS) have been : widely used in asphalt mixes in Texas. The use of RAP/RAS can significantly reduce the initial cost of : asphalt mixtures, conserve energy, and...

  9. 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.

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

    PubMed Central

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

    2017-01-01

    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. PMID:28772406

  11. Expanded clay hot mix study : final report: part I.

    DOT National Transportation Integrated Search

    1969-04-01

    This is part I of a two part final report on expanded clay hot mix to: (1) evaluate the use of various expanded clay bituminous mixtures under high traffic counts, (2) accumulate through experience testing, suitable information on the physical proper...

  12. 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

  13. Development of a design methodology for asphalt treated mixtures.

    DOT National Transportation Integrated Search

    2013-12-01

    This report summarizes the results of a study that was conducted to develop a simplified design methodology for asphalt : treated mixtures that are durable, stable, constructible, and cost effective through the examination of the performance of : mix...

  14. Influence of bitumen type on cracking resistance of asphalt mixtures used in pavement overlays

    NASA Astrophysics Data System (ADS)

    Jaskula, P.; Szydlowski, C.; Stienss, M.

    2018-05-01

    Cracking is one of the predominant distresses occurring in flexible pavements, especially in old pavements that were rehabilitated with an asphalt overlay. In such cases asphalt mixtures should be designed to ensure high resistance to reflective cracking because new asphalt layers are exposed to existing cracks of the old pavement. The nature of these cracks can be various (transverse, longitudinal as well as crazy cracking). One factor that minimizes this type of distress is the proper mix design process, which should involve selection of specific bitumen binder and mineral mix gradation. However, still there is no universally adopted laboratory test method that would allow to clearly assess resistance of asphalt mixtures to reflective cracking. This paper describes the usage of one of the devices developed to test asphalt mixtures in terms of such distress – Texas Overlay Tester. For this test, samples prepared in laboratory conditions (i.e. compacted with the use of Superpave Gyratory Compactor) as well as obtained in the field (by core drilling) can be used. The results are obtained not only quickly and easily, but also with sufficient repeatability. The described method characterizes both crack initiation and crack propagation properties of asphalt mixtures. In this work one type of mineral mixture was tested with 4 different types of bitumen (one neat bitumen, two ordinary polymer-modified and one polymer-modified with high polymer content). For selected cases extra additives (rubber and loose fibres) were also tested. In total, six asphalt mixtures were tested. A ranking of the used binders was created on the basis of the results in order to conclude which bitumen would ensure the best performance characteristics in terms of reflective cracking. The results have clearly shown that deliberate choice of the binder used in the asphalt mixture for the overlay will significantly improve its reflective cracking resistance or even fatigue resistance.

  15. Cooling time of porous asphalt pavement affecting compaction process due to various raining condition

    NASA Astrophysics Data System (ADS)

    Hashim, W.; Noor, M. N. M.; Shaffie, E.; Rahman, Z. A.; Arshad, A. K.

    2018-04-01

    While bright sunshine and warm temperatures make for the best paving weather, construction projects can get a bit rough in adverse weather conditions. In this case, porous asphalt is used on paving. Light sprinkles can usually be handled without any serious problems. Moderate rainfall events, on the other hand, will generally require the paving project to be postponed. Steady downpours will cool the porous asphalt mix and make proper compaction extremely difficult to obtain. For the viability of the project, contractors will always wait until the sky clears up. According to the JKR Specification 4(Clause 4.2.6.4), it clearly states that no pavement work should be done during rain. The rain is a cold medium where it will actually cools down everything that make contact with the water. Whereas, the mix porous asphalt (PA) is a hot medium. When these two elements combined, the surface and the PA will harden at a stage where it will not be well compacted. This will cause problems in the future. The test is conducted by pouring water onto the pavement(through raining simulation).Since the rain intensity can be determined by the size of the rain drops, the difference in the shower hole size is good enough to create different rain intensities to predict the PA cooling rate when it makes contact with water. These two variables will work as a comparison in this study between raining and no rain condition. As a result, whenever the water make a contact with the PA, the rates of cooling drops 98% from the normal rates of cooling of PA (without rain)giving the Time Available for Compaction (TAC) to be less than 60 seconds. This study may be a knowledge on how the rates of cooling work if the PA make contact with water. It can also be used as future reference on the study of cooling rates of porous pavement during raining condition.

  16. Formulation and Characterization of Solid Dispersion Prepared by Hot Melt Mixing: A Fast Screening Approach for Polymer Selection

    PubMed Central

    Enose, Arno A.; Dasan, Priya K.; Sivaramakrishnan, H.; Shah, Sanket M.

    2014-01-01

    Solid dispersion is molecular dispersion of drug in a polymer matrix which leads to improved solubility and hence better bioavailability. Solvent evaporation technique was employed to prepare films of different combinations of polymers, plasticizer, and a modal drug sulindac to narrow down on a few polymer-plasticizer-sulindac combinations. The sulindac-polymer-plasticizer combination that was stable with good film forming properties was processed by hot melt mixing, a technique close to hot melt extrusion, to predict its behavior in a hot melt extrusion process. Hot melt mixing is not a substitute to hot melt extrusion but is an aid in predicting the formation of molecularly dispersed form of a given set of drug-polymer-plasticizer combination in a hot melt extrusion process. The formulations were characterized by advanced techniques like optical microscopy, differential scanning calorimetry, hot stage microscopy, dynamic vapor sorption, and X-ray diffraction. Subsequently, the best drug-polymer-plasticizer combination obtained by hot melt mixing was subjected to hot melt extrusion process to validate the usefulness of hot melt mixing as a predictive tool in hot melt extrusion process. PMID:26556187

  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. 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.

