Chloride-induced corrosion mechanism and rate of enamel- and epoxy-coated deformed steel bars embedded in mortar

Journal Article · Fri Apr 15 04:00:00 EDT 2016 · Cement and Concrete Research

DOI:https://doi.org/10.1016/J.CEMCONRES.2015.12.015· OSTI ID:22696552

Tang, Fujian ^[1]; Chen, Genda ^[1]; Brow, Richard K. ^[2]

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1. Department of Civil, Architectural, and Environmental Engineering, Missouri University of Science and Technology, Rolla, MO 65409-0030 (United States)
2. Department of Materials Science and Engineering, Missouri University of Science and Technology, Rolla, MO 65401 (United States)

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.

• OSTI ID: 22696552
• Journal Information: Cement and Concrete Research, Journal Name: Cement and Concrete Research Vol. 82; ISSN 0008-8846; ISSN CCNRAI
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CEMENTS
ELECTROCHEMISTRY
ENAMELS
IONS
MATHEMATICAL SOLUTIONS
MORTARS
PITTING CORROSION
SODIUM CHLORIDES
STEELS
WATER