Details of precast concrete floor and it's benefits
Precast concrete floor units are extensively applied in various types of buildings. It is utilized to extent among supporting steel beams as a substitute to in-situ concrete and metal decking. The joints among the units are grouted with in-situ concrete and a concrete structural topping is arranged for some applications.
Precast concrete floor units are pre-stressed concrete slabs and found as solid materials or with longitudinal hollow cores. The units are accessible in several depths to fulfill the different performance necessary for span & loading. The units are generally 1200 mm wide and the length remains up to 20m.
Benefits of precast concrete floor
- It does not require formwork.
- Time is saved for concrete to be cured in the formwork.
- Superior quality control.
- Numbers of works are also reduced in terms of in-situ concrete construction.
- The process becomes rapid for finishing of construction project.
- Long spans are obtainable with precast concrete flooring systems and consequently the requirement for the number of secondary beam is decreased and the column free space is increased.
- Fire resistance ratings usually remain among 1 & 2 hours.
The following points should be taken into consideration prior to choose any precast concrete flooring system :-
- Maximum span
- Type of support
- Weight of units
- Thickness of units
- Amount of temporary support necessary
- Sound insulation
- Thermal insulation characteristics
- Fire resistance of units
- Speed of construction
The following types of precast concrete floors are available :-
Precast hollow floors
Precast hollow floor units are found in different types of selections like box planks, beams, tee section, I beam sections and channel sections.
Composite floors are formed by combining precast units and in-situ concrete.
Benefits of precast hollow floors
- More reasonable with regard to in-situ floor owning to cutback in concrete volume utilized, weight of reinforcement & size of foundation.
- Inexpensive as compared to composite floors.
- In-situ concrete is not necessary.
- Units are self centering, no temporary support is required.
- Construction period is curtailed.
Benefits of composite floors
- Precast units generally prestressed/reinforced with high yield bars are employed to offer the strength of the floor with the smallest depth feasible.
- It functions as permanent formwork to the in-situ topping that offers the necessary compressive strength.
- It functions in the same way as in-situ floor and as a result it can be designed for more complex loadings.