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...

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...

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...

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.

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...

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...

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.

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

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...

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 ...

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...

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.

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...

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...

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.

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

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...

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 ...

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...

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.

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.

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...

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...

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...

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...

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...

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...

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...

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...

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...

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.

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...

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 ...

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...

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.

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 ...

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...

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...

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 ...

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

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...

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...

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 ...

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

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.

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.

Effect of Warm Asphalt Additive on the Creep and Recovery Behaviour of Aged Binder Containing Waste Engine Oil

NASA Astrophysics Data System (ADS)

Hassan, Norhidayah Abdul; Kamaruddin, Nurul Hidayah Mohd; Rosli Hainin, Mohd; Ezree Abdullah, Mohd

2017-08-01

The use of waste engine oil as an additive in asphalt mixture has been reported to be able to offset the stiffening effect caused by the recycled asphalt mixture. Additionally, the fumes and odor of the waste engine oil has caused an uncomfortable condition for the workers during road construction particularly at higher production temperature. Therefore, this problem was addressed by integrating chemical warm asphalt additive into the mixture which functions to reduce the mixing and compaction temperature. This study was initiated by blending the additive in the asphalt binder of bitumen penetration grade 80/100 prior to the addition of pavement mixture. The effect of chemical warm asphalt additive, Rediset WMX was investigated by modifying the aged binder containing waste engine oil with 0%, 1%, 2% and 3% by weight of the binder. The samples were then tested for determining the rutting behaviour under different loading stress levels of 3Pa (low), 10Pa (medium) and 50Pa (high) using Dynamic Shear Rheometer (DSR). A reference temperature of 60 °C was fixed to reflect the maximum temperature of the pavement. The results found that the addition of Rediset did not affect the creep and recovery behavior of the modified binder under different loading. On the other hand, 2% Rediset resulted a slight decrease in its rutting resistance as shown by the reduction of non-recoverable compliance under high load stress. However, overall, the inclusion of chemical warm asphalt additive to the modified binder did not adversely affect the rutting resistance which could be beneficial in lowering the temperature of asphalt production and simultaneously not compromising the binder properties.

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 ...

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...

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...

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...

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...

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...

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...

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.

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...

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.

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...

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 ...

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...

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 ...

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...

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 ...

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.

Laboratory testing and economic analysis of high RAP warm mixed asphalt.

DOT National Transportation Integrated Search

2009-03-24

This report contains laboratory testing, economic analysis, literature review, and information obtained from multiple producers throughout the state of Mississippi regarding the use of high RAP (50 % to 100%) mixtures containing warm mix additives. T...

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 ...

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...

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...

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...

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...

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 ...

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.

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

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...

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...

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...

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...

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

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...

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 ...

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, ...

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...

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...

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...

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 ...

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...

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 ...

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.

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...

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.

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...

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...

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...

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...

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...

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...

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.

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...

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

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

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...

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...

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% ...

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...

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 ...

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…

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...

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....

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

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...

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...

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...

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...

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

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.

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...

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 ...

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...

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 ...

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 (...

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...

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).

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), ...

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...

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...

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...

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...

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 ...

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...

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...

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...

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.

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...

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...

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.

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

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...

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...

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, ...

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...

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...

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...

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.

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...

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...

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...

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

DTIC Science & Technology

2014-01-01

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

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...

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% ...

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...

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 ...

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...

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.

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

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...

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...

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

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.

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 ...

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.

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.

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...

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 ...

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

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...

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...

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...

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...

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...

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.

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...

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...

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

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.

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...

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...

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...

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...

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.

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.

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...

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

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...

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...

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...

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 ...

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.

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...

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

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...

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

Mixing processes following the final stratospheric warming

NASA Technical Reports Server (NTRS)

Hess, Peter G.

1991-01-01

An investigation is made of the dynamics responsible for the mixing and dissolution of the polar vortex during the final stratospheric warmings. The dynamics and transport during a Northern Hemisphere final stratospheric warming are simulated via a GCM and an associated offline N2O transport model. The results are compared with those obtained from LIMS data for the final warming of 1979, with emphasis on the potential vorticity evolution in the two datasets, the modeled N2O evolution, and the observed O3 evolution. Following each warming, the remnants of the originally intact vortex are found to gradually homogenize with the atmosphere at large. Two processes leading to this homogenization are identified following the final warmings, namely, the potential vorticity field becomes decorrelated from that of the chemical tracer, and the vortex remnants begin to tilt dramatically in a vertical direction.

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...

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

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...

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

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...

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...

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...

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.

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...

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...

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.

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

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...

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

NASA Astrophysics Data System (ADS)

Mohd Hasan, Mohd Rosli

The asphalt foaming techniques have been used over the last couple of decades as an alternative to the traditional method of preparing asphalt mixtures. Based on positive feedback from the industry, this study was initiated to explore and evaluate the performance of the Warm Mix Asphalt (WMA) mixture produced through a foaming process using physical and chemical foaming agents, which are ethanol and sodium bicarbonate (NaHCO3), respectively. The success of this project may lead to new theories and provide an environmentally friendly technique to produce asphalt mixtures. This may advance the understanding of the foaming process and improve the performance of WMA to support sustainable development. Theoretically, ethanol can function in the same manner as water but requires less energy to foam due to its lower boiling point, 78°C. During the asphalt foaming process, numerous bubbles were generated by the vaporized ethanol, which significantly increased the volume of the asphalt binder, hence the coating potential of aggregates improves. The sodium bicarbonate was incorporated to enhance the quantity of bubbles and its stability. Therefore, understanding foaming agents, their solubility, chemical reactions, chemical function groups and rheological properties of the foamed binder are essential to help control the foam structure and final properties of the foamed WMA mixture. In order to understand the overall performance of newly developed foaming WMA, this material was evaluated for moisture susceptibility, rutting potential, and resistance to fracture and thermal cracking. The coatability, workability and compactability of foamed asphalt mixtures during production were also evaluated. Based on the results, it was found that the newly proposed foaming WMA has high potential to promote sustainable development by lowering the energy consumption and impacts on the environment. The ethanol is efficient in lowering the viscosity of asphalt binders, enhancing the

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

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.

