Experimental analysis of the effects of chloride-induced reinforcement corrosion in smooth and ribbed rebars on the bond between steel and concrete

摘要

Corrosion of the reinforcement is one of the most common and most expensive deterioration mechanism in reinforced concrete (RC) structures. While a lot of research has been performed on the design of new RC structures, estimating the remaining capacity of existing structures with corroded reinforcement still requires dedicated attention. One of the important damage modes due to corrosion is the deterioration of bond between steel and concrete. In this paper, the effect of reinforcement corrosion on the bond strength was investigated for smooth and ribbed rebars. Bond behaviour was studied at different target corrosion levels: 0%, 1.5%, 5% and 10% steel mass loss. Reinforcement bars embedded in concrete were subjected to accelerated corrosion by imposing a constant direct current while the specimens were partially immersed in a 5% NaCl solution. During the corrosion process, one of the specimens of each rebar type and every corrosion level was monitored with the acoustic emission (AE) technique. At target corrosion levels, pull out tests were carried out to study the bond capacity. Results show that AE effectively detects effects of rebar corrosion. Bond-slip curves of specimens with smooth and ribbed reinforcement were compared and the effects of different corrosion levels were analysed. The results were also related to results obtained from the literature.