Abstract: This paper reviews the studies on the interaction between steel bar and concrete. Taking into account the thickness of concrete cover and section stress distribution in the concrete, a numerical model for evaluating the end slip and steel bond length of reinforced concrete specimen is proposed in this paper, which is verified by relevant tests. Under the assumption of linear stress distribution in the section and the given critical thickness of concrete cover, the proposed model is adopted to determine the end slip, critical steel stress and bond length of joint reinforcement of Xiaowan arch dam. The results indicate that the measure to control the opening of joint is feasible on the whole. In addition, the thickness of concrete cover and the allocation of joint reinforcement are suggested for engineering design.