Service Life Estimation of RC Structures Using Surface Resistivity: A Non-Destructive Approach

Reinforced concrete (RC) structures exposed to saline environments are highly susceptible to chloride-induced corrosion and estimating the service life of such vulnerable RC structures is essential for quality control and future risk assessment. Most service life estimation models rely on chloride migration coefficients, determined through destructive, time-consuming, and relatively costly rapid migration tests (RMT). This study aims to develop correlations between concrete resistivity and migration coefficients based on the silica (SiO2) contents of the binders as a non-destructive alternative to evaluate service life of RC structure exposed to chloride induced corrosion. A wide range of used concrete mixes (for three different design strengths) with different binder types having SiO2 content ranging from 15 to 35% has been utilized. Both fly-ash and slag were used as supplementary binders. The validity of the correlation has been established through a different set of experimental results of concrete mixes having dissimilar binder types than used in this study. From the comparison between the probabilistic service life estimated using the predicted (from developed correlations) and experimental migration coefficient values it can be concluded that the proposed correlations are considerably effective as a non-destructive and reliable approach for serviceability assessment of RC structures in saline exposures.