  19. Developing the elastic modulus measurement of asphalt concrete using the compressive strength test

    NASA Astrophysics Data System (ADS)

    Setiawan, Arief; Suparma, Latif Budi; Mulyono, Agus Taufik

    2017-11-01

    Elastic modulus is a fundamental property of an asphalt mixture. An analytical method of the elastic modulus is needed to determine the thickness of flexible pavement. It has a role as one of the input values on a stress-strain analysis in the finite element method. The aim of this study was to develop the measurement of the elastic modulus by using compressive strength testing. This research used a set of specimen mold tool and Delta Dimensi software to record strain changes occurring in the proving ring of compression machine and the specimens. The elastic modulus of the five types of aggregate gradation and 2 types of asphalt were measured at optimum asphalt content. Asphalt Cement 60/70 and Elastomer Modified Asphalt (EMA) were used as a binder. Manufacturing success indicators of the specimens used void-in-the-mix (VIM) 3-5 % criteria. The success rate of the specimen manufacturing was more than 76%. Thus, the procedure and the compressive strength test equipment could be used for the measurement of the elastic modulus. The aggregate gradation and asphalt types significantly affected the elastic modulus of the asphalt concrete.

  20. NCHRP project 20-07/task 361 : hamburg wheel-track test equipment requirements and improvements to AASHTO T 324 : research project capsule.

    DOT National Transportation Integrated Search

    2015-02-01

    The Loaded Wheel Test (LWT) is a laboratory-controlled rut depth test that uses loaded wheel(s) : to apply a moving load on hot-mix and warm-mix asphalt (HMA and WMA) specimens to simulate : tra c load applied on asphalt pavements. In the 1970s He...

  1. Mixing Hot and Cold Water Streams at a T-Junction

    ERIC Educational Resources Information Center

    Sharp, David; Zhang, Mingqian; Xu, Zhenghe; Ryan, Jim; Wanke, Sieghard; Afacan, Artin

    2008-01-01

    A simple mixing of a hot- and cold-water stream at a T-junction was investigated. The main objective was to use mass and energy balance equations to predict mass low rates and the temperature of the mixed stream after the T-junction, and then compare these with the measured values. Furthermore, the thermocouple location after the T-junction and…

  2. 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

  3. An evaluation of the moisture susceptibility of warm mix asphalt mixtures.

    DOT National Transportation Integrated Search

    2010-05-01

    This paper describes the results of a laboratory study conducted to evaluate the influence of Aspha-min and Sasobit : additives on the behaviour of warm asphalt mixtures. Specimens were compacted at two temperatures, 100 and 1458C, and : were sub...

  4. Open Graded Asphalt Friction Course: State of the Practice

    DOT National Transportation Integrated Search

    1988-05-01

    Open Graded Friction Course (OGFC) has been used since 1950 in the United States to improve the frictional resistance of asphalt pavements. However, experience of states with this kind of mix has been widely varied. While many transportation agencies...

  5. Dynamic modulus of nanosilica modified porous asphalt

    NASA Astrophysics Data System (ADS)

    Arshad, A. K.; Masri, K. A.; Ahmad, J.; Samsudin, M. S.

    2017-11-01

    Porous asphalt (PA) is a flexible pavement layer with high interconnected air void contents and constructed using open-graded aggregates. Due to high temperature environment and increased traffic volume in Malaysia, PA may have deficiencies particularly in rutting and stiffness of the mix. A possible way to improve these deficiencies is to improve the asphalt binder used. Binder is normally modified using polymer materials to improve its properties. However, nanotechnology presently is being gradually used for asphalt modification. Nanosilica (NS), a byproduct of rice husk and palm oil fuel ash is used as additive in this study. The aim of this study is to enhance the rutting resistance and stiffness performance of PA using NS. This study focused on the performance of PA in terms of dynamic modulus with the addition of NS modified binder to produce better and more durable PA. From the result of Dynamic SPT Test, it shows that the addition of NS was capable in enhancing the stiffness and rutting resistance of PA. The addition of NS also increase the dynamic modulus value of PA by 50%.

  6. Transportation Infrastructure Design and Construction \\0x16 Virtual Training Tools

    DOT National Transportation Integrated Search

    2003-09-01

    This project will develop 3D interactive computer-training environments for a major element of transportation infrastructure : hot mix asphalt paving. These tools will include elements of hot mix design (including laboratory equipment) and constructi...

  7. Problems in achieving density in asphaltic concrete : final report.

    DOT National Transportation Integrated Search

    1979-01-01

    This investigation was undertaken in an attempt to identify the causes of low densities in asphaltic concrete placed on 9 projects. The most prevalent cause, which accounted for the difficulties on 5 of the 9 projects, appeared to be improper mix des...

  8. Determine viscoelastic mechanical properties of warm mix asphalt (WMA)-reclaimed asphalt pavement (RAP) mixes under high stresses in air-field flexible pavements and its impact on design life.

    DOT National Transportation Integrated Search

    2014-06-01

    The introduction of larger aircrafts on flexible airfield pavements has led to a need for asphalt mixtures capable of sustaining such heavy : loads. This laboratory and analytical study investigated the mechanical responses of a number of modified as...

  9. 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

  10. Installation and performance of lightweight aggregate asphaltic concrete test sections.

    DOT National Transportation Integrated Search

    1970-01-01

    In 1966 and 1968 test sections of asphaltic concrete overlays fabricated with coarse lightweight aggregate and fine limestone were installed in the Roanoke-Bedford area. The experimental mixes used were designed in an attempt to develop skid resistan...

  11. Evaluation of HMA mixtures containing Sasobit.

    DOT National Transportation Integrated Search

    2009-07-01

    This limited study provided a laboratory and field comparative evaluation of PG 76-22 HMA : hot mix asphalt (HMA) mixture and a mixture containing the additive Sasobit. The : fundamental material characterization testing (asphalt cement binde...

