Classification of Bricks Types | Qualities | Uses.
According to physical requirements bricks are classified as:
1) First-class bricks
2) Second class bricks
3) Third class bricks
4) Fourth class bricks
1) First-class bricks:
The qualities of first-class bricks are:
- First-class bricks are table moulded, well and uniformly burnt, deep red or copper coloured.
- bricks are burnt in kilns
- Size is exactly 190×90×90mm
- The edges are square and sharp
- These bricks have Uniform texture
- The crushing strength should be about 10N/mm2
- Water absorption should not be more than 20% after 24 hours of immersion
- The bricks should produce clear metallic sound when struck with each other
- The brick should not break when dropped from a 1-metre height.
Uses of first-class bricks:
- Used for superior work
- Used for reinforced brickwork
- Used for load-bearing walls.
- Used for pavements and flooring.
2)Second class bricks:
These bricks are ground moulded and they are burnt in kilns.
The qualities of second class bricks are:
- The brick is well burnt
- Water absorption is not more than 22% of its own weight after 24 hours of immersion
- These bricks give a clear metallic ringing sound when struck with each other
- This bricks should not show signs of efflorescence.
- The shape and size should be uniform
- The crushing strength should not be less than 7N/mm2
Uses of second class bricks:
- Used in RCC work
- Used for load-bearing walls
- These bricks are provided with a coat of plaster.
3)Third class bricks:
These bricks are ground moulded and are burnt in clamps. These bricks are not properly burnt.
The qualities of third class bricks are:
- These bricks are under burnt
- These bricks are not hard and surface what is rough
- They are soft and light-coloured
- They have much sign of efflorescence
- They give a dull sound when struck with each other
- The water absorption should not be more than 25%
- They have a compressive strength of 3.5N/mm2
- They do not have sharp edges and corners
- The texture is not uniform.
Uses of third class bricks:
- Used for in-important structure
- Used for construction of walls of low height
- Used in areas where rain is not heavy
- Used for temporary structures.
4) Fourth class bricks:
These are over burnt bricks with irregular shape and dark colour.
Qualities of fourth class bricks:
- These bricks are a dark bluish colour
- These bricks have compact structure