11 Characteristics of First Class Bricks
Following are the 11 properties/characteristics of a first-class brick:
- First-class bricks are table moulded and they are burnt in Kilns.
- These are well burnt in kilns.
- The surface of the first-class brick should be smooth and rectangular.
- The edges of the brick are perpendicular(Make an angle 90°) to the adjoining edges.
- They are regular in shape and size with sharp edges and corners.
- They shall be of uniform deep red colour.
- They should be free from any cracks.
- They should be free from chips, efflorescence, flaws and lumps of any kind.
- Dry first-class bricks should not absorb water more than 16% of their own weight when immersed in water for 24 hours.
- They emit a clear ringing sound when two bricks are struck each other.
- The average compressive strength of the first-class bricks should not be less than 100kg/sq.cm and not more than 125 kg/sq.cm.
Note: First class bricks are recommended for permanent and superior work.