Download or read book Evaluation of Warm Mix Asphalt Technologies with Respect to Binder Aging and Emissions written by Faramarz Farshidi and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In recent years Warm Mix Asphalt (WMA) technologies have been used to modify asphalt binders, with the following objectives: to decrease production and construction temperatures, reduce fumes and emissions, increase haul distance, and improve the workability of the mix. Reduced temperatures at the plant and during laydown and compaction are hypothesized to positively impact long-term oxidative aging behavior due to less oxidation/aging and result in less emissions during production and construction due to reduced production and construction temperatures. The purpose of this investigation was to quantify these improvements with respect to long-term oxidative aging in the field and environmental benefits with respect to volatile organic compounds, semi-volatile organic compounds and poly cyclic aromatic hydrocarbons in order to confirm or deny this hypothesis. This research evaluated the potential durability of WMA and Rubberized Warm Mix Asphalt (R-WMA) binders with respect to long-term aging through characterization of field-aged binders extracted and recovered from field cores. The results were compared to the control conventional Hot Mix Asphalt (HMA) and Rubberized Hot Mix Asphalt (R-HMA) samples. Binders were extracted and recovered from thirteen different test sections and a total of seven different WMA technologies were evaluated in this study. The Dynamic Shear Rheometer (DSR) was used to evaluate the rheological properties of the binders at high temperatures with respect to rutting performance in the field. The Bending Beam Rheometer (BBR) was used to characterize low temperature properties of the binder samples. A new testing procedure was developed to measure and characterize the rheological properties of the R-HMA and R-WMA binders with respect to performance-related properties in the field. The rheological results indicated that depending on the WMA technology used, the addition of WMA technologies and reduced production and compaction temperatures result in increase or decrease rutting resistance performance for WMA and R-WMA binders with respect to permanent deformation at high temperatures in the field. Both WMA and R-WMA binders studied meet the established thermal cracking criteria with respect to low temperature cracking in the field. The aging kinetics curves for WMA-treated binders are parallel to the control binders and the addition of WMA technologies including organic, chemical and mechanical foaming technologies studied in this research did not result in a different aging kinetics trend with respect to long-term aging in the field. A portable "flux" chamber was designed and fabricated to capture and directly measure emissions during paving operations. Emissions were collected in activated charcoal sorbent tubes for characterizing volatile organic compounds and semi-volatile organic compounds. XAD-2 resin tubes and filters were used to capture the gaseous phase and particulate phase of the PAH compounds, respectively. A reliable analytical method was developed to identify and quantify alkane emissions using gas chromatography mass spectrometry (GC/MS) in the laboratory. A separate method was developed for identification and characterization of trace level PAH compounds of the asphalt fumes. The results demonstrated that the warm mix asphalt technology type, plant mixing temperature and level of compaction significantly influence the emission characteristics throughout paving operations. Moreover, the emissions kinetics indicated that the majority of the reactive organic gases are volatilized in the first hour after sampling initiation (immediately after production and before compaction). To better understand and identify any chemical composition changes of the binder due to WMA technologies, nuclear magnetic resonance spectroscopy (NMR) was used for understanding structural complexities of HMA and WMA binder molecules. Qualitative analysis of both carbon and hydrogen atoms with HMA and WMA binders showed that the molecular structures of the binders are not significantly changed by the effect of WMA technologies.

Download or read book Mix Design Practices for Warm Mix Asphalt written by Ramon Francis Bonaquist and published by Transportation Research Board. This book was released on 2011 with total page 111 pages. Available in PDF, EPUB and Kindle. Book excerpt: TRB's National Cooperative Highway Research Program (NCHRP) Report 691: Mix Design Practices for Warm-Mix Asphalt explores a mix design method tailored to the unique material properties of warm mix asphalt technologies. Warm mix asphalt (WMA) refers to asphalt concrete mixtures that are produced at temperatures approximately 50°F (28°C) or more cooler than typically used in the production of hot mix asphalt (HMA). The goal of WMA is to produce mixtures with similar strength, durability, and performance characteristics as HMA using substantially reduced production temperatures. There are important environmental and health benefits associated with reduced production temperatures including lower greenhouse gas emissions, lower fuel consumption, and reduced exposure of workers to asphalt fumes. Lower production temperatures can also potentially improve pavement performance by reducing binder aging, providing added time for mixture compaction, and allowing improved compaction during cold weather paving. Appendices to NCHRP Report 691 include the following. Appendices A, B, and D are included in the printed and PDF version of the report. Appendices C and E are available only online.

