An Experimental Study of the Effects of Chloride Ions on the Corrosion Performance of Polymer Coated Rebar in Concrete Pavement

Abstract

Construction materials have been greatly improved in recent years and reinforced concrete is no exception. However, corrosion inside reinforced concrete continues to be a primary problem in the construction field. This paper considers the corrosion rate of special kinds of steel inside reinforced concrete pavement. Corrosion is caused by chloride ions present in the deicing salts used to melt snow on pavement. These chloride ions cause endosmosis in the structure of steel and eventually destroy it. In order to prevent such corrosion, layers have been created to protect the steel. The authors use the polarization resistance method to check the ability of such barriers. The variables of this experimental study were four kinds of steel: black rebar, stainless steel 304 clad rebar, galvanized coated rebar A and galvanized coated rebar B. According to the test result, black steel corroded much more than the others with the presence of salt. Although the galvanized A rebar corroded more slowly than the galvanized B rebar in Ca(OH)₂ plus the threshold amount NaCl, the corroding resistance of the galvanized B rebar was better in the presence of 3.5% NaCl. However, of the four kinds of steel, the pure stainless steel 304 clad rebar proved to be the best in terms of corrosion resistance.