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....

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...

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...

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.

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...

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...

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.

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

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...

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...

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...

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 ...

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...

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).

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...

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

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.

The role stratification on Indian ocean mixing under global warming

NASA Astrophysics Data System (ADS)

Praveen, V.; Valsala, V.; Ravindran, A. M.

2017-12-01

The impact of changes in Indian ocean stratification on mixing under global warming is examined. Previous studies on global warming and associated weakening of winds reported to increase the stratification of the world ocean leading to a reduction in mixing, increased acidity, reduced oxygen and there by a reduction in productivity. However this processes is not uniform and are also modulated by changes in wind pattern of the future. Our study evaluate the role of stratification and surface fluxes on mixing focusing northern Indian ocean. A dynamical downscaling study using Regional ocean Modelling system (ROMS) forced with stratification and surface fluxes from selected CMIP5 models are presented. Results from an extensive set of historical and Representative Concentration Pathways 8.5 (rcp8.5) scenario simulations are used to quantify the distinctive role of stratification on mixing.

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.

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.

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.

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...

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...

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...

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...

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. ...

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.

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...

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...

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 ...

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 ...

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

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.

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.

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.

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.

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.

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...

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...

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

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...

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...

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...

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.

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…

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...

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...

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 ...

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...

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...

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...

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...

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...

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.

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...

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

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.

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...

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.

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.

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

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...

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 ...

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.

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...

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...

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....

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

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.

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

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.

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...

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.

Langmuir wave phase-mixing in warm electron-positron-dusty plasmas

NASA Astrophysics Data System (ADS)

Pramanik, Sourav; Maity, Chandan

2018-04-01

An analytical study on nonlinear evolution of Langmuir waves in warm electron-positron-dusty plasmas is presented. The massive dust grains of either positively or negatively charged are assumed to form a fixed charge neutralizing background. A perturbative analysis of the fluid-Maxwell's equations confirms that the excited Langmuir waves phase-mix and eventually break, even at arbitrarily low amplitudes. It is shown that the nature of the dust-charge as well as the amount of dust grains can significantly influence the Langmuir wave phase-mixing process. The phase-mixing time is also found to increase with the temperature.

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...

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...

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.

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 ...

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...

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 ...

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...

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

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...

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.

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

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.

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.

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...

Comparative Life Cycle Assessment between Warm SMA and Conventional SMA

DOT National Transportation Integrated Search

2011-09-01

This report presents the comparative life cycle assessment (LCA) between warm stone mastic asphalt (SMA) and conventional : SMA. Specifically, the study evaluated and compared the life cycle environmental and economic performances of two mixtures: a ...

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...

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

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...

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...

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...

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%.

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...

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.

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...

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...

Formation of well-mixed warm water column in central Bohai Sea during summer: Role of high-frequency atmospheric forcing

NASA Astrophysics Data System (ADS)

Ma, Weiwei; Wan, Xiuquan; Wang, Zhankun; Liu, Yulong; Wan, Kai

2017-12-01

The influence of high-frequency atmospheric forcing on the formation of a well-mixed summer warm water column in the central Bohai Sea is investigated comparing model simulations driven by daily surface forcing and those using monthly forcing data. In the absence of high-frequency atmospheric forcing, numerical simulations have repeatedly failed to reproduce this vertically uniform column of warm water measured over the past 35 years. However, high-frequency surface forcing is found to strongly influence the structure and distribution of the well-mixed warm water column, and simulations are in good agreement with observations. Results show that high frequency forcing enhances vertical mixing over the central bank, intensifies downward heat transport, and homogenizes the water column to form the Bohai central warm column. Evidence presented shows that high frequency forcing plays a dominant role in the formation of the well-mixed warm water column in summer, even without the effects of tidal and surface wave mixing. The present study thus provides a practical and rational way of further improving the performance of oceanic simulations in the Bohai Sea and can be used to adjust parameterization schemes of ocean models.

Determining changes in greenhouse gas emissions (1990-2010) due to pavement technology.

DOT National Transportation Integrated Search

2015-01-01

This research quantifies the changes in greenhouse gas (GHG) emissions and energy : consumption from WSDOT between 1990 and 2010 associated with (1) using warm mix asphalt : (WMA), reclaimed asphalt pavement (RAP), fly ash and slag in pavement materi...

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

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.

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

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...

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...

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.

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 ...

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...

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...

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.

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'...

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...

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...

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

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.

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...

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.

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...

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.

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.

Evaluation of Foaming Performance of Bitumen Modified with the Addition of Surface Active Agent

NASA Astrophysics Data System (ADS)

Chomicz-Kowalska, Anna; Mrugała, Justyna; Maciejewski, Krzysztof

2017-10-01

The article presents the analysis of the performance of foamed bitumen modified using surface active agents. Although, bitumen foaming permits production of asphalt concrete and other asphalt mix types without using chemical additives in significantly reduced temperatures, the decrease in processing temperatures still impacts the adhesion performance and bitumen coating of aggregates in final mixes. Therefore, in some cases it may be feasible to incorporate adhesion promoters and surface active agents into warm and half-warm mixes with foamed bitumen to increase their service life and resilience. Because of the various nature of the available surface active agents, varying bitumen compatibility and their possible impact on the rheological properties of bitumen, the introduction of surface active agents may significantly alter the bitumen foaming performance. The tests included basic performance tests of bitumen before and after foaming. The two tested bitumen were designated as 35/50 and 50/70 penetration grade binders, which were modified with a surface active agent widely used for improving mixture workability, compactibility and adhesion in a wide range of asphalt mixes and techniques, specifically Warm Mix Asphalt. Alongside to the reference unmodified bitumen, binders with 0.2%, 0.4% and 0.6% surface active agent concentration were tested. The analysis has shown a positive influence of the modifier on the foaming performance of both of the base bitumen increasing their maximum expansion ratio and bitumen foam halflife. In the investigations, it was found that the improvement was dependent on the bitumen type and modifier content. The improved expansion ratio and foam half-life has a positive impact on the aggregate coating and adhesion, which together with the adhesion promoting action of the modifier will have a combined positive effect on the quality of produced final asphalt mixes.