  12. Investigation of the Bailey Method for the design and analysis of dense-graded MHAC using Oregon aggregates.

    DOT National Transportation Integrated Search

    2007-09-01

    Historically Oregon has specified gradations for dense-graded hot mix asphalt concrete (HMAC) using a combination of broadband limits and recommended ideal gradations. The recent adoption of SuperPave and Stone Matrix Asphalt (SMA) technolog...

  13. Investigation of the Bailey Method for the design and analysis of dense-graded HMAC using Oregon aggregates : final report.

    DOT National Transportation Integrated Search

    2006-09-01

    Historically Oregon has specified gradations for dense-graded hot mix asphalt concrete (HMAC) using a combination of broadband limits and recommended ideal gradations. The recent adoption of SuperPave and Stone Matrix Asphalt (SMA) technolog...

  14. Perform an investigation of the effects of increased reclaimed asphalt pavement (RAP) levels in dense graded friction courses : [summary].

    DOT National Transportation Integrated Search

    2015-04-01

    The Florida Department of Transportation currently allows up to 20% recycled asphalt : pavement (RAP) in asphalt mixes to be used for roadway surfaces. The abundance of RAP and : savings in cost and to natural resources make increased use of RAP desi...

  15. Initial Self-Healing Temperatures of Asphalt Mastics Based on Flow Behavior Index.

    PubMed

    Li, Chao; Wu, Shaopeng; Tao, Guanyu; Xiao, Yue

    2018-05-29

    Increasing temperature is a simple and convenient method to accelerate the self-healing process of bitumen. However, bitumen may not achieve the healing capability at lower temperature, and may be aged if temperature is too high. In addition, the bitumen is mixed with mineral filler and formed as asphalt mastic in asphalt concrete, so it is more accurate to study the initial self-healing from the perspective of asphalt mastic. The primary purpose of this research was to examine the initial self-healing temperature of asphalt mastic, which was determined by the flow behavior index obtained from the flow characteristics. Firstly, the texture and geometry characteristics of two fillers were analyzed, and then the initial self-healing temperature of nine types of asphalt mastic, pure bitumen (PB) and styrene-butadiene-styrene (SBS) modified bitumen were determined by the flow behavior index. Results demonstrate that the average standard deviation of gray-scale texture value of limestone filler (LF) is 21.24% lower than that of steel slag filler (SSF), showing that the steel slag filler has a better particle distribution and geometry characteristics. Also the initial self-healing temperatures of asphalt mastics with 0.2, 0.4 and 0.6 LF-PB volume ratio are 46.5 °C, 47.2 °C and 49.4 °C, which are 1.4 °C, 0.8 °C and 0.4 °C higher than that of asphalt mastics with SSF-PB, but not suitable for the evaluation of asphalt mastic contained SBS modified bitumen because of unique structure and performance of SBS.

  16. Review and analysis of Hamburg Wheel Tracking Device test data : [technical summary].

    DOT National Transportation Integrated Search

    2014-02-01

    Approximately 89% of the paved-road network in Kansas is asphalt surfaced (bituminous and : composite). According to the Kansas Department of Transportation (KDOT), typical design : performance period of hot-mix asphalt (HMA) pavement for new constru...

  17. Evaluation of HMA mixtures containing Sasobit.

    DOT National Transportation Integrated Search

    2009-07-01

    This limited study provided a laboratory and field comparative evaluation of PG 76-22 HMA hot mix asphalt (HMA) mixture and a mixture containing the additive Sasobit. The fundamental material characterization testing (asphalt cement binder rh...

  18. Characterization of Alaskan HMA mixtures with the simple performance tester.

    DOT National Transportation Integrated Search

    2014-05-01

    Material characterization provides basic and essential information for pavement design and the evaluation of hot mix asphalt (HMA). : This study focused on the accurate characterization of an Alaskan HMA mixture using an asphalt mixture performance t...

  19. Improved overlay tester for fatigue cracking resistance of asphalt mixtures.

    DOT National Transportation Integrated Search

    2017-01-01

    Premature cracking of the asphalt concrete (AC) layer in flexible pavement is one of the major concerns of the pavement community. Over the past decade, AC mixes have been designed using the Hamburg wheel-tracking device to improve their rutting pote...

  20. Validation of hot-poured crack sealant performance-based guidelines.

    DOT National Transportation Integrated Search

    2017-06-01

    This report summarizes a comprehensive research effort to validate thresholds for performance-based guidelines and : grading system for hot-poured asphalt crack sealants. A series of performance tests were established in earlier research and : includ...

  1. 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.

  2. MnDOT thin whitetopping selection procedures : final report.

    DOT National Transportation Integrated Search

    2017-06-01

    This report provides an integrated selection procedure for evaluating whether an existing hot-mix asphalt (HMA) pavement is an appropriate candidate for a bonded concrete overlay of asphalt (BCOA). The selection procedure includes (1) a desk review, ...

  3. Impact of Recycled Asphalt Shingles (RAS) on Asphalt Binder Performance

    DOT National Transportation Integrated Search

    2018-01-01

    This study evaluated the effect of reclaimed asphalt pavement (RAP) and recycled asphalt shingles (RAS) on virgin binder true grade and fracture energy density (FED). A mortar approach, which avoids the need for binder extraction, was adopted to quan...

  4. Performance of high RAP pavement sections in NH.

    DOT National Transportation Integrated Search

    2015-06-01

    This report summarizes the University of New Hampshire (UNH) results of test pavements used to : determine the effect of using higher amounts of Recycled Asphalt Pavement (RAP) in Hot Mix Asphalt : (HMA). : The New Hampshire Department of Transportat...

