Download or read book Foamed Warm Mix Asphalt Design Issues written by Goad Williams and published by . This book was released on 2015 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Evaluation of Foamed Warm Mix Asphalt WMA for Mix Design and Quality Control Testing in Oklahoma written by Martha Elena Castellon Inestroza and published by . This book was released on 2013 with total page 45 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Special Mixture Design Considerations and Methods for Warm Mix Asphalt written by and published by Transportation Research Board. This book was released on 2012 with total page 53 pages. Available in PDF, EPUB and Kindle. Book excerpt: TRB's National Cooperative Highway Research Program (NCHRP) Report 714: Special Mixture Design Considerations and Methods for Warm-Mix Asphalt: A Supplement to NCHRP Report 673: A Manual for Design of Hot-Mix Asphalt with Commentary presents special mixture design considerations and methods used with warm-mix asphalt. NCHRP Report 714 is a supplement to NCHRP Report 673: A Manual for Design of Hot-Mix Asphalt. All references to chapters in NCHRP Report 714 refer to the corresponding chapters in NCHRP Report 673.
Download or read book Properties of Foamed Asphalt for Warm Mix Asphalt Applications written by David E. Newcomb and published by . This book was released on 2015 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt: "TRB's National Cooperative Highway Research Program (NCHRP) Report 807: Properties of Foamed Asphalt for Warm Mix Asphalt Applications presents methods for measuring the performance-related properties of foamed asphalts and designing foamed asphalt mixes with satisfactory aggregate coating and workability." --
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 Performance Evaluation of Foamed Warm Mix Asphalt Produced by Water Injection written by Ayman Ali and published by . This book was released on 2013 with total page 201 pages. Available in PDF, EPUB and Kindle. Book excerpt: In recent years, a new group of technologies has been introduced in the United States that allow producing asphalt mixtures at temperatures 30 to 100oF lower than what is used in traditional hot mix asphalt (HMA). These technologies are commonly referred to as Warm Mix Asphalt (WMA). From among these technologies, foamed WMA produced by water injection has gained increased attention from the asphalt paving industry in Ohio since it does not require the use of costly additives. This type of asphalt mixtures is advertised as an environmentally friendly alternative to traditional HMA and promoted to have better workability and compactability. In spite of these advantages, several concerns have been raised regarding the performance of foamed WMA because of the reduced production temperature and its impact on aggregate drying and asphalt binder aging. Main concerns include increased propensity for moisture-induced damage (durability) and increased susceptibility to permanent deformation (rutting). Other concerns include insufficient coating of coarse aggregates, and applicability of HMA mix design procedures to foamed WMA mixtures. This dissertation presents the results of a comprehensive study conducted to evaluate the laboratory performance of foamed WMA mixtures with regard to permanent deformation, moisture-induced damage, fatigue cracking, and low-temperature (thermal) cracking; and compare it to traditional HMA. In addition, the workability of foamed WMA and HMA mixtures was evaluated using a new device that was designed and fabricated at the University of Akron, and the compactability of both mixtures was examined by analyzing compaction data collected using the Superpave gyratory compactor. The effect of the temperature reduction, foaming water content, and aggregate moisture content on the performance of foamed WMA was also investigated. Furthermore, the rutting performance of plant-produced foamed WMA and HMA mixtures was evaluated in the Accelerated Pavement Load Facility (APLF) at Ohio University, and the long-term performance of pavement structures constructed using foamed WMA and HMA surface and intermediate courses was analyzed using the Mechanistic-Empirical Pavement Design Guide (MEPDG). Based on the experimental test results and the subsequent analyses findings, the following are the main conclusions made: In general, comparable laboratory test results were obtained for foamed WMA and HMA mixtures prepared using 30°F (16.7°C) temperature reduction, 1.8% foaming water content, and fully dried aggregates. Therefore, the performance of the resulting foamed WMA is expected to be similar to that of the HMA. Surface foamed WMA mixtures had comparable rutting performance in the APLF to that of the HMA mixtures. This was also the case for intermediate foamed WMA and HMA mixtures. These results indicate the field performance of the foamed WMA mixtures is similar to that of the HMA mixtures.
