Effect of Surface Applied Organic and Inorganic Corrosion Inhibitors on Reinforced Steel in Concrete

Abstract

This paper presents the results of an experimental investigation carried out to study the effect of surface applied organic and inorganic corrosion inhibitors on reinforced steel in concrete. The reinforcement bars were coated with Neem powder (organic inhibitor) and Zinc powder (inorganic inhibitor) as corrosion inhibitors. The samples of beams of size 100X100X640mm having 4 steel bars as reinforcement were prepared and cured in normal water for 15 days and in saline environment for 42 days. The inhibitors were applied in the form of 2 coats, 4 coats and blend of both. The grade of concrete used was M30. Half-cell Potential and Weight loss measurements were carried out to determine the efficiency of corrosion inhibitors [11]. The corrosion inhibition efficiency of controlled specimen and coated specimens were compared. From the results it was seen that samples with 4 coats of Neem showed 44% inhibition efficiency as compared to control specimens. Similarly specimens with two coats of Neem, four coats of Neem and Zinc also showed better corrosion inhibition efficiency. Highest weight loss was observed in case of control specimen. The study concludes that use of surface applied corrosion inhibitors prove efficient in enhancing the corrosion inhibition efficiency of concrete. Surface applied corrosion inhibitors provide protective layer to the reinforcement thereby protecting it from corrosion and increasing the durability of the structure. This type of technique of using corrosion inhibitors in concrete can be used in various structures such as buildings, bridges, sewage pipes, marine structures, abutments & piers, RCC roads which are subjected to harsh environmental conditions.