The normal process of design and construction is to support the slabs with beams and support the beams with the column. It is known as beam-slab construction. The beams help in minimizing the existing net clear ceiling height. Often, in warehouses, parking garages, ramps, offices and public halls, the slabs are used as a substitute of beams and they are directly supported with columns. These types of slabs are known as flat slabs.
A flat slab stands for a one-way or two-way system with solidities in the slab at the columns and load-bearing walls are known as ‘drop panels’ Drop panels function as T-beams over the supports. They raise the shear strength and the rigidity of the floor system against vertical loads, thus the economical span range becomes greater.
Normally, the height of drop panels remains about two times the height of the slab. The plan dimensions of the drop panels are a minimum of 1/3 of the distance in the direction being considered, normally rounded to the nearest 100 mm. Flat Slabs are useful for most of the construction and for irregular column layouts like floors having curved shapes and ramps etc.
Types of Flat Slab Construction
1- Simple flat slab
2- Flat slab with drop panels
3- Flat slab with column heads
4- Flat slab with both drop panels and column heads