An overview is presented of the characteristics and performance of galvanized steel reinforcement in concrete. Galvanizing produces a tough and adherent iron-zinc alloy layer coating which is metallurgically bonded to the base steel. It resists abrasion and fairly heavy handling, and can
generally be fabricated without substantial damage to the coating and with little or no effect on its corrosion resistance. Galvanized rebar can be treated in much the same way as conventional black steel bar and the same design criteria as used for black steels can be used with galvanized steels. No product-specific design practices are necessary and no special training of the construction workforce is necessary. When embedded in concrete, galvanized steel has a substantially higher chloride threshold than black steel and totally resists the effects of carbonation of the concrete. The net result of these effects is that galvanizing delays the initiation of the corrosion process and extends the life of the concrete structure or element. However, the extent of this life extension depends to a large extent on the quality of the concrete used and the severity of the environment to which it is exposed. Once
corrosive attack on the zinc alloys has commenced, barrier-type protection is afforded during the life of the coating. Where small regions of the underlying steel are exposed, sacrificial protection of the zinc
is afforded to the exposed steel. The results of field and experimental studies to assess the performance of galvanized rebar compared to black steel are presented and examples given of types of concrete
structures that have been reinforced with galvanized steel.
Keywords: galvanizing, rebar, concrete, corrosion, corrosion protection, economics