Classification of bricks as per BIS

        Classification of bricks as per BIS 

     As per BIS ( Bureau of Indian Standard ) the bricks are broadly classified into two categories: - 

 1) Sun - dried or unburnt bricks or Kaccha bricks 

 2) Burnt bricks or Pakka bricks

Classification of bricks

    Burnt bricks are further classified as :-

a) First class bricks

b) Second class bricks

c) Third class bricks

d) Over burnt bricks or jhama

 Characteristic of first class bricks

1. It should be well burnt raddish in colour having surface and perfectly rectangular in shape.
2. When two bricks are struck with each other a ringing metallic sound is produced.
3. Its compressive strength shall not be less than 140 kg per centimetre square.
4. It should not absorb water more than 15% of its weight when immersed in water for 24 hours.
5. Bricks should be free from cracks and other flaws.
6. A broken surface shows a uniform compact texture.

Uses 

1. Excellent for all types of construction. 
2. It is used in face work of structures not to be plastered but only pointed. 
3. It is also suitable for flooring.

Characteristics of second class bricks

1. It should be well burnt, even slight burning is expected.
2. Metallic running sound is produced when to break system with each other.
3. Its shape with rectangular but slight irregularity is permitted. Surface may be slightly uneven.
4. Its compressive strength shall not be less than 70 kg per centimetre square.
5. Its should not absorb water more than 20% of its weight when immersed in water for 24 hours.
6. Broken surface shows uniform compact texture.

Uses 

1. It is used for exterior work when plastering is to be done.
2. It is used for interior work this bricks me not be used for flooring.

Characteristic of third class bricks 

1. These are poorly and unevenly under burnt.
2. These are soft and yellow in colour.
3. They produced a dull sound when struck with each other.
4. These bricks have compressive strength between 35 to 70 kg per centimetre square.
5. These bricks absorb water more than 25% when immersed in water for 24 hours.

 Uses 

1. It is used mostly in ordinary or temporary type of construction and dry condition.

 Characteristic of over burnt bricks 

1. These are irregular  in shape and dark in colour which is due to over burning. 
2. These are quite strong in compressive strength or crushing strength generally above 150 kg per centimeter square and low in porosity and absorption.

 Uses

1. Despite their good strength over burnt bricks are unfit for use in building construction. This is because of their distorted shape and irregular size.
2. They are very commonly used in broken form( ballast ), in road construction, foundation and floor as a coarse aggregate.