Studies on the evaluation of the performance of organic coatings used for the prevention of corrosion of steel rebars in concrete structures

Corrosion of steel rebars in reinforced concrete constructions, particularly those located in marine environments and industrially polluted areas is one of the major problems baffling the construction industry all over the world including India. A suitable protective coating to rebar is found to improve the durability of such structures under aggressive exposures. The performance of a few polymeric coatings based on different resins such as acrylic polyol-aromatic isocyanate, polyester polyol-aromatic isocyanate, acrylic resin and epoxy–silicone–polyamide containing ordinary Portland cement or flyash as extenders and titanium dioxide and zinc phosphate as main pigments on rebar in concrete has been evaluated using mechanical strength tests and accelerated corrosion tests. It is observed that, of the 16 coating formulations, four have been found to perform well as effective and durable coatings.