Effect of Steel Fibers on Bond Strength of Hooked Bars in Normal-Strength Concrete

The effect of steel fibers in improving the bond performance of hooked-bar anchorages and the ductility of the failure mode of beam-column connections was evaluated by testing 12 beam-column-type specimens. The specimen simulated the rigid connection of a vertical cantilever beam to a base column. The tensile beam. reinforcement consisted of two bars anchored in the column outside the column reinforcement cage using hooked-bar anchorages. The variables used in the study were the beam bar size (16, 25, or 32 mm [No. 5, No. 8, or No. 10]) and the volume fraction of steel fibers added and dispersed in the concrete mixture (0, 0.5, 1.0, or 1.5%). The analysis of the test results revealed that steel fibers were effective in increasing the anchorage capacity and the ductility of the load-deflection history of specimens with steel fibers as compared with companion specimens identical in geometry and bar size but without steel fibers.