Influence of Water Repellent Treatment on Corrosion of Steel in Concrete with Chloride Ingress

Abstract

Abstract. Corrosion of steel due to chloride ingress is a worldwide problem in reinforced concrete. In order to control such chloride-induced corrosion and evaluate the effectiveness of silane water repellent surface treatment on steel corrosion in concretes with different chloride ingress, two series of reinforced concrete specimens were used to investigate experimentally. In the first series, concrete was applied permanent migrating chloride from a reservoir of 3% NaCl solution which was placed on the top surface of each specimen. For comparison, the same concrete was made with silane water repellenet treatment correspondly. Tests were taken with half-cell potential and polarization resistance methods. Results show that steels in concrete without water repellent treatment have more negative half cell potential, higher mass loss ratio and bigger corrosion current density, and the effect of improvement through silane liquid surface treatment is evident. In the second series,concrete was same to the first one, but for wetting and drying cycle chloride ingress. Results indict that corrosion potentials decreased in negative little and later keep stable in the beginning period after water repellent treatment. Relatively for specimens without treatment, the value of corrosion negative corrosion potentials and corrosion current densities increase all the time.