Study on <scp>3D</scp> mesoscopic bond‐slip performance for crescent ribbed steel bar in lightweight aggregate concrete

Abstract The excellent bond‐slip performance between crescent ribbed steel bar and lightweight aggregate concrete is the foundation for the good working of the overall structure. In this paper, a 3D mesoscopic refinement bond‐slip simulation method for reinforced lightweight aggregate concrete was established. The validity of the 3D mesoscopic bond‐slip model was verified through experimental results. And meanwhile, the damage mechanism of different macro‐meso structures during the bond‐slip process was analyzed. Moreover, the effects of meso‐structural characteristics on the bonding performance were explored. The results show that when in the same bond‐slip state, the damage degree of lightweight aggregates is the highest. However, the damage degree of mortar is relatively light. The damage distribution areas of both are extended from the overall periphery to the central slip area, and the damage area of the mortar exhibits an inverted cone shape. In addition, the bond‐slip performance is more sensitive to the damage degree of interface fracture energy than other meso‐structural characteristics. When the damage degree of fracture energy reaches 80%, the ultimate bond stress decreases by 20.26%. Furthermore, the relationship between the damage degree of each meso‐structural characteristic and the ultimate bond strength is determined. The bond stress‐slip relationship characterized by the damage degree of meso‐structural characteristics is also established.