Laboratory performance of asphalt mixtures incorporating electric arc furnace slag and basic oxygen furnace slag as partial replacement for conventional aggregates

The usage of unconventional aggregate materials in road construction is still in the experimental stage. A possible environmental risk is the continued use of conventional aggregates in the construction of roads and highways. The issue may be resolved by sensible mitigating measures and essential research on substitute aggregate materials. The present article investigates the laboratory performance of asphalt mixtures incorporating electric arc furnace slag (EAF) and basic oxygen furnace (BOF) slag as partial replacements (10%, 30%, and 50%) for conventional aggregates. Surface morphology and chemical composition of aggregates have been studied using SEM and EDAX analysis. The characteristics of the asphalt mixture's mix design, including abrasion loss, moisture sensitivity, rutting resistance, fatigue behaviour, and resilient modulus, were investigated. Results indicate that the mix design properties of asphalt mixtures with EAF and BOF slag were within the requirements. Further, the incorporation of EAF and BOF slag in asphalt mixtures reduced abrasion loss irrespective of replacement percentage. Moisture sensitivity, rutting, fatigue, and resilient modulus properties of asphalt mixtures with 30% EAF slag were higher compared to asphalt mixtures with 30% BOF slag and conventional mixtures. However, asphalt mixtures with 50% replacement of EAF and BOF slag were lower compared to control mixtures. According to the findings, the optimum replacement percentage for EAF and BOF steel slag is 30% conventional aggregate. When compared to BOF steel slag, EAF steel slag performed better in terms of moisture sensitivity, rutting resistance, fatigue behaviour, and resilient modulus. The results of this study can be used as a reference for creating recycled asphalt mixtures with slag aggregates sourced from the steel industry.