Abstract
This study was carried out to make clear the behavior of macro-cell corrosion generated in RC slabs repaired by partial patching. Macro-cell corrosion current in patched test slabs was periodically measured for about 2 years using segmented steel bars. Based on the test results, the following topics were particularly discussed: 1) Mechanism of the macro-cell corrosion of steel bars in patched concrete, 2) The effect of intersections of steel bars on the behavior of macro-cell corrosion, and 3) The possibility of corrosion of steel bars in the patched area. Through the analysis of test results, the following conclusions were obtained: 1) The steel bar in chloride-contaminated concrete near the joint acted as macro-cell cathode in the early stage of exposure, however, the electrochemical incompatibility in the RC member made the steel bar anodic. 2) Corrosion currents at the intersections in chloride-contaminated concrete were re-markably large in the early stage of exposure. It was considered to be caused by the flow of a two-dimensional electrical current. 3) Steel bars in patched area had the possibility of macro-cell corrosion formation.
