Moisture susceptibility of warm mix asphalt: A statistical analysis of the laboratory testing results

Warm Mix Asphalt (WMA), an alternative to Hot Mix Asphalt, has gained popularity in the recent years. In this research, the effects of aggregate gradation, hydrated lime and Sasobit has been investigated in WMA mixes. Indirect Tensile Testing was performed on dry and saturated samples. Response Surface Methodology was applied to analyze the data. The results indicated that in the case of Indirect Tensile Strength at saturation condition (ITSsat) all the first and second order terms of the aggregate grading, hydrated lime and Sasobit contents, as well as their interactive terms, were statistically significant at 90% confidence level. In the case of Tensile Strength Ratio (TSR) and Indirect Tensile Strength at dry condition (ITSdry) parameters, the interactions between grading and Sasobit contents were rather poor.