Corrosion inhibitors in concrete repair systems

Corrosion of reinforcing steel represents the most widespread form of deter ioration of concrete structures. It affects reinforced concrete which is ex posed to the effects of carbonation and/or to significant concentrations of chloride salts. Effective procedures employed in the past to combat reinfo rcement corrosion have required either extensive cutting out and replacemen t of contaminated but otherwise sound concrete at the level of the embedded steel or the use of electrochemical measures such as impressed-current cat hodic protection. Over the past decade, however; the concrete repair indust ry has developed novel techniques that are claimed to restore the protectiv e character of cover concrete by introducing corrosion inhibitors into the carbonated and/or chloride-contaminated material As this approach requries only physically unsound or heavily contaminated regions of the concrete to be removed and reinstated it can involve reduced costs, pollution and incon venience to owners and users of affected structures. This paper presents a critical review of current knowledge of various types of corrosion inhibito r treatment that are in use, or under consideration for rise, in repair sys tems for concrete structures with corrosion problems resulting from carbona tion and/or chloride salts.