Effect of Organic and Chemical warm additive on WMA performance

Warm mix asphalt (WMA) is a mixture with a mixing and compaction temperature 30–40 degree less than conventional asphalt mixture. Lower product temperature of WMA leads to increase use of this but this temperature reduction has raised concerns about rutting and fatigue performance. The object of this study is to in to investigate the effect of type of warm mix additives on moisture susceptibility and rutting resistance. For this purpose, limestone and steel slag, two type of filler and Zycotherm and Asphalten-B as warm additive were used for samples preparation and evaluating performance. Indirect tension, resilient modulus and Dynamic creep tests were performed on prepared samples for evaluating the effect of aggregate type, filler and additives on moisture susceptibility and rutting resistance. Results indicate that mixture containing Asphalten-B improve the performance of WMA as compared to HMA in ITS, MR, rutting by 10, 15 and 5%, respectively and in moisture susceptibility, asphalt mixture contain Zycotherm can increase the moisture resistance by about 10%. Also, result show that asphalt mixture containing steel slag aggregate and cement filler the highest durability and rutting resistance.