Study on Cracking Behavior of Steel Slag Asphalt Mixture at Different Healing Efficiencies Based on Discrete Element Method

Steel slag is a green low-carbon building material, and it has been widely used in the construction of road projects in recent years. Steel slag asphalt mixture can self-heal to a certain extent while not bearing external load. To investigate the influence of different healing efficiency on the performance of steel slag asphalt mixture, a discrete element simulation model was established based on the CT scanning image processing method in this study. The load response of steel slag asphalt mixture specimens with different healing efficiency (80%, 60%, 40%, 20%) was analyzed, and the number and behavior of cracks at different healing efficiency were tracked. The results showed that the load displacement curve obtained from the virtual discrete element simulation was in good agreement with the load displacement curve obtained from the semicircular bending test. With the decrease of healing efficiencies, the ultimate load and fatigue life of the semi-circular specimen decreased and the number of cracks increased gradually. When the load reaches the ultimate bearing capacity, the crack grew rapidly, and the number of cracks grew slowly after this period.