Corrosion resistance of Cr-bearing rebar in simulated concrete pore solutions

Abstract

As a fundamental study on the Cr-bearing rebar with the necessary corrosion resistance for use in steel reinforced concrete structures under corrosive environments This study was investigated to corrosion resistance of Cr-bearing rebars in simulated concrete pore solutions with content of chloride ion. The rebars were made from steels containing Cr from 0 to 16%. SUS304 stainless steel and SD345 carbon steel were also used. Simulated concrete pore solutions were saturated with Ca(OH)(2), containing 0.27%, 1.07% and 21.4% NaCl. The pH value of the solutions was adjusted to 12.5,11, 10 and 9 by HCl. Pitting potential and impedance, corrosion morphology of the steels in the solutions were investigated. The results of the study showed that the corrosion resistance increased as the Cr content increased regardless of the content of chloride ions, and that the Cr-bearing rebars with a Cr content of 5C% and 9% showed good corrosion resistance in 1.07% NaCl solutions at pH 12.5 and pH 10, respectively. Cr-bearing rebar with a Cr content of 16% showed as good corrosion resistance as SUS304 steel even in21.4% NaCl solutions at pH 10.