Corrosion Resistance of a Sand Particle-Modified Enamel Coating Applied to Smooth Steel Bars

Materials

Fujian Tang¹  Genda Chen¹  Richard K. Brow² 

[1] Department of Civil, Architectural and Environmental Engineering, Missouri University of Science and Technology, Rolla, MO 65401, USA; E-Mail:;Department of Materials Science and Engineering, Missouri University of Science and Technology, Rolla, MO 65401, USA; E-Mail:

关键词: corrosion resistance;    enamel coating;    sand particles;    EIS;    SEM;    XRD;   

DOI  :  10.3390/ma7096632

来源: mdpi

【 摘 要 】

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.

【 授权许可】

CC BY   
© 2014 by the authors; licensee MDPI, Basel, Switzerland.