Factors influencing standardization:-
1) To select the most rational type of member for each element from the point of production, assembly, serviceability and economy.
2) To limit the number of types of elements and to use them in large quantities.
3) preferred by the weight in overall dimension that can be handled by the handling and erection equipment and by the limitation of transportation.
4) To have all the pre fabricates approximately of same weight very near to the lifting capacity of the equipment.
The word system is referred to a particular method of construction of buildings by using prefabricated components which are inter-related in functions and are produced to a set of instructions, with certain constraints, several plans are possible, using the same set of components. The degree of flexibility varies from system to system.
a prefabrication system
The following characteristics among others, are to be considered in devising a system.
1. Intensified usage of spaces.
2. Straight and simple walling scheme.
3. Limited sizes and number of components.
4. Limited opening in bearing walls.
5. Regulated locations of partitions
6. Standardized service and stair units.
7. Limited sizes of doors and windows with regulated portions.
8. Structural clarity ad efficiencly.
9. Suitability for adoption in law rise ad high rise blocks.
10. Ease of manufacturing, storing ad transporting.
Prefabricated construction system
The system of prefabricated construction depends in the extent of the use of prefab components, their material sizes and the technique adopted for their manufacture and use in build. The various prefabrication system are outlined below.
1. Open prefab system
a. Partial prefab open system.
b. Full prefab open system.
2. Large : panel prefab system
3. Wall system
a. Cross wall system.
b. Longitudinal wall system.
4. Floor system
5. Staircase system
6. Box type system
This system is based on the use of the basic structural elements to form whoe or part of a building. The standard prefab concrete components which can be used are,
1. Reinforced concrete channel units.
2. Hollw cost slabs
3. Hollow blocks ad patterns.
4. Precast plank and buttons.
5. Precast forsts ad tiles.
6. Cellular concrete slabs.
7. Prestressed / reinforced concrete slabs.
8. Reinforced / prestressed concrete beams.
9. Reinforced / pre stressed concrete columns.
10. Precast lintels ad sub standby.
11. Reinforced concrete waffle slabs /
12. concrete panels.
13. Reinforced / prestressed concrete walling elements.
14. Reinforced / prestressed concrete trusses.
The elements may be cost at the sit or off the site.
Foundation for the columns could be of prefabricated type of the conventional cast insites type depending upon the soil conditions and loads. The columns may have hinged of fixed base connections depending upon the type of components used ad the method of design adopted.
There are two categories of open prefabrication used in the construction as given
1. Partial prefab open system.
2. Full prefab open system.
The system basically emphaises the use of precast roofing ad flooring components and other minor elements like lintels, sunshades, kitchen sills in conventional building construction. The structural system could be in the form of insite frame work or load bearing walls.