ABSTRACT
ABSTRACT Steel bars in concrete structures usually maintain a passivation state due to high pH in the concrete pore solution. However, it is known that the passivation film of a steel bar in concrete is destroyed by chloride attack in a marine environment. Among past studies in the field of concrete engineering, there is little theoretical explanation of the mechanism of breakdown of the passivation film around a steel bar; therefore, a theoretical model of the mechanism needs to be developed. This paper derives such a theoretical model and verifies its validity based on experimental data. As a result, it can be concluded that the relationship between the steel bar potential and the critical chloride ion concentration for passivation film breakdown is an exponential relation, and the relationship between the pH and the critical chloride ion concentration for passivation film breakdown is a linear relation.
