A flat slab is a two-way reinforced concrete slab that usually does not have beams and girders, and the loads are transferred directly to the supporting concrete columns.
The flat plate is a two-way reinforced concrete framing system utilizing a slab of uniform thickness, the simplest of structural shapes. The flat slab is a two-way reinforced structural system that includes either drop panels or column capitals at columns to resist heavier loads and thus permit longer spans.
Advantages of Flat Slab
1. Flexibility in room layout
- Partition walls can be placed anywhere.
- Offers a variety of room layouts to the owner.
- False ceilings can be omitted.
2. Reinforcement placement is easier
- As reinforcement detailing of the flat slab is simple, it is easier to place
3. Ease of Framework installation.
- Big table framework can be used in flat slab
4. Building height can be reduced.
- Floor height can be reduced and consequently the building height will be reduced.
- Approximately 10% of the vertical member could be saved.
- Foundation load will also reduce.
5. Less construction time
- Use of a big table framework helps to reduce construction time
What is column capital & drop panel?
Uses of column heads (capital):
⋅ Shear strength of flat slab is increased by using column heads.
⋅ Column heads reduce the clear or effective span, and therefore, reduce the moment in the flat slab floor.
Uses of drop panels:
⋅ Drop panels increase the shear strength of flat slab floor.
⋅ Drop panels increase flat slab's negative moment capacity.
⋅ Drop panels reduce deflection by stiffening the flat slabs.
How to determine the thickness of the flat slab
When using fy=420Mpa,
In case of flat slab with drop Panel, Slab thickness = Ln/36 = 7.0m/36 = 0.194m → Apply0.20m
* I will set the drop panels in this example
In case of flat slab without drop Panel, Slab thickness = Ln/ 33 = 7.0m / 33 = 0.212m → Apply 0.22m
How to determine the size of the drop panel.
Please download the white paper of Structural Design Guide for Flat Slabs below to see the full contents.