Download or read book Warm mix Asphalt Study written by Frank Farshidi and published by . This book was released on 2013 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Performance Assessment of Warm Mix Asphalt WMA Pavements written by and published by . This book was released on 2009 with total page 138 pages. Available in PDF, EPUB and Kindle. Book excerpt: Warm Mix Asphalt (WMA) is a new technology that was introduced in Europe in 1995. WMA offers several advantages over conventional asphalt concrete mixtures, including: reduced energy consumption, reduced emissions, improved or more uniform binder coating of aggregate which should reduce mix surface aging, and extended construction season in temperate climates. Three WMA techniques, Aspha-min, Sasobit, and Evotherm, were used to reduce the viscosity of the asphalt binder at certain temperatures and to dry and fully coat the aggregates at a lower production temperature than conventional hot mix asphalt. The reduction in mixing and compaction temperatures of asphalt mixtures leads to a reduction in both fuel consumption and emissions. This research project had two major components, the outdoor field study on SR541 in Guernsey County and the indoor study in the Accelerated Pavement Load Facility (APLF). Each study included the application of four types of asphalt surface layer, including standard hot mix asphalt as a control and three warm mixes: Evotherm, Aspha-min, and Sasobit. The outdoor study began with testing of the preexisting pavement and subgrade, the results of which indicated that while the pavement and subgrade were not uniform, there were no significant problems or variations that would be expected to lead to differences in performance of the planned test sections. During construction, the outdoor study included collection of emissions samples at the plant and on the construction site as well as thermal readings from the site. Afterwards, the outdoor study included the periodic collection and laboratory analysis of core samples and visual inspections of the road. Roughness (IRI) measurements were made shortly after construction and after a year of service. The indoor study involved the construction of four lanes of perpetual pavement, each topped with one of the test mixes. The lanes were further divided into northern and southern halves, with the northern halves having a full 16 in (40 cm) perpetual pavement, and with the southern halves with thicknesses decreasing in one in (2.5 cm) increments by reducing the intermediate layer. The dense graded aggregate base was increased to compensate for the change in pavement thickness. The southern half of each lane was instrumented to measure temperature, subgrade pressure, deflection relative to top of subgrade and to a point 5 ft (1.5 m) down, and longitudinal and transverse strains at the base of the fatigue resistance layer (FRL). The APLF had the temperature set to 40°F (4.4°C), 70°F (21.1°C), and 104°F (40°C), in that order. At each temperature, rolling wheel loads of 6000 lb (26.7 kN), 9000 lb (40 kN), and 12,000 lb (53.4 kN) were applied at lateral shifts of 3 in (76 mm), 1 in (25 mm), -4 in ( -102 mm), and -9 in ( - 229 mm) and the response measured. Then each plane was subjected to 10,000 passes of the rolling wheel load of 9000 lb (40 kN) at about 5 mph (8 km/h). Profiles were measured after 100, 300, 1000, 3000, and 10,000 passes with a profilometer to assess consolidation of each surface. After the 10,000 passes of the rolling wheel load were completed, a second set of measurements was made under rolling wheel loads of 6000 lb (26.7 kN), 9000 lb (40 kN), and 12,000 lb (53.4 kN) at the same lateral shifts as before. Additionally, the response of the pavement instrumentation was recorded during drops of a Falling Weight Deflectometer (FWD).

Download or read book Laboratory Evaluation of Warm Mix Asphalt Influence on Theoretical Maximum Specific Gravity written by Jianhua Yu and published by . This book was released on 2012 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: Warm mix asphalt (WMA) technology provides sufficient workability for asphalt mixtures at reduced mixing and compaction temperatures. Depending on the WMA technology, the typical temperature reduction range is 20 °C to 55 °C below hot mix asphalt (HMA) production temperatures. WMA involves chemical and wax additives that are added to an asphalt binder or incorporated through the use of foaming technology. The main advantages of WMA are reduced emissions and a reduction in combustible fuel consumption. Ongoing WMA research projects have documented some differences between HMA and WMA mixes, prompting numerous research projects that are investigating these concerns. The purpose of this research is to evaluate the volumetric properties by directly comparing laboratory produced WMA and HMA mixes. This study investigates the impact of WMA additives on the volumetric properties, specifically, the theoretical maximum specific gravity (Gmm). The Gmm testing followed the procedure of ASTM D2041. Two mix designs with HMA binder were produced, one without recycled asphalt pavement (RAP) and the other with 30 % RAP. After the mix designs were completed, no additional changes were made to account for the addition of the WMA technology. The mixes included the WMA technologies Sasobit and Advera, as well as an HMA control, for a total of six different laboratory produced mixes. Each mix was produced at 120 °C, 135 °C, and 150 °C, and each mix was oven cured for 1, 2, and 4 h. The test results were analyzed using statistical principles to determine whether differences in the Gmm values were statistically significant. The results show that temperature has little impact on Gmm. Gmm was not affected by curing times of 1 and 2 h, but the longer curing time of 4 h resulted in a statistically significant increase in Gmm. Further analysis revealed that the mix sensitivity to curing time depends on the amount of RAP in the mix. For the mix designs studied, the Advera Gmm values were similar to the HMA values, but the Sasobit Gmm values were statistically lower than the Advera values.

