Corrosion behavior of steel bars in reinforced concrete slabs repaired by partial patching

摘要

This study investigated the long-term behavior of macro-cell corrosion of steel bars generated in reinforced concrete slabs repaired by partial patching. Macro-cell corrosion current density in repaired test slabs was periodically measured for about 2 years. To measure the macro-cell corrosion current, segmented steel bars were embedded in the test slabs. Based on the test results, the following conclusions were obtained: 1) The steel bars in chloride-contaminated concrete near the joint acted as a macro-cell cathode in the early stage of exposure, however, a change in the electrochemical balance made the steel bars anodic; 2) The macro-cell current density at the intersection element in chloride-contaminated concrete became high, which is considered to be caused by a two-dimensional electrical current flow; and 3) Steel bars in the repair material part may tend to cause the formation of distinctive macro-cell corrosion.