Utilization of steel slags to produce thermal conductive asphalt concretes for snow melting pavements

This study focuses on the thermal conductivity of steel slag asphalt mixtures. The initial aim of this study was to verify the feasibility of adding steel slag to asphalt mixtures as a thermal aggregate to increase the thermal conductivity for electrical-thermal snow melting. The thermal conductivity of different rock aggregates and steel slags were firstly tested, before the surface temperatures of different-sized particles of the target steel slag was measured. In addition, the thermal conductivity and engineering performances of asphalt mixtures with different steel slags contents were measured. Experiment results indicate that diabase and hot-stuffy steel slag possesses higher thermal conductivity, and that particles of sizes 9.5–13.2, 1.18–2.36 and 0.3–0.6 mm are the most effective sizes. The thermal conductivities of the asphalt mixtures firstly increased, before decreasing with increasing steel slag replacement, and the thermal conductivity reached a peak for a steel slag volume replacement of 6%. All of the steel slag asphalt mixtures meet the required engineering performance, and the steel slag asphalt mixtures played a positive role in the snow melting process on an electrical-thermal pavement system, compared with ordinary asphalt mixtures.