Reclaimed asphalt binder aging and its implications in the management of RAP stockpiles

Abstract

Reclaimed asphalt pavement (RAP) is a granular composite geomaterial that is highly reactive to the environment under normal atmospheric conditions. The binder aging processes that contribute to pavement deterioration do not stop upon reclamation. Here we report on the results of conventional and a novel RAP characterization test. RAP binder content has been observed to increase as RAP-particle size decreases. A simple analytical model is proposed to explain the results. Binder properties also change as a function of RAP-particle size. A simple thermomechanical test developed as part of this study shows differences in the temperature-dependent deformation of RAP particles of different sizes. These results evidence qualitative differences in binder viscosity, which can be attributed to RAP-binder aging.