Moisture susceptibility of hot mix asphalt containing asphalt binder modified with nanocomposite

There are several methods to improve moisture susceptibility of asphalt mixtures that using additives or modifiers is the most common method in this regard. In this research, a new nanocomposite material was used for improving the moisture susceptibility of the asphalt mixtures. The experimental design included one base asphalt binder, two types of aggregates (granite and limestone) and 2% of nanocomposite (polypropylene/nanoclay). Indirect tensile strength and surface free energy tests were conducted to evaluate the moisture susceptibility of the asphalt mixtures. The surface free energy components of the aggregates and asphalt binders were obtained using universal sorption device and Wilhelmy plate methods, respectively. The test results showed that the tensile-strength-ratio values of the asphalt mixtures containing nanocomposite had improved. In addition, the results of surface free energy test indicated that the nanocomposite could be used to improve the moisture susceptibility of the asphalt mixtures.