Q1. What is brick ?
Ans. A brick is a type of block used to build walls
pavements and other elements in masonry construction .
The term brick denotes a block composed of dried clay ,
but is now also used informally to denote other
chemically cured construction blocks . Bricks are
produced in numerous classes , types , material , and
sizes which vary with region and time period and are
produced in bulk quantities .
Q2. Explain its manufacturing process ?
Ans. There are four different operations are
involved in the process of manufacturing of bricks :-
1.Preparation of clay - In this step is excavated in steps
and then laid on leveled ground . Then the soil is
cleaned of impurities such as vegetation matter ,
stones or pebbles etc. After removing impurities it is
exposed to weather for few months . This is called
the process of weathering . Then the mixed soil is
tempered by being thoroughly broken up , watered
and keaded . The tempering is usually done in pug
2.Moulding of bricks – Bricks are moulded in many
ways depending on the quality of the product to be
made . Generally the moulding is done in the
following two ways :
. Hand Moulding – For hand moulding the tempered
clay is forced in the mould in such a way that fills all
the corners of the mould . Extra clay is removed
either by wooden strike or frame with wire .
. Machine Moulding - Machine moulding is used
where large number of bricks are to be made .
Machines used for moulding is generally two types :
. Plastic clay machines – In plastic clay machines the
clay machine the clay in plastic state is forced to
rectangular openings of a size to the length and
breadth of the bricks and are then cut into strips of
thickness of the brick with wire in frames .
. Dry clay machines – In dry clay machines , dry clay
is reduced to powder , filled dry into mould by the
machine and then are subjected to high pressure to
form hard and well shaped bricks .
3. Drying of bricks – Drying is usually done by placing
the bricks in sheds with open sides so as to ensure
free circulation of air and protection from bad
weather and rains . The bricks are allowed to dry till
they are left with 5 to 7 percent moisture content .
The drying period usually varies from 7 to 14 days .
4. Burning of the bricks - It is the very important step
in manufacture of bricks . Bricks may be burnt by
two distinct methods given below.
. Burning in a camp or pazwah known as clamp
. Burning is a flame kiln or Bhatta known as kiln burning .
Q3 . Explain its composition ?
Ans- Following are the constituents of the good brick
1. Alumina : If is the chief constituent of every kind of
clay . A good brick should contain 20% to 30% of
alumina . If alumina is present in excess , with
inadequate quantity of sand , the raw bricks shrink
and wrap during drying / burning and become too
hard when burnt .
2. Silica – If exists in clay either as free or combined .
As free sand , it is mechanically mixed with clay . In
combine form , it exists in chemical composition
with alumina . The excess of silica destroys the
cohesion between particles and the bricks become
3. Lime – A small quantity of lime not exceeding 5% is
desirable in good brick material . It should be
present in a very finely powered state because even
small particles of the size of a pin head cause flaking
of the brick . The lime prevents shrinkage of raw
bricks . The sand alone is infusible . The lumps of
lime are converted into quick lime slakes and
expands in presence of moisture .
4. Oxide and Iron – A small quantity of oxide of iron to
the extent of about 5 to 6 percent is desirable in
good brick material . It also imparts red colour
to the bricks . The excess of oxide of iron makes the
bricks dark blue or blackish .
5. Magnesia – A small quantity of magnesia in brick
material imparts yellow tint to the bricks and
decreases shrinkage . However , excess of magnesia
leads to the decay of bricks .