Macrocell Corrosion Studies of Coated Rebars

The corrosion of steel in concrete and its subsequent consequence is a globally accepted multibillion dollar problem. The application of a protective coating to the steel rebars is one of the easy methods for controlling corrosion. The macrocell corrosion test analysed the performance of rebar coatings such as cement polymer composite coating, inhibited cement slurry coating, galvanizing and cement polymer anticorrosive coating exposed to severe chloride environment. The performance of 1 % intentionally damaged coated rebars were also studied. The type of rebar, the macrocell current behavior, the total corrosion current development and the percentage of corroded area were considered as performance evaluators. It is concluded that coated rebars could significantly prolong the onset of corrosion despite severe chloride environment. The 1 % intentionally damaged coating did not bring about any appreciable impact on the macrocell current development, irrespective of the type of rebar and the type of coating used. The performance of the newly developed cement polymer anticorrosive coating is better compared to the other established coatings. Thermo-mechanically treated rebars performed appreciably better than the cold-twisted deformed rebars, irrespective of the coating applied.