Galvanized steel reinforcement

Galvanized steel reinforcementThe integrity of concrete structures heavily relies on concrete steel reinforcing durability. The steel used to reinforce concrete structures is normally protected from corrosion by the passive film formed on its surface because of the high alkalinity of the concrete. In the presence of water and oxygen combined with a sufficient amount of chlorine and / or carbon dioxide, however, this film may be destroyed, thus occurring the corrosion. The expansion of iron corrosion products with a  three times greater volume generates tension in the concrete, which then damage cracks it, and the process of corrosion is thus accelerated.

Following this phenomenon, often extremely costly maintenance works and repairs are necessary, resulting in economic burden for the authorities. Hot dip galvanizing as method of protecting steel against corrosion can significantly delay the occurrence of these problems and reduce the need for maintenance works, thus representing a very effective means of protecting public funds. Zinc coating isolates the steel from the surrounding concrete cement matrix acting as a barrier, and the steel substrate corrosion starts only when the zinc is consumed completely. Since the corrosion rate of the zinc in the concrete is usually very low, the consumption of the zinc coating will be a long process, and the corrosion will thus be significantly delayed. Another important advantage of the hot dip galvanization is that even when the zinc is fully worn out in a certain area or if the coating is mechanically damaged so that the steel substrate is exposed, the adjacent zinc becomes anode and protects the steel, consuming before the steel because of its more electronegative potential. Thus corrosion of steel substrate is further delayed.

Technical details