Punching Shear in Voided Slab

The revolutionary technology of flat slab construction by using hollow sphere to replace the ineffective concrete in the center of the slab (Bubble Beck) has many advantages, beside it is reduce the material, the load, lower the coast and increasing the span length it is also a green technology, And Since the punching shear capacity is one of the most interesting properties of flat slab, the influence of the cavities due to using the plastic balls on the punching behavior of self compacted concrete was study in this paper. also the effect of strengthening the punching zone by using different percentage of steel fiber ( 0.8%, 1%) on the maximum punching load and deflection were included