Research On Bond Performance Between The Rusted Bar And Concrete By Pullout Tests

The topic of this paper is from the Chinese National Natural Science Foundation Item (50278039) - Analysis and research on the whole life of concrete structures, which is presided over by Associate Prof. Luo Xiaohui.Bond action is the basic precondition for conjunct work of steel bar and concrete in reinforced concrete structures. When the steel bar is rusted, the bond stress will decrease much, which will impair the safety and durability of the structure severely. Research on bond issue of corroded reinforced concrete is important in both theory and practice. However, due to multitudinous influencing factors and intricate mechanism, bond action of corroded reinforced concrete is a sort of complicated interaction. A comprehensive and credible bond theory system when the steel bar is rusted hasn't been established. Therefore, research on bond performance of corroded reinforced concrete is one of the most active and promising research fields.In this paper, bond issue of corroded reinforced concrete is analyzed comprehensively based on summary of existing research productions. Based on a lot of precise experiments, the influence of the rust-degree of steel bar acting on bond performance is analyzed particularly, the formula of bond intensity which considers the influence of the rust-degree is got by fitting the test data. After getting the average bond stress-slip relation, the constitutive relation of bond-slip between the rusted steel bar and concrete which considers the influence of anchoring position is established, which can be used to the finite element analysis. Otherwise, the pullout test is emulated through the finite element analysis. The stress and strain of the corroded bar and concrete,the slip at the both side of the corroded bar and the bond stress between the corroded bar and the concrete which are acted on different kinds of load is got by using the commercial software ANSYS. By comparing the test results with the calculated results, the availability of the calculated results is proved, which can be used on researching the bond mechanics between the rusted steel bar and concrete.The research productions in this paper promoted the development of the bond theory, and the experiment research on bond performance between the corroded bar with the concrete improved the cognitive level. Reference for future research and instructions for engineering practice are also provided.