Abstract
In steel reinforced and prestressed concrete structures depassivation of the reinforcing steel can take place due to carbonation of the concrete cover. Depending on humidity and oxygen availability subsequent corrosion reactions will be initiated. Such conditions require measures to exclude corrosion induced damages during the designed lifetime of the structure. In the last few years an electrochemical realkalization treatment has been proposed as adequate rehabilitation technique for carbonated concrete. This temporary treatment should increase the pH-value of the concrete pore water solution due to penetration of alkaline electrolyte from the surface as well as repassivating of the reinforcement due to electrochemical reactions at the steel surface.
In order to clarify the different mechanisms taking place during electrochemical realkalization laboratory tests have been carried out using carbonated reinforced mortar specimens. The investigations were aimed at checking the influence of various parameters, e.g. treatment time or current density, as well as the efficiency and long-term durability of this new rehabilitation method.