Download or read book Advances in Asphalt Materials written by Shin-Che Huang and published by Woodhead Publishing. This book was released on 2015-04-08 with total page 493 pages. Available in PDF, EPUB and Kindle. Book excerpt: The urgent need for infrastructure rehabilitation and maintenance has led to a rise in the levels of research into bituminous materials. Breakthroughs in sustainable and environmentally friendly bituminous materials are certain to have a significant impact on national economies and energy sustainability. This book will provide a comprehensive review on recent advances in research and technological developments in bituminous materials. Opening with an introductory chapter on asphalt materials and a section on the perspective of bituminous binder specifications, Part One covers the physiochemical characterisation and analysis of asphalt materials. Part Two reviews the range of distress (damage) mechanisms in asphalt materials, with chapters covering cracking, deformation, fatigue cracking and healing of asphalt mixtures, as well as moisture damage and the multiscale oxidative aging modelling approach for asphalt concrete. The final section of this book investigates alternative asphalt materials. Chapters within this section review such aspects as alternative binders for asphalt pavements such as bio binders and RAP, paving with asphalt emulsions and aggregate grading optimization. Provides an insight into advances and techniques for bituminous materials Comprehensively reviews the physicochemical characteristics of bituminous materials Investigate asphalt materials on the nano-scale, including how RAP/RAS materials can be recycled and how asphalt materials can self-heal and rejuvenator selection
Download or read book Asphalt Materials Science and Technology written by James G. Speight and published by Butterworth-Heinemann. This book was released on 2015-10-01 with total page 652 pages. Available in PDF, EPUB and Kindle. Book excerpt: Asphalt is a complex but popular civil engineering material. Design engineers must understand these complexities in order to optimize its use. Whether or not it is used to pave a busy highway, waterproof a rooftop or smooth out an airport runway, Asphalt Materials Science and Technology acquaints engineers with the issues and technologies surrounding the proper selection and uses of asphalts. With this book in hand, researchers and engineering will find a valuable guide to the production, use and environmental aspect of asphalt. Covers the Nomenclature and Terminology for Asphalt including: Performance Graded (PG) Binders, Asphalt Cement (AC), Asphalt-Rubber (A-R) Binder, Asphalt Emulsion and Cutback Asphalt Includes Material Selection Considerations, Testing, and applications Biodegradation of Asphalt and environmental aspects of asphalt use
Download or read book Characteristics of Foamed Asphalt Binders for Warm Mix Asphalt Applications written by Zelalem Alebel Arega and published by . This book was released on 2014 with total page 242 pages. Available in PDF, EPUB and Kindle. Book excerpt: An increase in environmental awareness and energy concerns had recently prompted efforts to make pavement construction cheaper and more environmentally friendly. Warm mix asphalt (WMA) is an asphalt mixture production technology that promises to reduce production costs and greenhouse gas emissions. Foamed asphalt binder is increasingly being used to produce WMA. This dissertation addresses several issues related to the use of foamed asphalt binder for WMA applications. The first objective of the research presented in this dissertation is to develop a method and metrics to precisely quantify the characteristics of asphalt binder foams. Laboratory measurements were obtained using the newly developed method to evaluate the extent and stability of foams produced using different asphalt binders at different water contents and laboratory foaming devices. Results demonstrate that the method developed is promising in terms of its ability to provide a detailed history of the behavior of foamed asphalt binder as the foam collapses. In addition, results indicate that the method is sensitive to distinguish between foaming characteristics of different asphalt binders as well as different water contents and foaming devices. The second objective of this study was to relate intrinsic properties of the asphalt binder to its foaming characteristics. A physical model was developed for expansion of asphalt binder foam based on foam physics and fluid mechanics of micro-droplets. The model relates foamant water and asphalt binder mixing efficiency with the surface tension of the asphalt binder. The model can be used to predict which binder can be effectively foamed and used, and whether any chemical modification to the binder is necessary to achieve the same. Results indicate that only a small percentage of water is effective in foaming the asphalt binder. The last objective of this research was to evaluate the influence of foaming on asphalt binder residues and mixture workability and coatability. The influence of foaming process on the rheological properties of asphalt binder residue was investigated. In addition, the significance of foamed asphalt binder characteristics on mixture workability and coatability was evaluated. Results from this last part of the study can be used to optimize binder foaming such that the resulting mixture is coated and compacted without compromising performance.
