Evaluation of the moisture damage of warm asphalt mixtures

Utilizing warm mix asphalt (WMA) for pavements attracts attention from around the world due to its benefits. The major benefit is decrease in fuel consumption and emissions. Warm asphalt mixtures are investigated by using organic additives; two additives (Asphaltan A and Asphaltan B) are utilized in this research. A program of laboratory testing is performed on WMA mixtures and hot mix asphalt (HMA) mixtures using two different additives and three contents. Two aggregate gradations were utilized with three values for each additive, and a total of 12 types of warm mixture and two types of HMA were produced. Warm asphalt mixtures were compacted utilizing a Marshall procedure, and optimum asphalt contents were found for each asphalt mixture. A moisture sensitivity test was carried out for all mixture types to find their moisture resistance. From the outcomes, most warm mixtures passed the minimum value of tensile strength ratio (TSR) (80%) as required by the AASHTO and some mixtures failed to meet this criterion, which indicates that the moisture resistance is a concern in warm mixtures. Also, the fracture energy values were higher for warm mixtures than HMA mixtures, which indicates a better resistance to cracking for WMA.