Corrosion of reinforcing steel increases the probability of the fracturing of longitudinal reinforcing bars and leads to the loss of load-carrying capacity in reinforced concrete (RC) members. Twenty-four reinforcing steel bars were subjected to the buckled bar tension (BBT) test, and the critical bending strain was obtained at different corrosion levels. The specimens were passivated reinforcing steel bars that were corroded through accelerated electrolytic corrosion. The results show that the critical bending strain decreases as the corrosion level increases. The critical bending strain influences the post-buckling bar fracture limit state and reduces the displacement capacity of columns as the corrosion level in the longitudinal reinforcing bar increases. In addition, the degradation of yield strength, ultimate strength, and uniform axial elongation for corroded reinforcing steel bars were observed.