Corrosion characteristics of straight epoxy-coated reinforcing steel (which met aashto and astm specifications) in concrete were studied. Specimens were exposed outdoors in a northern environment for more than 6.5 Years, including about 3.1 Years of salting cycles with a 3% sodium chloride solution. Straight epoxy-coated bars were evaluated when they were used in both mats and when they were used in the top mat only. An additional study variable was the use of uncoated bars in both mats. Results indicated that epoxy-coated rebars are many times more resistant to corrosion-induced damage than uncoated bars when embedded in salt-contaminated concrete and coupled to coated or uncoated bars in salt-free concrete. Overall best performance was achieved when the bars in both mats were epoxy coated. An observed softening of the coating in top- and bottom-mat bars after long-term exposure in the highly alkaline environment is also discussed. This paper appears in transportation research board record no. 1284, Cement, admixtures, and concrete 1990.
Samenvatting