Comparing different rutting specification parameters using high temperature characteristics of rubber-modified asphalt binders

In this research, three different methods of rutting resistance evaluation of asphalt binders were compared using high temperature characteristics of rubber-modified binders. For this purpose, implementing dynamic shear rheometer, frequency sweep test and repeated creep and recovery test were conducted on neat and modified samples at 60°C. Rutting resistance of asphalt binders were determined by three approaches: the Superpave specification parameter, G*/sin δ, the cross model for calculating zero shear viscosity, and the Burgers model to determine viscous component of creep stiffness. Utilising these three approaches, rutting resistance of modified asphalt binders were determined and then normalised to rutting resistance of the neat asphalt binder in order to calculate rutting resistance improvement ratio. Results showed that ranking of modified asphalt binders according to three approaches is the same while the quantity of improvement was significantly different. Also, based on these methods, it was observed that crumb rubber has better anti-rutting properties than reclaimed rubber.