Sustainable production of WMA with pine gum wax modification

Abstract

Warm mix asphalt (WMA) (S®-WMA) produced with Sasobit® (S®), a widely used organic admixture, shows a significant increase in softening point value and a decrease in stripping resistance. These two characteristics of S®-WMA are considered as some problems to be solved. Therefore, this study was established to evaluate possible solutions to these two problems through another modification process. In this study, it was investigated whether modifying S®-WMA using a previously unstudied product, pine gum wax (PGW), could be a solution to the problem. In this context, WMA was produced with S® at 1, 2 and 3 in percent by mass of bitumen. As PGW has not been previously used as an additive to modify S®-WMA, it was added within a limit of 1% (by bitumen mass) for initial investigation. Physical and rheological standard tests were performed on each sample to demonstrate the change in properties of S®-WMA produced with 1% PGW compared to S®-WMA. The results indicated that the addition of 1% PGW to S®-WMA resulted in a significant reduction in softening point and an improvement in stripping resistance compared to S®-WMA. Thus, it seems that the use of PGW could be a potential solution for the two mentioned problems. It can also be pointed out that modifying the S®-WMA specimen with PGW without compromising its properties can help in an efficient, economical and environmentally friendly solution. However, due to the use of PGW, more in-depth research is required.