Properties of First class brick

Properties of First class bricks

Properties of first-class bricks are given below:

• Dry first-class bricks should not absorb water more than 20% of their own weight when immersed in water for 24 hours.
• No impression should be left on the brick when a scratch is made by finger nail.
• They emit a clear ringing sound when two bricks are struck by each other.
• First-class bricks are table molded 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 of 90°) to the adjoining edges.
• They are regular in shape and size with sharp edges and corners.
• They shall be of uniform deep red color.
• They should be free from any cracks.
• They should be free from chips, efflorescence, flaws, and lumps of any kind.
• The average compressive strength of the first-class bricks should not be less than 100 kg/cm2 and not more than 125 kg/cm2.