CATHODIC CORROSION PROTECTION OF PRE-CORRODED STEEL IN CONCRETE WITH GALVANIC ZINC ANODES

摘要

This paper studies the effectiveness of galvanic sacrificial zinc anodes on pre-corroded steel in concrete. Concrete test blocks were contaminated with various concentrations of chloride. Pre-corrosion was performed by polarizing the steel anodically by an external steel cathode with impressed currents. Zinc was thermally sprayed on the concrete surface after the pre-corrosion treatment. An outdoor test device permanently monitors both the electrochemical potential of the steel reinforcement and the protection current of the galvanic anodes. The influences of atmospheric conditions, chloride content, exposure time and treatment with hygroscopic salts on the efficiency of the protection system are evaluated.