Chloride threshold for corrosion of galvanized reinforcement in concrete exposed in the mexican Caribbean

The time of incubation (TI) and chloride threshold (CT) necessary to initiate corrosion of reinforcement steel are crucial variables to predict the useful life of an infrastructure in any model. For black steel there is a great amount of data in the bibliography. However, for galvanized steel, is very scarce and in tropical climates no data exist. In this research, CT and TI were determined for galvanized steel embedded in concretes with water/cement (w/c) ratios of 0.4, 0.5, 0.6, and 0.7. The samples were corroded under natural conditions in the north coast of the Yucatan Peninsula for nine years. The results show that galvanized reinforcement can resist chloride levels 2.6–3 times higher than black steel, even in poor quality concretes. Likewise, it was possible to observe that TI for galvanized steel is twice that of black reinforcement, and so the former offers the possibility of extending the useful life of structures.