Effect of Nano-Kaolinite Clay on Rebar Corrosion and Bond Behavior Between Rebar and Concrete

Abstract

The effect of nano-kaolinite clay (NKC) on the bond behavior between rebar and concrete was studied in a series of experiments. An electrical corrosion method was used to corrode the rebar embedded in concrete specimens. Chloride diffusion and chloride content tests were performed to evaluate the effect of nanoclay on the chloride diffusion depth and chloride ion content in concrete. Pullout tests were performed to assess the bond properties, including the bond-slip curve and ultimate bond strength, between concrete and rebar before and after corrosion. The results revealed that NKC improved the chloride resistivity and bonding in the concrete specimens. The specimens with a 5% nanoclay addition showed the lowest percentage of the rebar corrosion level and bond strength degradation due to corrosion. After 48 h of corrosion, the rebar corrosion ratio decreased by 52%, and the ultimate bond strength increased by 35% compared to the control specimen.