Effects of moisture on warm mix asphalt containing Sasobit

Abstract

The asphalt industry has been at the forefront of sustainable development. Warm Mix Asphalt (WMA) has been developed to cope with issues such as high energy prices and air pollution. These mixes require less energy and generate fewer pollutants during production in comparison with conventional Hot Mix Asphalt (HMA). Although a promising technology, the durability of WMA is not clear because long-term WMA field performance data is limited. This study investigated the susceptibility of Sasobit-modified WMA to moisture, since moisture damage is a major cause of premature pavement failure in asphalt concrete. To this end, WMA samples were made using different concentrations of Sasobit and the results were compared with those from HMA mixtures. The effect of hydrated lime as an anti-stripping agent was also investigated. The tensile strength ratios indicate that the introduction of hydrated lime and Sasobit increased the resistance of asphalt mixtures to moisture. Fracture energy and toughness were used to evaluate the crack resistance of specimens under dry and wet conditions. In comparison with Sasobit, hydrated lime increased crack resistance of mixtures. The results indicate that hydrated lime can be used as a compatible and effective anti-stripping agent for WMAs containing Sasobit.