Experimental Investigation of the Bond Performance between Nonuniformly Corroded Reinforcing Bar and Concrete

In this study, bond failure tests were carried out on eight beam anchorage specimens after accelerated corrosion, and the crack widths on the concrete surface and the nonuniform corrosion characteristics of the reinforcing bars were analyzed. The testing results show that the pitting volume and maximum crack width on the concrete surface both increase exponentially as the mass loss rate increases. According to the testing results, the pitting coefficient and uniform coefficient are introduced to reflect the effect of the pitting corrosion and uniform corrosion, respectively, on the bond strength, and as these two coefficients increase, the bond strength greatly decreases. In addition, based on the maximum crack width on the concrete surface, bond strength and peak slip models are developed, and a bond stress-slip model of the nonuniformly corroded reinforcing bar is proposed, combined with that of uncorroded reinforcing bar. It is proved that the proposed models provide good predictions.