Flat slab systems are vastly used in multi-story buildings because of their savings in story height and construction time,\nas well as for their flexibility in architectural remodeling. However, they frequently suffer brittle punching-shear failure around\ncolumns, especially when subjected to lateral loads. Therefore, seismic codes labeled flat slabs as non-ductile systems. This\nresearch goal is investigating some construction alternatives to enhance flat slab ductility and deformability. The alternatives are:\nadding different types of punching-shear reinforcement, using discreet fibers in concrete mixes, and increasing thickness of slab\naround columns. The experimental study included preparation and testing of seven half-scale interior slab-column connections up\nto failure. The first specimen is considered a reference, the second two specimens made of concrete mixes with different volumetric\nratios of polymer fibers. Another three specimens reinforced with different types of punching-shear reinforcement, and the last\nspecimen constructed with drop panel of inverted pyramidal shape. It is found that using the inverted pyramid-shape drop panel of\nspecimen, increases the punching-shear capacity, and the initial and the post-cracking stiffnesses. The initial elastic stiffnesses are\ndifferent for all specimens especially for the slab with closed stirrups where it is experienced the highest initial stiffness compared\nto the reference slab.
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