Bond-slip model for reinforced concrete based on wedge theory

The bond plays a significant role in ensuring that the reinforcement and concrete can transfer stress effectively in concrete structures. First, an expression for the relationship between the bond force and the radial force of the concrete on the reinforcement is derived based on the localized compression wedge-splitting theory. Second, the formula for the radial force of concrete on steel bars and the formation of concrete fractures is determined using the thick-walled cylinder and combined rod models. Third, a continuous bond-slip model for reinforced concrete is presented. The model accounts for the impacts of concrete cover and the size of the extracted reinforcement on the bonding action by applying a finite element analysis of the length factor of the wedge-splitting effect. The radial equivalent characteristic strain of the indirect reinforcement is employed to conduct a simultaneous analysis of the influence of indirect reinforcement confinement on bond performance. At last, the model's applicability and validity are confirmed by the available experimental data. Meanwhile, the impact of variables such as steel bar diameter and anchoring length on bond strength is investigated. The results demonstrate that the suggested theoretical and experimental curves correspond well. The bond strength is proportional to the radial force. The development pattern of splitting cracks and tensile cracks in concrete is explored. At the same time, the law of influence of parameters on bond strength is reflected, such as diameter of reinforcement, thickness of concrete, and anchorage length.