Prefabrication is the assemblance of the components of a structure in the manufacturing site and transportation of complete assemblies or sub-assemblies to the construction site where the structured is to be located.
Uses of Prefabrication Construction:
- Uses to affect the economy in cost.
- Manufacturing of the components under controlled conditions
- Construction speed is increased
- Helps in locally available material along with the characteristics such as light weight, easy workability, thermal insulation, etc.
Materials and Components of Prefabrication System:
- Treated wood
- Cellular concrete
- Light weight concrete element
- Ceramic products
- Sunshade Projections
Prefabrication System:The system is depended upon the use of the Prefab Components, their material sizes and the technique which are used for the manufacturing.
Various Prefabrication Systems:
- Open Prefab System: This system is used with the basic structural elements for the formation of the whole or a part of a building.
Categories of Open Prefab System: The categories of open prefab systems are based upon the extent of prefabrication used in the construction are:
- Partial prefab open system
- Full prefab open system
Partial prefab open system: It emphasizes the use of precast the roofing and flooring components which act in the form of in-situ framework.
Full prefab open system: All the structural components are almost prefabricated.
- Large Panel Prefab System: It is based on the use of large prefab system and the casting of the components can be at the site or off the site.
Classification of Structural Scheme with Precast Large Panel
- Cross wall System: In this scheme, the cross walls are the load bearing walls and this system is useful for the high rose building
- Longitudinal Wall System: In this scheme, the cross walls are non-load bearing whereas Longitudinal walls are load bearing walls and it is useful for the low rise building.
Precast Floors: Precast flooring units can be Homogeneous i.e. solid slabs, ribbed or waffle slabs and Non-Homogeneous i.e. can be multi-layered with the combination of light weight Concrete or reinforced with filler blocks.
Staircase System: It consists of a single flight with in-built risers and trends in the elements only.
Box-type Construction: In this system, the size units of the rooms are prefabricated and erected in size. The box unit rests on the plinth foundation which may be conventional type or precast type.
- Individual Mould Method: It is the easy process of assembling out of bottom and sides and is used in Rib Slabs, Box type units and special element.
- Battery Form Method: These are the shuttering panel which can be adjusted in form of battery at the required distance which is used in the interior walls.
- Stack Method: It is also a battery form method which is used in floor and roof slabs panel.
- Tilting Method: A battery form method which is used in mould exterior walls.
- Long Line Prestressing Bed Method: A battery form method which is used in double tees, rib slabs and beams.
- Extrusion Method: A battery form method which moulds with constant cross section and vibration will be done automatically just as in concrete roads and used in roof slabs, panels and beams.
Advantages of Prefabrication
- High quality product
- Labor related savings
- Savings in time
- Overall efficiency is greatly increased
- Mass production is easier and quick
- Protected and controlled production environment
- Potential for lower production costs and other cost saving
- Independence of climate conditions
- Ensures high degree of safety