  5. Evaluation of cement and fly ash treated RAP and aggregates for base construction : research project capsule

    DOT National Transportation Integrated Search

    2009-03-01

    INTRODUCTION: Many entities currently use recycled asphalt pavement (RAP) and other aggregates as base material, temporary haul roads, and in hot mix asphalt construction. Several states allow the use of RAP combined with cement for stabilized base c...

  6. Dead sea asphalts: historical aspects

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Nissenbaum, A.

    1978-05-01

    Asphalts are present in the Dead Sea basin in three forms: (1) huge blocks, up to 100 tons in weight, composed of extremely pure (>99.99%) solid asphalt occasionally found floating on the lake, (2) veins, seepages, and cavity and fissure fillings in Lower Cretaceous to Holocene rocks, and (3) ozocerite veins on the eastern shore of the lake. Dead Sea asphalts probably have been documented over a longer period of time than any other hydrocarbon deposit--from antiquity to the 19th century. Major uses of asphalt from the Dead Sea have been as an ingredient in the embalming process, for medicinalmore » purposes, for fumigation, and for agriculture. The first known war for control of a hydrocarbon deposit was in the Dead Sea area in 312 B.C. between the Seleucid Syrians and the Nabatean Arabs who lived around the lake. Surface manifestations of asphalt are linked closely to tectonic activity. In the lake itself, the asphalt is associated with diapirs During certain historic periods, tectonic and diapiric activity caused frequent liberation to the Dead Sea surface of semiliquid asphalt associated with large amounts of hydrogen sulfide gas. When the tectonic activity was attenuated, as in the 19th and 20th centuries, the rate of asphalt seepage to the bottom sediments of the Dead Sea was much slower and the asphalt solidified on the lake bottom. The release of asphalt to the surface became much more sporadic, and may have resulted in part from earthquakes. Thus, future asphalt prospecting in the Dead Sea area should be conducted along the boundaries of diapirs or their associated faults.« less

  7. Design and verification of bituminous mixtures with the increased content of reclaimed asphalt pavement

    NASA Astrophysics Data System (ADS)

    Bańkowski, Wojciech; Król, Jan; Gałązka, Karol; Liphardt, Adam; Horodecka, Renata

    2018-05-01

    Recycling of bituminous pavements is an issue increasingly being discussed in Poland. The analysis of domestic and foreign experience indicates a need to develop this technology in our country, in particular the hot feeding and production technologies. Various steps are being taken in this direction, including research projects. One of them is the InnGA project entitled: “Reclaimed asphalt pavement: Innovative technology of bituminous mixtures using material from reclaimed asphalt pavement”. The paper presents the results of research involving the design of bituminous mixtures in accordance with the required properties and in excess of the content of reclaimed asphalt permitted by the technical guidelines. It presents selected bituminous mixtures with the content of RAP of up to 50% and the results of tests from verification of industrial production of those mixtures. The article discusses the details of the design process of mixtures with a high content of reclaimed asphalt, the carried out production tests and discusses the results of tests under the verification of industrial production. Testing included basic tests according to the Polish technical requirements of WT- 2 and the extended functional testing. The conducted tests and analyses helped to determine the usefulness of the developed bituminous mixtures for use in experimental sections and confirmed the possibility of using an increased amount of reclaimed asphalt up to 50% in mixtures intended for construction of national roads.

  8. Evaluation of Tack Coat Bond Strength Tests

    DOT National Transportation Integrated Search

    2018-05-01

    Poor bonding between asphalt pavement overlays and the substrate pavement layer can greatly influence the long term performance of hot mix asphalt (HMA) in the form of premature cracking and fatigue. The primary method to achieve bonding between laye...

  9. Towards an integrated pavement design approach : using HWTD to support the MEPDG

    DOT National Transportation Integrated Search

    2010-11-01

    Variability of hot-mix asphalt (HMA) production can have drastic effects on pavement performance. A poor : gradation or an inappropriate amount of asphalt binder could lead to early distresses and shorter pavement life. Other : factors, such as the a...

  10. Effectiveness of asphalt penetrating sealers in extending new asphalt pavement life.

    DOT National Transportation Integrated Search

    2017-01-01

    Numerous methods are being employed for asphalt pavement preservation, including rejuvenator emulsions, asphalt emulsion fog seals, and a variety of non-structural surface treatments (including slurry and micro surfacing technologies). To make the mo...

  11. Aggregate absorption in HMA mixtures.

    DOT National Transportation Integrated Search

    2013-12-01

    Designing hot mix asphalt (HMA) that will perform for many years is a complex balancing act of selecting an : appropriate design asphalt binder content that is sufficiently high to provide durability but not so high as to lead : to rutting problems. ...

  12. Technical advisory guide (TAG) for bonded wearing course pilot projects.

    DOT National Transportation Integrated Search

    2003-10-01

    A bonded wearing course (BWC) is a gap graded, ultra thin hot-mix asphalt (HMA) mixture applied : over a thick polymer modified asphalt emulsion membrane. The emulsion membrane seals the : existing surface and produces high binder content at the inte...

  13. Longitudinal Joint Repair Best Practices for the Ohio Department of Transportation

    DOT National Transportation Integrated Search

    2017-07-01

    The Ohio Department of Transportation (ODOT) has identified longitudinal joint (LJ) failure of existing hot-mix asphalt (HMA) paving as a systemic weakness in the structure of some asphalt surfaces. In the past, these joint failures were treated as i...

  14. 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.

  15. 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.

  16. Microstructural Analysis and Rheological Modeling of Asphalt Mixtures Containing Recycled Asphalt Materials.

    PubMed

    Falchetto, Augusto Cannone; Moon, Ki Hoon; Wistuba, Michael P

    2014-09-02

    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.

  17. 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

  18. Potential of using stone matrix asphalt (SMA) for thin overlays

    DOT National Transportation Integrated Search

    2003-04-01

    Stone matrix asphalt (SMA) has been used within the U.S. since 1991. To date almost all of the SMA mixes have had either a 12.5 or 19.0 mm nominal maximum aggregate size (NMAS). These two NMASs have been predominant because they conform to informatio...

