Influence of Corrosion on the Bond–Slip Behaviour between Corroded Bars and Concrete

Pull-out tests were conducted to investigate the effects of corrosion of both the longitudinal bars and stirrups on the bond slip behaviour of reinforced concrete specimens. The main experimental variables include concrete strength (26.7 MPa, 37.7 MPa and 45.2 MPa) and expected corrosion loss (0%, 4%, 8% and 12%), with a total of 63 specimens fabricated. The results show that the relative bonding strength of specimens under different concrete strengths gradually decreases with increasing corrosion loss, but the higher the concrete strength is, the faster its degradation rate. The influence of stirrup corrosion on the peak slip can be ignored, but it will further aggravate the degradation of the bonding strength of the specimens. This reduction in bonding strength is linearly related to the stirrup corrosion loss. Based on the experimental results of this work and the achievements of other scholars, a modified relative bonding strength degradation model and a bond–slipbond–slip constitutive model of corroded reinforced concrete are presented by accounting for the influence coefficient of concrete strength. The results show that the constitutive model is in good agreement with the relevant experimental results.