The Laboratory Study of the Effect of Using Liquid Anti-Stripping Materials on Reducing Moisture Damage of HMA

Abstract

Liquid anti-stripping materials are the most popular materials used to improve moisture resistance of hot mix asphalt (HMA). In this study, the effect of two types of liquid anti-stripping materials (Wetfix N422 and Wetfix 312) with different percentages on the moisture susceptibility of HMA have been studied. HMA specimens with three types of aggregates (limestone, granite and quartzite) and two types of liquid anti-stripping materials are used in different percentages that are studied by modified Lottman test. In order to evaluate the effect of additive more accurately, 1, 3 and 5 freeze-thaw cycles are applied to the specimens. The results of this study indicate that the impact of additives used leads to the increased proportion of indirect tensile strength (ITS) in dry and wet conditions of HMA. The results of this study indicate that the additives used in this study increase tensile strength ratio (TSR) and the asphalt mixes’ resistance against moisture damage. In this study, the effect of anti-stripping additives in specimens under the wet conditions is more evident at higher freeze-thaw cycles compared to control specimens. In addition, the results show that the specimens prepared with limestone aggregate and Wetfix 312 additives have the highest TSR values.