Empirical correlation between electrical resistivity and strain development in concrete under compression

Electrical Resistivity of concrete is one of the Non-Destructive Testing methods (NDT) for assessing the durability of existing degraded structures. However, few studies discuss the change in resistivity with the mechanical response under loading. This study aims to find a relationship between resistivity and strain during monotonic loading, up to the ultimate strain. The paper adopts an experimental approach to relate surface resistivity of concrete cylinders with uniaxial compressive loading. However, Digital Image Correlation (DIC) was used to monitor strain progress during loading. Results show a multi-phase behaviour with exponential correlation as follows: decreasing during the elastic stage, quasi-constant in plastic, and increasing in the post-failure stage.