Slab directly supported on columns without beams are called Flat slabs or flat plates.
Followings are the difference between Flat slab and Flat plate slab:
|Flat Plate Slab
|Flat slab is one with either drop panel or column capital (or both at the same time) that helps reduce shear stress on the column slab junction.
|On the other hand, flat plates are slabs systems with the slab connected to the column directly.
|Flat slabs can bridge larger spans because of higher shear capacity & deflection control.
|Flat slabs can bridge smaller spans because of lower shear capacity & deflection control.
|According to MacGregor and Whites book, mechanics and design of reinforced concrete Structures, flat slabs can be used easily for spans upto 30 ft [upto 9 m]
|According to MacGregor and Whites book, mechanics and design of reinforced concrete Structures, flat plates are most economical for spans from 15 to 20ft [4.5 to 6 m]