Relation between colourimetric chloride penetration depth and charge passed in migration tests of the type of standard ASTM C1202-91

摘要

The great interest in the knowledge of the amountof chlorides that have penetrated into concrete is due to the factthat corrosion of reinforcement in concrete initiates whenchloride content in contact with rebars exceeds a threshold value.So, a number of methods to measure the diffusion coefficient ofCl-in concrete have been developed; one of them, from the use ofa colourimetric method, derived from its ease in practice. Somequestions have been raised about this method, concerning theamount of chlorides at which the colour change takes place. Inthis article, comparison between total chloride profiles inmigration experiments of the AASHTO type (ASTM C1202-91),and results form colourimetric test, as well as a relationshipbetween colourimetric penetration depth and charge passed, are given.