  19. Mix design of asphalt mixture used for the waterproof and anti-cracking layer in the rainy area of South China.

    PubMed

    Liu, Fuming; Dong, Aixia; Liu, Chaoqun; Wu, Wenqing

    2018-01-01

    In this study, the asphalt mixture (porosity <2%) was tested for use between the upper and middle layers of the asphalt pavement to improve its interlayer structure and to enhance its related waterproof and anti-cracking ability. Considering the weather characteristics and traffic conditions in Jiangxi Province, appropriate raw materials were selected. Based on the technical indexes of the raw materials, expected porosity (<2%), and AC-5 standard for the asphalt mixture, experiments were conducted to determine the best gradation range of the waterproof and anti-cracking layer, and to obtain the optimum amount of the asphalt and fiber used based on Marshall tests. The high-temperature rutting test, low-temperature cracking test, and water stability test were conducted to evaluate the pavement performance of the waterproof and anti-cracking layer. A waterproof and anti-cracking layer was added between the upper and middle layers of the asphalt pavement, which has excellent performance for avoiding cracks and water damage.

  20. Laboratory evaluation of high asphalt binder replacement with recycled asphalt shingles (RAS) for a low n-design asphalt mixture.

    DOT National Transportation Integrated Search

    2012-10-01

    This study investigated the effect of high asphalt binder replacement for a low N-design asphalt mixture including : RAP and RAS on performance indicators such as permanent deformation, fracture, fatigue potentials, and : stiffness, was studied. An e...

  1. Production of al-si alloy feedstocks using the solvent hot mixing method

    NASA Astrophysics Data System (ADS)

    Ni, J. Q.; Han, K. Q.; Yu, M. H.

    2018-05-01

    Powder injection molding is a promising low-cost technique for net shape processing of metal and ceramic components. This study aimed to investigate a new method for preparing aluminium (Al) – silicon (Si) alloy feedstock using the solvent hot mixing process. For this purpose, micron-sized Al-Si (20 wt. %) alloy powder was mixed with a binder consisting of 55 wt. % carnauba wax, 45 wt. % high-density polyethylene, and 3 wt. % stearic acid in a hot xylene bath. The scanning electron microscopy technique, thermogravimetric analysis, density measurement and torque measurements were used to verify the homogeneity of the feedstock. Moreover, the feedstock was chosen to perform the molding, debinding cycle and sintering. An Al-Si (20 wt. %) alloy part was successfully produced using this new method.

  2. Natural asphalt modified binders used for high stiffness modulus asphalt concrete

    NASA Astrophysics Data System (ADS)

    Bilski, Marcin; Słowik, Mieczysław

    2018-05-01

    This paper presents a set of test results supporting the possibility of replacing, in Polish climate conditions, hard road 20/30 penetration grade bitumen used in the binder course and/or base course made of high stiffness modulus asphalt concrete with binders comprising of 35/50 or 50/70 penetration grade bitumens and additives in the form of natural Gilsonite or Trinidad Epuré asphalts. For the purpose of comparing the properties of the discussed asphalt binders, values of the Performance Grade have been determined according to the American Superpave system criteria.

  3. A model for predicting thermal properties of asphalt mixtures from their constituents

    NASA Astrophysics Data System (ADS)

    Keller, Merlin; Roche, Alexis; Lavielle, Marc

    Numerous theoretical and experimental approaches have been developed to predict the effective thermal conductivity of composite materials such as polymers, foams, epoxies, soils and concrete. None of such models have been applied to asphalt concrete. This study attempts to develop a model to predict the thermal conductivity of asphalt concrete from its constituents that will contribute to the asphalt industry by reducing costs and saving time on laboratory testing. The necessity to do the laboratory testing would be no longer required when a mix for the pavement is created with desired thermal properties at the design stage by selecting correct constituents. This thesis investigated six existing predictive models for applicability to asphalt mixtures, and four standard mathematical techniques were used to develop a regression model to predict the effective thermal conductivity. The effective thermal conductivities of 81 asphalt specimens were used as the response variables, and the thermal conductivities and volume fractions of their constituents were used as the predictors. The conducted statistical analyses showed that the measured values of thermal conductivities of the mixtures are affected by the bitumen and aggregate content, but not by the air content. Contrarily, the predicted data for some investigated models are highly sensitive to air voids, but not to bitumen and/or aggregate content. Additionally, the comparison of the experimental with analytical data showed that none of the existing models gave satisfactory results; on the other hand, two regression models (Exponential 1* and Linear 3*) are promising for asphalt concrete.

  4. Assessment of asphalt concrete acoustic performance in urban streets.

    PubMed

    Paje, S E; Bueno, M; Terán, F; Viñuela, U; Luong, J

    2008-03-01

    Geo-referenced close proximity rolling noise and sound absorption measurements are used for acoustical characterization of asphalt concrete surfaces in an urban environment. A close proximity noise map of streets with low speed limits is presented for a reference speed of 50 km/h. Different pavements and pavement conditions, common in urban streets, are analyzed: dense and semidense asphalt concrete, with Spanish denomination D-8 and S-12, respectively, and on the other hand, dense pavement at the end of its service life (D-8(*)). From the acoustics point of view, the most favorable surface, by more than 4 dB(A) compared with the S-12 mix, is the smoothest surface, i.e., the D-8 mix, even though it presents a minor absorption coefficient in normal incidence. Noise levels from dense surfaces (D-8) increase significantly over time, principally due to the appearance of surface defects such as cracks and ruts. Longitudinal variability of the close proximity tire/pavement noise emission and surface homogeneity are also analyzed.

