Title: Bond of Concrete to Reinforcing Bars
Author(s): Arthur P. Clark
Publication: Journal Proceedings
Appears on pages(s): 161-184
Keywords: no keywords
The tests reported were made to compare the resistance to slip in concrete (bond) of deformed bars when tested in beams and co,panion pull-out specimens, to secure information on the effects of size of bar, the type of deformations on the bars and the strength of concrete on the bond. The bars were cast in a horizontal position in all test specimens. The variables were depth of concrete under the bar, length of embedment of the bar in the concrete, strength of concrete and diameter of bar. Slip of the bar was measured at the loaded and free ends. Three tests were made with 2 in. of concrete under the bar and with 8-in., 12-in., and 16-in. embedments. Bond strengths for the beams and pull-out specimens were affected similarly by changes in the geometry of the bars and the bond test specimens. They were greater when the bars were near the bottom then when they were near the top of the specimens. The highest bond strengths were obtained with bars having deformations conforming to suggested requirements for maximum spacing and minimum height and providing ratios of shearing to bearing areas less then 10, usually less then 6.