Second Class Bricks

Bricks

Bricks used for the construction work can be classified into two categories they are Unburnt or sun dried bricks and burnt bricks.

Unburnt or sundried bricks

Soon after moulding, these kinds of bricks are getting dried in sun. This kind of bricks is 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.

Burnt Bricks

For permanent constructions, Burnt bricks are the one which is used and this can be 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. However bricks should be in standard size, so that it can be placed one handed during constructions. 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.

Quality of Bricks

The qualities of good bricks depends on following factors,

Chemical composition of moulding clay, preparation of clay, method of moulding and care taken during moulding, method of drying and care taken during drying and method of burning and care taken during burning.

Second Class Bricks

This brick is the well burnt table moulded brick, which is red or copper colour. This second class bricks has the uniform length and width and sharp well defined edges. This kind of bricks have reasonable smooth surface with fine hair cracks and mild distortion.

Characteristics of Second Class Bricks

• They are well burnt or slightly over burnt
• If the struck against the same type of brick they use to emit ringing sound.
• They are rectangular in shape and have well defined edges but not in equal size
• They have clean surface but with certain small irregularities
• They are free from cracks but have slight flaws and chips
• Even if it soaked for 24hours it will absorb less than 22% of water.
• They have the minimum crushing strength of 7 N/mm².

Uses of Second Class Bricks

The second class bricks are used in masonry constructions, where ate faces are to be plastered, is used for the construction of load bearing walls of single storey houses, used as brick ballast in R.C.C work and in lime concentrate.

Questions:

• What is a second class brick?
• What are the characteristics of second class bricks?