Comparative evaluation of dense-graded and gap-graded asphalt mix incorporating electric arc furnace steel slag and copper mine tailings

The use of non-conventional aggregate materials in road works is still at an experimental stage in Malaysia. The persistent utilization of conventional aggregates in the construction of roads and highways is a potential hazard to the environment. Effective extenuation actions and invaluable research on alternative aggregate materials could alleviate the problem. In this study, an investigation on the suitability of electric arc furnace (EAF) steel slag and copper mine tailings (CMT) as alternative asphalt paving materials is proposed. Laboratory tests to evaluate the performance of mixtures incorporating EAF steel slag and CMT were conducted. Four material mixtures of sixteen mix designs, eight ACW 14 designed and eight SMA 14 designed were evaluated. Mix 1 was 100% granite, Mix 2 consisted of 80% granite and 20% CMT, Mix 3 consisted of 80% EAF steel slag and 20% CMT while Mix 4 consisted of 40% EAF steel slag, 40% granite and 20% CMT. The test results indicated that mixes containing EAF steel slag and CMT performed better in rutting and are less susceptible to permanent deformation compared to control mix. Hence, it is envisioned that EAF steel slag and CMT are promising alternative aggregate to be used as asphalt paving material.