The protective performance of a sand particle-modified enamel coating on reinforcing steel bars was evaluated in 3.5 wt% NaCl solution by electrochemical impedance spectroscopy (EIS). Seven percentages of sand particles by weight were investigated: 0%, 5%, 10%, 20%, 30%, 50% and 70%. The phase composition of the enamel coating and sand particles were determined with the X-ray diffraction (XRD) technique. The surface and cross-sectional morphologies of the sand particle-modified enamel coating were characterized using scanning electron microscopy (SEM). XRD tests revealed three phases of sand particles: SiO2, CaCO3 and MgCO3. SEM images demonstrated that the enamel coating wetted well with the sand particles. However, a weak enamel coating zone was formed around the sand particles due to concentrated air bubbles, leading to micro-cracks as hydrogen gas pressure builds up and exceeds the tensile strength of the weak zone. As a result, the addition of sand particles into the enamel coating reduced both the coating and corrosion resistances.
F. Tang et al., "Corrosion Resistance of a Sand Particle-Modified Enamel Coating Applied to Smooth Steel Bars," Materials, vol. 6, no. 9, pp. 6632-6645, MDPI AG, Sep 2014.
The definitive version is available at https://doi.org/10.3390/ma7096632
Civil, Architectural and Environmental Engineering
Materials Science and Engineering
Keywords and Phrases
Bars (metal); Calcium carbonate; Coatings; Corrosion resistance; Electrochemical corrosion; Electrochemical impedance spectroscopy; Enamels; Scanning electron microscopy; Tensile strength; X ray diffraction; 3.5 wt% NaCl solution; Cross-sectional morphology; EIS; Enamel coatings; Hydrogen gas pressure; Protective performance; Sand particles; XRD; Sand
International Standard Serial Number (ISSN)
Article - Journal
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01 Sep 2014