CORROSION OF REBAR UNDER CARBONATION AND SALT ENVIRONMENT

Abstract

In this study, the behavior of reinforced concrete under carbonation and in a salt environment was investigated. Three types of cements- Type I cement, Type II cement and high alumina cement (HAC) - were used to study the influence of cement on reinforced concrete behavior. To simulate chloride contaminated concrete, 1% NaCl (by cement weight) was added to some groups of specimens. Results revealed that the carbonation released chloride ions from Friedel's salt, which increased the chloride content near the carbonation front. The carbonation rate of HAC concrete was higher than that of Type I and Type II cement concrete. The corrosion rate of rebars embedded in HAC concrete was slower than that of rebars in Type I and Type II cement concrete because of the denser microstructure of HAC. However, carbonation enhanced the corrosion rate of rebars embedded in HAC concrete because of the release of chloride ions from Friedel's salt.