Download or read book Evaluation of Warm Mix Additives for Use in Modified Asphalt Mixtures written by Corina Borroel Wong and published by . This book was released on 2011 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt: The intention of this research effort is to evaluate the use of warm mix additives with typical polymer-modified and terminal blend tire rubber asphalt mixtures from Nevada and California. The research effort is broken into three phases that are intended to evaluate the impacts of warm mix additives with typical polymer-modified and terminal blend tire rubber asphalt mixtures from Nevada and California: moisture damage, performance characteristics, and mechanistic analysis. In Phase I of this research effort, mixture resistance to moisture damage was evaluated using the indirect tensile test and the dynamic modulus at multiple freeze-thaw cycles. Laboratory testing was conducted to address the following: (1) the impact of warm mix additive and reduced production temperatures on the moisture damage resistance of asphalt mixtures, (2) the impact of residual aggregate moisture on the moisture damage resistance of WMA mixtures, (3) the impact of warm mix additives on the moisture damage resistance of anti-strip treated WMA mixtures, and (3) the impact of long-term aging on strength gain and the moisture damage resistance of WMA mixtures. A total of one aggregate source, four warm mix asphalt technologies (Advera, Sasobit, Revix and Foaming) and three asphalt binder types (neat, polymer-modified and terminal blend tire rubber modified asphalt binders) typically used in both Nevada and California are being evaluated in this study. This thesis will only summarize the test results and findings of the Phase I of the study for two warm-mix additives: Advera and Sasobit. The evaluation of the other two technologies (i.e. Revix and Foaming) as well as the Phase II testing are still in progress and have not been completed.

Download or read book Evaluation of Binder Aging and Its Influence in Aging of Hot Mix Asphalt Concrete written by Charles J. Glover and published by . This book was released on 2014 with total page 192 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Manual for Design of Hot Mix Asphalt with Commentary written by and published by Transportation Research Board. This book was released on 2011 with total page 285 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Evaluation of Binder Aging and Its Influence in Aging of Hot Mix Asphalt Concrete written by Charles J. Glover and published by . This book was released on 2014 with total page 505 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Performance Evaluation of Warm Mix Recycled Asphalt Binders After Long Term Aging written by Qiang Li and published by . This book was released on 2019 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study evaluates the pavement performance evolution of warm-mix recycled asphalt binders during the secondary service period. Warm-mix recycled asphalt binders with various long-term aging levels and recycling plans were produced by the laboratory simulation method. Conventional physical properties tests, the dynamic shear rheometer test, and the bending beam rheometer test were conducted to measure the performance of recycled binders. Effects of the aging level and recycling plan on the resistance to rutting, fatigue cracking, and low temperature cracking were investigated by statistical methods. It was found that after secondary long-term aging, recycled binders are more resistant to rutting, while they are less resistant to fatigue and low temperature cracking. The modified aging kinetic model can be used to accurately characterize the effect of secondary aging time on rutting or fatigue factors for recycled binders. The resistance of aged binders to fatigue and low temperature cracking is obviously improved by adding the warm mix asphalt additive. By comparison, using styrene butadiene rubber latex enhances the binder performance in almost all aspects. The aging level has a more significant effect than the recycling plan for all performance parameters.

Download or read book Quantifying the Impacts of Warm Mix Asphalt on Constructability and Performance written by and published by . This book was released on 2012 with total page 500 pages. Available in PDF, EPUB and Kindle. Book excerpt: Joint efforts by the federal government and HMA industry to minimize cost and the environmental impacts of asphalt pavement construction have resulted in development of warm mix asphalt (WMA). This technology has gained such interest due to the potential to deliver pavements at lower temperatures, allowing for reduced energy consumption and emissions. In order to be effective WMA must meet the specified values of in-place density at reduced temperatures during construction and demonstrate sufficient resistance to pavement distresses while in-service. The overall objective of this research was to promote effective use of WMA through development of a procedure to recommend additive specific mixing and compaction temperature ranges that will provide adequate workability during construction, and an acceptable level of in-service performance. To pursue this objective an experiment was designed to evaluate the effects of various WMA technologies on the workability and performance properties of asphalt binders and mixtures using existing standards and new test methods developed during the study. The new test methods were pursued to better define the role of asphalt binder as a lubricant during compaction and to properly account for the effects of reduced production temperatures on asphalt binder performance and potential for moisture damage. Results found that use of WMA impacts both construction and performance properties. To account for these factors an evaluation framework to select appropriate production temperatures for WMA was introduced that is based on evaluation of mixture volumetrics, compactability, resistance to moisture damage, and rutting performance. Furthermore, to facilitate the mixture design and temperature selection process surrogate test methods to evaluate workability and performance properties of the asphalt binder as well as the integrity of the bond at the asphalt/binder aggregate interface were proposed and verified through relationships with mixture performance.

