Electrochemical chloride extraction of a beam polluted by chlorides after 40 years in the sea

Abstract
A beam element, naturally polluted by chlorides after 40 years of a marine tidal exposure, has been treated by electrochemical chloride extraction. The chloride profiles, before and after treatment, show that free chlorides are extracted with an efficiency of 70 % close to the steel, 50% in the intermediate cover and only 5% at the concrete surface. From the electrochemical characterizations (before, after, 1, 2 and 17 months after treatment), the steel potential values can, somehow, indicate a passivity of the rebars, but, this phenomenon is not confirmed by the corrosion current values. Chloride content, 17 months after treatment, continue to decrease on the first cm of the cover.