Testing of bricks

TESTING OF BRICKS

1. Shape and Size Test: The shape of bricks should be truly rectangular with sharp edges. Bricks should be of standard size (190 mm × 90 mm × 90 mm).

2. Soundness Test: This test is performed by striking two specimen bricks with each other. The bricks should not break. A clear ringing sound should be produced.

3. Structure Test: A specimen brick is broken. Its structure is studied. Its structure should be homogeneous, compact and free from any defects such as holes, lumps, etc.

4. Test for Colour Uniformity: Bricks should have a uniform deep red or cherry colour.

5. Hardness Test: It is conducted by making a scratch on brick surface with finger nail. If no impression is left on the surface, the brick is hard. The brick should not break when dropped flat on hard ground from a height of about one meter.

6. Crushing or Compressive Strength Test: Brick is tested in Compression Testing Machine.

7. Test for the Presence of Soluble Salts / Efflorescence Test: Efflorescence is a defect caused by soluble salts. Patches of white or grey deposits on its surface indicates the presence of soluble salts. It spoils both the appearance and the strength of the bricks.

8. Water Absorption Test: The specimen brick is first weighed dry. It is then immersed in water for 16 hours and weighed again. The difference in weight indicates the amount of water absorbed by the brick. It should not exceed 20% of the weight of dry brick.