FAQ
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In RCC constructions steel needs to be protected from rusting.
This is done by providing a layer of concrete around steel bars. Gap
between steel and shuttering is required to provide layer of concrete.
This gap is maintained by a spacer or cover block.
It is the gap between steel bars and shuttering. This gap is filled by concrete during casting process.
Steel is prone to rusting due to atmospheric conditions. This layer of concrete protect steel from rusting.
It is the gap between steel bars and shuttering. This gap is filled by concrete during casting process.
Steel is prone to rusting due to atmospheric conditions. This layer of concrete protect steel from rusting.
- Ordinary cover blocks have poor fixity with steel bars. They does not have any system to bind themselves with steel bars. So they generally come out during the casting due to human movement, vibration due to vibrator and flow of concrete.
- Both ordinary concrete and PVC cover blocks have solid block type construction. So there is cold joint formation.
- Where as CROSS LOCK Cover Blocks locks itself at crossing of two steel bars without use of any binding wire.
- As CROSS LOCK Cover blocks locks itself with the crossing of steel bars restricting both linear and rotational movement. It neither comes out nor it rotates before or during casting despite human movement, vibrations and flow of concrete.
- High load bearing capacity of about 400 Kg ensures that it can take up loads of repeated human movements at the time of casting.
- Hollow structure with more than 60% void area ensures homogeneous concreting without cold joint formation.
- Slab = 20mm
- Beam = 25mm
- Column = 40mm
- Footings = 50mm
- Slab = CL-20
- Beam = CLB-25
- Column = SL-2540 or CL-40
- Footings = CL-50
Indian building code is not comprehensive on cover blocks and its spacing. As per Indian building code IS:456 the distance between two cover blocks should not be more than 1 Meter. Closer spacing may be required.
It’s important to note the term “closer spacing may be required”. Because when steel bars of lower thickness is used slag of steel can result into uneven concrete cover. As BS:7973 part II the spacing between two spacers should be 50D.
Based on practical site conditions and commonly used steel diameters our recommendations for spacing between cover blocks is as following :-
Slab = 2 Feet
Beam = 3 Feet ( 2 Pieces for better balance)
Column = 8 Pieces at the top side on each shuttering.
Footing = 3 Feet + (4 Pieces under the column steel to take it’s load)
Concrete Wall = 3 Feet
Rebar Chair for Top Steel = 3 Feet
Electrical conduit Pipe = 4 Feet
Generally these spacing recommendations work very well. But some adjustments may be required some times based on design of steel binding schedule.
Indian building code is not comprehensive on cover blocks and its spacing. As per Indian building code IS:456 the distance between two cover blocks should not be more than 1 Meter. Closer spacing may be required.
It’s important to note the term “closer spacing may be required”. Because when steel bars of lower thickness is used slag of steel can result into uneven concrete cover. As BS:7973 part II the spacing between two spacers should be 50D.
Based on practical site conditions and commonly used steel diameters our recommendations for spacing between cover blocks is as following :-
Slab = 2 Feet
Beam = 3 Feet ( 2 Pieces for better balance)
Column = 8 Pieces at the top side on each shuttering.
Footing = 3 Feet + (4 Pieces under the column steel to take it’s load)
Concrete Wall = 3 Feet
Rebar Chair for Top Steel = 3 Feet
Electrical conduit Pipe = 4 Feet
Generally these spacing recommendations work very well. But some adjustments may be required some times based on design of steel binding schedule.
Life of steel in concrete against corrosion depends upon adequate thickness of good quality concrete. Life of structure can be increased by providing proper concrete cover to steel. Structures are stronger when steel bars are at proper position.
All the CROSS LOCK products are provided in packets.
As a thumb rule generally one packet covers 1000 Sq Feet or 100 Sq Meter per application.You can check at our pricing section to work out the cost.
Frequently Asked Questions
Most frequent questions and answers
What is a spacer or PVC cover block ?
In RCC constructions steel needs to be protected from rusting. This is done by providing a layer of concrete around steel bars. Gap between steel and shuttering is required to provide layer of concrete. This gap is maintained by a spacer or cover block.
What is cover and why it's required ?
It is the gap between steel bars and shuttering. This gap is filled by concrete during casting process.
Steel is prone to rusting due to atmospheric conditions. This layer of concrete protect steel from rusting.