Compressive strength of Brick

      COMPRESSIVE STRENGTH OF BRICK
The  compressive strength of brick test involves following steps:

1. Take five bricks and immersed in water for one day.
2. Then take out the bricks and clean the surface water with clothes.
3. Fill the frog with cement paste 1:2 and level the surface of bricks.
4. Rest the bricks in shadow for 1 days.
5. Then  immersed the bricks in water for 7 days .
6. Take out the bricks from water and clean the surface and place the brick between the plywood.
7. Then place the brick under machine which apply load on brick till brick is broken
8. Perform the same procedure for all 5 bricks and take the mean value.

The compressive strength for 

    First class bricks      - above 14N/sq.mm

    Second class bricks - 7-14N/sq.mm

    Third class bricks       below 7N/sq.mm

The minimum compressive strength of bricks is 3.5N/sq.mm otherwise the bricks is not safe for use.