Title: Performance Comparison of Hooked Plain and Deformed Bars in Concrete
Author(s): Bjorn E. Vors and Lisa R. Feldman
Publication: Structural Journal
Appears on pages(s): 91-99
Keywords: anchorage; beam-column joint specimen; bond and develop-ment; deformed reinforcement; hooks; plain reinforcement; reinforced concrete
Ninety- and 180-degree hooked plain and deformed bars were tested in beam-column specimens. Six replicate specimens were tested for each bar type and bend angle to evaluate whether differences in the reported quantitative results were statistically significant. Statistically significant differences were identified in the maximum normalized tensile resistance between 90-degree hooked plain and deformed bars, 180-degree hooked plain and deformed bars, and 90- and 180-degree hooked deformed bars. Side and front face blowout were visually identified as the primary failure modes for specimens containing 90- and 180-degree hooked bars, respectively, with tail kickout noted as a secondary failure mode in select specimens containing 90-degree hooked bars. The influence of bearing capacity of concrete in advance of the bend region resulted in no statistically significant differences between displacements of the hooked bars at the maximum tensile resistance for the range of concrete strengths investigated in this study.