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 Determining the Limitations of Warm Mix Asphalt by Water Injection in Mix Design Quality Control and Placement written by Ala R. Abbas and published by . This book was released on 2013 with total page 125 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this project, a comprehensive study was conducted to evaluate the laboratory performance of foamed WMA mixtures with regard to permanent deformation, moisture-induced damage, fatigue cracking, and low-temperature (thermal) cracking; and compare it to traditional HMA. In addition, the workability of foamed WMA and HMA mixtures was evaluated using a new device that was designed and fabricated at the University of Akron, and the compactability of both mixtures was examined by analyzing compaction data collected using the Superpave gyratory compactor. The effect of the temperature reduction, foaming water content, and aggregate moisture content on the performance of foamed WMA was also investigated. Furthermore, the rutting performance of plant-produced foamed WMA and HMA mixtures was evaluated in the Ohio University (OU) Accelerated Pavement Load Facility (APLF), and the long-term performance of pavement structures constructed using foamed WMA and HMA surface and intermediate courses was analyzed using the Mechanistic-Empirical Pavement Design Guide (MEPDG). The laboratory test results revealed comparable resistance to permanent deformation, moisture-induced damage, and fatigue cracking for foamed WMA and HMA mixtures. However, the HMA mixtures had significantly higher ITS values at 14°F (-10°C) and comparable failure strains to the foamed WMA mixtures, which indicates that the traditional HMA mixtures have better resistance to low-temperature (thermal) cracking. The laboratory tests conducted to evaluate the effect of the temperature reduction, foaming water content, and aggregate moisture content revealed that the performance of foamed WMA mixtures prepared using 30°F (16.7°C) temperature reduction, 1.8% foaming water content, and fully dried aggregates was comparable to that of the HMA mixtures. However, reducing the production temperature of foamed WMA resulted in increased susceptibility to permanent deformation and moisture-induced damage. In addition, producing foamed WMA using moist aggregates resulted in inadequate aggregate coating leading to concerns with regard to long-term durability. Increasing the foaming water content (up to 2.6% of the weight of the asphalt binder) did not seem to have a negative effect on the rutting performance or moisture sensitivity of the foamed WMA. The rut depth measurements obtained at the OU APLF confirmed the laboratory APA test results. It was found through these tests that the foamed WMA mixtures have comparable rutting resistance to the HMA mixtures. Finally, the long-term pavement performance predictions obtained using the MEPDG showed comparable service lives for pavement structures constructed using foamed WMA and HMA surface and intermediate mixtures.
Download or read book Determining the Limitations of Warm Mix Asphalt by Water Injection in Mix Design Quality Control and Placement written by and published by . This book was released on 2013 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this project, a comprehensive study was conducted to evaluate the laboratory performance of foamed WMA mixtures with regard to permanent deformation, moisture-induced damage, fatigue cracking, and low-temperature (thermal) cracking; and compare it to traditional HMA. In addition, the workability of foamed WMA and HMA mixtures was evaluated using a new device that was designed and fabricated at the University of Akron, and the compactability of both mixtures was examined by analyzing compaction data collected using the Superpave gyratory compactor. The effect of the temperature reduction, foaming water content, and aggregate moisture content on the performance of foamed WMA was also investigated. Furthermore, the rutting performance of plant-produced foamed WMA and HMA mixtures was evaluated in the Ohio University (OU) Accelerated Pavement Load Facility (APLF), and the long-term performance of pavement structures constructed using foamed WMA and HMA surface and intermediate courses was analyzed using the Mechanistic-Empirical Pavement Design Guide (MEPDG). The laboratory test results revealed comparable resistance to permanent deformation, moisture-induced damage, and fatigue cracking for foamed WMA and HMA mixtures. However, the HMA mixtures had significantly higher ITS values at 14°F ( -10°C) and comparable failure strains to the foamed WMA mixtures, which indicates that the traditional HMA mixtures have better resistance to low-temperature (thermal) cracking. The laboratory tests conducted to evaluate the effect of the temperature reduction, foaming water content, and aggregate moisture content revealed that the performance of foamed WMA mixtures prepared using 30°F (16.7°C) temperature reduction, 1.8% foaming water content, and fully dried aggregates was comparable to that of the HMA mixtures. However, reducing the production temperature of foamed WMA resulted in increased susceptibility to permanent deformation and moisture-induced damage. In addition, producing foamed WMA using moist aggregates resulted in inadequate aggregate coating leading to concerns with regard to long-term durability. Increasing the foaming water content (up to 2.6% of the weight of the asphalt binder) did not seem to have a negative effect on the rutting performance or moisture sensitivity of the foamed WMA. The rut depth measurements obtained at the OU APLF confirmed the laboratory APA test results. It was found through these tests that the foamed WMA mixtures have comparable rutting resistance to the HMA mixtures. Finally, the long-term pavement performance predictions obtained using the MEPDG showed comparable service lives for pavement structures constructed using foamed WMA and HMA surface and intermediate mixtures.
Download or read book Warm Mix Asphalt written by Paula Cristina Arroyo-Martínez and published by . This book was released on 2019 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Warm mix asphalt (WMA) is a technology that emerges to achieve environmental challenges of reducing greenhouse gas emissions. There are several technologies that allow diminishing the mixing and compaction temperature of the asphalt mixtures while improving workability. The benefits of using warm mix asphalt are not just environmental but also include better working conditions and the capability of introducing greater percentages of recycled materials into the mixture. Foamed asphalt is the most used technology to obtained warm mix asphalt in the United States of America (USA), and the performance of the resultant mixtures could be increased by controlling and improving the characteristics of the foam.