  5. Quality control analysis : part I : asphaltic concrete.

    DOT National Transportation Integrated Search

    1964-11-01

    This report deals with the statistical evaluation of results from several hot mix plants to determine the pattern of variability with respect to bituminous hot mix characteristics. : Individual tests results when subjected to frequency distribution i...

  6. Improved rice method for determining theoretical maximum density of asphalt paving mixtures

    DOT National Transportation Integrated Search

    1992-05-01

    Rice method (ASTM D2041 ) is used for determining the theoretical maximum specific gravity of asphalt paving mixtures which is one of the main test parameters used for mix design and construction quality control. The repeatability and reproducibility...

  7. Evaluation of Warm-Mix Asphalt Technologies for Use on Airfield Pavements

    DTIC Science & Technology

    2013-12-01

    three different ways: mechanical injection of water at the plant, adding a material containing internal water, such as zeolites , and using a two...the nozzles, causing the asphalt binder to expand (Prowell and Hurley 2007). Zeolites are crystalline-hydrated aluminum silicates that are typically...sold in granular form with approximately a No. 50 mesh size and contain approximately 20% water by weight. The water is released from the zeolite

  8. Emissions into the Air from Bitumen and Rubber Bitumen-Implications for Asphalt Workers' Exposure.

    PubMed

    Nilsson, Patrik T; Bergendorf, Ulf; Tinnerberg, Håkan; Nordin, Erik; Gustavsson, Mats; Strandberg, Bo; Albin, Maria; Gudmundsson, Anders

    2018-06-21

    The risk among asphalt workers of developing adverse health effects may increase due to their occupational exposure. One area of special concern arises when rubber granules are mixed into bitumen to enhance asphalt properties. This research characterizes and compares bitumen and rubber bitumen regarding the emissions of and workers' exposure to particulates, polycyclic aromatic hydrocarbons (PAHs) and benzothiazole. A laboratory and a field study were carried out. In the laboratory, two types of bitumen, one with and one without rubber, were heated up to two temperatures (140°C and 160°C). The concentrations and chemical compositions of the emissions were determined. In the field at asphalt work sites, both emissions and worker exposure measurements were performed. The methods applied included direct-reading sampling techniques next to the asphalt work area and personal sampling techniques on asphalt workers. The exposure measurements on asphalt workers for respirable dust, total dust, particle number and mass, and total PAH concentrations showed similar concentrations when both standard and rubber bitumen were used. The asphalt-surfacing machine operators were the workers with the highest observed exposure followed by the screed operators and roller drivers. Both laboratory and field measurements showed higher concentrations of benzothiazole when rubber bitumen was used, up to 7.5 times higher in the laboratory. The levels of naphthalene, benzo(a)pyrene, and total particles were lower for both types compared with the Swedish occupational exposure limits, 8-h time weighted average concentrations. Benzo(a)pyrene exceeded however the health-based guideline value given by the WHO for both types of bitumen. The study concludes that several air pollutants such as benzothiazole and PAHs are emitted into the air during asphalt work, but it is not evident if exposure to rubber bitumen possesses a higher risk than exposure to standard bitumen in terms of asphalt worker

  9. The role of hot spot mix in the low-foot and high-foot implosions on the NIF

    NASA Astrophysics Data System (ADS)

    Ma, T.; Patel, P. K.; Izumi, N.; Springer, P. T.; Key, M. H.; Atherton, L. J.; Barrios, M. A.; Benedetti, L. R.; Bionta, R.; Bond, E.; Bradley, D. K.; Caggiano, J.; Callahan, D. A.; Casey, D. T.; Celliers, P. M.; Cerjan, C. J.; Church, J. A.; Clark, D. S.; Dewald, E. L.; Dittrich, T. R.; Dixit, S. N.; Döppner, T.; Dylla-Spears, R.; Edgell, D. H.; Epstein, R.; Field, J.; Fittinghoff, D. N.; Frenje, J. A.; Gatu Johnson, M.; Glenn, S.; Glenzer, S. H.; Grim, G.; Guler, N.; Haan, S. W.; Hammel, B. A.; Hatarik, R.; Herrmann, H. W.; Hicks, D.; Hinkel, D. E.; Berzak Hopkins, L. F.; Hsing, W. W.; Hurricane, O. A.; Jones, O. S.; Kauffman, R.; Khan, S. F.; Kilkenny, J. D.; Kline, J. L.; Kozioziemski, B.; Kritcher, A.; Kyrala, G. A.; Landen, O. L.; Lindl, J. D.; Le Pape, S.; MacGowan, B. J.; Mackinnon, A. J.; MacPhee, A. G.; Meezan, N. B.; Merrill, F. E.; Moody, J. D.; Moses, E. I.; Nagel, S. R.; Nikroo, A.; Pak, A.; Parham, T.; Park, H.-S.; Ralph, J. E.; Regan, S. P.; Remington, B. A.; Robey, H. F.; Rosen, M. D.; Rygg, J. R.; Ross, J. S.; Salmonson, J. D.; Sater, J.; Sayre, D.; Schneider, M. B.; Shaughnessy, D.; Sio, H.; Spears, B. K.; Smalyuk, V.; Suter, L. J.; Tommasini, R.; Town, R. P. J.; Volegov, P. L.; Wan, A.; Weber, S. V.; Widmann, K.; Wilde, C. H.; Yeamans, C.; Edwards, M. J.

    2017-05-01

    Hydrodynamic mix of the ablator into the DT fuel layer and hot spot can be a critical performance limitation in inertial confinement fusion implosions. This mix results in increased radiation loss, cooling of the hot spot, and reduced neutron yield. To quantify the level of mix, we have developed a simple model that infers the level of contamination using the ratio of the measured x-ray emission to the neutron yield. The principal source for the performance limitation of the "low-foot" class of implosions appears to have been mix. Lower convergence "high-foot" implosions are found to be less susceptible to mix, allowing velocities of >380 km/s to be achieved.

