Applicability of the Cox-Merz relationship for asphalt binder

摘要

Asphalt binder has a critical effect on the performance of asphalt mixtures. Thus, asphalt binder is of great concern to pavement engineers and researchers. Usually, asphalt binder is studied in dynamic space and steady-state space separately, and the property indices are researched separately. As researchers delved deeper, they found that it is important to combine the dynamic properties and steady-state properties, especially for establishing rheological curves and constitutive equations. The Cox-Merz relationship can connect the properties in dynamic space to those in steady-state space. This relationship is widely used in polymer system and shows good results. This study focused on the applicability of the Cox-Merz relationship as it pertains to asphalt binder. The Cox-Merz relationship was applied to six neat asphalt binders. Then, the applicability of the Cox-Merz relationship for asphalt binder was studied and the criterion to verify whether the Cox-Merz relationship is followed or not was established. Finally the viscosity functions when the Cox-Merz relationship used were studied, and the Cross model and the Carreau model were compared. The results show that the Cox-Merz relationship is followed in the shear-thinning region and not always followed in the zero-shear-rate-limiting viscosity region, and it is useful when obtaining the viscosity function.