Download or read book Influence of Warm Mix Asphalt on Aging of Asphalt Binders written by Ala R. Abbas and published by . This book was released on 2014 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Influence of Aging on Foamed Warm Mix Asphalt written by Sunday Akinbowale and published by . This book was released on 2014 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Over the years, the use of warm mix in pavement structures has continued to gain increasing attention in United States because of its implicit advantages over the traditional hot mix. This has necessitated increased research efforts into understanding different aspects of its behaviour and performance. Aging of asphalt is particularly of much importance because it leads to several problems such as pavement rutting, fatigue cracking and thermal cracking. The aging that occurs during mixing and compaction is commonly referred to as short term aging while the aging that occurs during the pavement service life is called long term aging. The main reason for aging in binders is oxidation and binders become stiffer due to oxidation. Several research projects have been carried out on investigating the aging behavior of warm mix asphalt (WMA) produced by different chemical additives. But no major study has been conducted to understand the aging behavior of foamed WMA. Therefore, this study characterizes the aging behavior of foamed (WMA) as it compares to the traditional hot mix asphalt (HMA) using the Dynamic Shear Rheometer (DSR), Fourier Transforms Infrared Spectroscopy (FTIR), and Gel Permeation Chromatography (GPC) tests. Investigation of the effect of extraction and recovery with trichloroethylene on the stiffness of binders was initially carried out. In addition to preparation of mixtures, aging of binders (RTFO and PAV) and aging of mixtures (STOA and LTOA) being simulated in the laboratory using PG 70-22M and PG 64-22 binder grades, field cores were also obtained from test sections which had been in service for five years. Binders were extracted and recovered from both laboratory and field samples for subsequent physical and chemical tests. These results were analysed and used to evaluate the aging behavior of foamed WMA as it compares to HMA. It was observed that extraction and recovery procedure with trichloroethylene had minimal effect on PG 70-22M binders while it had a reductive effect on rutting and fatigue parameter values of PG 64-22 binders at different levels of aging. Both foamed WMA and HMA for PG 70-22M responded similarly to field and laboratory-simulated aging conditions. But for PG 64-22 binders, foamed WMA was found to be less susceptible to aging than the traditional HMA. Therefore, it implies that when the foamed warm mix technology is used, it may be expected to have a better performance in fatigue cracking but more susceptible to rutting or permanent deformation that takes place in pavement early years when compared to the traditional Hot Mix Asphalt.

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 Long term Aging of Asphalt Mixtures for Performance Testing and Prediction written by Y. Richard Kim and published by . This book was released on 2018 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book CIGOS 2021 Emerging Technologies and Applications for Green Infrastructure written by Cuong Ha-Minh and published by Springer Nature. This book was released on 2021-10-28 with total page 1861 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book highlights the key role of green infrastructure (GI) in providing natural and ecosystem solutions, helping alleviate many of the environmental, social, and economic problems caused by rapid urbanization. The book gathers the emerging technologies and applications in various disciplines involving geotechnics, civil engineering, and structures, which are presented in numerous high-quality papers by worldwide researchers, practitioners, policymakers, and entrepreneurs at the 6th CIGOS event, 2021. Moreover, by sharing knowledge and experiences around emerging GI technologies and policy issues, the book aims at encouraging adoption of GI technologies as well as building capacity for implementing GI practices at all scales. This book is useful for researchers and professionals in designing, building, and managing sustainable buildings and infrastructure.

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 Binder Rheology and Performance in Warm Mix Asphalt written by Zelalem Arega and published by . This book was released on 2012 with total page 39 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since the introduction of warm mix asphalt (WMA) in the United States, a variety of different technologies and processes have been developed and used to achieve proper mixing and compaction at reduced temperatures compared to conventional hot mix asphalt (HMA). A better understanding of the effect of WMA additives and reduced aging on the rheology of asphalt binders is a crucial step towards the successful implementation of WMA. This report presents the findings from a study conducted to investigate the influence of chemical WMA additives and reduced short-term aging on the properties of asphalt binders, mortars, and mixtures. This report presents the details of the test methods and findings relevant to mortars and mixtures prepared using warm mix additives.

