Methodology to develop design guidelines to construct unbound base course with reclaimed asphalt pavement (RAP)

Reclaimed asphalt pavement (RAP) has been considered as one of the sources to create unbound base aggregate (UBA) for pavement structures for several years. There are number of previous research studies that focuses on testing the modulus and deformation characteristics of the RAP and RAP blended with virgin aggregate (VA), however results vary significantly from one study to another and there are no clear-cut guidelines on how much RAP should be blended with VA for the best outcome. In this study, the focus of the research was to develop a methodology that will allow the Owner's to develop design guidelines to create UBA with RAP-VA blends where the created blend will have similar performance criteria as the VA used in that region. To achieve this goal, factors affecting the performance of RAP-VA blends have been investigated and a guideline to select and how to meet the target modulus and deformation thresholds are presented. RAP obtained from 14 different asphalt plants and virgin aggregate collected from a source in Virginia have been investigated. The results showed that although there are differences in RAP from one source to another, following the proposed methodology in this article, it is possible to recycle RAP to create UBA that will have similar performance criteria as the VA by itself. (C) 2019 Elsevier Ltd. All rights reserved.