Download or read book Long Term Effectiveness of Recycling Agents to Improve Performance Properties of Asphalt Concrete written by Mahsa Tofighian and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recycled materials such as reclaimed asphalt pavement (RAP) have been incorporated into asphalt mixtures for many years. However, their usage has increased over time as they are seen as a way to reduce the cost of asphalt mixtures, save energy, and protect the environment. Similarly, there has been a growing focus on the utilization of recycled asphalt shingles (RAS) in asphalt mixtures, a pursuit undertaken by various state highway agencies. However, unless appropriate precautions are taken, as the proportion of RAP and RAS in the asphalt mixture is raised, the mixture becomes more brittle, leading to a higher risk of cracking and raveling in the asphalt pavement. Furthermore, the mixture becomes less workable and more challenging to compact in the field, increasing the potential for premature field failure. One strategy to incorporate more RAP and RAS into asphalt mixtures involves the use of specialized recycling agents (RAs), known as rejuvenating agents. Over time, asphalt mixtures undergo aging during construction and over the extended service life of asphalt pavements, resulting in the oxidation of the mix and the loss of a significant portion of the maltenes in the binder composition. Maltenes contribute to the softening effect of the binder, and these recycling agents, when used appropriately, are expected to compensate for this reduction in maltenes. The ultimate result of this rebalancing of components is the softening of the aged binder and an improvement in its resistance to cracking. This study investigates the long-term impact of bio-based and petroleum-based recycling agents (RA's) on recycled asphalt binders with varying levels of reclaimed asphalt pavement (RAP) and reclaimed asphalt shingles (RAS) content, specifically low (15%) and high (30%) RAP content and 0% and 5% RAS content. The rejuvenated binders underwent short-term and long-term aging through the use of a Rolling Thin Film Oven (RTFO) and Pressure Aging Vessel (PAV), respectively. The performance characteristics of these modified binders at various aging stages were assessed using a dynamic shear rheometer (DSR) and bending beam rheometer (BBR). The study revealed that all RA's used in this research maintained their effectiveness even after long-term aging, though the degree of effectiveness varied. Additionally, the results indicated that the petroleum-based RA required a higher dosage to achieve the same effect as the bio-based RA's. The findings from this research also demonstrated that when rejuvenators are added to mixtures with a high RAP content or a combination of RAP and RAS, the mixture's performance is enhanced in terms of low-temperature cracking and fatigue cracking. Nevertheless, it is crucial to extend this work to field pilot projects to ensure the effective application of these rejuvenating products.

Download or read book Engineered Frameworks for Evaluating the Use of Recycling Agents in Surface Asphalt Mixtures for Virginia written by Jhony Habbouche and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In recent years, several state highway agencies have introduced special provisions and specifications to allow the use of higher contents of reclaimed asphalt pavement (RAP) in asphalt surface mixtures. The challenges associated with high RAP mixtures can be addressed through the use of additives such as recycling agents (RAs) and/or softer binders. Currently, there are no specific guidelines or specifications available to evaluate the acceptability of RAs in Virginia. The purpose of this study was to evaluate the short- and long-term effectiveness of RAs in improving the performance of asphalt mixtures, particularly those with high RAP contents. Another objective of the study was to establish a performance-based framework to determine the acceptability of a specific RA product for inclusion in the Virginia Department of Transportation’s Approved Product List. Both objectives were achieved by benchmarking recycled binder blends (Phase I) and mixtures (Phase II). These were then compared in terms of laboratory performance to commonly used virgin asphalt binders and mixtures in Virginia. Moreover, a comprehensive review of the literature and information from state departments of transportation and RA suppliers on the current state of the practice regarding the use of recycled materials and RAs in asphalt mixtures was summarized. Component materials, including three virgin asphalt binders, RAP and aggregate materials from three different sources, and six RAs, were collected and tested. Phase I involved testing virgin and RAP binders; combinations of virgin binder and RAP binder; and combination of virgin binder, RAP binder, and RAs. A total of 26 binder blends were evaluated at various aging conditions through numerous rheology- and chemistry-based tests. In Phase II, 10 asphalt mixtures were designed and evaluated for durability, resistance to rutting, and resistance to cracking at various aging conditions. Cross-scale evaluation of asphalt binder and mixture testing data was established. Finally, preliminary verification was performed using data collected from various field trials constructed in Virginia. Based on the binders and mixtures tested in this study, the effectiveness of RAs in improving the properties of asphalt binder blends is specific to the product being used and to the targeted temperatures or conditions. Moreover, RAs can enhance the performance and increase the use of recycled materials in asphalt mixtures provided that the correct and suitable dosage of RA product is determined through a performance-based testing framework. The study recommends the following: (1) adopting the streamlined frameworks presented in this study to determine the acceptability of a given RA; (2) further validating the presented framework using different component materials; (3) employing balanced mix design tests to assess the performance characteristics of surface mixtures (with A and D designations) with RAs and drafting a roadmap; (4) collecting and further evaluating the field performance of all trials involving high RAP, RAs, and/or softer binders; (5) investigating the availability and activity of binders, especially with RAs, in RAP materials; (6) evaluating and establishing a protocol to assess the consistency of RAP materials; and (7) quantifying the environmental and economic impacts of using surface mixtures with high RAP contents and/or RAs.

