The thickness of most long-span flat slabs, two-way slabs without beams, is controlled by the shear strength of the concrete slab surrounding the supporting column. The shear resistance of these slabs can be increased by means of shear reinforcement. If the shear resistance is increased, slab thickness can be decreased resulting in less concrete materials and lower structure deadweight, reducing costs. But installing typical shear reinforcement, shear heads, and stirrup cages is difficult and costly. To take advantage of the reduced slab thickness and decreased cost that shear reinforcement could provide, a more efficient shear reinforcement has been developed.
This shear reinforcement consists of large-head studs welded to steel strips. The steel strip is positioned with bar chairs and fastened to the form by nails driven through holes in the steel strip. The chairs provide the required concrete cover and the nails anchor the stirrup to prevent movement during construction and concrete placing. In one case, using studded steel strips instead of a conventional stirrup cage decreased the amount of steel required from 82 pounds to 20 pounds per column.