Flat Slabs

Information to provide in scheme design:

     Constant thickness of flat slab

     Thickness of drop panels, if required. These drop panels serve as thickened section surrounding columns to provide additional shear strength at the ends of the columns.

     Clear floor height

Reasons to use this slab type:

Capabilities

     Support directly by and transfer loads directly to columns

     Provides higher headroom due to unobstructed ceilings and lack of beams

     Lack of beams that can otherwise interfere with light and air flow

     Provides robustness

     Provides space for partition wall placement

     Flat soffit decreases concrete spalling, decreasing maintenance cost

     Accommodates voids for service installation and distribution

     Absent of sharp corners which increases fire resistance and safety protection

     Adequate for resistance to heat, sound, vibration, and acoustics

Construction

     Structural design provides repetitive construction sequence of components which speeds up schedule and decreases cost of construction

     Uses standardized and simple formworks, reinforcement placement, and shuttering methods that speed up construction

Advantages over other slabs:

Flat Slab vs Beam Slab

     Flat slabs provide a more aesthetic appearance due to unobstructed ceilings and lack of beams which show beam underside

     Beam slabs require more labor for shuttering and complicated reinforcement positioning

     In Beam Slabs, the penetrations through downstand beams may affect the strength of the beams. The size and location of slab openings will also be limited due to limited openings for services and floor to floor openings.

Disadvantages

     Need to design to suit concentrated loads and partitions

     Less flexibility for openings. Trimming beams are needed around openings for support of slab.

     Flat slabs are larger in thickness so the structure will be heavier. This will incur a higher cost for the amount of concrete and steel reinforcement needed for the foundation.

     Not a lot of stiffness provided for wind resistance If there are no core walls

     Can only utilize a limited span range

In your Detail Designed Calculations, you will need to put more emphasize on calculations and check on punching shear and deflection, if flat slabs are used.