Binder rheological predictive models to evaluate rutting performance of asphalt mixtures

Abstract

This study investigated the rutting performance of asphalt mixtures through prediction of resilient modulus (Mr) based on the binder rheological stiffness parameter: G∗/sinδ. A total of seven different asphalt binder types from three sources were used, including: (a) three viscosity grade virgin (VG-10, VG-30 and VG-40) binders; (b) two polymer-modified (PMB-40 and PMB-70); and (c) two crumb-rubber modified (CRMB-55 and CRMB-60) binders. A total of 860 data points were obtained for evaluation of G∗/sinδ and a predictive model as a function of binder viscosity. In order to correlate binder properties with that of the mixes, eleven asphalt mixtures with three sample replicates each were prepared: six dense graded with virgin binders; two gap-graded with polymer-modified binders; and three gap-graded rubber-modified binders. Mr test parameters were obtained for the mixtures at 15, 25, and 35°C and 0.5, 1, 1.5 and 2Hz covering 396 data points. A Mr predictive model based on G∗/sinδ stiffness parameter was established with excellent statistical goodness of fit measures. Finally, advanced viscoelastic Mr parameters were estimated and the viscoelastic indicators were correlated to binder stiffness parameter to assess rutting performance of asphalt mixtures. A novel attempt was made in this study that presents a promising approach to correlate asphalt binder and mixture performance by using only one single rheological parameter based on the DSR test: G∗/sinδ; so as to minimize the experimentation during binder and asphalt pavement material characterization in future.