Bond Studies Of different Types Of Reinforcing Bars
George Robert Wernisch
Appears on pages(s):
Results of bond tests on 148 6 x 6-in cylindricalpull-out specimens and 58 6 x I2 x 36-in. beams fnomi-nal effective depth 9.0 in.) containing I3 types of ‘/2- and 3/4--in. diameter reinforcing bars are reported. Pull-out test seems a poor-measure of ‘bond resistance of reinforcing bars placed in beams of the dimensions noted, both in initial and ultimate end slip. Type of bar has a marked effect on the resistance of bars subjected to a pull-out test, whereas, with the exception of threaded and smooth bars, the type of bar has slight influence on bond resistance of the bars embedded in beams. Increasing strength of concrete usually results in a moderate increase in bond resistance of both beams and pull-outs, not in direct proportion to increase concrete strength. initial slip in beams occurs at a much greater calculated bond stress than in pull-out tests. Commercial bars are stronger than ordinary plain bars in bond resistance determined by beam tests.