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...

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.

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

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...

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.

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...

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.

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...

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.

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.

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.

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 ...

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...

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.

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...

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

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...

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...

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...

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...

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 ...

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...

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

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.

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 ...

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...

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 ...

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...

Suppressing four-wave mixing in warm-atomic-vapor quantum memory

NASA Astrophysics Data System (ADS)

Vurgaftman, Igor; Bashkansky, Mark

2013-06-01

Warm-atomic-vapor cells may be employed as quantum-memory components in an experimentally convenient implementation of the Duan-Lukin-Cirac-Zoller protocol. Previous studies have shown the performance of these cells is limited by the combination of collisional fluorescence during the writing process and four-wave mixing during the reading process and have proposed to overcome this by a combination of optimized detuning and prepumping with circularly polarized write and read beams. Here we show that the Raman matrix elements involving the excited P (F'=I-(1)/(2) and F'=I+(1)/(2)) levels of all alkali atoms are always equal in magnitude and opposite in sign when the write and the anti-Stokes (Stokes) photons have the opposite helicity, and the Raman transitions via the two levels interfere destructively. The existence of an optimal detuning is demonstrated for a given dark-count rate of the single-photon detector. The predicted behavior is observed experimentally in a warm Rb cell with buffer gas.

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 ...

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...

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...

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...

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.

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...

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.

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

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.

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

DTIC Science & Technology

2014-06-01

decrease of approximately 20% for CO, CO2, and NOx and a slight increase in SO2 for WMA ( Evotherm ) compared to conventional HMA. It is important to note...personal sampling) BSF and TP Evotherm ET All exposures were below the LOD Kriech et al. (2011) Kriech et al. (2002) method (personal sampling...TOM BituTech PER, Cecabase RT, Evotherm DAT, Sonne Warmix, Ultrafoam GX2, and wax 33% reduction for WMA compared to HMA Hurley at al. (2010

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

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...

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.

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

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...

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,...

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...

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.

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…

Latex improvement of recycled asphalt pavement

NASA Astrophysics Data System (ADS)

Drennon, C.

1982-08-01

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

Simulation, imaging, and mechanics of asphalt pavement (SIMAP) initiative

DOT National Transportation Integrated Search

1998-07-01

Asphalt concrete is a complex material that consists of aggregates, asphalt, and air voids. Aggregates are held together by asphalt and form a skeleton to support the weight of vehicles. The stiffer the asphalt, the tighter the aggregates are held to...

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...

Mechanical Performance of Asphalt Mortar Containing Hydrated Lime and EAFSS at Low and High Temperatures

PubMed Central

Moon, Ki Hoon; Wang, Di; Riccardi, Chiara; Wistuba, Michael P.

2017-01-01

In this paper, the possibility of improving the global response of asphalt materials for pavement applications through the use of hydrated lime and Electric Arc-Furnace Steel Slag (EAFSS) was investigated. For this purpose, a set of asphalt mortars was prepared by mixing two different asphalt binders with fine granite aggregate together with hydrated lime or EAFSS at three different percentages. Bending Beam Rheometer (BBR) creep tests and Dynamic Shear Rheometer (DSR) complex modulus tests were performed to evaluate the material response both at low and high temperature. Then, the rheological Huet model was fitted to the BBR creep results for estimating the impact of filler content on the model parameters. It was found that an addition of hydrated lime and EAFSS up to 10% and 5%, respectively, results in satisfactory low-temperature performance with a substantial improvement of the high-temperature behavior. PMID:28773100

Paving asphalts : reduction of oxidative hardening of asphalts by treatment with hydrated lime : a mechanistic study

DOT National Transportation Integrated Search

1977-04-01

This study showed that lime treatment removes polar, viscosity-building components and reduces the susceptibility of the asphalt to laboratory oxidative hardening. The beneficial effects of lime treatment in reducing asphalt oxidative hardening were ...

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...

Final Rule to Reduce Toxic Air Emissions from Asphalt Processing and Asphalt Roofing Manufacturing Facilities Fact Sheet

EPA Pesticide Factsheets

This page contains a February 2003 fact sheet with information regarding the National Emissions Standards for Hazardous Air Pollutants (NESHAP) for Asphalt Processing and Asphalt Roofing Manufacturing.

Design and evaluation of foamed asphalt base materials.

DOT National Transportation Integrated Search

2013-05-01

Foamed asphalt stabilized base (FASB) combines reclaimed asphalt pavement (RAP), recycled : concrete (RC), and/or graded aggregate base (GAB) with a foamed asphalt binder to produce a : partially stabilized base material. The objectives of this study...

Rapid determination of actinides in asphalt samples

DOE PAGES

Maxwell, Sherrod L.; Culligan, Brian K.; Hutchison, Jay B.

2014-01-12

A new rapid method for the determination of actinides in asphalt samples has been developed that can be used in emergency response situations or for routine analysis If a radiological dispersive device (RDD), Improvised Nuclear Device (IND) or a nuclear accident such as the accident at the Fukushima Nuclear Power Plant in March, 2011 occurs, there will be an urgent need for rapid analyses of many different environmental matrices, including asphalt materials, to support dose mitigation and environmental clean up. The new method for the determination of actinides in asphalt utilizes a rapid furnace step to destroy bitumen and organicsmore » present in the asphalt and sodium hydroxide fusion to digest the remaining sample. Sample preconcentration steps are used to collect the actinides and a new stacked TRU Resin + DGA Resin column method is employed to separate the actinide isotopes in the asphalt samples. The TRU Resin plus DGA Resin separation approach, which allows sequential separation of plutonium, uranium, americium and curium isotopes in asphalt samples, can be applied to soil samples as well.« less

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...

