Title: A Critical Review of Deterioration of Concrete Due to Corrosion of Reinforcing Steel

Author(s): Kimberly E. Kurtis and Kumar Mehta

Publication: Symposium Paper

Volume: 170

Issue:

Appears on pages(s): 535-554

Keywords: Carbonation; chlorides; concretes; corrosion; durability; permeability; reinforced concrete; reinforcing steels.

DOI: 10.14359/6840

Date: 7/1/1997

Abstract:
Throughout the world, sizable portions of national budgets must be appropriated for the repair and rehabilitation of concrete structures which have suffered damage due to corrosion of reinforcing steel. This paper presents a critical review of the current state-of-the-art on the mechanisms responsible for deterioration of concrete and reinforcing steel. The protective effect of the passive film and the depassivation of reinforcing steel by carbonation and chloride ingress are discussed. In addition to the passive film, some researchers believe that a mineral scale may contribute to the protection of embedded steel against corrosion. The following ambiguities in the current understanding of the deterioration of concrete due to corrosion of the reinforcing steel are discussed: mechanisms of passivation of steel in the concrete environment; stoichiometry of the passive film; applicability of Fick’s second law for the prediction of chloride diffusion in concrete; mechanisms of depassivation of steel by chloride ions; threshold Cl-/OH ratio; the composition and mechanism of protection provided by mineral scales; mechanisms of expansion of the steel corrosion product in concrete; and the detrimental effects of aggressive ions on concrete properties.