  10. Effects of various asphalt binder additives/modifiers on moisture susceptible asphaltic mixtures.

    DOT National Transportation Integrated Search

    2014-01-01

    Moisture damage of asphalt concrete is defined as the loss of strength and stability caused by the active presence of : moisture. The most common technique to mitigate moisture damage is using additives or modifiers with the asphalt binder or : the a...

  11. Improving the sustainability of asphalt pavements through developing a predictive model with fundamental material properties.

    DOT National Transportation Integrated Search

    2009-08-01

    This study presents the numerical implementation and validation of general constitutive relationships for describing the : nonlinear behavior of asphalt concrete mixes. These constitutive relationships incorporate nonlinear viscoelasticity and : visc...

  12. Asphalt rubber usage guide.

    DOT National Transportation Integrated Search

    2003-01-01

    This Asphalt Rubber Usage Guide is intended for use by California Department of Transportation : (Caltrans) design, construction, and maintenance managers and engineers, as well as by field personnel : involved in placement of asphalt rubber paving m...

  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. The role of hot spot mix in the low-foot and high-foot implosions on the NIF

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ma, T.; Patel, P. K.; Izumi, N.

    Hydrodynamic mix of the ablator into the DT fuel layer and hot spot can be a critical performance limitation in inertial confinement fusion implosions. This mix results in increased radiation loss, cooling of the hot spot, and reduced neutron yield. To quantify the level of mix, we have developed a simple model that infers the level of contamination using the ratio of the measured x-ray emission to the neutron yield. The principal source for the performance limitation of the “low-foot” class of implosions appears to have been mix. As a result, lower convergence “high-foot” implosions are found to be lessmore » susceptible to mix, allowing velocities of >380 km/s to be achieved.« less

  15. The role of hot spot mix in the low-foot and high-foot implosions on the NIF

    DOE PAGES

    Ma, T.; Patel, P. K.; Izumi, N.; ...

    2017-05-18

    Hydrodynamic mix of the ablator into the DT fuel layer and hot spot can be a critical performance limitation in inertial confinement fusion implosions. This mix results in increased radiation loss, cooling of the hot spot, and reduced neutron yield. To quantify the level of mix, we have developed a simple model that infers the level of contamination using the ratio of the measured x-ray emission to the neutron yield. The principal source for the performance limitation of the “low-foot” class of implosions appears to have been mix. As a result, lower convergence “high-foot” implosions are found to be lessmore » susceptible to mix, allowing velocities of >380 km/s to be achieved.« less

  16. Evaluation of moisture damage in asphalt concrete with CRM motorcycle tire waste passing #50 sieve size

    NASA Astrophysics Data System (ADS)

    Siswanto, Henri; Supriyanto, Bambang; Pranoto, Pranoto; Chandra, Pria Rizky; Hakim, Arief Rahman

    2017-09-01

    The objective of this experimental research is to evaluate moisture damage in Asphalt Concrete (AC) with Crumb Rubber Modified (CRM) motorcycle tire waste passing #50 and retaining #100 sieve size. Two gradations were used in this research, the first gradation is usual for asphalt concrete base (ACB) and the second gradation is for asphalt concrete wearing course (ACWC). Marshall testing apparatus was used for testing the Marshall specimens. Seven levels of CRM content were used, namely 0%, 0.5%, 1%, 1.5%, 3%, 4.5% and 6% by weight of mixtures. Retained stability represent the level of moisture damage of AC pavement. The result indicates that addition CRM to the AC mixture increases their the stability to a maximum value and subsequent addition decrease the stability. The addition CRM to AC decreases their moisture damage susceptibility. AC with 1% CRM is the best asphalt-CRM mix.

  17. Evaluation of an asphalt-treated drainage blanket in a rigid pavement section : final report.

    DOT National Transportation Integrated Search

    1978-01-01

    This study was undertaken to develop a permeable yet stable, asphalt-treated, layered shoulder drainage system for a typical pavement section. Stability and permeability characteristics of several mixes were evaluated in the laboratory. Two installat...

  18. Characteristics of dynamic triaxial testing of asphalt mixtures

    NASA Astrophysics Data System (ADS)

    Ulloa Calderon, Alvaro

    Due to the increasing traffic loads and tire pressures, a serious detrimental impact has occurred on flexible pavements in the form of excessive permanent deformation once the critical combination of loading and environmental conditions are reached. This distress, also known as rutting, leads to an increase in road roughness and ultimately jeopardizes the road users' safety. The flow number (FN) simple performance test for asphalt mixtures was one of the final three tests selected for further evaluation from the twenty-four test/material properties initially examined under the NCHRP 9-19 project. Currently, no standard triaxial testing conditions in terms of the magnitude of the deviator and confining stresses have been specified. In addition, a repeated haversine axial compressive load pulse of 0.1 second and a rest period of 0.9 second are commonly used as part of the triaxial testing conditions. The overall objective of this research was to define the loading conditions that created by a moving truck load in the hot mixed asphalt (HMA) layer. The loading conditions were defined in terms of the triaxial stress levels and the corresponding loading time. Dynamic mechanistic analysis with circular stress distribution was used to closely simulate field loading conditions. Extensive mechanistic analyses of three different asphalt pavement structures subjected to moving traffic loads at various speeds and under braking and non-braking conditions were conducted using the 3D-Move model. Prediction equations for estimating the anticipated deviator and confining stresses along with the equivalent deviator stress pulse duration as a function of pavement temperature, vehicle speed, and asphalt mixture's stiffness have been developed. The magnitude of deviator stress, sigmad and confining stress, sigmac, were determined by converting the stress tensor computed in the HMA layer at 2" below pavement surface under a moving 18-wheel truck using the octahedral normal and shear

  19. Asphaltic concrete pavement survey.

    DOT National Transportation Integrated Search

    1963-04-01

    The ever increasing problem of wheel path rutting and excessive desification of asphaltic concrete pavement has been the subject of asphalt technology for quite sometime. It is known that the density of the pavement, which is significant for several ...

