Inhibition mechanism of carboxylate-based inhibitors on HRB400E steel in simulated concrete pore solutions: A comprehensive consideration of passivation behavior and corrosion resistance

Abstract

Given the long-term durability needs, environmental concerns, and low-carbon requirements, the development of eco-friendly and highly effective corrosion inhibitors becomes imperative. This study selected three types of cost-effective and non-toxic carboxylate-based organic inhibitors, and comprehensively explored their impacts on the passivation behavior and corrosion resistance of HRB400E reinforcing steel in simulated concrete pore solutions. Furthermore, computational simulations were utilized to investigate the adsorption configurations of inhibitors on the steel surface, revealing their inhibition mechanisms. While carboxylate groups can enhance the effective adsorption of inhibitors onto the steel surface, the corrosion susceptibility of steel with different inhibitors varies. Despite citrate's negative effect on steel passivity, it exhibits remarkable inhibition capability, whether the steel is naturally passivated or not. These findings of this study could provide a comprehensive theoretical foundation for the application of these inhibitors in reinforced concrete structures.