Download or read book Evaluation of Properties of Recycled Asphalt Concrete Hot Mix written by Elton R. Brown and published by . This book was released on 1983 with total page 314 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recycling of aged asphalt concrete pavements has been demonstrated to be cost-effective and to reduce the demand for natural resources such as aggregate and asphalt. Because of the advantages derived when using recycled materials, the capability to predict long-term performance is needed so that optimum benefits can be obtained. This study was undertaken to evaluate the laboratory performance to recycled asphalt concrete mixtures and to compare these results to those measured for conventional asphalt concrete mixtures. Results of this study indicated a satisfactory comparison between laboratory performance of recycled mixtures and conventional mixtures. Fatigue analysis indicated that conventional mixtures would provide the greatest fatigue resistance in thick asphalt concrete layers at lower temperatures, while the recycled mixtures would provide the greatest fatigue resistance in thin asphalt layers at higher temperatures. Water susceptability was shown to be related more to aggregate type than to mixture type. The data show that recycled mixtures prepared with the recycling agent produced mixtures with the lowest durability and poorest low temperature performance when compared with the recycled mixtures prepared with AC-5 or compared with the conventional mixtures.

Download or read book Eco efficient Pavement Construction Materials written by F. Pacheco-Torgal and published by Woodhead Publishing. This book was released on 2020-01-18 with total page 424 pages. Available in PDF, EPUB and Kindle. Book excerpt: Eco-efficient Pavement Construction Materials acquaints engineers with research findings on new eco-efficient pavement materials and how they can be incorporated into future pavements. Divided into three distinctive parts, the book emphasizes current research topics such as pavements with recycled waste, pavements for climate change mitigation, self-healing pavements, and pavements with energy harvesting potential. Part One considers techniques for recycling, Part Two reviews the contribution of pavements for climate change mitigation, including cool pavements, the development of new coatings for high albedo targets, and the design of pervious pavements. Finally, Part Three focuses on self-healing pavements, addressing novel materials and design and performance. Finally, the book discusses the case of pavements with energy harvesting potential, addressing different technologies on this field. - Offers a clear and concise lifecycle assessment of asphalt pavement recycling for greenhouse gas emission with temporal aspects - Applies key research trends to green the pavement industry - Includes techniques for recycling waste materials, the design of cool pavements, self-healing mechanisms, and key steps in energy harvesting

