Chloride-Induced Corrosion Mechanism and Rate of Enamel- and Epoxy-Coated Deformed Steel Bars Embedded in Mortar


The chloride-induced corrosion mechanisms of uncoated, pure enamel (PE)-coated, mixed enamel (ME)-coated, double enamel (DE)-coated, and fusion bonded epoxy (FBE)-coated deformed steel bars embedded in mortar cylinders are investigated in 3.5 wt.% NaCl solution and compared through electrochemical tests and visual inspection. Corrosion initiated after 29 or 61 days of tests in all uncoated and enamel-coated steel bars, and after 244 days of tests in some FBE-coated steel bars. In active stage, DE- and FBE-coated steel bars are subjected to the highest and lowest corrosion rates, respectively. The uncoated and ME-coated steel bars revealed relatively uniform corrosion while the PE-, DE-, and FBE-coated steel bars experienced pitting corrosion around damaged coating areas. Due to the combined effect of ion diffusion and capillary suction, wet-dry cyclic immersion caused more severe corrosion than continuous immersion. Both exposure conditions affected the corrosion rate more significantly than the water-cement ratio in mortar design.


Civil, Architectural and Environmental Engineering

Second Department

Materials Science and Engineering

Keywords and Phrases

Bars (metal); Chlorine compounds; Enamels; Mortar; Pitting; Chloride induced corrosion; Chlorides (d); Deformed steel bar; Electrochemical test; Exposure conditions; Fusion bonded epoxy; Long-term performances (c); Sem (b); Corrosion rate

International Standard Serial Number (ISSN)


Document Type

Article - Journal

Document Version


File Type





© 2016 Elsevier Ltd, All rights reserved.

Publication Date

01 Apr 2016