Abstract

MURTHY, Yogesh Iyer; GANDHI, Sumit  and  KUMAR, Abhishek. Comparative Study of Pure Mg and AZ91D as Sacrificial Anodes for Reinforced Cement Concrete Structures in a Chloride Atmosphere. Port. Electrochim. Acta [online]. 2020, vol.38, n.4, pp.243-252. ISSN 0872-1904.  https://doi.org/10.4152/pea.202004243.

A comparative study of the corrosion behavior of pure magnesium and AZ91D anodes in reinforced cement concrete was undertaken in the present work. The steel reinforcements were electrochemically kept in contact with these anodes in a chloride atmosphere, and the half-cell potential drop was observed. Bare steel reinforcements were tied to the anodes and were also kept in a high chloride atmosphere to test the mechanical properties. The yield stress and ultimate tensile stress were found to decrease by approximately 50 MPa, while the reduction in percentage elongation was approximately 25% for reinforcements tied to AZ91D and pure Mg, at the end of 80 days, compared to the fresh steel reinforcement. The rate of corrosion of pure Mg was reportedly slightly higher compared to AZ91D, due to the presence of inter-metallics, as inferred through micro-graphs.

Keywords : cathodic protection; AZ91D; mechanical properties; half-cell potential; micro-characterization; inter-metallics.

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