Download or read book Federally Coordinated Program of Highway Research Development and Technology written by and published by . This book was released on 1983 with total page 838 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Asphalt Mixture Components written by and published by . This book was released on 1998 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Recycled Materials in Geotechnical and Pavement Applications written by Amin Chegenizadeh and published by Springer Nature. This book was released on 2022-02-28 with total page 114 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book considers the application of recycled materials both in pavement and geotechnical engineering. Currently, Australia has faced the fundamental concern of recycling waste plastic. On 1 January 2018, China enforced a prohibition on the importation of waste plastic. China's ban is followed by other countries like India, Indonesia, and Malaysia. The ban caused many corporations to abandon waste collection agreements, and the stockpiling of waste, as there is nowhere to safely deposit this waste. This issue seems, to a great extent, to have placed Australia's recycling industry in a crisis. As a result, local councils will have to find strategic ways of recycling accumulated waste that will become a more significant issue in the coming years. In Australia, apart from economic growth, the road pavement has weakened rapidly as the current pavement unable to withstand this urgent traffic load demand. The adding of polymers to the mixtures improves the stiffness, rutting resistance, and fatigue cracking [1]. However, the application of virgin polymer is costly. Thus, using waste polymer such as waste plastic polymer is an inexpensive substitute. The potential for recycled plastic to improve the performance properties of asphalt mixtures has been demonstrated in many countries the UK, Canada, The Netherlands, and India [2]. Similarly, another application of recycled materials can be in geotechnical infrastructure. This book considers the application of recycled materials both in pavement and geotechnical engineering. References [1] Airey, G.D., Singleton, T.M., & Collop, A.C.(2002). Properties of polymer modified bitumen after rubber- bitumen interaction. Journal of Materials in Civil Engineering .14(4), 344- 354. [2] K. O'Farrell. Australian Plastics Recycling Survey- National Report. Australian Government, Department of Environment and Energy, Australia. Project reference,2018 A21502.

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 Investigation of Binder Rheology and Performance Outcomes of Recycled Hot mix Asphalt Using Different Rejuvenation Agents written by Kerry Jean King and published by . This book was released on 2015 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt: The research presented in this thesis investigated the effect of various rejuvenation agents on the performance of hot-mix asphalt (HMA) surfacing mixes containing high levels of recycled asphalt pavement (RAP) material (30%). The research aimed to develop testing methodologies for evaluating the mechanical performance properties of HMA mixes and for the characterisation of extracted binder properties. The methodologies were used determine the effects of various rejuvenators on the mechanical performance properties and binder properties fundamental to the long-term performance of pavement surfaces. A testing methodology was developed to investigate the performance properties of five HMA mixes including four mixes that were rejuvenated using different rejuvenation agents and one control. The mechanical testing methodology provided a comprehensive assessment of mix properties that are fundamental to the long-term performance of recycled pavements. A methodology for the characterisation of extracted binders was developed to evaluate properties that had a significant effect on the performance of the binder and therefore the overall mix. The binder properties were compared to results obtained from mechanical performance tests to establish a relationship between binder rejuvenation and performance observations. The results obtained from mechanical testing demonstrated that the cracking resistance of recycled mixes could be significantly improved through the use of rejuvenation agents. Rejuvenation also decreased the stiffness of the mix and had a negative effect on the resistance of a mix to permanent deformation. From the characterisation of the binder, it was found that rejuvenation agents altered the rheological properties of the binder but did not have a notable effect on chemical composition. The rheological performance parameters of the binder correlated to the mix performance observed from mechanical tests. Overall this research has shown that rejuvenation agents can be utilised to enhance the performance of recycled mixes by restoring binder properties.

Download or read book Functional Pavement Design written by Sandra Erkens and published by CRC Press. This book was released on 2016-10-14 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt: Functional Pavement Design is a collections of 186 papers from 27 different countries, which were presented at the 4th Chinese-European Workshops (CEW) on Functional Pavement Design (Delft, the Netherlands, 29 June-1 July 2016). The focus of the CEW series is on field tests, laboratory test methods and advanced analysis techniques, and cover analysis, material development and production, experimental characterization, design and construction of pavements. The main areas covered by the book include: - Flexible pavements - Pavement and bitumen - Pavement performance and LCCA - Pavement structures - Pavements and environment - Pavements and innovation - Rigid pavements - Safety - Traffic engineering Functional Pavement Design is for contributing to the establishment of a new generation of pavement design methodologies in which rational mechanics principles, advanced constitutive models and advanced material characterization techniques shall constitute the backbone of the design process. The book will be much of interest to professionals and academics in pavement engineering and related disciplines.

