ABSTRACT

Corrosion of steel elements in masonry and concrete structures is a major cause of material and structural damage. This chapter presents typical steel and iron corrosion damage phenomena. It explains the basic principles of cathodic protection using galvanic anodes or impressed current. The chapter discusses examples of how cathodic protection can be applied to steel reinforcement in reinforced concrete as well as to steel elements in masonry constructions. Cathodic protection comprises the methods by which the total steel surface is transformed into one big cathode, so that no iron atoms will come into solution and will further oxidize to steel rust. The galvanic cathodic protection technique consists in electrically connecting a metal with lower electric chemical potential to the metal element, which has to be protected. In particular the practical impact and advantages of the technique used on historical buildings will be emphasized and clarified with executed cathodic protection projects.