Download or read book Performance of Foamed Warm Mix Asphalt In Virginia Over Four to Six Years written by Stacey D. Diefenderfer and published by . This book was released on 2017 with total page 27 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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 implementation; however, foamed WMA was not. This study was designed to evaluate the properties and performance of foamed WMA placed during the initial implementation of the technology to determine if the technology has performed as expected. Six mixtures produced using plant foaming technologies and placed between 2008 and 2010 were identified and subjected to field coring and laboratory testing to provide insight as to the performance of foamed WMA mixtures. All coring was performed in 2014, which resulted in pavement ages ranging from 4 to 6 years. Three comparable hot mix asphalt (HMA) mixtures were cored and evaluated to provide average values for comparison. All cores were tested to determine air-void contents and permeability and were subjected to dynamic modulus, repeated load permanent deformation, and Texas overlay testing. In addition, binder was extracted and recovered for performance grading. Test results found similar properties for the WMA and HMA mixtures evaluated. One WMA mixture exhibited high dynamic modulus and binder stiffness, but overlay testing did not indicate any tendency toward premature cracking. All binders were found to have aged between two and three performance grades above that which was specified at construction. WMA binders and one HMA binder aged two grades higher, and the remaining two HMA binders aged three grades, indicating a likely influence on aging from the reduced temperatures at which the early foamed mixtures were typically produced. Overall results indicated that foamed WMA should be expected to perform similarly to HMA. WMA has been fully adopted by VDOT as an alternative to HMA since 2008; however, at the time of implementation of foamed WMA, no studies had been conducted by VDOT to assess the performance of WMA relative to that of HMA. This study validated the assumption that the properties and performance of foamed WMA are similar to those of HMA.
Download or read book The Utilization of Slag in Civil Infrastructure Construction written by George C. Wang and published by Woodhead Publishing. This book was released on 2016-06-24 with total page 444 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Utilization of Slag in Civil Infrastructure Construction strives to integrate the theory, research, and practice of slag utilization, including the production and processing of slags. The topics covered include: production and smelting processes for metals; chemical and physical properties of slags; pretreatment and post-treatment technology to enhance slag properties; potential environmental impact; mechanisms of potential expansion; special testing methods and characteristics; slag processing for aggregate and cementitious applications; suitability of slags for use in specific applications; overall properties of materials containing slags; and commercialization and economics. The focus of the book is on slag utilization technology, with a review of the basic properties and an exploration of how its use in the end product will be technically sound, environment-friendly, and economic. Covers the production, processing, and utilization of a broad range of ferrous, non-ferrous, and non-metallurgical slags Provides information on applicable methods for a particular slag and its utilization to reduce potential environmental impacts and promote natural resource sustainability Presents the overall technology of transferring a slag from the waste stream into a useful materials resource Provides a detailed review of the appropriate utilization of each slag from processing right through to aggregate and cementitious use requirements
Download or read book Low Temperature Characterization of Foamed Warm Mix Asphalt written by Ahmad Alhasan and published by . This book was released on 2013 with total page 112 pages. Available in PDF, EPUB and Kindle. Book excerpt: In recent years, a group of technologies has been introduced in the United States that allows producing asphalt mixtures at temperatures 30 to 100oF lower than what is used in traditional hot mix asphalt (HMA). This group of technologies is commonly referred to as Warm Mix Asphalt (WMA). From among these technologies, foamed WMA produced by water injection has gained increased attention from the asphalt paving industry in Ohio since it does not require the use of costly additives. This study evaluated the low-temperature performance of foamed WMA and compared it to traditional HMA. Two asphalt binders (PG 70-22 and PG 64-28), two aggregate types (limestone and crushed gravel), and two aggregate gradations (12.5 mm NMAS and 19.0 mm NMAS) were used in this study. The low-temperature behavior of the asphalt mixtures was evaluated using the thermal stress restrained specimen test (TSRST). In addition, the low-temperature properties of the asphalt binders were measured using the bending beam rheometer (BBR). This allowed for comparing the fracture temperature obtained from the TSRST to the low-temperature performance grade obtained using the BBR test.In general, the foamed WMA mixtures exhibited warmer fracture temperatures and lower fracture stresses in the TSRST than the traditional HMA mixtures. This indicates that the HMA mixtures have better resistance to low-temperature cracking. It was found that the binder grade had the most significant effect on the fracture temperature followed by the mix type, while the aggregate type had the most significant effect on the fracture stress followed by the binder grade and the mix type. The fracture temperatures measured in the TSRST were also found to be consistent with the low-temperature performance grades obtained using the BBR test.