Physical and rheological properties of Titanium Dioxide modified asphalt

NASA Astrophysics Data System (ADS)

Buhari, Rosnawati; Ezree Abdullah, Mohd; Khairul Ahmad, Mohd; Chong, Ai Ling; Haini, Rosli; Khatijah Abu Bakar, Siti

2018-03-01

Titanium Dioxide (TiO2) has been known as a useful photocatalytic material that is attributed to the several characteristics includes high photocatalytic activity compared with other metal oxide photocatalysts, compatible with traditional construction materials without changing any original performance. This study investigates the physical and rheological properties of modified asphalt with TiO2. Five samples of asphalt with different concentration of TiO2 were studied, namely asphalt 2%, 4%, 6% 8% and 10% TiO2. The tests includes are penetration, softening point, ductility, rotational viscosity and dynamic shear rheometer (DSR) test. From the results of this study, it is noted that addition of TiO2 has significant effect on the physical properties of asphalt. The viscosity tests revealed that asphalt 10% TiO2 has good workability among with reducing approximately 15°C compared to base asphalt. Based on the results from DSR measurements, asphalt 10% TiO2 has reduced temperature susceptibility and increase stiffness and elastic behaviour in comparison to base asphalt. As a result, TiO2 can be considered to be an additive to modify the properties of asphalt.

Laboratory evaluation of asphalt concrete mixtures containing high contents of reclaimed asphalt pavement (RAP) and binder.

DOT National Transportation Integrated Search

2014-11-01

This study investigated the effect of added asphalt : binder content on the performance and volumetric p : roperties of : asphalt concrete mixtures containing reclaimed asph : alt pavement (RAP) in the amounts of 0%, 20%, and 4 : 0%. A laboratory- : ...

Comparing Production and Placement of Warm-Mix Asphalt to Traditional Hot-Mix Asphalt for Constructing Airfield Pavements

DTIC Science & Technology

2013-08-01

Sasobit® STA 0+35 cross-section layer thicknesses as constructed............................... 36  Figure 50. Evotherm ™ center-line layer thicknesses...as constructed. ................................................ 37  Figure 51. Evotherm ™ STA 0+15 cross-section layer thicknesses as constructed...37  Figure 52. Evotherm ™ STA 0+25 cross-section layer thicknesses as constructed. .......................... 38  Figure 53

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...

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...

Lung function in asphalt pavers: a longitudinal study.

PubMed

Ulvestad, Bente; Randem, Britt Grethe; Skare, Øivind; Aaløkken, Trond Mogens; Myranek, Georg Karl; Elihn, Karine; Lund, May Brit

2017-01-01

To study longitudinal changes in lung function in asphalt pavers and a reference group of road maintenance workers, and to detect possible signs of lung disease by high-resolution computed tomography (HRCT) scans. Seventy-five asphalt pavers and 71 road maintenance workers were followed up with questionnaires and measurements of lung function. Not every worker was tested every year, but most of them had four or more measurement points. The 75 asphalt pavers were also invited to have HRCT scans of the lungs at the end of the follow-up period. Mean annual decline in forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV 1 ) of the asphalt pavers was 58 and 35 ml, respectively. Adjusted for age at baseline, packyears of smoking and BMI, the asphalt pavers had a significant excess annual decline in FVC and FEV 1 compared to the references. The screedmen, the most exposed group of the asphalt pavers, showed a significantly larger decline in FVC than the other asphalt pavers (P = 0.029). Fine intralobular fibrosis without evident cysts was identified with HRCT in three subjects (4 %). We conclude that our findings may indicate an excess annual decline in FVC and FEV 1 related to exposure to asphalt fumes. The screedmen, who carry out their work behind and close to the paving machine, had the largest decline in lung function. The finding of adverse pulmonary effects in asphalt pavers calls for better technological solutions to prevent exposure.

Characterization and Modeling of Asphalt Binder Fatigue

NASA Astrophysics Data System (ADS)

Safaei, Farinaz

Fatigue cracking is a primary distress in asphalt pavements caused by the accumulation of damage under repeated traffic loading. Many factors influence fatigue damage in pavements, including pavement structure, environmental conditions, and asphalt mixture volumetric properties. 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. A comprehensive understanding and prediction of asphalt binder fatigue performance require a suitable experiment coupled with a model to predict how the binder will perform under various traffic, temperature, and structural conditions encountered in the field. 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. Although the literature shows promise for applying VECD modeling to asphalt binder fatigue, the past efforts have several shortcomings. It has been demonstrated that flow and adhesion loss can impede DSR fatigue test results. Thus, definition of test conditions (e.g., temperature) where cyclic DSR tests are appropriate for fatigue characterization of binders is necessary. In addition, the applicability of the model to predict fatigue performance under varying loading and thermal history has not been rigorously evaluated. Furthermore, the effects of material nonlinearity have been largely neglected in past modeling efforts for simplicity. In addition, past efforts have employed the parallel plate DSR geometry for the fatigue characterization of asphalt binders. In the parallel plate geometry, the strain depends on the radial distance from the specimen center. Therefore, the material will fail at different rates as a function of

Detection of asphalt pavement cracks using remote sensing techniques

NASA Astrophysics Data System (ADS)

Mettas, Christodoulos; Agapiou, Athos; Themistocleous, Kyriacos; Neocleous, Kyriacos; Hadjimitsis, Diofantos G.

2016-10-01

Deterioration of asphalt road pavements is inevitable throughout its life cycle. There are several types of deterioration that take place on these surfaces, like surface defects and deformations. One of the most common asphalt defects is cracking. Fatigue, transverse, longitudinal, reflective, edge, block and slippage are types of cracking that can be observed anywhere in the world. Monitoring and preventative/periodic maintenance of these types of wears are two very important actions that have to take place to avoid "costly" solutions. This paper aims to introduce the spectral characteristics of uncracked (healthy) and cracked asphalt surfaces which can give a new asphalt crack index. This is performed through remote sensing applications in the area of asphalt pavements. Multispectral images can be elaborated using the index to enhance crack marks on asphalt surfaces. Ground spectral signatures were acquired from both uncracked and cracked asphalted areas of Cyprus (Limassol). Evaluation separability indices can be used to identify the optimum wavelength regions that can distinguish better the uncracked and cracked asphalt surfaces. The results revealed that the spectral sensitivity for the enhancement of cracked asphalt was detected using the Euclidean, Mahalanobis and Cosine Distance Indices in the Vis range (approximately at 450 nm) and in the SWIR 1 range (approximately at 1750 nm).

