A Rapid Test to Screen the Functionality of Galvanic Anodes for Cathodic Protection of Reinforced Concrete

Abstract

Galvanic anodes are increasingly popular in the repair, rehabilitation, and maintenance of reinforced concrete structures suffering from chloride-induced corrosion for the added durability benefits. There is a consensus among engineers that demand will increase due to ageing infrastructure stock, climate change, and the option to reuse structures which is a logical solution to help reduce carbon emissions. New manufacturers will likely emerge to meet the needs of a growing market. However, there is no standard for galvanic anodes for use in concrete. In theory, products may come to market that fails to work as anodes, and hence corrosion may not be arrested, and repeated intervention could be required. This paper presents a methodology that has been developed for demonstrating anodes function as intended in a short-term test. Anodes were cast into concrete, and drive voltage, resistivity, and resultant current were measured when connected to an external cathode. The test setup was applied to several commercially available galvanic anodes. All anodes achieved a current output of 0.35 mA in this experimental setup. This could provide a rapid test to screen anodes new to the market. The analyses show inherent anode behaviour varied with different manufacturers, and there were also performance differences among replicate anodes. Such behavioural characteristics may affect the long-term performance of the anodes. These results provide new data on galvanic anodes and demonstrate the potential need for standardisation in the industry.