Wear resistance analysis of steel slag aggregates based on morphology characteristics

Steel slag can be utilized in the wearing course of highway asphalt pavement. However, further research is needed to explore the impact of steel slag on the wear resistance of asphalt pavement. This study aimed to evaluate the wear resistance of two steel slag samples and compare them with three stone aggregates based on morphological characteristics. The Los Angeles abrasion test was conducted at different revolution levels, and the micro-morphology characteristics of the aggregates were analyzed through image analysis using six morphology parameters. The results showed that the steel slag samples had the lowest Los Angeles abrasion rates, indicating their superior hardness and wear resistance compared to limestone and granite aggregates. The steel slag aggregates also exhibited higher values in morphological indices of arithmetic mean height Sa, peak apex density Spd, and arithmetic mean curvature of peak apex Spc, indicating a rougher surface, more contact points and more durable wear resistance. Fluctuations were observed on variation curves of the maximum height Sz, surface skewness Ssk, and surface sharpness Sku of the steel slag during the abrasion process, suggesting the presence of numerous pits and spikes that contribute to the skid resistance of the steel slag asphalt mixture. The arithmetic mean height Sa, peak density Spd, and arithmetic mean curvature of peak apex Spc showed a consistent decrease over the number of revolutions, making them reliable indices for future research on the wear resistance of steel slag asphalt mixtures. Overall, this study provides a basis for further research on investigation the correlation between the morphology changes of steel slag aggregates and the anti-skid performance of pavement wearing courses.