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 Evaluation of Short Term Aging Effect of Hot Mix Asphalt Due to Elevated Temperatures and Extended Aging Time written by Rubben Lolly and published by . This book was released on 2013 with total page 97 pages. Available in PDF, EPUB and Kindle. Book excerpt: Heating of asphalt during production and construction causes the volatilization and oxidation of binders used in mixes. Volatilization and oxidation causes degradation of asphalt pavements by increasing the stiffness of the binders, increasing susceptibility to cracking and negatively affecting the functional and structural performance of the pavements. Degradation of asphalt binders by volatilization and oxidation due to high production temperature occur during early stages of pavement life and are known as Short Term Aging (STA). Elevated temperatures and increased exposure time to elevated temperatures causes increased STA of asphalt. The objective of this research was to investigate how elevated mixing temperatures and exposure time to elevated temperatures affect aging and stiffening of binders, thus influencing properties of the asphalt mixtures. The study was conducted in two stages. The first stage evaluated STA effect of asphalt binders. It involved aging two Performance Graded (PG) virgin asphalt binders, PG 76-16 and PG 64-22 at two different temperatures and durations, then measuring their viscosities. The second stage involved evaluating the effects of elevated STA temperature and time on properties of the asphalt mixtures. It involved STA of asphalt mixtures produced in the laboratory with the PG 64-22 binder at mixing temperatures elevated 25OF above standard practice; STA times at 2 and 4 hours longer than standard practices, and then compacted in a gyratory compactor. Dynamic modulus (E*) and Indirect Tensile Strength (IDT) were measured for the aged mixtures for each temperature and duration to determine the effect of different aging times and temperatures on the stiffness and fatigue properties of the aged asphalt mixtures. The binder test results showed that in all cases, there was increased viscosity. The results showed the highest increase in viscosity resulted from increased aging time. The results also indicated that PG 64-22 was more susceptible to elevated STA temperature and extended time than the PG 76-16 binders. The asphalt mixture test results confirmed the expected outcome that increasing the STA and mixing temperature by 25oF alters the stiffness of mixtures. Significant change in the dynamic modulus mostly occurred at four hour increase in STA time regardless of temperature.

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 A Comparison of Warm Asphalt Binder Aging with Laboratory Aging Procedures written by Tejash Gandhi and published by . This book was released on 2010 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: Warm asphalt has been gaining increasing popularity in recent years; however there are several characteristics about warm asphalt that are still unknown. While several studies have been conducted to study the performance of warm asphalt mixtures, aging characteristics of warm mix asphalt (WMA) binders are not known in great detail. This paper presents the results of a limited study to evaluate the aging characteristics of two WMA binders artificially aged in the rolling thin film oven (RTFO) and the pressure aging vessel and comparing them with binder extracted from freshly prepared and artificially aged warm asphalt mixtures. RTFO aging was performed at 163°C and a lower temperature to simulate warm asphalt aging. Tests on binders aged in the laboratory and binders extracted from freshly mixed and aged mixtures indicated that the WMA binders extracted from WMA mixtures had significantly lower viscosities and G*/sin ? compared to binders extracted from hot mix asphalt (HMA) and binders aged in the RTFO at 163°C (325°F). This indicates that the lower mixing and compaction temperatures reduce the aging of the warm asphalt binders. Also, binders extracted from WMA had significantly lower creep stiffness values and significantly higher m-values compared to warm asphalt binders aged in the RTFO at 163°C (325°F) and binders extracted from HMA. Binders containing WMA additives did not have higher G* sin ? values, indicating that the warm asphalt additives do not negatively affect the fatigue properties of the binders. Gel permeation chromatography analysis indicated that the addition of the warm asphalt additives did not have any significant effect on the %LMS of the binders used in this study.

Download or read book Characteristics of Asphalt Binders written by and published by . This book was released on 1996 with total page 144 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 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 Recommendations and Guidelines for the Use of WMA Mixtures written by Zelalem Arega and published by . This book was released on 2012 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: The main objective of this research study was to evaluate the influence of warm mix additives on the rheology and performance characteristics of asphalt binders with emphasis on the affects of long-term aging and use of recycled asphalt binder. In order to achieve this objective the asphalt binders were first screened based on their chemical makeup. The selected asphalt binders were combined with different warm mix asphalt additives and evaluated for their mechanical properties. Subsets of these binders were also used to evaluate the affect of long-term aging and the affect of using recycled asphalt binder on performance characteristics. Tests were also conducted using a limited number of sand-asphalt mortars and full asphalt mixtures to further corroborate the findings from the binder study.

Download or read book Effects of Additives for Warm Mix Asphalt on Performance Grades of Asphalt Binders written by Chaofan Wu and published by . This book was released on 2012 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: Laboratory tests were carried out on a neat asphalt binder and a styrene-butadiene-styrene (SBS) asphalt binder containing Sasobit and Aspha-min as warm mix asphalt (WMA) additives to quantitatively evaluate the effects of the additives on the continuous grading temperatures and grades of asphalt binders in the framework of the performance grading system. Test results and data analyses indicate that the significances of the effects of WMA additives depend on the asphalt binder type, additive type, additive content, and rolling thin film oven (RTFO) aging temperature. The wax-type additive Sasobit has a stiffening effect on the grading temperatures. At typical 3 % content, the upper temperatures can be increased by up to 13.5 °C, the lower temperatures can be increased by up to 6.9 °C, and the intermediate temperatures can be increased by up to 5.0 °C. In the commonly used content range, the zeolite-type additive Aspha-min has little effects on the upper, lower, and intermediate grading temperatures. Although there is a special case, in which the upper grading temperature increase is canceled out by 3.8 °C, the reduction in RTFO aging temperature from 163 °C to 133 °C does not generally result in notable changes in the grading temperatures.

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.