Effect of using various waste materials as mineral filler on the properties of asphalt mix

Environmental waste caused by technological and industrial development is increasing. In Egypt, tens of thousands of tons of industrial waste are disposed of each year. One of the cheapest and most effective ways to eliminate such waste and protect the environment is recycling in hot mix asphalt (HMA) mixture. We carried out a laboratory investigation into the effects of different fillers on some properties of such HMA mixtures, considering two types of industrial and byproduct waste filler, namely ceramic waste dust (CWD) and marble waste dust (MWD). Ceramic waste dust (CWD) was enhanced using cement dust at 1:1 ratio to remove its plasticity. Lime stone dust (LSD) was used as control filler. Subsequently, 17 HMA specimens were prepared using the Marshall mix design method for wearing surface mix (mix 4C). Marshall stability (MS) and flow tests were applied to the specimens, and MS and flow values recorded. For the optimum bitumen content (OBC) and different waste ratios, the Marshall parameters were determined. Then, some special tests were performed to measure the different mix characteristics, including loss of stability and wheel tracking tests. The results led to important conclusions regarding use of ceramic waste dust (CWD) enhanced by cement dust and marble waste dust (MWD) to improve most of the properties of HMA mixtures. Finally, this study recommends a proposed mix with mineral filler formed of 35 wt.% CWD enhanced by cement dust or 15 wt.% MWD respectively.