Bricks

BRICKS

Brick is obtained by moulding good clay into a block, which is dried and then burnt. This is the oldest

building block to replace stone. Manufacture of brick started with hand moulding, sun drying and

burning in clamps. A considerable amount of technological development has taken place with better

knowledge about to properties of raw materials, better machinaries and improved techniques of moulding drying and burning.

The size of the bricks are of 90 mm × 90 mm × 90 mm and 190 mm × 90 mm × 40 mm. With

mortar joints, the size of these bricks are taken as 200 mm × 100 mm × 100 mm and 200 mm × 100 mm × 50 mm.

Types of Bricks

Bricks may be broadly classified as:

(i) Building bricks

(ii) Paving bricks

(iii) Fire bricks

(iv) Special bricks.

(i) Building Bricks: These bricks are used for the construction of walls.

(ii) Paving Bricks: These are vitrified bricks and are used as pavers.

(iii) Fire Bricks: These bricks are specially made to withstand furnace temperature. Silica bricks

belong to this category.

(iv) Special Bricks: These bricks are different from the commonly used building bricks with

respect to their shape and the purpose for which they are made. Some of such bricks are listed below:

(a) Specially shaped bricks

(b) Facing bricks

(c) Perforated building bricks

(d) Burnt clay hollow bricks

(e) Sewer bricks

( f ) Acid resistant bricks.

(a) Specially Shaped Bricks: Bricks of special shapes are manufactured to meet the

requirements of different situations.

(b) Facing Bricks: These bricks are used in the outer face of masonry. Once these bricks are

provided, plastering is not required. The standard size of these bricks are 190 × 90 ×

90 mm or 190 × 90 × 40 mm.

(c) Perforated Building Bricks: These bricks are manufactured with area of perforation of

30 to 45 per cent. The area of each perforation should not exceed 500 mm2. The perforation

should be uniformly distributed over the surface. They are manufactured in the size 190

× 190 × 90 mm and 290 × 90 × 90 mm.

(d) Burn’t Clay Hollow Bricks: Figure 1.4 shows a burnt clay hollow brick. They are light

in weight. They are used for the construction of partition walls. They provide good thermal

insulation to buildings. They are manufactured in the sizes 190 × 190 × 90 mm,

290 × 90 × 90 mm and 290 × 140 × 90 mm. The thickness of any shell should not be less

than 11 mm and that of any web not less than 8 mm.

(e) Sewer Bricks: These bricks are used for the construction of sewage lines. They are

manufactured from surface clay, fire clay shale or with the combination of these. They

are manufactured in the sizes 190 × 90 × 90 mm and 190 × 90 × 40 mm. The average

strength of these bricks should be a minimum of 17.5 N/mm2 . The water absorption

should not be more than 10 per cent.

( f ) Acid Resistant Bricks: These bricks are used for floorings likely to be subjected to acid

attacks, lining of chambers in chemical plants, lining of sewers carrying industrial wastes

etc. These bricks are made of clay or shale of suitable composition with low lime and

iron content, flint or sand and vitrified at high temperature in a ceramic kiln.