Download or read book Short term Laboratory Conditioning of Asphalt Mixtures written by David Newcomb and published by . This book was released on 2015 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report develops procedures and associated criteria for laboratory conditioning of asphalt mixtures to simulate short-term aging. The report presents proposed changes to the American Association of State Highway and Transportation Officials (AASHTO) R 30, Mixture Conditioning of Hot-Mix Asphalt (HMA), and a proposed AASHTO practice for conducting plant aging studies. The report will be of immediate interest to materials engineers in state highway agencies and the construction industry with responsibility for design and production of hot and warm mix asphalt.
Download or read book Field Verification of Proposed Changes to the AASHTO R 30 Procedures for Laboratory Conditioning of Asphalt Mixtures written by David E. Newcomb and published by . This book was released on 2019 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: Laboratory conditioning of asphalt mixtures during the mix design process to simulate their short-term aging influences the selection of the optimum asphalt content. In addition, long-term conditioning affects the mixture and binder stiffness, deformation, and strength evaluated with fundamental characterization tests to assess mixture performance. The current standard conditioning procedure, AASHTO R 30, Standard Practice for Mixture Conditioning of Hot-Mix Asphalt, was developed over two decades ago. In reviewing whether to update the standard, TRB's National Cooperative Highway Research Program (NCHRP) Research Report 919: Field Verification of Proposed Changes to the AASHTO R 30 Procedures for Laboratory Conditioning of Asphalt Mixtures seeks to (a) develop a laboratory short-term aging protocol to simulate the aging and asphalt absorption of an asphalt mixture during production and transportation based on factors thought to affect aging, and (b) develop a laboratory longer-term aging protocol to simulate the aging of the asphalt mixtures after construction. The key outcome of the research is that the current long-term oven aging (LTOA) procedure in AASHTO R 30 is not realistic. Replacing the aging of a compacted specimen with aging of loose mix for 5 days at 85°C (185°F) before compaction for testing should be considered by the AASHTO Committee on Materials and Pavements.
Download or read book Short term Laboratory Conditioning of Asphalt Mixtures written by David Newcomb and published by . This book was released on 2015 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report develops procedures and associated criteria for laboratory conditioning of asphalt mixtures to simulate short-term aging. The report presents proposed changes to the American Association of State Highway and Transportation Officials (AASHTO) R 30, Mixture Conditioning of Hot-Mix Asphalt (HMA), and a proposed AASHTO practice for conducting plant aging studies. The report will be of immediate interest to materials engineers in state highway agencies and the construction industry with responsibility for design and production of hot and warm mix asphalt.
Download or read book Validation of Guidelines for Evaluating the Moisture Susceptibility of WMA Technologies written by Amy Epps Martin and published by . This book was released on 2016 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt: TRB's National Cooperative Highway Research Program (NCHRP) Report 817: Validation of Guidelines for Evaluating the Moisture Susceptibility of WMA Technologies presents validated guidelines proposed for identifying potential moisture susceptibility in warm mix asphalt (WMA) during mix design. The report further corroborates the moisture susceptibility thresholds described in NCHRP Report 763: Evaluation of the Moisture Susceptibility of WMA Technologies.
Download or read book Short term Laboratory Conditioning of Asphalt Mixtures written by David Newcomb and published by . This book was released on 2015 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report develops procedures and associated criteria for laboratory conditioning of asphalt mixtures to simulate short-term aging. The report presents proposed changes to the American Association of State Highway and Transportation Officials (AASHTO) R 30, Mixture Conditioning of Hot-Mix Asphalt (HMA), and a proposed AASHTO practice for conducting plant aging studies. The report will be of immediate interest to materials engineers in state highway agencies and the construction industry with responsibility for design and production of hot and warm mix asphalt.
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 Asphalt Binder Aging Methods to Accurately Reflect Mixture Aging written by and published by . This book was released on 2021 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt: Asphalt binders experience aging that occurs in two distinct stages under quite different conditions: (1) short-term during construction (plant mixing, storage, placement, and compaction) and (2) long-term during the service life of the pavement. The TRB National Cooperative Highway Research Program's pre-publication of NCHRP Research Report 967: Asphalt Binder Aging Methods to Accurately Reflect Mixture Aging documents research conducted to improve laboratory binder conditioning methods to accurately simulate the short-term and long-term aging of asphalt binders, and to calibrate the improved procedures to the aging that occurs during mixture production, transport, and placement as well as during the service life of the pavement structure.
