Anodic behaviour of carbon steel bars in realkalised concrete: potentiodynamic and potentiostatic tests in solution

Electrochemical realkalisation is a technique used for the repair of reinforced concrete structures sufferingcarbonation-induced corrosion. It aims at restoring high levels of pH through the application of a temporarycathodic current. Although this technique was introduced in the 1980s and has been used since then, there arestill some aspects connected with its application that need investigation. In particular, it is not clear whether theusual techniques for measuring the corrosion activity of steel after the treatment can be considered reliable.This paper presents an experimental study on the anodic potentiodynamic and potentiostatic behaviour of steelin solutions simulating realkalised concrete and, for comparison, in solutions simulating alkaline and carbonatedconcrete. Results showed that in the alkaline solution used in the treatment steel bars are characterised bypassivity, in spite of the high values of corrosion rate measured with linear polarisation technique