Download or read book Effect of Recycling Agents on the Structural Performance of Recycled Asphalt Concrete Materials written by Dallas N. Little and published by . This book was released on 1981 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Cold recycled Bituminous Concrete Using Bituminous Materials written by Jon A. Epps and published by Transportation Research Board. This book was released on 1990 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt: This synthesis will be of interest to pavement designers, construction engineers, and others interested in economical methods for reconstructing or rehabilitating bituminous pavements. Information is provided on the processes and procedures used by a number of states to recycle asphalt pavements in place without application of heat. Since 1975 a growing number of state highway agencies have reconstructed or rehabilitated asphalt pavements by recycling the old pavement in place. This report of the Transportation Research Board describes the processes used for cold in-place recycling, including construction procedures, mix designs, mixture properties, performance, and specifications.

Download or read book Hot mix Asphalt Mixtures written by and published by . This book was released on 1999 with total page 192 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Evaluating the Effects of Recycling Agents on Asphalt Mixtures with High RAS and RAP Binder Ratios written by Amy Epps Martin and published by . This book was released on 2020 with total page 284 pages. Available in PDF, EPUB and Kindle. Book excerpt: "More than 90 percent of highways and roads in the United States are built using hot-mix asphalt (HMA) or warm-mix asphalt (WMA) mixtures, and these mixtures now recycle more than 99 percent of some 76.2 million tons of reclaimed asphalt pavement (RAP) and about 1 million tons of recycled asphalt shingles (RAS) each year. Cost savings in 2017 totaled approximately $2.2 billion with these recycled materials replacing virgin materials. The TRB National Cooperative Highway Research Program's NCHRP Research Report 927: Evaluating the Effects of Recycling Agents on Asphalt Mixtures with High RAS and RAP Binder Ratios presents an evaluation of how commercially available recycling agents affect the performance of asphalt mixtures incorporating RAP and RAS at high recycled binder ratios."--

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 Simple Performance Tester for Superpave Mix Design written by Ramon Francis Bonaquist and published by Transportation Research Board. This book was released on 2003 with total page 169 pages. Available in PDF, EPUB and Kindle. Book excerpt: The global response to COVID-19 has demonstrated the importance of vigilance and preparedness for infectious diseases, particularly influenza. There is a need for more effective influenza vaccines and modern manufacturing technologies that are adaptable and scalable to meet demand during a pandemic. The rapid development of COVID-19 vaccines has demonstrated what is possible with extensive data sharing, researchers who have the necessary resources and novel technologies to conduct and apply their research, rolling review by regulators, and public-private partnerships. As demonstrated throughout the response to COVID-19, the process of research and development of novel vaccines can be significantly optimized when stakeholders are provided with the resources and technologies needed to support their response. Vaccine Research and Development to Advance Pandemic and Seasonal Influenza Preparedness and Response focuses on how to leverage the knowledge gained from the COVID-19 pandemic to optimize vaccine research and development (R&D) to support the prevention and control of seasonal and pandemic influenza. The committee's findings address four dimensions of vaccine R&D: (1) basic and translational science, (2) clinical science, (3) manufacturing science, and (4) regulatory science.

Download or read book Pavement Roadway and Bridge Life Cycle Assessment 2020 written by John Harvey and published by CRC Press. This book was released on 2020-07-02 with total page 557 pages. Available in PDF, EPUB and Kindle. Book excerpt: An increasing number of agencies, academic institutes, and governmental and industrial bodies are embracing the principles of sustainability in managing their activities. Life Cycle Assessment (LCA) is an approach developed to provide decision support regarding the environmental impact of industrial processes and products. LCA is a field with ongoing research, development and improvement and is being implemented world-wide, particularly in the areas of pavement, roadways and bridges. Pavement, Roadway, and Bridge Life Cycle Assessment 2020 contains the contributions to the International Symposium on Pavement, Roadway, and Bridge Life Cycle Assessment 2020 (Davis, CA, USA, June 3-6, 2020) covering research and practical issues related to pavement, roadway and bridge LCA, including data and tools, asset management, environmental product declarations, procurement, planning, vehicle interaction, and impact of materials, structure, and construction. Pavement, Roadway, and Bridge Life Cycle Assessment 2020 will be of interest to researchers, professionals, and policymakers in academia, industry, and government who are interested in the sustainability of pavements, roadways and bridges.