Comparative analysis of stiffness modulus and fatigue resistance of asphalt concretes containing RAP materials

The paper discusses the results of a comparative laboratory investigation on the mechanical performance of bituminous mixtures for pavement base courses, made with Reclaimed Asphalt Pavement (RAP). Five Asphalt Concretes (AC) were used in this study: a control AC mixture with limestone aggregates and two AC mixtures with 20 and 40 % RAP (by weight of aggregate) respectively. The RAP material used came from two different sources, one from Italy and one from Greece. The mix design procedure was based on the optimization of the volumetric properties and the moisture resistance of the bituminous mixtures. Then, the stiffness modulus of the mixtures was evaluated by the Indirect Tensile Stiffness Modulus test, at various temperatures and rise times. The Indirect Tensile Fatigue Test, concluded the experimental trial. Depending on the RAP sources and content, the bituminous mixtures made with RAP aggregates showed improved indirect tensile strength as well as higher stiffness modulus values and fatigue resistance, with respect to the control asphalt concrete prepared with natural aggregate. © RILEM 2016