Evaluation of Temperature Stability and Pavement Performance of Steel Slag Asphalt Concrete Based on an Experimental Roadway

With the growing focus on the concept of net-zero carbon reduction, the application performance of steel slag asphalt concrete has attracted increasing attention. However, numerous factors at construction sites influence construction quality, and steel slag, as a recycled material, often raises concerns about the stability of its construction quality. In this study, steel slag asphalt concrete (with a steel slag content of 39%) was evaluated on two experimental roads located on heavy traffic routes: Experimental Road A and Experimental Road B. Both roads are situated at similar distances from the asphalt mixing plant, allowing for an analysis of temperature changes and performance stability across different conditions. Experimental Road A’s length is 2,395 meters, while Experimental Road B’s length is 640 meters, with both roads surface layers having a pavement thickness of 5 cm. This study monitored temperature variations during the transportation and paving processes as well as road smoothness and rut depth over 18 months after opening to traffic. Results indicated that the average temperature drop during transportation was 14.6°C for Experimental Road A and 16.8°C for Experimental Road B, with an identical average paving temperature of 166.5°C for both. These findings suggest stable temperature control during transportation and paving. Performance analysis under heavy traffic over 18 months revealed that the standard deviation of pavement smoothness increased by 0.9 mm for both experimental roads. Meanwhile, the maximum rut depth increased by 5.5 mm for Experimental Road A and 5.4 mm for Experimental Road B. The results show that steel slag asphalt concrete exhibited excellent load-bearing capacity and stability across different experimental roads.