Punching Shear Behavior of Reinforced Slab-Column ConnectionsMade with Steel Fiber Concrete

Punching shear failures occur suddenly and produce catastrophic results. The effect of fiber reinforcement on the deformation and strength characteristics of punching shear failures is discussed in this paper. The fibers were used throughout the slab or in the punching shear zone of the column head, and comparative tests were carried out on connections with bent-up steel bars. The results show that fibers reduce deformations at all stages of loading, increase ultimate punching shear loads, and produce ductile shear failures. Substantial increases in ductility and energy absorption can be obtained by using fiber concrete. Fibers can not only produce flexural failures for the same load capacity in shear but can achieve it with considerable saving in flexural steel. Bent-up bars are clearly more effecti•·e than fiber reinforcement but are very labor-imensive.