Tests for Bricks

 A brick is generally  subjected to following tests to find out its suitability  of the construction work.

1) Absorption:  A good should not absorb not  more than 20 percent of weight of  dry  brick 

2) Compressive strength:  crushing or compressive strength of brick is found out by  placing it in compression testing  machine. It is pressed till it breaks. Minimum  crushing strength of brick is 35kg/cm2  and for superior bricks, it  may  vary from  70 to 140 kg/cm2. 

3) Hardness:  No impression is left on the surface the brick is treated to be sufficiently  hard 

4) Presence of  soluble salts: The bricks should not show any grey or white deposits after immerted in water for 24 hours 

5) Shape and  size:  It should be standard size and shape with sharp edges 

6) Soundness: The brick should give clear ringing sound struck each  other 

7) Structure:  The  structure  should be homogeneous, compact and free from  any  defects