Effects of Carbonation on Chloride Penetration in Concrete

Previous studies were confined mostly to the deterioration of concrete structures under a single deteriorating factor, such as chloride ingress only or carbonation only, although the real environment may be a combination of such factors. Therefore, the purpose of this study is to explore the influence of carbonation on chloride penetration in concrete structures. Several series of concrete specimens were tested. The test results indicate that the chloride penetration is more pronounced when the carbonation process is combined with the chloride ingress. It is also shown that the ratio of water-soluble chloride to the acid-soluble chloride content is higher for the case of the carbonated test series than the case of the normal noncarbonated test series. This may cause a more vulnerable situation to the corrosion of steel bars when chloride ingress is combined with carbonation. This study allows for a more realistic assessment of durability for concrete structures that are subjected to a combined environment of chlorides and carbonation.