Types of bricks

Types of Bricks

There are two main types of Bricks.

1. Unburnt Bricks:-

Unburnt bricks are dried into sun light. It is also called Sun-dried Bricks. They have very low strength as compared to other types of bricks.

It is believed that first-time bricks were used, in sun-dried form (unburnt Bricks), in Egypt some 6000 years ago.

2. Burnt Bricks:-

These  bricks which are used commonly in now a day age are burnt bricks. They are prepared and burnt in a kiln.

They have high strength as compared to unburnt bricks. burnt bricks are further classified into the following categories.

i. First Class Bricks:-

Its  19 x 9 x 9 cm in size. They are made from good earth, free from saline deposits. They should be thoroughly burnt.

They should be of good color. They should be of regular shape with square edges and parallel faces.

These bricks are free from flaws, cracks, chips, stones, etc. They should give a ringing sound when two bricks are struck together.

Its compressive strength shall not be less than 140 kg/cm2. And they shall not absorb more than 20% of water when immersed in water for 24 hours.

USE: Excellent for all types of construction in the exterior walls and  also suitable for flooring.

ii. Second Class Bricks:-

Second class bricks are also fully burnt and give a clear ringing sound when struck together. Slightly irregularities in shape, size or color are accepted.

Its compression strength shall not be less than 70 kg/cm2, and absorption value should not be greater than 22 percent when soaked for 24 hours in water.

Slight difference in the structure on fractured surfaces is admissible.

Use: For exterior work when plastering is to be done. And can also be used for interior works but they may not be used for flooring.

iii. Third Class Bricks:-

These are not burnt so fully as in previous two cases but are generally of uniform reddish yellow color.

Defects in uniformity or shape are tolerated. On striking together, they produce a dull thud sound.

Its compressive strength lies between 35 – 70 kg/cm2 and absorption between 22 – 25 percent

Use: They are used mostly in the ordinary type of construction and in dry situations.

iv. Fourth Class Bricks:-

These types of bricks are irregular in shape and dark in color which is due to overburning.

They are quite strong in compressive strength, generally above 150 kg/cm2and low in porosity and absorption.

Use: Despite their high strength, these types of bricks are unfit for use in building construction. This is because of their distorted shape and irregular size.

They are, however, very commonly used in a

broken form, in road construction, foundations and floors as a coarse aggregate material.

Special Types of Bricks:-

Ordinary building bricks is typically rectangular in shape, solid in structure and made from a Suitable type of brick-clays.

now a day  building construction, however, bricks of modified Shapes, porous or hollow structure and also made from materials other than clay are also sometimes used.