Temperature Performance and Rutting Prediction of Steel Slag Asphalt Mixtures

Steel slag, an industrial by-product, can replace basalt aggregate in road construction, helping to reduce the extraction of natural resources. By combining steel slag with waste rubber powder to produce steel slag–rubber-modified asphalt mixtures, both the material performance is enhanced and resource recycling is promoted. However, due to slight differences in high-temperature behavior between steel slag–rubber-modified asphalt mixtures and traditional basalt-based mixtures, existing rutting prediction models fail to accurately characterize the rutting development of the modified materials. To address this, four different types of asphalt mixtures were prepared in this study: full steel slag–rubber-modified warm-mix asphalt (CR-WSAM), partial steel slag–rubber-modified warm-mix asphalt (CR-WSBAM), full steel slag–rubber-modified hot-mix asphalt (CR-HSAM), and partial steel slag–rubber-modified hot-mix asphalt (CR-HSBAM). Uniaxial compression, Hamburg wheel tracking, and dynamic modulus tests were conducted, and a new rutting prediction model was developed by incorporating key factors influencing the rut formation. The results show that the proposed model outperforms existing models in terms of both accuracy and applicability, providing a more precise description of the rutting behavior of steel slag–rubber-modified asphalt mixtures. Furthermore, the model’s predictions show a higher correlation with measured rut depth values, indicating improved prediction accuracy.