  20. Field management of asphalt concrete mixes.

    DOT National Transportation Integrated Search

    1988-01-01

    Marshall properties were determined on mixes from three different contractors each producing a 1/2-in and a 3/4-in top-sized aggregate mix. From these data, statistical analyses were made to determine differences among contractors and between mix typ...

  1. Performance of warranted asphalt pavements : smoothness and performance of Indiana warranted asphalt pavements.

    DOT National Transportation Integrated Search

    2016-06-01

    In the early 1990s the Indiana Department of Transportation (INDOT) developed a five-year warranty specification for asphalt pavements : with the first project being built in 1996. In 2004, results indicated that the asphalt pavements built with the ...

  2. 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...

  3. 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...

  4. Product (P1) from project 0-6738 : performance studies and future directions for mixes containing RAP and RAS.

    DOT National Transportation Integrated Search

    2013-01-01

    In recent years both reclaimed asphalt pavement (RAP) and recycled asphalt shingles (RAS) have been widely used in asphalt mixes by the asphalt paving industry in Texas. The use of RAP and RAS can save tax payers money, and it is also good for the...

  5. 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.

  6. Evaluation of the gyratory compactor for use in designing asphaltic concrete mixtures : final report.

    DOT National Transportation Integrated Search

    1966-12-01

    The primary objective of this study was to evaluate the gyratory kneading compactor and to investigate the possibilities and capabilities of this type of equipment. : Curves were developed for six different asphaltic concrete mixes with varying compa...

  7. Sustainability and training materials for in-place recycling.

    DOT National Transportation Integrated Search

    2016-04-22

    Hot and cold in-place recycling techniques recycle 100 percent of a hot mix asphalt (HMA) pavement, in place, during the maintenance/rehabilitation process. Numerous studies have shown in-place recycling to be a sustainable, cost-effective procedure ...

  8. The overlay tester (OT) : comparison with other crack test methods and recommendations for surrogate crack tests.

    DOT National Transportation Integrated Search

    2012-10-01

    Presently, one of the principal performance concerns of hot-mix asphalt (HMA) pavements is premature : cracking, particularly of HMA surfacing mixes. Regrettably, however, while many USA transportation agencies have : implemented design-level tests t...

  9. 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.

  10. 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.

  11. Use of Adhesion Promoters in Asphalt Mixtures

    NASA Astrophysics Data System (ADS)

    Cihlářová, Denisa; Fencl, Ivan; Cápayová, Silvia; Pospíšil, Petr

    2018-03-01

    The purpose of asphalt binder as a significant binder in road constructions is to permanently bind aggregates of different compositions and grain sizes. The asphalt binder itself does not have suitable adhesiveness, so after a period of time, bare grains can appear. This results in a gradual separation of the grains from an asphalt layer and the presence of potholes in a pavement. Adhesion promoters or adhesive agents are important and proven promoters in practice. They are substances mainly based on the fatty acids of polyamides which should increase the reliability of the asphalt's binder adhesion to the aggregates, thus increasing the lifetime period of the asphalt mixture as well as its resistance to mechanical strain. The amount of a promoter or agent added to the asphalt mixture is negligible and constitutes about 0.3% of the asphalt's binder weight. Nevertheless, even this quantity significantly increases the adhesive qualities of an asphalt binder. The article was created in cooperatation with the Slovak University of Technology, in Bratislava, Slovakia, and focuses on proving the new AD2 adhesive additive and comparing it with the Addibit and Wetfix BE promoters used on aggregates from the Skuteč - Litická and Bystřec quarries.

  12. 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

  13. Evaluation of Nontraditional Airfield Pavement Surfaces for Contingency Operations

    DTIC Science & Technology

    2014-01-01

    such as asphalt or portland cement concrete are not readily available or are too cost-, labor-, or equipment-intensive to use. This report presents a...courses) are generally constructed using hot mix asphalt (HMA) or portland cement concrete (PCC), both of which are suitable for C-17 and C-130...associated with PCC or HMA surfacing. Stabilization can be accomplished by blending additives such as portland cement , lime, fly ash, asphalt binder

  14. Use of screenings to produce HMA mixtures

    DOT National Transportation Integrated Search

    2002-10-01

    Thin-lift hot mix asphalt (HMA) layers are utilized in almost every maintenance and rehabilitation application. These mix types require smaller maximum particle sizes than most conventional HMA surface layers. Although the primary functions of thin-l...

  15. Evaluation of recycled asphaltic concrete : final report.

    DOT National Transportation Integrated Search

    1977-01-01

    This report describes a project in which approximately 6,200 tons (5,630 Mg) of asphaltic concrete were recycled through a conventional asphalt batch plant. During the construction of the project, a buildup of asphalt-coated fines occurred in the dry...

  16. 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.

  17. 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…

  18. Applicability Determination for PSD- Hot Mix Asphalt Operations

    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.

  19. Evaluation of hot mix asphalt (HMA) lift thickness.

    DOT National Transportation Integrated Search

    2009-10-01

    The range of lift thicknesses allowed by the Mississippi Department of Transportation has worked well for many years. However, because of the current availability of gravels of sufficient size to crush, modification to the allowed lift thicknesses am...

  20. Waste Materials in Hot Mix Asphalt - An Overview

    DOT National Transportation Integrated Search

    1992-12-01

    Numerous waste materials result from manufacturing operations, service industries, sewage treatment plants, households and mining. Legislation has been enacted by several states in recent years to either mandate the use of some waste materials or to ...