%0 Book %A Transportation Research Board %A National Academies of Sciences, Engineering, and Medicine %E Newcomb, David %E Arámbula-Mercado, Edith %E Martin, Amy Epps %E Yuan, Mengge %E Tran, Nam %E Yin, Fan %T Field Verification of Proposed Changes to the AASHTO R 30 Procedures for Laboratory Conditioning of Asphalt Mixtures %D 2019 %U https://nap.nationalacademies.org/catalog/25608/field-verification-of-proposed-changes-to-the-aashto-r-30-procedures-for-laboratory-conditioning-of-asphalt-mixtures %> https://nap.nationalacademies.org/catalog/25608/field-verification-of-proposed-changes-to-the-aashto-r-30-procedures-for-laboratory-conditioning-of-asphalt-mixtures %I The National Academies Press %C Washington, DC %G English %K Transportation and Infrastructure %P 46 %R doi:10.17226/25608 %X 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.