Exposure to ultrafine particles in asphalt work.

PubMed

Elihn, Karine; Ulvestad, Bente; Hetland, Siri; Wallen, Anna; Randem, Britt Grethe

2008-12-01

An epidemiologic study has demonstrated that asphalt workers show increased loss of lung function and an increase of biomarkers of inflammation over the asphalt paving season. The aim of this study was to investigate which possible agent(s) causes the inflammatory reaction, with emphasis on ultrafine particles. The workers' exposure to total dust, polycyclic aromatic hydrocarbons, and NO(2) was determined by personal sampling. Exposure to ultrafine particles was measured by means of particle counters and scanning mobility particle sizer mounted on a van following the paving machine. The fractions of organic and elemental carbon were determined. Asphalt paving workers were exposed to ultrafine particles with medium concentration of about 3.4 x 10(4)/cm(3). Ultrafine particles at the paving site originated mainly from asphalt paving activities and traffic exhaust; most seemed to originate from asphalt fumes. Oil mist exceeded occupational limits on some occasions. Diesel particulate matter was measured as elemental carbon, which was low, around 3 microg/m(3). NO(2) and total dust did not exceed limits. Asphalt pavers were exposed to relatively high concentrations of ultrafine particles throughout their working day, with possible adverse health effects.

Characterization of asphalt drainage course layers.

DOT National Transportation Integrated Search

2010-08-01

Asphalt Drainage Courses (ADCs) have generally been required under all four-lane flexible : pavements in Mississippi. Asphalt drainage courses are designed in Mississippi using No. 57 limestone, : sandstone or granite combined with 2.5 percent asphal...

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

Evaluation of warm mix asphalt for Alaska conditions : [summary].

DOT National Transportation Integrated Search

2010-09-01

This project developed and tested protocols to determine concrete curing strength during the construction process, so that : building under very cold conditions can be performed safely and quickly. Researchers determined the laboratory strengthmaturi...

Evaluation of warm mix asphalt technology in flexible pavements.

DOT National Transportation Integrated Search

2009-09-01

The primary goal of this research project is to quantify the performance of field produced and placed mixtures that utilize WMA technology and develop a framework for design, construction, and implementation of this technology in Louisiana. This rese...

Evaluation of the combined effects of reclaimed asphalt pavement (RAP), reclaimed asphalt shingles (RAS), and different virgin binder sources on the performance of blended binders for mixes with higher percentages of RAP and RAS : a research report from t

DOT National Transportation Integrated Search

2015-11-01

This report summarizes the main findings from a project funded by the National Center for : Sustainable Transportation (NCST) to investigate the use of higher percentages of reclaimed : asphalt pavement (RAP) and reclaimed asphalt shingles (RAS) as a...

Evaluation of the combined effects of reclaimed asphalt pavement (RAP), reclaimed asphalt shingles (RAS), and different virgin binder sources on the performance of blended binders for mixes with higher percentages of RAP and RAS : a national center for su

DOT National Transportation Integrated Search

2015-11-01

This report summarizes the main findings from a project funded by the National Center for : Sustainable Transportation (NCST) to investigate the use of higher percentages of reclaimed : asphalt pavement (RAP) and reclaimed asphalt shingles (RAS) as a...

Installation report : evaluation of asphalt additives.

DOT National Transportation Integrated Search

1987-01-01

Five asphalt additives that are supposed to improve the stability and flexibility characteristics of asphalt concrete were installed in pavement test sections on Route 58 in Halifax County. Polymers, latex rubbers, and a diatomaceous deposit were use...

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

NASA Astrophysics Data System (ADS)

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

2017-09-01

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

Thermal behavior of crumb-rubber modified asphalt concrete mixtures

NASA Astrophysics Data System (ADS)

Epps, Amy Louise

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

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...

Best practices for the design, evaluation and quality control of high percentage RAP mixes.

DOT National Transportation Integrated Search

2015-12-01

Placing reclaimed asphalt pavement (RAP) back on the roadway is a common and popular technique in the paving industry. There are always challenges associated with this type of recycling, especially when the RAP content in the newly paved asphalt mix ...

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

0-6674 : improving fracture resistance measurement in asphalt binder specification with verification on asphalt mixture cracking performance.

DOT National Transportation Integrated Search

2014-08-01

The current performance grading (PG) specification for asphalt binders is based primarily on the study of unmodified asphalt binders. Over the years, experience has proven that the PG grading system, while good for ensuring overall quality, fails in ...

Development of quality standards for inclusion of high recycled asphalt pavement content in asphalt mixtures - phase II.

DOT National Transportation Integrated Search

2015-03-01

To conserve natural resources and energy, the amount of recycled asphalt pavement has been steadily increasing in the construction : of asphalt pavements. The objective of this study is to develop quality standards for inclusion of high RAP content. ...

Asphalt-Rubber SAMI (Stress-Absorbing Membrane Interlayers) Field Evaluation.

DTIC Science & Technology

1986-04-01

revealed that there was promise in using the material as an interlayer to prevent the reflection of cracks from an old pavement to a new asphalt -concrete...reflection cracking , and (2) that asphalt - rubber interlayers should be investigated in conjunction with conventional asphalt -concrete overlays. An... Asphalt -rubber samples were taken and tested and construction activities were documented. The performance has been monitored by conducting crack

7 CFR 3201.76 - Asphalt and tar removers.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 15 2014-01-01 2014-01-01 false Asphalt and tar removers. 3201.76 Section 3201.76... Designated Items § 3201.76 Asphalt and tar removers. (a) Definition. Cleaning agents designed to remove asphalt or tar from equipment, roads, or other surfaces. (b) Minimum biobased content. The Federal...

