What is Concrete covering in R.C.C

Concrete covering in the R.C.C. structure (Clear Cover) is the distance between the concrete surface and the nearest steel reinforcement surface.

The covering between the concrete surface and steel reinforcement depends on the concrete grade. The exposure condition based on this structural consultant will specify the covering space for the different structural components.

Fig: Beam Cover

Fig: Beam Cover

Fig: Column Cover

 

Fig: Slab Cover

Fig: Footing Cover

Fig: Footing Cover

Why and how is it important?

• If covering concrete is not provided, steel reinforcement will be exposed to moisture in the environment; this exposure leads to rusting or corroding steel reinforcement.
• Once the corrosion of steel starts it is continuous like a chain reaction, it weakens the entire structural element. Hence it is necessary to provide coverage as per structural design.  
• By providing cover as per structural design, the structure will function efficiently, thus avoiding premature failure of the structure.
• The cover also acts as a thermal insulator for the steel reinforcement.

 

Covering Blocks

The cover block is essentially a spacer used in concreting to lift the reinforcement off the ground to provide the desired cover.

• A calculated distance is maintained between the rebar and the shuttering.
• A single covering concrete block can get three different spacing ranges from 20mm to 60 mm.
• Cover block takes live load during the concrete and remains intact.
• Achieve uniform spacing throughout the concrete member.
• Reinforcement bar is provided with adequate embedding enabling them to be stressed without slipping.

Two type of cover blocks:

• Concrete cover blocks

Fig: Concrete covering blocks

• PVC cover blocks

Fig: PVC covering blocks

Specifications	Concrete Cover Blocks	PVC Cover Blocks
Compatibility	It is in harmony with concrete which result in good bonding between concrete and covering blocks	It is a foreign body within concrete which results in improper bonding.
Fire resistance	Yes	No
Availability	Adequately available in market	Available in market
Cost	Average rate of 1.7Rs per piece	Average rate of 1.2Rs per piece

Conclusion

Concrete covering process is to ensure that there is no erosion after reinforcement of cement concrete. It is important to perform the process as it is prone to fire and corrosion due to atmospheric conditions. Furthermore, to avoid cracks in the hardened R.C.C., covering is performed.  Covering is done for all the building elements where reinforcement is used. Therefore it is an important process to the foundation of a building.

Therefore, the right and complete procedure is taken care of by Constructure. Learn about the unique approach that is followed at Constructure that ensures the best foundation for your dream building.