Chloride Sensitivity of the Corrosion Rate of Zinc-Coated Reinforcing Bars.

摘要

This laboratory study was undertaken to determine whether zinc coatings can be relied on for long-term protection of reinforcing bars subject to environments of variable salt concentrations. Hot-dip galvanized reinforcing bars were coupled to bare carbon steel rebars in various concentrations of CaCl2 in saturated Ca(OH)2-distilled water solutions. Galvanic current output was monitored as a function of time and percent CaCl2 for a zinc-steel couple with an anode-cathode area ratio of unity. Current output became stable after 20 days for CaCl2 concentrations less than 1 percent. For concentrations at 1 percent or greater, current fluctuations were cyclical, increasing in magnitude as percent CaCl2 increased. At 4 percent CaCl2, current output rose sharply. (Author)