A Combined Experimental and Analytical Analysis of the Prediction of the Bonding Strength in Corroded Reinforced Concrete Through Half-Cell Potential Measurements

This study examines the relationship between bond strength degradation in corroded reinforced concrete and Half-Cell Potential (HCP) measurements through a combined experimental and numerical approach. Fifty-four concrete specimens reinforced with D19 and D22 rebars underwent impressed-current corrosion to induce specific levels of mass loss. The experimental results showed a progressive reduction in bond strength with increasing corrosion; at approximately 20% mass loss, D19 specimens exhibited up to ~45% reduction, while D22 specimens showed a reduction in ~30%. Correspondingly, HCP values became more negative as corrosion intensified, shifting from around −200 mV at 0% corrosion to values below −900 mV at higher corrosion levels. Although HCP effectively reflected corrosion severity, it did not correlate linearly with bond strength degradation. Numerical simulations performed using COMSOL Multiphysics reproduced the observed electrochemical trends, demonstrating increasingly negative potential distributions with higher corrosion current densities. The findings confirm that HCP is a reliable indicator of corrosion activity but has limited predictive capacity for bond strength loss. This work contributes quantitative insight into the electrochemical–mechanical relationship in corroded reinforced concrete and supports the development of improved assessment frameworks for early maintenance and structural integrity evaluation.