Comparison between several methods for determining the depassivation threshold value for corrosion onset

Abstract
Numerous studies have been already carried out to study the chloride threshold value for depassivation of the steel embedded in concrete. Most of them were based on natural penetration of chlorides, whose main disadvantage is that it is very time consuming and makes necessary a long time to obtain reliable data. Other methods used are the potentiostatic tests that, depending on the potential applied, may also take very long. Recently, an accelerated method to determine the threshold value of corrosion of steel by application of electrical fields has been developed. In this paper, results obtained, for the same concrete, using every method are given as well as a comparison of the advantages and drawbacks of each of them.