Analysis of corrosion rate, inhibition efficiency, and economic cost of XD3 reinforced concrete related to inhibitor and plasticiser types

Abstract

Abstract The main problem in concrete structure is rebar corrosion, which is caused by the penetration and diffusion of chloride ions into reinforced concrete structures; therefore, it is essential to give the most attention to preventing or limiting the impact of this condition. So, in order to find a practical solution to the problem of corrosion of rebar, the current article focuses on demonstrating the beneficial effects of green and calcium nitrate inhibitors on chloride-induced corrosion. Thus, this paper presented an analytical procedure based on corrosion rates and the economic cost to evaluate the efficacy of such an inhibitor. Ten samples with various concrete mixtures were divided into two groups according to the type of plasticiser and inhibitor have been immersed in an aqueous solution of 3.5 wt% sodium chloride at room temperature for 18 months. The optimal results in which the corrosion rate was significantly reduced were for the two groups of concrete mixtures, first group was (C2), which contains 3 wt% orange peels extract inhibitor mixed with 2.4 wt% Oxydtron as water-resisting admixture, and the second group was (E2) included 3 wt% calcium nitrate inhibitor with 2.4 wt% Oxydtron as water-resisting admixture. These two groups samples have been showed more excellent corrosion resistance against the saline solution after the completed immersion period. The inhibition efficiency analysis showed that there is a direct relationship between the inhibitor concentration and the efficiency of corrosion inhibition. However, the inhibition efficiency in the case of samples containing calcium nitrate inhibitor was higher than their counterparts containing green inhibitor extract. Finally, the economic cost analysis showed that the cost of the green inhibitor extract-containing samples was lower than that of the calcium nitrate inhibitor-containing samples.