Determination of chloride diffusion coefficients in concrete by electrical resistivity method

The chloride diffusion coefficient in concrete is of primary importance in determining the service life of concrete structures exposed to marine environments or deicing salt. Traditional methods (such as bulk diffusion test and migration test) used to determine the chloride diffusion coefficients are usually time- and labor-consuming. The electrical resistivity method has been developed as a nondestructive technique to evaluate the chloride permeability of concrete specimens. As a quality control method, however, the disadvantage of the resistivity method is that its values cannot be directly applied in the service life-prediction models to predict the chloride diffusion coefficients. In this paper, a comprehensive investigation was performed to study the empirical correlations between electrical resistivity and diffusion coefficients. The results of this investigation indicate that electrical resistivity is well-correlated to chloride diffusion coefficients. Based on these findings, a methodology is proposed to determine the chloride diffusion coefficients by the nondestructive electrical resistivity method. © 2015, American Concrete Institute. All rights reserved.