Laboratory investigation of anti-stripping agents for improving the interfacial interaction between PE wax modified asphalt binder and aggregate

Abstract

The utilization of wax obtained from waste PE (PEW) as warm-mix additive (WMA) in asphalt pavement was attractive for environmental and economic benefits. However, this may lead to a decrease in the interfacial interaction between asphalt binder and aggregate, thus causing a moisture damage of asphalt pavement. In order to achieve the increase of PEW modified asphalt (WA) adhesion, this work investigated the effects of two types of anti-stripping agents (ASAs) with or without amino-group (XT-1 and KH-550) on the adhesion property and high-and-low temperature performance. Fourier transform infrared (FTIR) spectroscopy and Fluorescence microscope (FM) were employed to analyze the micro-properties of ASA modified WA binders. The DSR and BBR tests were used to evaluate the high-and-low temperature performance of the binders. The adhesion property of the binders was evaluated based upon surface free energy theory as well as using water-boiling method. The results indicated that both of the ASA and PEW can be dispersed into asphalt binder uniformly. Both the XT-1 and KH-550 improved the high temperature performance of WA. KH-550 improved the low temperature performance of WA based upon BBR results. In the terms of adhesion property of WA to limestone aggregate, the XT-1 and KH-550 improved the adhesion work of WA by 14% and 16%, respectively. This study suggested that the KH-550 with trimethylsilyl ether group and amino group can improve both the adhesion property and high-low temperature performance of WA.