Simulation of Steel Corrosion in Concrete Based on the Model of Macro-cell Corrosion Circuit

T. Maruya, H. Takeda, K. Horiguchi, S. Koyama and K.-L. Hsu Journal of Advanced Concrete Technology, 5(3) 343-362, 2007 A comprehensive numerical simulation system is proposed for solving the problem of steel corrosion in concrete related to deterioration of reinforced concrete structures in an environment contaminated by chloride ions. The distribution of the corrosion amount and the corrosion rate along the reinforced bar were calculated based on macro-cell circuit models consisting of micro-cell circuits. The models were quantified according to the results of exposure experiments under two environments, one under cyclic wetting and drying in a laboratory and the other in a splash zone located offshore. The comparisons on time-dependent half-cell potential, corrosion location and corrosion amount indicate qualitative coincidence between the experimental and numerical simulation results. In addition, based on the proposed system, numerical simulation of the macro-cell corrosion circuit between patched area and not-yet-patched area is reasonably achieved.

The authors' effort to develop the macro-cell corrosion model together with the concept of multi-circuit model for being integrated it into their comprehensive analytical method to predict corrosion of steel in chloride environment is another step of progress in the field although verification with test results still shows some inconsistencies and future development is still needed. (Prof. Somnuk Tangtermsirikul, Sirindhorn International Institute of Technology, Thammasat University, Thailand)