Cathodic protection is rapidly becoming accepted as a repair option for steel-reinforced structures that are undergoing corrosion caused by the presence of chlorides. Tests used to assess the effectiveness of cathodic protection systems are known as "criteria". Several different criteria have been suggested for use with concrete structures, and from those used in the underground cathodic protection industry and are only recently being verified in concrete. The number of tests, together with the complexity of some has led to confusion and disagreement regarding the use of such criteria. The Strategic Highway Research Program (SHRP) issued a contract on cathodic protection of reinforced concrete bridge elements. The objective of part of that contract was to investigate the feasibility of improved and simplified control criteria. Under this contract, corrosion rates of steel in a concrete environment were measured relative to many factors. These data were used to appraise control criteria. This technical alert presents the results and recommendations based on that part of the work. (A)
Abstract