Corrosion Resistance of Functionally Graded Coatings on Plain Steel Rebars

Abstract

The experimental results obtained on steel rebars with coatings of Si-based particles are described in this paper. It is well known that adding Si to metals generally increases their corrosion, oxidation, and erosion resistance. In this study, it is chosen to use Si-based coatings because of their proven capacity for corrosion protection in Cl^- environments. In addition, this paper presents impedance spectroscopy as an alternate technique in determining the corrosion activity of coated steel rebars. Impedance spectroscopy is an electrochemical measurement technique, which measures the response of a system to an applied alternating signal. A major benefit of the technique is its ability to monitor both the bulk and interfacial responses. This research was conducted to characterize the impedance response of several coatings on steel rebars, and in so doing, further understanding of the corrosion susceptibility of the systems. The results suggest that impedance spectroscopy may be useful for monitoring corrosion activity on coated rebar.