Bond Behavior between Steel Rebar and RCA Concrete after Exposure to Elevated Temperatures

To explore the bond behavior between steel rebar and recycled coarse aggregate (RCA) concrete after exposure to elevated temperatures, an experimental study was carried out. The results demonstrated that the bond strength of RCA concrete pullout specimens decreased greatly with increasing temperature. As the exposure temperature elevated, the slope of the ascending portion of the bond-slip curves gradually declined, and the descending portion of the curves tended to flatten. A modified model was developed to predict the bond strength between RCA concrete and steel rebar after exposure to elevated temperature, and the predicted results showed a very good fit in the experimental test results. Besides, the proposed bond-slip relations for steel rebar in RCA concrete after elevated temperatures showed satisfactory agreement with test results.