Precast concrete is used extensively in building structures, for e.g. structural frames, floors and roofs, claddings etc.
Use of Precast Concrete in frames:
There are two main types of precast building frame. The structural frame consists of slabs, beams and columns. Structural frames are mainly used for offices, car parks and retail developments.
The cross-wall frame consists of floor slabs and solid walls. It is used mainly for hotels, schools and hospitals.
Use of Precast Concrete for Floors:
Each year the industry makes about 5 million square meters of precast floor slabs. That’s equivalent in area to 714 football pitches. The main types of floors are shown in figure below:
The reason for their success is:
- Fast construction
- Economic production
- Standardized cross=section
- Good strength to weight ratio
- Smooth surface finishes
Use of Precast concrete in Cladding:
Precast concrete cladding may be used as a structural element.
However, it is used more frequently as a non-structural decorative façade.
The backing concrete is made from an ordinary mix, whereas the façade may consist of a special mix, e.g. white Portland cement. A great variety of forms, details and colours can be produced.
Precast concrete cladding is not exclusive to precast frames. The majority is used with in-situ concrete or steel frames, and for refurbishments.