Download or read book 0 6613 Evaluate Binder and Mixture Aging for Warm Mix Asphalt written by Charles J. Glover and published by . This book was released on 2013 with total page 2 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Warm mix Asphalt Study written by Frank Farshidi and published by . This book was released on 2013 with total page 58 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Evaluation of Binder Aging and Its Influence in Aging of Hot Mix Asphalt Concrete written by Charles J. Glover and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Performance Evaluation of Warm Mix Asphalt Mixtures Incorporating Reclaimed Asphalt Pavement written by Brian Hill and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Sustainability is a cornerstone of today0́9s engineering world. Warm mix asphalt (WMA) and reclaimed asphalt pavement (RAP) are the most prominent sustainable materials in asphalt concrete pavements. WMA is a not a new concept, however new innovations and increased usage of WMA has been spurred by the increased focus on sustainable infrastructure systems. WMA enables reduced production temperatures through the use of wax, water, or other chemical packages. The effects of reduced production temperatures include fuel use and emissions reductions, improved compaction, and possible RAP concentration increases. RAP is the primary recycled product of the aged asphalt concrete pavements and its use leads to reductions in virgin aggregate and asphalt demand. However, significant performance issues can stem from the individual integration of WMA or RAP materials in asphalt concrete. In particular, WMA technologies can increase moisture and rutting susceptibility while RAP significantly increases the stiffness of the resulting mixture. Consequently, quality performance of sustainable asphalt pavements may require the combined use of WMA and RAP to produce mixtures with sufficient stiffness and moisture and fracture resistance. This study evaluates the potential of WMA technologies and their integration with RAP. Initially, an extensive literature review was completed to understand the advantages, disadvantages, and past field and lab performance of WMA and RAP mixtures. Rotational viscometer and bending beam rheometer tests were then used to evaluate Sasobit, Evotherm M1, and Advera WMA modified and unmodified binders. Finally, virgin and 45% RAP mixtures were designed and tested to examine the rutting, moisture, and fracture resistance of WMA and HMA mixtures. The results of this experiment provided several key observations. First, viscosity reductions may not be the primary cause for the availability of reduced production temperatures for WMA technologies. Second, WMA additive properties have a significant effect upon fracture, moisture, and rutting resistance. Furthermore, the addition of RAP to WMA mixtures improved the rutting and moisture sensitivity performance as characterized in the Hamburg and Tensile Strength Ratio testing procedures.

Download or read book Superpave Mix Design written by Asphalt Institute and published by . This book was released on 2001-01-01 with total page 102 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Review of Warm Mix Asphalt written by Arif Chowdhury and published by . This book was released on 2008 with total page 61 pages. Available in PDF, EPUB and Kindle. Book excerpt: Warm Mix Asphalt (WMA) technology, recently developed in Europe, is gaining strong interest in the US. By lowering the viscosity of asphalt binder and/or increasing the workability of mixture using minimal heat, WMA technology allows the mixing, transporting, and paving process at significantly lower temperature. Using this new technology, asphalt mix can be produced as much as 1000 F lower than traditional hot mix asphalt (HMA). Several benefits of lower mixing and compaction temperature include: less emission, savings in energy cost, longer construction season, less odor, and construction during non-peak periods. Despite the apparent benefits, some researchers are concerned about the long-term performance of this new mixture. In last few years, dozens of field test sections have been constructed thorough out the USA using different WMA technologies. It is too early to report the performance; but so far, no negative performance has been reported in the literature. In the last few years, several large national and state level research projects have been initiated to evaluate, validate, and implement this new technology. This report documents the results of a comprehensive review of worldwide information dealing with the following issues as related to warm mix asphalt: Current state of the art/practice of WMA; cost and benefits of WMA technology; plant modifications to accommodate WMA; mixture design; durability and performance; performance related testing; quality control; specifications; and construction guidelines.