Effect of copper slag on performance of warm mix asphalt

Copper Slag (CS) is a by-product obtained during the matte smelting and refining of copper. It is classified as waste materials and, therefore, is considered as an environmental issue to cope with. It can be effectively used for construction of pavement layers. On the other hand, in order to save energy and reduce the amount of pollutants released during asphalt production, Warm Mix Asphalt (WMA) technology can also be employed. This paper presents the influence of replacing limestone aggregates by copper slag on the performance of warm mix asphalt. Optimal Binder Contents (O.B.C) of asphalt mixes containing CS proportions of 0, 10, 20, 30 and 40% by total weight of aggregate were determined using Marshall procedure. Results of Indirect Tensile Strength, resilient modulus, flow number and wheel tracking tests indicated that 20% CS in WMA enhances resilient modulus, Marshall stability, rutting and cracking resistance the most and has substantial positive effect on moisture susceptibility.