In RCC framed structure, the load is transferred from a slab to the beam then to the columns, further to the lower columns and finally to the foundation which transfers load to the soil.
In such structures the walls are constructed after the frame is prepared, most tall buildings use RCC technology.
Cement concrete is robust in compressive strength however weak in tensile strength, to increase the tensile strength we use the mild steel bar in cement concrete.
Necessity in RCC framed structure:
- The steel bars utilized in cement concrete provide good strength to the structure.
- Usually, the steel bars are scratched or corrugated to enhance the bonding or cohesion between concrete and steel.
- Care should be taken that the steel bars used for RCC work should not have any joints, so should noticed that the steel used for RCC work has a longer length.
- If full-length steel bars are not available, the steel bar must be given the appropriate overlap and the overlap must be vibrated.
- Care should be taken that steel should not be disturbed during concreting.
- The steel rods must be properly tied and have proper planks or plates for walking.
- Curing of concrete is treated for a minimum of 20 days.
structural components in RCC framed structure:
The flat roof of a story known as a ‘slab’.
Beam: The peripheral horizontal members supporting the slab are referred to as ‘beams’.
Plinth Beams: The beam on the ground level or plinth level (the lowest liveable level) known as ‘plinth beams’.
The vertical members supporting the beam are referred to as ‘columns’.
Foundation: The system under the ground that transfers all the weight of the structure to the soil known as ‘foundation’.
A slab or a beam is supported only on one side and projected horizontally on the other side, called a ‘cantilever’ slab or beam, e.g. Balconies, lofts and canopies.
Advantages of RCC framed structure:
- Construction of floor area is often 10% to 12% larger than that of a load-bearing wall in an RCC framed structure, therefore, such a building is ideally economical where the worth of the land may be very excessive.
- It is very easy to change the internal plan of a room, bathroom, WC, etc. by changing the actual position of the partition walls which ultimately gives more freedom in planning.
- Monolithic construction will be adopted to withstand shocks and vibrations more effectively than load-bearing walled buildings.
- Normal earthquake effects can be resisted by offering the mandatory design.
- It is faster in construction, saves time, initial finishing.
- No matter soil is soft or hard, buildings with RCC frames can be installed anywhere.
- Maintenance costs are also minimal which can be ignored.
Disadvantages of RCC framed structure:
- Difficulty in repair, modification and expansion.
- It has Low tensile strength.
- Conventional formwork construction methods slow things down.
- Cracks develop in concrete due to shrinkage and load.