Rheological properties of dioctyl adipate-modified asphalt binder

By referring to the successful application of a cold-resistant plasticizer in the plastic industry, dioctyl adipate (DOA) plasticizer was selected to improve the low-temperature performance of asphalt. Dynamic shear rheometer (DSR) and bending beam rheometer (BBR) tests were conducted to analyse the high and low temperature performance of plasticizer-modified asphalt binder. The residual creep rate ratio was put forward to evaluate the improvement effect of the anti-aging performance of asphalt binder. The rheological characteristics analysis shows that DOA could increase the viscous components in asphalt binder. However, with the increase of plasticizer content to 3.0%, the creep rate increased by 35% and the creep stiffness decreased by 39% at −24°C. The low temperature performance of DOA modified asphalt binder was improved by 30%. The residual creep rate ratio of the plasticizer-modified asphalt binder was more than 15% higher than base asphalt at the same temperature and softening point increment was 22.5% lower than base asphalt which means that the anti-aging performance was improved. Comprehensive analysis of the high and low temperature performance of DOA modified asphalt shows that the optimum content is 3.0%. Fourier-Transform Infrared Spectroscopy (FT-IR) indicates that the plasticizer and asphalt binder mainly undergo a physical blending reaction.