Effect of corrosion inhibitors on bond strength of reinforced concrete under various exposure conditions

Corrosion inhibitors delay the incidence of reinforcement corrosion by decreasing the permeability of concrete. The impact of the commercially available inhibitors on the durability attributes of cover concrete needs more studies, especially the ones exposed to severe environmental conditions. This study mainly aims to investigate commercial inhibitors' efficacy in the bond characteristics of reinforced concrete for three different chloride-induced corrosion exposures. Eighteen specimens with dimensions of 150 mm x 150 mm x 150 mm, with optimum inhibitor dosage, were exposed to one of the three corrosion acceleration methods (induced current, sodium chloride saltwater immersion, and potable water immersion) after normal curing. The bond specimens peak slip, pull-out force, bond strength, and rebar mass loss were assessed after three, five, or seven cycles of wet-dry corrosion exposure. With the rise in immersion cycles, a general decline in bond strength was observed in all specimens. For instance, OW3 exhibited abond strength of 11.78 N/mm2, which diminished to 9.08 N/mm2 by the time of OW7. In contrast, adding corrosion inhibitors to the concrete mix increased bond strength, measuring 13.06 N/mm2 for OIW3 and 10.03 N/mm2 for OIW7. Using corrosion inhibitors enhanced the bond properties and reduced the mass loss in steel under severe corrosion exposures.