Experimental Study on Bonding Performance of Corroded Steel Bars and Grout in Sleeve

In order to study the influence of the corrosion of steel bars on the connection performance of grouting sleeve joints, a pull-out test was carried out on 20 specimens subjected to artificial corrosion. The test obtained the failure modes of the steel bars of different diameters in the grouting sleeves under different corrosion rates, the strain of the anchoring internal steel bars vs the load slip curves. The bond stress distribution curves, relative slip curves, and bond-slip curves at different anchorage positions with different diameter steel bars under different corrosion rates are compared and analyzed. Through the test results and theoretical analysis, it is found that as the corrosion rate increases, the pull-out ability of the steel bars is attenuated to varying degrees. When the corrosion rate reaches 12%, the pull-out ability of the steel bars in the grouting sleeve is reduced by about 50%. The bond stress attenuation mechanism of corroded steel bars in the grouting sleeve is obtained. A function model of the bonding and anchoring position of the steel bars before and after corrosion is established, and the parameter values are determined. The bond-slip constitutive relationship between the steel bars before and after corrosion and the grouting material is established considering the bond and anchor position function, which provides a reference for the finite element analysis of steel bars and the grouting material before and after corrosion. © 2022, Editorial Department of Journal of Hunan University. All right reserved.