Performance study of Warm Asphalt Mixtures (WAM) made with recycled modified asphalt pavement

Abstract

The incorporation and reuse of Reclaimed Asphalt Pavement (RAP) is increasingly vital within the framework ofa circular economy. In the coming years, RAP sources will predominantly consist of modified asphalt pavements. This Modified RAP (RAP M) can significantly influence the performance of new asphalt mixtures, particularly when incorporated at high dosages. Furthermore, combining RAP M with Warm Asphalt Mixtures (WAM)techniques, which are seeing increased global adoption, could substantially enhance environmental sustainability. The primary objective of this study was to evaluate the performance improvements of WAM containing 20 % and 40 % RAP M. The mixtures were characterized based on rutting, fatigue behaviour, dynamic modulus, and moisture susceptibility, and compared against control mixture. Results indicated that RAP M substantially improved resistance to rutting and moisture damage compared to both the control (virgin hot asphalt mixture) and recycled mixtures produced with conventional RAP. The reduction in rutting was particularly notable in the 40 % RAP M mixture, performing comparably to high-performance virgin mixtures made with modified binders. Additionally, the 20 % RAP M dosage showed a significant improvement in the wheel tracking slope. Regarding moisture sensitivity, RAP M had a positive impact, no detachment of the binder film from the aggregates was noted meanwhile permanent deformation was significantly reduced. Also, fatigue response improvements were noted for recycled mixture with RAP M with increasing in fatigue life.