Laboratory investigation of the effect of ABS polymer on moisture susceptibility of asphalt mixtures

Abstract

ABSTRACTThis paper investigates the effects of Acrylonitrile Butadiene Styrene (ABS) polymer as an asphalt binder modifier on reducing the moisture susceptibility of hot asphalt mixtures. In order to recognise the efficiency of ABS polymer, repeated load tests in dry and wet conditions along with the thermodynamic parameters calculated through measuring the surface free energy (SFE) components of asphalt binders and aggregates were used. The results showed that ABS polymer caused an increase in the cohesion free energy and a reduction in the released energy of the system during stripping, indicating the reduced tendency of the system toward stripping. The results of repeated load tests supported the results obtained from the SFE method, demonstrating an improvement in moisture susceptibility of modified mixtures, especially the samples constructed by acidic aggregates. In addition, moisture sensitivity index was calculated using the thermodynamic parameters and asphalt mixtures modulus from cyclic loading tests. The results were similar to those of wet-to-dry modulus ratio and showed that ABS significantly reduced the stripping percentage of modified mixtures.