Effect of w/cm and Composition on Correlations of Concrete Electrical Resistivity and Chloride Migration Coefficients

The performance with regard to chloride penetration of specimens made with three base compositions (supplementary cementitious materials: 20% fly ash, 20% fly ash + 8% silica fume, and 50% slag replacement by weight of cement), and water-to-cementitious ratios of 0.35, 0.41, or 0.47 were investigated here. In this investigation, laboratory experiments were carried out to study the correlation between electrical resistivity and non-steady state chloride ion migration coefficients ( D nssm ) of concrete. NT Build 492 was used to determine chloride migration coefficients. Rapid migration tests and resistivity measurements were performed several times over two years, and the non-steady state migration coefficient ( D nssm ) vs. resistivity values were correlated. Experimental results show that a good correlation was found between electrical resistivity and D nssm . Based on the relationships developed from this investigation, it appears that the correlations are age and composition dependent.