The brick is the most commonly used building material and used for constructing walls, columns, roofs, paving floors etc. A good brick clay contains 20 to 30 percent of alumina, 50 to 60 percent of silica and the remaining constituents are lime, magnesia, sodium, potassium, manganese and iron oxide.
Notes:-
1. The standard size of bricks are 19 cm x 9 cm x 4 cm or 19 cm x 9 cm x 9 cm.
2. The specific gravity of bricks is about 2.
3. The number of bricks required for one cubic metre of brick masonry are 550.
🔴 Following points gives the requirement of good brickwork :-
1) A good brick masonry should utilise bricks which are sound, hard, well burnt and tough with uniform colour, shape and size.
2) The bricks should be compact, homogeneous, free from holes, cracks, flaws, air bubbles and stone lumps. These bricks should be properly soaked in water for atleast two hours before use.
3) In the brickwork, the bricks should be laid on their beds with the frogs pointing upwards.
4) The brick courses should be laid truly horizontal and should have truly vertical joints.
5) The brick walls should be raised uniformly with proper bond. The height of brick masonry construction in a day should not exceed 1.5 m.
6) Finished brickwork is cured for a period of 1 to 2 weeks.
7) A good brick should have a fine, compact and uniform texture. When struck with hammer, it should give a good metallic sound. When dropped from a height of about 1 metre on another brick, it should not break.
8) A good brickwork should have maximum compressive strength and durability.
9) A good brickwork should have maximum resistance to weathering.
10) A good brickwork should be fire resistant.
🔴 Classification of Bricks :-
A) First class bricks :- These bricks are well burnt having smooth and even surface with perfect rectangular shape and uniform reddish colour. These bricks should not absorb water more than 20 percent of its own dry weight after 24 hours immersion in water. It should have a minimum eshing strength of 10.5 MN/m².
B) Second class bricks :- These bricks are slightly over burnt having rough surface and not perfectly rectangular in shape. These bricks should not absorb water more than 22 percent of its own dry weight after 24 hours immersion in water
C) Third class bricks :- These bricks are not properly burnt (under burnt) in the kiln and hence these are soft and can be easily broken. These bricks should not absorb water more than 25 percent of its own dry weight after 24 hours immersion in water.
D) Jhama bricks :- These bricks are over burnt with irregular shape. These bricks are dark bluish in colour.