- Author
- Mathey, R. G. | Clifton, J. R. | Anderson, E. D. | Beeghly, H. F.
- Title
- Performance of Coated Steel Reinforcement in Concrete. Part 1. Investigation of Bond in Pullout Specimens.
- Coporate
- National Bureau of Standards, Washington, DC
- Sponsor
- Department of Transportation, Washington, DC
- Report
- NBSIR 73-401, May 1973, 28 p.
- Distribution
- Available from National Technical Information Service
- Keywords
- concretes | bond strenghts | epoxy coatings | polyvinyl chloride coatings | pullout tests | steel reinforcing bars
- Abstract
- Bond strengths of coated deformed steel reinforcing bars were compared with uncoated bars by means of pullout specimens. The bond strengths were determined for 23 epoxy-coated (10 different epoxy coatings), 6 polyvinyl chloride-coated (3 different coating materials), and 5 uncoated deformed reinforcing bars. The tensile reinforcement in the pullout specimen consisted of No. 6 deformed bars, having either a barrell or diamond shaped deformation pattern, with a nominal yield strength of 60,000 psi. The length of embedment of the reinforcing bar in the concrete was 12 inches. The load or bond stresses corresponding to a loaded-end slip of 0.01 inch or a free-end slip of 0.002 inch were considered as critical values in determining the bond strength, depending on which of these values of slip developed first. For coating film thickness of approximately 10 mils or less, the epoxy-coated bars developed bond strengths essentially equal to the bond strengths for the uncoated bars. Experimental values of bond strengths for these coated bars were higher than minimum acceptable values given in building code and highway bridge requirements. Bond strengths of the polyvinyl chloride-coated bars and bars with thick epoxy coatings were unacceptable.