Synergistic effect of inhibitors on corrosion of reinforced concrete structures according to American Concrete Institute standards

The application of low-cost, low-toxic corrosion inhibitors lowers the rate of corrosion of reinforced concrete in a salt-aqueous medium. The purpose of this work is to compare an innovative, supposedly environmentally benign inhibitor derived from fruit waste (pomegranate peels extract (PPE)) with sodium benzoate, an organic inhibitor. The inhibitors were introduced to the concrete mixture at quantities of two and four percent by weight of cement according to ACI standards. The maximum extraction yield in terms of entire phenolic content was obtained by using an aqueous solvent and the Soxlet technique. The efficiency of corrosion inhibitors in preventing corrosion was investigated using compressive strength and optical microscopy methods. PPE forms an organic layer made up of several components in a variety of salt environments, providing both a chemical antioxidant activity and a mixed-type corrosion inhibitor, most likely due to the polyphenol concentrations.