Performance evaluation of galvanic anodes through laboratory testing and on-site monitoring

Abstract

This study examines the effectiveness of galvanic anodes installed both within the patch repair and surrounding parent concrete through laboratory testing and on-site monitoring. Sodium chloride was added during casting of the laboratory concrete specimens to induce corrosion. The anodes were tested using surface potential mapping at 7 days, 8 months and also 26 months after repair. Site monitoring of galvanic anodes was performed over a period of 215 days. The results showed that galvanic anodes installed in the parent concrete had a greater polarisation effect on the surrounding steel, which is generally considered to be at highest risk, as compared to galvanic anodes installed within the patch repair itself. This was in-line with data obtained from similar installations in full-scale reinforced concrete structures. It was also noted that, with increasing chloride content, the polarisation extent was reduced.