7 CFR 3201.76 - Asphalt and tar removers.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 15 2013-01-01 2013-01-01 false Asphalt and tar removers. 3201.76 Section 3201.76... Designated Items § 3201.76 Asphalt and tar removers. (a) Definition. Cleaning agents designed to remove asphalt or tar from equipment, roads, or other surfaces. (b) Minimum biobased content. The Federal...

[PAH exposure in asphalt workers].

PubMed

Garattini, Siria; Sarnico, Michela; Benvenuti, Alessandra; Barbieri, P G

2010-01-01

There has been interest in evaluating the potential carcinogenicity of bitumen fumes in asphalt workers since the 1960's. The IARC classified air-refined bitumens as possible human carcinogens, while coal-tar fumes were classified as known carcinogens. Occupational/environmental PAH exposure can be measured by several urinary markers. Urinary 1-OHP has become the most commonly used biological marker of PAH exposure in asphalt workers. The aim of this study was to assess asphalt workers' exposure levels by monitoring 1-OHP urinary excretion and compare this data with those of non-occupationally exposed subjects. We investigated three groups of asphalt workers: 100 in summer 2007, 29 in winter 2007, and 148 during summer 2008 and compared 1-OHP urinary concentrations using Kruskall-Wallis test. Median 1-OHP urinary concentrations during the three biomonitoring sampling periods were 0.65, 0.17 and 0.53 microg/g creatinine respectively. There was a significant difference in 1-OHP values between the three groups (p < 0.001). our study showed that PAH exposure of asphalt workers' is higher than that observed in the general population and in workers in urban areas. Our results suggest that PAH exposure in the three groups studied is not sufficiently kept under control by the use of personal protective equipment and that biomonitoring is useful in evaluating PAH exposure and for risk assessment. Regulations need to be enforced for workers exposed to cancer risk, such as the register of workers exposed to carcinogens.

Modelling of Asphalt Concrete Stiffness in the Linear Viscoelastic Region

NASA Astrophysics Data System (ADS)

Mazurek, Grzegorz; Iwański, Marek

2017-10-01

Stiffness modulus is a fundamental parameter used in the modelling of the viscoelastic behaviour of bituminous mixtures. On the basis of the master curve in the linear viscoelasticity range, the mechanical properties of asphalt concrete at different loading times and temperatures can be predicted. This paper discusses the construction of master curves under rheological mathematical models i.e. the sigmoidal function model (MEPDG), the fractional model, and Bahia and co-workers’ model in comparison to the results from mechanistic rheological models i.e. the generalized Huet-Sayegh model, the generalized Maxwell model and the Burgers model. For the purposes of this analysis, the reference asphalt concrete mix (denoted as AC16W) intended for the binder coarse layer and for traffic category KR3 (5×105 asphalt concrete under steady-state strain was performed using the simple axial compression-tensile test under controlled strain mode. The fixed strain level was set at 25με to guarantee that the stiffness modulus of the asphalt concrete would be tested in a linear viscoelasticity range. The master curve was formed using the time-temperature superposition principle (TTSP). The stiffness modulus of asphalt concrete was determined at temperatures 10°C, 20°C and 40°C and at loading times (frequency) of 0.1, 0.3, 1, 3, 10, 20 Hz. The model parameters were fitted to the rheological models using the original programs based on the nonlinear least squares sum method. All the rheological models under analysis were found to be capable of predicting changes in the stiffness modulus of the reference asphalt concrete to satisfactory accuracy. In the cases of the fractional model and the generalized Maxwell model, their accuracy depends on a number of elements in series. The best fit was registered for Bahia and co-workers model, generalized Maxwell model and fractional model. As for predicting the

Observation of asphalt binder microstructure with ESEM.

PubMed

Mikhailenko, P; Kadhim, H; Baaj, H; Tighe, S

2017-09-01

The observation of asphalt binder with the environmental scanning electron microscope (ESEM) has shown the potential to observe asphalt binder microstructure and its evolution with binder aging. A procedure for the induction and identification of the microstructure in asphalt binder was established in this study and included sample preparation and observation parameters. A suitable heat-sampling asphalt binder sample preparation method was determined for the test and several stainless steel and Teflon sample moulds developed, finding that stainless steel was the preferable material. The magnification and ESEM settings conducive to observing the 3D microstructure were determined through a number of observations to be 1000×, although other magnifications could be considered. Both straight run binder (PG 58-28) and an air blown oxidised binder were analysed; their structures being compared for their relative size, abundance and other characteristics, showing a clear evolution in the fibril microstructure. The microstructure took longer to appear for the oxidised binder. It was confirmed that the fibril microstructure corresponded to actual characteristics in the asphalt binder. Additionally, a 'bee' micelle structure was found as a transitional structure in ESEM observation. The test methods in this study will be used for more comprehensive analysis of asphalt binder microstructure. © 2017 The Authors Journal of Microscopy © 2017 Royal Microscopical Society.

Best practices for full-depth reclamation using asphalt emulsions.

DOT National Transportation Integrated Search

2015-07-01

Full depth reclamation of asphalt pavements using asphalt emulsions (AEFDR) is a process that recycles and rejuvenates the existing : asphalt pavement surface, base, and, sometimes, the subgrade, providing an improved underlying structure for the new...

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...

Asphalt rheology and strengthening through polymer binders : final report.

DOT National Transportation Integrated Search

2016-11-01

This term paper investigates the influences of polymer modifications to asphalt rheology as compared to : conventional asphalt pavement sections. The addition of 2% to 3% of polymers into the wearing and base courses : of asphalt (flexible) pavements...

EVALUATION OF EMISSIONS FROM PAVING ASPHALTS

EPA Science Inventory

The report provides data from pilot-scale measurements of the emissions of specific air pollutants from paving asphalt both with and without recycled crumb rubber additives. The methods used in this work measured emissions from a static layer of asphalt maintained for several hou...

Influence of DAD-TA temperature-reducing additive on physical and mechanical properties of bitumen and compaction of asphalt concrete.

