Study on the influence of compound rust inhibitor on corrosion of steel bars in chloride concrete by electrical parameters

Abstract

In this paper, the influence of compound rust inhibitor on corrosion and passivation film’s composition of rebars in chloride concrete was investigated. Na2CrO4 and Na2MoO4 were used as anode rust inhibitor, while benzotriazole and N-N-dimethylethanolamine selected as cathodic rust inhibitor. Moreover, assembly unit of these anode and cathodic rust inhibitors were considered. Electrical parameters (spontaneous potential, Tafel curves, electrochemical impedance spectroscopy) and the weight loss rate were studied to reflect the corrosion of rebars in samples. Furthermore, X-ray photoelectron spectroscopy (XPS) was used to research the composition of passivation film on the surface of rebars. The research results showed that the corrosion of steel bars in specimens with compound rust inhibitor (assembly unit of Na2MoO4 and Benzotriazole (BTA)) was the best. However, steel bars reinforced concrete with anode rust inhibitor behaved the worst corrosion resistance. The iron oxide of passivation film on the surface of steel bars in specimens with Na2CrO4 was the highest, while iron oxide on that with Na2MoO4 + BTA was the lowest.