Numerical and Experimental Correlation Between Half-Cell Potential and Steel Mass Loss in Corroded Reinforced Concrete

Half-cell potential (HCP) measurement is widely applied as a non-destructive technique for assessing corrosion probability, yet its diagnostic capacity remains limited to probabilistic interpretations rather than quantifying the extent of steel mass loss. Conventional HCP measurements can indicate corrosion probability, but not the actual extent of deterioration. The objective of this study is to examine the potential of HCP measurements to indicate actual corrosion severity by numerically simulating HCP values and correlating them with steel mass loss data. Using published experimental datasets, relationships among corrosion current density (J(corr)), electrical resistivity (ER), HCP, and steel mass loss (mL) were established through regression analysis, while COMSOL Multiphysics v6.2 was employed to simulate HCP responses. The simulations revealed increasingly negative HCP values with higher J(corr) and conductivity. A second-order polynomial correlation (R2 = 0.9999) was obtained between simulated HCP and measured mass loss (0–20%), enabling quantitative interpretation of corrosion severity, demonstrating that HCP can serve as a predictive indicator of corrosion severity. It is demonstrated that the interpretative value of HCP has potential for quantifying corrosion severity to improve monitoring and maintenance strategies.