Download or read book Investigation of Short term Laboratory Aging of Neat and Modified Asphalt Binders written by David A. Anderson and published by Transportation Research Board. This book was released on 2012 with total page 78 pages. Available in PDF, EPUB and Kindle. Book excerpt: "TRB's National Cooperative Highway Research Program (NCHRP) Report 709: Investigation of Short-Term Laboratory Aging of Neat and Modified Asphalt Binders provides a proposed method of testing for short-term laboratory aging of neat and modified asphalt binders using the modified German rotating flask as an alternative to the rolling thin film oven test. The following appendixes A-E to NCHRP Report 709 are only available in electronic format."--
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 Aging Characterization of Foamed Warm Mix Asphalt written by Mir Shahnewaz Arefin and published by . This book was released on 2015 with total page 129 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study evaluated the aging characteristic of foamed warm mix asphalt (WMA) produced by water injection in comparison to traditional hot mix asphalt (HMA). Four types of asphalt binders (PG 64-22, PG 64-28, PG 70-22, PG 76-22) were used in the preparation of the foamed WMA and HMA mixtures. All mixtures were prepared using limestone aggregates with a nominal maximum aggregate size (NMAS) of 12.5 mm that met the Ohio Department of Transportation (ODOT) Construction and Material Specifications (C&MS) for Item 442 (Superpave Asphalt Concrete).The short-term and long-term aging of the asphalt binders were simulated using the rolling thin film oven (RTFO) and the pressure aging vessel (PAV), respectively, while the short-term and long-term aging of the laboratory-prepared asphalt mixtures were simulated according to AASHTO R 30 (Mixture Conditioning of Hot Mix Asphalt).The dynamic shear rheometer (DSR) was used to characterize the viscoelastic behavior of the unaged, RTFO-aged, and PAV-aged asphalt binders, while the dynamic modulus (lE*l) test was used to characterize the viscoelastic behavior of the short-term and long-term aged foamed WMA and HMA mixtures.In addition, the mechanistic-empirical pavement design guide (MEPDG) global aging model was used to predict the effect of aging on the dynamic modulus (lE*l) of foamed WMA and HMA mixtures, and the MEPDG global aging model predictions were compared to dynamic modulus (lE*l) test results obtained in the laboratory for both asphalt mixtures. By comparing the DSR test results following RTFO and PAV to those obtained for the unaged asphalt binders, it was observed that PG 64-22 was the least susceptible to aging followed by PG 70-22, PG 76-22, and PG 64-28. Similar trends were also observed from the dynamic modulus test, where little difference was noticed between the short-term and long-term aged specimens prepared using PG 64-22 for both foamed WMA and HMA mixtures.The dynamic modulus test results also revealed slightly lower lE*l values for foamed WMA mixtures in comparison to traditional HMA mixtures. This indicates that foamed WMA mixtures are slightly more susceptible to rutting than HMA mixtures. However, by comparing the dynamic modulus of the long-term aged specimens to the short-term aged specimens, it was observed that the increase in stiffness for the foamed WMA mixtures was less than that for the traditional HMA mixtures. This indicates that foamed WMA mixtures are less susceptible to aging and subsequently fatigue cracking than HMA mixtures.Finally, by the comparing the MEPDG global aging model predictions to the dynamic modulus test results for both foamed WMA and HMA mixtures, it was observed that the MEPDG global aging model provided more reasonable predictions, especially at higher frequencies, but overestimated or underestimated the dynamic modulus at lower frequencies. This was observed for both foamed WMA and HMA mixtures, which suggests that this model can be used for both types of mixtures.
