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

• Published in: Construction & building materials 2015-12, Vol.101, p.611-616
• Main Authors: De Lira, Rodolfo Rascon, Cortes, Douglas D., Pasten, Cesar
• Format: Article
• Language: English
• Subjects: Asphalt binder aging; Geomaterials testing; Reclaimed asphalt pavement; Recycling; Thermoactive composite geomaterial
• ISSN: 0950-0618; 1879-0526
• DOI: 10.1016/j.conbuildmat.2015.10.125

•The binder content in recycled asphalt pavements (RAP) is particle-size dependent.•RAP binder aging is particle-size dependent. Small particles age faster.•Binder from larger RAP particles is expected to experience less extent of oxidation.•Harvesting and stockpiling larger particles should maximize RAP-binder shelf life. 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.