Shear transfer between ribbed slab and edge column

The results of tests on six micro-concrete wide beam ribbed slabs at edge column locations are presented. It was found that punching shear failure of a wide beam ribbed slab can occur at an edge column. Although a punching shear failure of a wide beam ribbed slab is very similar to that of a solid slab, the shear capacity is reduced relatively, because some of the potential shear failure surface is lost when it enters the ribbed section. A plastic theory for punching shear was developed, which gave good agreement with the test failure loads.