Third Class Bricks

Bricks

For construction work, bricks are used and can be classified into two categories they are Unburnt or sun dried bricks and burnt bricks.

Unburnt or sundried bricks

These kinds of bricks are used to get dried in sun soon after moulding, these bricks are called as kucha bricks. These bricks are used in the temporary constructions like wall of the huts; it cannot be used in the area, where it is exposed to rains. Therefore it is not used for permanent constructions.

Burnt Bricks

Burnt brick is the one, which is used for permanent constructions, like dam, bridges, Buildings, etc, and these bricks are exposed to rain also. They are classified into four classes; first class bricks, second class bricks, third class, bricks, and Kiln rejects: Zhama bricks and pila bricks.

Size of the bricks

The bricks may be prepared in various sizes depending upon practice of locality; the bricks which are not of standard size are called traditional bricks. During construction it is easy to handle the brick one handedly if it is properly sized .Bureau of Indian standards has recommended the following dimensions; length; 190mm, Width; 90mm, and Thickness; 90mm, with mortar thickness, the size of above thickness bricks becomes 200mm*100mm*100mm, this is the normal size of modular bricks.

Third class Bricks

This third class bricks are burned in clamps and they are ground moulded bricks, and also they may be table moulded bricks which are slightly under burnt.

Characteristics of Second class Bricks

• The bricks are slightly under burnt.
• They are light colored and are relatively soft.
• When they stuck with the same type of brick it emits dull sound.
• They are not in uniform sizes and slightly distorted.
• They do not have well defined sharp edges and corners.
• They may show intensive sign of efflorescence
• In the fractured surface of the bricks they don’t have the proper uniform textures, it may show pebbles.
• These bricks will have the water absorptions of 20 % to 25 %.
• They have the minimum compressive strength of 3.5 N/mm².

Third class bricks uses

This third class bricks are used in the construction of unimportant structures; they are used in the constructions of low height, where the loads are much less, such as construction of huts, sheds, etc; used in the construction of boundary walls; used in the areas where it is not exposed to rain.

Questions:

• What are called third class bricks?
• What is Burnt brick?