Feasibility of Using Electric Induction Furnace Steel Slag and Copper Slag in the Production of Hot Mix Asphalt

Industries produce large amounts of electric induction furnace steel slag (EIF) and copper slag (CuS) as waste, and their disposal poses serious economic and environmental issues. The use of these slags in pavement could ease environmental concerns and promote the conservation of non-renewable resources. This paper is based on an experimental investigation into the potential for employing EIF and CuS at 0, 5, 10, 15, 20, and 25% as a partial replacement of fine Natural Granite Aggregate (NGA), whose size ranges from 4.75 mm to 0.075 mm, in producing dense Hot Mix Asphalt (HMA) mixes. The physical, chemical, morphological, and expansive properties of EIF and CuS were investigated. The Marshall method of mix design was adopted to produce HMA mixes. The results showed that for EIF-based HMA mixes, stability, Indirect Tensile Strength (ITS), and rutting resistance increased, whereas for CuS-based HMA mixes, these properties decreased but satisfied their required permissible criteria. The Tensile Strength Ratio (TSR) of EIF and CuS-based HMA mixes was found to be increased. The findings of this study indicated a high possibility for using EIF and CuS as aggregates, and a replacement level of 20% of these slags in HMA mixes was suggested as optimal.