Diffusion of moisture and chloride ions in repaired concrete subjected to complex deterioration factors

Abstract

Repairing a reinforced concrete structure reduces various deterioration factors, such as chloride ions, and extends its service life. However, short-term redeterioration has frequently been reported in re-paired concrete. Although many researchers have tried to find the cause of short-term redeterioration in re-paired concrete, the mechanism remains unclear. In this study, experimental investigation was conducted into the causes of short-term redeterioration in repaired concretes subjected to chloride-induced damage and complex deterioration (chloride-induced damage and frost damage) environments. According to the results, the complex deterioration environment increases the ingress of chloride ions into concrete to a greater degree than the chloride-induced damage environment. A patch material with frost resistance and dense structure, such as polymer cement mortar, reduces the transfer of chloride ions and moisture. These characteristics pro-tect repaired concrete from short-term redeterioration.