Effects of non-foaming WMA additives on asphalt binders at high performance temperatures

Abstract

Due to many reasons including the energy reductions and environmental benefits, warm asphalt has been gaining increasing popularity in recent years around the world. In the present study, the objective was to conduct a laboratory investigation of rheological properties of non-foaming WMA additives at high performance temperatures. The conventional testing procedures such as viscosity, performance grade, creep and creep recovery, amplitude sweep and frequency sweep as well as specific Fourier Transform Infrared Spectroscopy (FTIR) were performed to determine the influences of non-foaming additives on asphalt binders. The experimental design included eight binders and four non-foaming WMA additives. The test results indicated that, the non-foaming WMA additive can slightly reduce the viscosity value of asphalt binder and thus decrease the mixing and compaction temperatures of the mixture. The binders containing non-foam additive have a slight increase in high failure temperatures compared to control binder and thus improving the rutting resistance of the mixtures. In addition, creep recovery, amplitude and frequency sweep tests show that the binders with Sasobit has a slightly higher complex modulus but exhibits lower creep compliance and phase angle than the binder containing other WMA additives regardless of asphalt type and grade. Furthermore, FTIR analysis results indicate that the binder type plays a key role in determining the rheological properties of WMA binders.