What Is Superstructures?
The portion above the ground level and below the ground floor level is known as a plinth. The portion above the ground floor level is known as super-structure.
It includes columns, walls, beams, floors, roofs, doors, windows, lintels, staircases, etc. In this article types of super-structures based on the method of load, a transfer is first presented and then the various components are discussed giving their functions and types.
Types of Super Structures
On this basis, there are two types
1. Load Bearing Structures
2. Framed Structures
What Is Load Bearing Structures?
In this type of structure, the load in the structure is moved vertically downward through walls. Loads from roof and floors get moved to wall and then the wall must transfer these loads as well as self-weight.
Such constructions are used in residential buildings in which the dimension of rooms is less. Residential buildings up to ground + 2 floors can be built economically with such structures.
What Are Framed Structures?
In this type of structures, a framework of columns, beams, and floors is built first. Then the walls are built to partition the living area.
The walls are subjected to self-weight only. This type of super-structures is needed when a number of stories in a building are more and also when larger areas must be covered free from walls.
Load-Bearing Vs Framed Structures
|Sr. No.||Load Bearing Structure||Framed Structure|
|1||Cost is less.||Cost is more.|
|2||Suitable up to three stories.||Suitable for any number of stories.
|3||Walls are thicker and hence floor area is reduced.||Walls are thinner and hence more floor area available for use.|
|4||Slow construction.||Speedy construction.|
|5||Not possible to alter the position of walls, after the construction||Position of walls may be changed, whenever necessary.|
|6||Resistance to earthquake is poor.||Resistance to earthquake forces is good.|
|7||Taken deep into the subsoil foundation.||Only column are taken deep into subsoil and provided with foundation footing.|
|8||Load Bearing Structure type of construction does not favor toomany openings for windows, doors, ventilation etc., in the ground floor as required for show room etc., as the load bearing length of wall is considerably reduced||The space between column can remains as open space as the case with multi – storeyed residential flats where the ground floor is left with no walls for easy parking of vehicle.|
|9||In case of multi – storeyed buildings, the room area is reduced as we go down due to thicker walls.||Thickness of wall remains uniform, therefore the carpet area in any floor remains the same.|
|10||Plans of the different floors must be the same. Very little changes are only possible between one floor and the one above.||Plans of different floor are independent of each floor. The ground floor may have a commercial complex, first floor an office or a bank and second floor onward of residential complexes of different types of plans and function within the same building.|
|11||May not withstand seismic forces and other forces and other type of vibration because composed of different blocks as bricks and stones being bonded together.||More rigid and withstand seismic forces because of the entire frame of column, beam and slabs act as one unit of R.C.C.|
|12||This construction more labor intensive.||This construction less labor intensive, but it needs different skills.|
|13||In this Construction Life is not much affected even though some standards are not strictly followed.||In this Construction Life is reduced if not done with proper technique, and specifications i.e. codes are not strictly followed.|
|14||Construction of a load bearing structure is cumbersome, particularly for earthquake resistant structures.||Construction of a framed structure is otherwise simple.|
|15||Limitations for providing openings in walls, which will affect the light and ventilation in room.||Large openings in walls are possible.|
|16||Load bearing structures can be constructed without expensive plant and machines as compared to a framed structure.||Framed structures require expensive plant and machines to construct.|
|17||Walls have to be built first as they support the slab / roof and hence all walls have to be built simultaneously which is time consuming||Generally, RCC framed structure is constructed first and the external as well as partition walls are constructed later, hence speed is more.|
|18||In case of a load bearing structure, large span areas are not possible. Limitation of span i.e. room sizes.||In case of a framed structure, large span areas are possible. No Limitation of span i.e. room sizes.|