Effect of High Temperature on the Bond Performance of Reinforcing Bars in Inorganic Polymer Concrete

This paper discusses the effect of the compressive and tensile strength of inorganic polymer concrete (IPC), protection layer thickness and bonded length of reinforcing bars (rebars) on the bond performance between IPC and rebars through laboratory tests of IPC at high temperatures. In addition, the bond performances of IPC and ordinary concrete at high temperatures are compared. The experimental results indicate that IPC at high temperatures exhibits superior bond performance with rebar compared with ordinary concrete. As the temperature increases, the reduction in the IPC-rebar bond strength exhibits similar behavior as the reduction in the compressive and tensile strengths of IPC. Thin protection layers contribute to significant degradation of the IPC-rebar bond strength at high temperatures. The degradation of the bond strength is affected by the rebar bonded length at room temperature but is not influenced at high temperatures. The analytical expression of the IPC-rebar bond strength at high temperatures can be derived by best fitting the experimental results. Based on the expression of the ultimate bond strength and the expression of rebar slip, a two-segment regression analysis is performed to obtain the local bond-slip relationship of rebars in IPC after exposure to high temperatures. This study provides theoretical contributions to the engineering application of IPC.