Corrosion of galvanized steel reinforcements in alkaline solutions: Part 1: Electrochemical results

Abstract

The behaviour of galvanized corrugated reinforcing bars has been studied in 0 multiplied by (times) 001-1 multiplied by (times) 5M solutions of KOH and NaOH to simulate aqueous environments found in concrete pores. Specimens were immersed for 33 days, corrosion potential, corrosion intensity, and pH being monitored throughout. It was possible to establish pH ranges in which localized corrosion ( less than 12), stability (12-13 multiplied by (times) 4), and complete dissolution of the galvanic coating ( greater than 13 multiplied by (times) 4) occurred. A white, dusty corrosion product was observed at the conclusion of the tests. Hydrogen dissolution on the galvanized bars occurred at pH values higher than the threshold level of 12 multiplied by (times) 8 plus or minus 0 multiplied by (times) 1.