Corrosion of galvanized steel in dilute Ca(OH) 2 solutions (pH 11·1

Abstract

The corrosion behaviour of. galvanized bars was studied in 0·1–3 g Ca(OH)₂ (pH 11·1–12·6) solutions designed to simulate the aqueous phase found in concrete pores. Corrosion potential and current density were monitored over the course of the 33 day tests and the corrosion products were examined by light and electron microscopy, X-ray diffraction, and IR absorption spectroscopy. Most specimens showed high initial corrosion rates which fell to a lower, nearly constant level after ∼6 days. The corrosion kinetics were found to depend only on solution pH. Ca²⁺ concentration had no effect other than on the nature of the corrosion products: Ca(Zn(OH)₃)₂.2H₂O is the passivation product in the presence of calcium ions, Zn(OH)₂ in their absence. Localized corrosion was observed at pH <11·5.

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Corrosion of galvanized steel in dilute Ca(OH) 2 solutions (pH 11·1–12·6)

Abstract

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References