What is Cover Block, Importance of Cover Block ,Size of Cover Blocks for Structural Members

What is Cover Block?
The cover block is the spacer between the reinforcement matrix and the outer surface of the concrete. In order to prevent corrosion of the rebar, it needs to be fully encased in concrete. By code, it usually needs about 2 to 3 inches of coverage on all sides.

There are different type of cover blocks are used based on type of material

1. Cement masonry cover block
2. PCC Concrete cover block
3. RCC Concrete cover Block
4. PVC Cover Block
5. Stone Cover Block
6. Steel Cover Block
7. Aluminum Cover Block
8. Wooden cover block
   

   Size of Cover Blocks for Structural Members

   Si. No	Strctural Member	Minimum Size
   1.	Footings	50 mm
   2.	Raft Foundation Top	50 mm
   3.	Raft Foundation Bottom	75 mm
   4.	Strap Beam	50 mm
   5.	Beam	25 mm
   6.	Grade Slab	20 mm
   7.	Slab	15 mm
   8.	Flat Slab	20 mm
   9.	Column	40 mm
   10.	Shear Wall	25 mm
   11.	Stair case	15 mm
   12.	Retaining Wall	20 - 25 mm
   13.	Water Retaining Structure	20 - 30 mm
   14.	Sunshade	25mm

IMPORTANT POINTS FOR COVER BLOCK

• The cover must be the same grade of concrete that you’re using in the building component. 
• For slab reinforcement 4 cover block should be used per Square meter
• For Beams or column 12 cover block should be used per meter together all four sides
• Thus the use of cover block gives higher life to the structure at a very low cost

IMPORTANCE (OR) USES OF COVER BLOCK

• It is used to prevent the corrosion of reinforcement
• Cover block maintain required gap between Rebar and concrete surface.
• It is caused to concrete may proper adjust and flow underneath the rebar.
• It gives proper strength to Reinforcement.
• It prevent from Corrosion to Rebar.
• It Provide better reinforcement to Fire & moisture resistance to rebar.
• Provide thermal insulation, which protects the reinforcement bars from fire