Inhibition of galvanized rebars active corrosion in fresh concrete using hydrogen peroxide

Hydrogen evolution determined by the interaction between galvanized reinforcing bars and cement paste is commonly considered an issue for concrete structures during early-age curing. As a consequence, in this period, the adherence between galvanized rebars and concrete matrix can be lower than that of bare steel bars. This depends on the passivation rate of the zinc coating. The aim of the present work is to find a solution by accelerating the passivation of zinc-based coatings with an oxidizing agent like hydrogen peroxide. The experimentation was performed by monitoring the corrosion potential of galvanized rebars immersed in concrete specimens, where hydrogen peroxide was added. The results showed that the adherence of galvanized rebars with respect to the concrete matrix, at early-age curing, increases with the addition of hydrogen peroxide into the mixture. Nevertheless, it has been found that additions of hydrogen peroxide reduce the compressive strength of the concrete due to the increase in its porosity.