Study of the Influence of the Mastic Coating of Untreated Reclaimed Asphalt Pavement on the Permanent and Resilient Behavior

Abstract

Asphalt aggregates arise from the demolition of asphalt road layers. The ORRAP (Optimal Recycling of Reclaimed Asphalts in low-traffic Pavements) Project concerns the cold recycling of 100% Reclaimed Asphalt Pavement (RAP) without binder addition in base and subbase layers of low-traffic roads. In this context, a test program was performed with Rhine Region materials to evaluate the impact of the mastic coating of untreated RAP. A source of reclaimed asphalts with 4.4% of bitumen is tested before (RAP) and after binder extraction (RAP-BE), then is compared to an unbound granular material (UGM) with a similar particle size distribution. Repeated Load Triaxial (RLT) tests were conducted at several frequencies to study the permanent and resilient behaviors. The results show that the RAP before binder extraction and the UGM present similar permanent behaviors, while the aggregates without binder reveal low strains. Concerning the resilient phase, the RAP and the RAP-BE show similar levels of strains, but the resilient moduli