Effect of initial curing on chloride ingress and corrosion resistance characteristics of concretes made with plain and blended cements

This paper reports the results of an experimental study conducted to evaluate the effect of initial curing conditions on the chloride ingress characteristics of concretes made with plain and four different blended cements. In addition, the corrosive behavior of steel bars embedded in plain and blended cement concretes were studied through half-cell potential measurements. A total of ten different concrete mixtures having water–cement (w/c) ratios of 0.65 and 0.45 were cast and tested. Test specimens were subjected to three different initial curing conditions, namely uncontrolled, controlled, and wet before exposure to high chloride environment. The research variables included cement type (i.e., plain and blended cements), w/c ratio, and initial curing condition. The results indicated that the initial curing condition had pronounced effects on the related properties: in particular, the most prominent effects were observed on blended cement concretes, which performed extremely well when initially cured in wet conditions. Inadequate or poor initial curing practice resulted in remarkably lower chloride penetration resistance for both plain and especially blended cement concretes.