Development of a new asphalt mixture containing reacted and activated rubber and reclaimed asphalt pavement via Superpave mix design and Marshall mix design

Reacted and Activated Rubber (RAR) is one of the pre-treated crumb rubber technologies. It has been developed as a new approach to produce crumb rubber modified asphalt mixture in the field. However, most of the previous studies are limited to the Marshall design method to obtain the optimum asphalt content. Further, none of these studies tried to add reclaimed asphalt pavement (RAP) to the RAR modified asphalt mixtures. The objective of this study was to conduct a Superpave mix design for determining the optimum asphalt content of asphalt mixture with RAR and RAP, and analyze the performance of RAR modified binder and mixture through a series of laboratory tests. Performance Grade (PG) 58-28 binder was used for this study. Both the Superpave mix design method and the Marshall mix design method selected the optimum asphalt binder content as 11.0% by weight of the mixture, where the virgin binder content was 6.6% and the RAR content was 4.4%. In general, the test results were favorable in rutting resistance performance and moisture resistance. The designed RAR modified mixtures will be used to construct trial sections in early August 2018 in Kalamazoo, Michigan