Composite Corrosion Protection System in Rehabilitation of Steel Structures in Corrosive Environment—A Case Study

Abstract

India loses USD 33 billion every year due to corrosion of infrastructure, industrial equipment and other vital installations, according to latest estimates from Corrosion Management Committee of Confederation of Indian Industry[1]. This paper addresses corrosion management and prevention using Galvanic Systems, through a case study of a structural steel bridge in Goa, a coastal and corrosive zone of West India. The bridge was found to be in advanced stage of corrosion damage merely one year after its construction, and was treated with a composite treatment of galvanic corrosion protection using custom designed sacrificial anodes, and systematic protective coating system of acyclic, polyisocyanate reticulant based polyurethane. The performance against atmospheric corrosion of this system was observed through of periodic visual observations and physical measurements since early 2012; electrochemical readings were taken at the end of 30 months of treatment. It is seen that the composite system exhibits satisfactory protective behaviour, and may be considered for treatment of similar structures in corrosive environments.