Studies on corrosion resistance of galvanized reinforcement bars in simulated concrete environments

Corrosion of concrete structures is a major concern all over the world. A number of methods such as coating steel rebars, coating concrete surfaces, cathodic protection, addition of inhibitors, etc. are available to mitigate corrosion. Galvanizing is one of the protective coatings for steel rebars. In the present work, a study has been made of the performance of galvanized rebars, with and without chromate treatment, when compared to uncoated rebars in the presence and absence of chloride under simulated concrete environments. The corrosion performance of galvanized rebars has been studied by using Electrochemical Impedance Spectroscopy (EIS) and gravimetric techniques. The galvanized rebars were evaluated under two different chloride levels viz. 0 and 0.5% chloride added to the simulated concrete environments. The duration of the test period was 90 days. From the above study, it was found that the galvanized rebars had shown a minimum of 4 to a maximum of 40 times higher corrosion resistance values than the bare steel rebar. Excellent agreement between the gravimetric data and EIS experimental results is obtained.