Clarification of Bricks as per is code

 Bricks

      Made of burnt clay or maximum of sand and lime, clay bricks are commonly used. It's constriction one of the best building material. 

First class Bricks :characteristics of good bricks.

1. Thoroughly burnt with deep red, cherry or copper colour.
2. Surface should be smooth and rectangular, with parallel, sharp and straight edges and square corners.
3. Should be free form, cracks and stones.
4. No impression should be on the bricks when a scratch is made by a finger nail.
5. Water Absorption should be 12-15% of its dry wt. when impressed in a cold water 24 hrs
6. Should be uniform texture.
7. The fracture surface of the bricks should not show lumps of lime.
8. A metallic or ringing sound should come when two bricks are struck again each other.
9. Crushing strength of Brick should not be less than 10.5 N/mm2

Uses: Reinforced brick work

        Exposed face work in masonry structure

        Flooring and pointing

        Load bearing structure

         Heavy structure load bearing level like well

Second class Bricks:

1. Small cracks and distortions are permitted.
2. Water Absorption about 16-20% is allowed. 
3. Crushing strength should not be less then 7 N/mm2

Uses: all important and unimportant masonry work 

Third class bricks 

Under burnt, soft and light colored producing dull sound.

Water Absorption is about 25 % of Dry wet

Uses: for building temporary structures 

Fourth class Bricks 

Over burnt and badly distorted in shape and size and brittle in nature .

Uses:Blast of such bricks is used for foundation and floor in a lime concrete and Road metal.

Ingredients of good brick Earth :

Silica   : 50 - 60 %

Alumina  : 20 - 30 %

Lime       : <10%

Magnesia   :  <1%

Ferric Oxide :<7%

Alkali   :<10%

Tasting of bricks 

1. Water Absorption Test
2. Compressive Strength Test
3. Effervescence Test.
4. Warping Test

Additives in the manufacture of Bricks :

1. Fly ash 
2. Sandy
3. Rice husk

               4. Basalt stone dust