Examining the electrical properties of plain and blended cement concretes: Relationship between charge passed and initial current

The rapid chloride permeability test has been widely used to assess the chloride permeability or migration in concrete. Recently, the suitability of using the initial current instead of the total charge passed has been investigated. It was shown that the two measured electrical properties were interdependent with each other, suggesting the possibility of evaluating the relative quality of concrete using this parameter. However, the results derived from the previous investigations on the mentioned correlations emphasized on the necessity of considering different test parameters (regarding the concrete features). For this, a test program was carried out to develop more information about the relationship between two measured electrical properties. For this purpose, 144 pairs of concrete cylinder specimens of 100-mm diameter and 200-mm height were cast and tested. The test specimens were prepared with plain and blended cement concrete mixtures varying in w/c ratio, cement type, age, and curing condition. The results obtained from the rapid chloride permeability test were analyzed statistically. It was found that the simple measurement of the initial current could provide an effective alternative to the charge passed (total coulombs) and these two measured electrical properties were significantly correlated with each other under different conditions.