The evaluation of heavy duty binders in bituminous road materials

The effect of polymers and epoxy resin on the properties of bitumen were evaluated. The rheological properties of mixtures were measured and the stress-strain relationships in model pavements were analysed, Mixtures with high viscosity had high strength, a high modulus, low compliance and a low rate of deformation, and consequently had high deformation resistance to wheel load and low tensile strain in the surface on a model steel plate deck, The failure envelope concept was introduced to find the temperature at which thermal cracking was induced in the surface of the pavement; mixtures with low viscosity had lower thermal cracking temperatures, Relaxation moduli and shift factors obtained from various test methods were similar to each other, and were similar at the specific temperature for each mixture, Creep compliance results from the bending creep test were a little higher than those from the tensile creep test with longer loading times.