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 Phenomenological Modeling and Laboratory Simulation of Long Term Aging of Asphalt Mixtures written by Michael Dawoud Elwardany and published by . This book was released on 2017 with total page 427 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Durability and Performance Characteristics of Hot Mix Asphalt Containing Polymer Additives written by Robert Y. Liang and published by . This book was released on 2001 with total page 286 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ohio Department of Transportation has adopted the hot mix asphalt concrete containing polymer modifiers for use in the interstate highway pavement. Among the various reasons cited for the adoption of polymer modifiers are the favorable field experiences by ODOT, extensive literatures reporting enhanced performance, such as rutting resistance, low temperature thermal cracking resistance, and possibly fatigue endurance. However, despite these favorable findings, there are still cases involving premature failure of hot mixtures containing polymer modifiers. Concerns regarding optimum polymer content, compatibility between polymer additives and asphalt cement, proper mixing and compaction procedure remain to be resolved. Furthermore, performance based specifications to ensure production of desirable final asphalt concrete product require additional development. Questions regarding the suitability of Superpave binder testing procedures for the polymer-modified binders need to be clarified.
Download or read book Asphalt Paving Technology 2013 written by Eugene Skok and published by DEStech Publications, Inc. This book was released on 2014-02-04 with total page 752 pages. Available in PDF, EPUB and Kindle. Book excerpt: New developments in mixing, testing, modeling Research findings on sustainable asphalt technology Bitumen use and specifications in Europe Fully-searchable text on accompanying CD-ROM Asphalt Paving Technology 2013, a series volume, contains 26 original research papers devoted to the formulation, chemistry, mixing, modeling, testing and optimization of asphalt—with applications to highway and infrastructure engineering. Written by leading civil and structural engineers from universities and government agencies around the world, the book offers information for designing and producing higher-quality asphalt. Selected keywords: photocatalytic asphalt; fatigue loading; skid-resistance; low-temperature cracking software; long-term aging; fracture properties; moisture damage; RAP; rejuvenators; binders; flexible pavement; healing. The CD-ROM displays figures and illustrations in articles in full color along with a title screen and main menu screen. Each user can link to all papers from the Table of Contents and Author Index and also link to papers and front matter by using the global bookmarks which allow navigation of the entire CD-ROM from every article. Search features on the CD-ROM can be by full text including all key words, article title, author name, and session title. The CD-ROM has Autorun feature for Windows 2000 with Service Pack 4 or higher products along with the program for Adobe Acrobat Reader with Search 11.0. One year of technical support is included with your purchase of this product.
Download or read book Selection of Laboratory Aging Procedures for Asphalt aggregate Mixtures written by C. A. Bell and published by Strategic Highway Research Program (Shrp). This book was released on 1994 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt: Two major effects dominate aging of asphalt-aggregate mixtures: 1) loss of volatile components and oxidation in the construction phase (short-term aging) and 2) progressive oxidation of the in-place mixture in the field (long-term aging). Aging results in hardening (stiffening) of a mixture, which alters its performance both positively and negatively. This report presents the results of a preliminary investigation to evaluate aging methods for asphalt-aggregate mixtures. Short-term methods included oven aging and extended mixing, while long-term methods included oven aging and oxygen enrichment. The effects of temperature and aging duration are presented. The effects of aging were determined using the diametral resilient modulus test. Recommendations for short- and long-term aging are provided.
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 Effects of Short Term Oven Aging on Volumetrics and Selection of N design written by Bradley J. McMullen and published by . This book was released on 2000 with total page 82 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report presents findings on the effect of conditioning time on the volumetric properties of Superpave Gyratory Compactor (SGC) prepared asphalt mixtures. Field mixtures were sampled from the producing plants and then recreated in the laboratory following 3 different short-term conditioning procedures to measure the effect on the N-design value of the mixture. The projects selected represent three different N-design levels, have different nominal maximum aggregate size, aggregate sources, and asphalt binder types. Bulk Specific Gravity (Gmb) samples were aged at compaction temperature for 1-hr, 2-hr, and 4-hr. Maximum Specific Gravity (Gmm) samples were also aged at compaction temperature for 0-hr, 2-hr, and 4-hr. The short-term aging times are based off of Illinois Department of Transportation aging procedures, current National Center for Asphalt Technology recommendations, and the original Superpave conditioning specifications. It was observed in this study that increased conditioning time has a greater impact on the volumetric properties of polymer-modified binder mixes than on neat binder mixes. Also, noticed is that the presence of polymers in the binder appears to have greater effect than the higher temperatures used for conditioning polymer-modified HMA.
