Abstract
The practice of incorporating reclaimed asphalt pavement (RAP) into hot mix asphalt (HMA) is common within the paving industry as a cost-effective source of quality paving binder and aggregate. Recently, research efforts have focussed on investigating the potential of using reclaimed asphalt shingles (RAS) in HMA. This study provides a comparison of the laboratory performance of several HMA mixtures with varied RAS sources and contents. Performance testing for the mixtures included dynamic modulus and phase angle. Fatigue testing was also performed for several of the mixtures. Mixtures with higher amounts of binder replacement from RAS showed stiffer performance at high temperatures and less stiff performance at low temperatures. The mixture with greater amounts of RAS showed better fatigue performance. The mixtures with various sources of RAS, whether pre- or post-consumer, showed similar low-temperature performance, while the mixture with a blend of both sources was stiffest at high temperatures. A set of mixtures comparing different RAS sources was also compared with a mixture containing RAP as the only recycled binder source. The results of testing of these mixtures showed that the RAP mix was stiffer at intermediate and high temperatures but had similar results to the RAS mixtures in low-temperature performance.
Acknowledgements
A special thank is acknowledged to The New Hampshire Industrial Research Council, UNH Summer Undergraduate Research Fellowship Program, Pike Industries, Inc., ERRCO, and RAS-Tech Inc. for donations of materials and funding for this project. Additionally, special thanks are extended to Marcelo Medeiros and Aravind Krishna Swamy for their assistance with specimen preparation and laboratory testing at UNH.