PROTECTION OF CONCRETE STRUCTURES IN IMMERSION SERVICE FROM BIOLOGICAL FOULING WITH SILICONE-BASED COATINGS

The unrestricted growth of aquatic organisms (macrofouling) on surface s of submerged concrete intake structures and circulating water system s of power plants is a significant problem in the industry, resulting in substantial operating and maintenance costs. Traditional chemical a pproaches to control the problem are under increasing legislative scru tiny, and regulatory actions that limit chemical discharge and require toxic use reduction may also further curtail the use of biocides. Non toxic, silicone-based foul release coating systems appear to be an esp ecially attractive solution to conventional treatment methods; however , criteria for coating selection and successful application are not we ll defined due to the relatively limited use of this technology in the industry. This article presents case histories from two utilities, re views their testing and coating selection strategies, and discusses th e application difficulties with coating-aged concrete surfaces in imme rsion service.