Laboratory evaluation of rutting susceptibility of polymer-modified asphalt mixtures containing recycled pavements

This paper presents the results of the laboratory study on rutting susceptibility of polymer-modified asphalt mixtures containing Reclaimed Asphalt Pavement (RAP). Accelerated rutting tests were conducted in the Asphalt Pavement Analyzer (APA) and binders were evaluated in the Dynamic Shear Rheometer in order to construct dynamic shear modulus (|G∗|) master curves and to evaluate their viscoelastic and recovery properties using the Multi-Stress Creep Recovery Test (MSCR). Polymer content and level of oxidation of different binders were analyzed using an Attenuated Total Reflection Fourier Transform Infrared spectrometer while X-ray diffraction and X-ray fluorescence spectrometers were employed to verify the mineral content of RAP aggregates. The effect of RAP binder on the APA and MSCR results showed reasonable correlation with reduced rutting for less-modified binders. Highly-modified binders were the least affected. Aggregate properties of RAP mix had a noticeable effect on rutting results and adding RAP binder to the mix lead to reduced rutting.