Principal research petrographer, Portland Cement Association, Skokie, Ill.
Pages: 10 Published: Jan 1980
The performance of galvanized reinforcing steel in concrete structures exposed to seawater in Bermuda was evaluated by measurements of chloride concentrations in the concrete, and average depths of corrosion of the galvanized coatings. Results indicate that little more than superficial corrosion of the coatings has occurred in 7- to 23-year-old normal-quality concretes containing as much as 10 times the chloride concentrations needed to induce corrosion of untreated steel. In all but one case the outer free zinc layer was still present on the coating. In these instances, the average depths of corrosion ranged from zero to 0.013 mm, with the amount of coating remaining ranging from 92 to 100 percent of the original thickness. Localized corrosion to the steel substrate was found only in uncompacted highly porous concrete in a poorly bonded cold joint.
corrosion, galvanized, reinforcing steel, concrete, chloride, metallographic
Paper ID: STP27473S