NASA Astrophysics Data System (ADS)

Yadykina, V. V.; Akimov, A. E.; Trautvain, A. I.; Kholopov, V. S.

2018-03-01

The paper is devoted to the use of DAD-TA temperature-reducing additive for the preparation and pouring of asphalt concrete mixes at reduced temperatures. It also shows positive influence of the modified bitumen on the efficiency of organo-mineral composite compaction at reduced temperatures. Physical and mechanical properties of asphalt concrete with the use of bitumen modified by DAD-TA additive including indicators characterizing road surfacing life are presented. Arguments to use this material from the point of view of its production technology and environmental impact are given.

Five years of phenology observations from a mixed-grass prairie exposed to warming and elevated CO2.

PubMed

Reyes-Fox, Melissa; Steltzer, Heidi; LeCain, Daniel R; McMaster, Gregory S

2016-10-11

Atmospheric CO 2 concentrations have been steadily increasing since the Industrial Era and contribute to concurrent increases in global temperatures. Many observational studies suggest climate warming alone contributes to a longer growing season. To determine the relative effect of warming on plant phenology, we investigated the individual and joint effects of warming and CO 2 enrichment on a mixed-grass prairie plant community by following the development of six common grassland species and recording four major life history events. Our data support that, in a semi-arid system, while warming advances leaf emergence and flower production, it also expedites seed maturation and senescence at the species level. However, the additive effect can be an overall lengthening of the growing and reproductive seasons since CO 2 enrichment, particularly when combined with warming, contributed to a longer growing season by delaying plant maturation and senescence. Fostering synthesis across multiple phenology datasets and identifying key factors affecting plant phenology will be vital for understanding regional plant community responses to climate change.

Five years of phenology observations from a mixed-grass prairie exposed to warming and elevated CO2

PubMed Central

Reyes-Fox, Melissa; Steltzer, Heidi; LeCain, Daniel R.; McMaster, Gregory S.

2016-01-01

Atmospheric CO2 concentrations have been steadily increasing since the Industrial Era and contribute to concurrent increases in global temperatures. Many observational studies suggest climate warming alone contributes to a longer growing season. To determine the relative effect of warming on plant phenology, we investigated the individual and joint effects of warming and CO2 enrichment on a mixed-grass prairie plant community by following the development of six common grassland species and recording four major life history events. Our data support that, in a semi-arid system, while warming advances leaf emergence and flower production, it also expedites seed maturation and senescence at the species level. However, the additive effect can be an overall lengthening of the growing and reproductive seasons since CO2 enrichment, particularly when combined with warming, contributed to a longer growing season by delaying plant maturation and senescence. Fostering synthesis across multiple phenology datasets and identifying key factors affecting plant phenology will be vital for understanding regional plant community responses to climate change. PMID:27727235

Practical experiences with new types of highly modified asphalt binders

NASA Astrophysics Data System (ADS)

Špaček, Petr; Hegr, Zdeněk; Beneš, Jan

2017-09-01

As a result of steadily increasing traffic load on the roads in the Czech Republic, we should be focused on the innovative technical solutions, which will lead to extending the life time of asphalt pavements. One of these ways could be the future use of bitumen with a higher degree of polymer modification. This paper discusses experience with comparison of new highly polymer modified asphalt binder type with conventional polymer modified asphalt binder and unmodified binder with penetration grade 50/70. There are compared the results of various types laboratory tests of asphalt binders, as well as the results of asphalt mixtures laboratory tests. The paper also mentions the experience with workability and compactability of asphalt mixture with highly polymer modified asphalt binder during the realization of the experimental reference road section by the Skanska company in the Czech Republic.

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...

Respiratory symptoms and airflow limitation in asphalt workers

PubMed Central

Randem, B; Ulvestad, B; Burstyn, I; Kongerud, J

2004-01-01

Aims: To assess the occurrence of respiratory symptoms and signs of airflow limitations in a group of asphalt workers. Methods: All 64 asphalt workers and a reference group of 195 outdoor construction workers from the same company participated in a cross-sectional study. Spirometric tests and a questionnaire on respiratory symptoms and smoking habits were administered. Respiratory symptoms and lung function were adjusted for age and smoking. Results: The FEV1/FVC% ratio was significantly lower in the asphalt workers than in the referents. Symptoms of eye irritation, chest tightness, shortness of breath on exertion, chest wheezing, physician diagnosed asthma, and chronic obstructive pulmonary disease (COPD) were all significantly more prevalent among the asphalt workers. Conclusion: In asphalt workers there is an increased risk of respiratory symptoms, lung function decline, and COPD compared to other construction workers. PMID:15031397

Field Control and Performance of Asphalt Mixtures Containing Greater than 25 Percent Reclaimed Asphalt Pavement : Draft Final Report

DOT National Transportation Integrated Search

2018-02-02

The Alabama Department of Transportation (ALDOT) and other highway agencies are interested in utilization of higher percentages of reclaimed asphalt pavement (RAP) in asphalt mixtures. There are a number of research studies at both state and national...

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.

Rutting and fatigue properties of plant mixes from AE stone.

DOT National Transportation Integrated Search

2006-06-01

Loose mix from A.E. Stone, Inc. in Egg Harbor Township, NJ was supplied to the : Rutgers Asphalt Pavement Laboratory (RAPL) for evaluation. Three different plant : mixes were supplied for permanent deformation (rutting) and flexural fatigue testing; ...

A report on Virginia specifications for penetration asphalt cements.

DOT National Transportation Integrated Search

1970-01-01

Asphaltic pavements in Virginia had shown cracks in the surface layers only, and this had led to the belief that the durability properties of the asphalt had not been what they should have been and that the asphalt specifications needed to be revised...

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

Warm Homes, Healthy People Fund 2011/12: a mixed methods evaluation.

