Problems connected with use of hot-dip galvanized reinforcement in concrete elements

Abstract

The goal of this article is to evaluate risks arising from using hot-dip galvanized reinforcement in concrete elements. The article provides detailed summary of current experimental activities but also earlier positive remarks about applicability of hot-dip galvanized reinforcement, mainly from the perspective of corrosion and bond strength with concrete. Based on previously obtained data, the article disproves barrier effect of zinc coating on base steel. The reason is the initial corrosion reaction of zinc coating in fresh concrete producing hydrogen. Further data prove that forming hydrogen irreversibly increases porosity of cement on reinforcement/concrete interface which can significantly reduce bond strength. Sufficient filling of pores by zinc corrosion product could not be confirmed.