The effect of heating and cooling on the bond strength between concrete and steel reinforcement bars with and without epoxy coating

The purpose of this study is to investigate the temperature effects on the bond strength between concrete and steel reinforcement bars. For two different steel bars (epoxy-coated and uncoated bars), three experimental parameters (heating rate, target temperature, and cooling condition) are examined. At a target temperature of 200 °C, the epoxy-coated rebar has much higher bond strength than the uncoated rebar. However, in the specimens exposed to target temperatures higher than 200 °C, the test results show that the epoxy coated rebar has less bond strength than the uncoated rebar. Also, the test results demonstrated that as the heating rate and target temperature increase the bond strength decreases. The cooling method does not affect the ultimate bond stress of the specimens using uncoated rebar very much but can greatly affect specimens that contained epoxy coated rebar. A more in-depth study can be considered regarding the cooling effect on the bond strength.