Abstract

Durability of an asphalt mixture is directly related to the optimum asphalt binder content, which guarantees coverage of the aggregate particles and suitable volumetric properties to ensure a good performance in service, producing an asphalt mixture that is less susceptible to aging and moisture damage. Previous research has shown that the polygon-of-voids tool, or polyvoids, is an analytical technique to determine the optimum asphalt binder content of asphalt mixtures with virgin aggregates based on the specification limits of voids, allowing a saving in time and material. However, current trends to develop new asphalt mixtures which incorporate reclaimed asphalt pavement (RAP) have created additional challenges given the nature of the design of a mixture containing aggregates with residual asphalt that make the property measurement of the bulk specific gravity of the RAP aggregate (Gsb^RAP) difficult. This paper aims to demonstrate the application of the polygon-of-voids tool for the design of recycled hot-mix asphalt. The results show that the method of substitution, where the value of the actual specific gravity of the RAP aggregate (Gse^RAP) is assumed as the bulk specific gravity of the RAP aggregate (Gsb^RAP), gives the optimum asphalt contents closest to those determined by the traditional Marshall method for the design of asphalt mixtures.