PubMed

Madden, V; Carmichael, C; Petrokofsky, C; Murray, V

2014-03-01

To assess how the Warm Homes Healthy People Fund 2011/12 was used by English local authorities and their partners to tackle excess winter mortality. Mixed-methods evaluation. Three sources of data were used: an online survey to local authority leads, document analysis of local evaluation reports and telephone interviews of local leads. These were analysed to provide numerical estimates, key themes and case studies. There was universal approval of the fund, with all survey respondents requesting the fund to continue. An estimated 130,000 to 200,000 people in England (62% of them elderly) received a wide range of interventions, including structural interventions (such as loft insulation), provision of warm goods and income maximization. Raising awareness was another component, with all survey respondents launching a local media campaign. Strong local partnerships helped to facilitate the implementation of projects. The speed of delivery may have resulted in less strategic targeting of the most vulnerable residents. The Fund was popular and achieved much in winter 2011/2012, although its impact on cold-related morbidity and mortality is unknown. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

Microbial Diversity in Natural Asphalts of the Rancho La Brea Tar Pits▿

PubMed Central

Kim, Jong-Shik; Crowley, David E.

2007-01-01

Bacteria commonly inhabit subsurface oil reservoirs, but almost nothing is known yet about microorganisms that live in naturally occurring terrestrial oil seeps and natural asphalts that are comprised of highly recalcitrant petroleum hydrocarbons. Here we report the first survey of microbial diversity in ca. 28,000-year-old samples of natural asphalts from the Rancho La Brea Tar Pits in Los Angeles, CA. Microbiological studies included analyses of 16S rRNA gene sequences and DNA encoding aromatic ring-hydroxylating dioxygenases from two tar pits differing in chemical composition. Our results revealed a wide range of phylogenetic groups within the Archaea and Bacteria domains, in which individual taxonomic clusters were comprised of sets of closely related species within novel genera and families. Fluorescent staining of asphalt-soil particles using phylogenetic probes for Archaea, Bacteria, and Pseudomonas showed coexistence of mixed microbial communities at high cell densities. Genes encoding dioxygenases included three novel clusters of enzymes. The discovery of life in the tar pits provides an avenue for further studies of the evolution of enzymes and catabolic pathways for bacteria that have been exposed to complex hydrocarbons for millennia. These bacteria also should have application for industrial microbiology and bioremediation. PMID:17416692

Controlling conductivity of asphalt concrete with graphite.

DOT National Transportation Integrated Search

2014-08-01

Electrically conductive asphalt concrete has a huge potential for various multifunctional applications such as : self-healing, self-sensing, and deicing. In order to utilize the full spectrum of applications of electrically conductive : asphalt compo...

Quantitative exposure matrix for asphalt fume, total particulate matter, and respirable crystalline silica among roofing and asphalt manufacturing workers.

PubMed

Fayerweather, William E; Trumbore, David C; Johnson, Kathleen A; Niebo, Ronald W; Maxim, L Daniel

2011-09-01

This paper summarizes available data on worker exposures to asphalt fume (soluble fraction), total particulate matter, and respirable crystalline silica (quartz) [hereinafter RCS] over a 30-year period in Owens Corning's asphalt production and roofing manufacturing plants. For the period 1977 through 2006, the air-monitoring database contains more than 1,400 personal samples for asphalt fume (soluble fraction), 2,400 personal samples for total particulate, and 1,300 personal samples for RCS. Unique process-job categories were identified for the asphalt production and roofing shingle manufacturing plants. Quantitative exposures were tabulated by agent, process-job, and calendar period to form an exposure matrix for use in subsequent epidemiologic studies of the respiratory health of these workers. Analysis of time trends in exposure data shows substantial and statistically significant exposure reductions for asphalt fume (soluble fraction), total particulate matter, and respirable crystalline silica at Owens Corning plants. Cumulative distribution plots for the most recent sampling period (2001-2006) show that 95% of the asphalt fume (soluble fraction) measurements were less than 0.25 mg/m3; 95% of the total particulate measurements were less than 2.2 mg/m3; and 95% of the RCS measurements were less than 0.05 mg/m3. Several recommendations are offered to improve the design of future monitoring efforts.

40 CFR 443.10 - Applicability; description of the asphalt emulsion subcategory.

Code of Federal Regulations, 2014 CFR

2014-07-01

... asphalt emulsion subcategory. 443.10 Section 443.10 Protection of Environment ENVIRONMENTAL PROTECTION... ROOFING MATERIALS (TARS AND ASPHALT) POINT SOURCE CATEGORY Asphalt Emulsion Subcategory § 443.10 Applicability; description of the asphalt emulsion subcategory. The provisions of this subpart are applicable to...

40 CFR 443.10 - Applicability; description of the asphalt emulsion subcategory.

Code of Federal Regulations, 2010 CFR

2010-07-01

... asphalt emulsion subcategory. 443.10 Section 443.10 Protection of Environment ENVIRONMENTAL PROTECTION... MATERIALS (TARS AND ASPHALT) POINT SOURCE CATEGORY Asphalt Emulsion Subcategory § 443.10 Applicability; description of the asphalt emulsion subcategory. The provisions of this subpart are applicable to discharges...

40 CFR 443.10 - Applicability; description of the asphalt emulsion subcategory.

Code of Federal Regulations, 2011 CFR

2011-07-01

... asphalt emulsion subcategory. 443.10 Section 443.10 Protection of Environment ENVIRONMENTAL PROTECTION... MATERIALS (TARS AND ASPHALT) POINT SOURCE CATEGORY Asphalt Emulsion Subcategory § 443.10 Applicability; description of the asphalt emulsion subcategory. The provisions of this subpart are applicable to discharges...

40 CFR 443.10 - Applicability; description of the asphalt emulsion subcategory.

Code of Federal Regulations, 2012 CFR

2012-07-01

... asphalt emulsion subcategory. 443.10 Section 443.10 Protection of Environment ENVIRONMENTAL PROTECTION... ROOFING MATERIALS (TARS AND ASPHALT) POINT SOURCE CATEGORY Asphalt Emulsion Subcategory § 443.10 Applicability; description of the asphalt emulsion subcategory. The provisions of this subpart are applicable to...