The effect of carboxylate compounds on controlling nitrite’s environmental side effects for carbon steel corrosion protection in the simulated concrete pore solution

Abstract In this study, the effect of simultaneous application of two carboxylate-based inhibitors and sodium nitrite on the corrosion behaviour of steel reinforcements has been investigated. The aim was to achieve a high efficient mixture with a low nitrite concentration to avoid problems, such as toxicity and reduction in concrete compressive strength. Electrochemical measurements and weight loss tests were used to evaluate the corrosion behaviour in simulated concrete pore solution (SCPS). In order to study the adsorption behaviour of inhibitors and surface topography, XPS, FE-SEM and AFM analyses were utilized. XPS results showed that nitrite at low concentrations improved the adsorption of organic inhibitors and thus increased efficiency. Also, the synergistic use of these inhibitors improved the quality of the passive layer.