Evaluating the use of different fillers and Kaowax additive in warm mix asphalt mixtures

Abstract

The existing concerns about the global warming have prompted many researchers to study the warm mix asphalt (WMA) mixtures. Although WMA enjoys several advantages over the hot mix asphalt (HMA), it suffers from certain flaws such as moisture susceptibility and low temperature cracking. Therefore, it is important to enhance the performance of WMA, and one way of doing it is to use suitable fillers in the asphalt mixtures. The study aim is to evaluate the impact of the Portland cement type-II, fly ash, and the calcium carbonate as filler, on the WMA performance that made with Kaowax additive. We performed the semi-circular bending (SCB) test at low temperature, the four-point bending fatigue test, the indirect tensile strength (ITS), resilient modulus tests at medium temperature, and the dynamic creep test at high temperature. According to the obtained results, the presence of Kaowax increased resilient modulus and the rutting strength of the asphalt mix. The WMA samples containing the fly ash filler had good moisture susceptibility. The use of cement filler in the WMA resulted in improved rutting resistance. The calcium carbonate filler increased the performance of the WMA mixtures at all temperatures.