Evaluation of electric arc furnace steel slag coarse aggregate in warm mix asphalt subjected to long-term aging

Abstract

Considering the sustainable development principle, it seems necessary to reduce the temperature demands in producing asphalt mixtures and to replace mineral aggregates with secondary materials. In this study, the long-term performance of warm mix asphalt containing electric arc furnace steel slag was investigated. For this, Marshall Stability, resilient modulus at 25°C and 40°C, indirect tensile strength and moisture susceptibility tests were conducted. In the last stage, the ratio between the results of long-term and short-term aging of these tests was presented as an aging index. Using warm mix asphalt and replacing mineral aggregates with steel slag aggregate cause Marshall Stability, stiffness, resilient modulus and indirect tensile strength to increase. Although the tests conducted in this study indicate that using steel slag results in increased aging of the asphalt mixtures, warm asphalt mixtures containing steel slag experience less aging compared to control specimens (hot mix asphalt with limestone). Therefore, warm asphalt mixtures containing steel slag exhibit enhanced short-term and long-term performance as well as less aging. Hence, utilizing warm mix asphalt containing steel slag is generally recommended.