2. NAME : SAQIB KABIR (141)
CLASS:CIVIL ENG 1ST SEMESTER SECTION E
Basically a major construction material
used to build walls, barriers, paths etc.
Bricks are obtained by moulding clay in
rectangular blocks of uniform size and then by
drying and burning these blocks. As bricks are
of uniform size, they can be properly arranged,
light in weight and hence bricks replace
Main constituents are alumina and silica,
where as small amount of lime, oxides of iron
and magnesia is also added.
4. MANUFACTURING OF BRICKS:
The manufacturing of brick, the following
operations are involved
1. Preparation of clay : Dug out from the soil, and than cleaned
2. Moulding : can be done by hand or machine (molds are hollow
3. Drying : before burning to prevent cracks.
4. Burning : clamps for small scale and kiln for large scale
Bricks can broadly be divided into
(i) Unburnt or sundried
dried with the help of heat
received from sun after the
process of moulding.
used in the constructions of
temporary and cheap structures.
Such bricks should not be used at
places exposed to heavy rains.
They can be lime sand bricks,
fly ash bricks and slag bricks
7. BURNT BRICKS
The bricks used in construction works are burnt bricks and they are
classified into the following four categories,
First Class bricks:
These are table moulded and of standard and regular shape.,
The surface and edges of the bricks are sharp, square, smooth and
The comply all the qualities of good bricks and used for superior work of
permanent nature. Are normally uniform in colour and expensive,/ well burnt
8. Second class bricks:
These are ground moulded and they are burnt in kilns.
They are not well burnt so the quality is inferior.
The surface is some what rough and shape is also slightly irregular.
The commonly used at places where brick work is to be provided with a
coat of plaster.
Not so hard and colour is not uniform.
Used in interior walls.
9. Third class bricks: (pilla bricks)
These are ground moulded and they burnt in clamps.
not hard and have rough surfaces with irregular and distorted edges.
give dull sound when struck together.
Not uniform shape and size,
used for unimportant and temporary structures and at places where
rainfall is not heavy.
10. Fourth class bricks:
over burnt bricks with irregular shape and dark colour.
used as aggregate for concrete in foundation, floors, roads, etc
because of the fact that the over burnt bricks have compacted structure
and hence, they are some times found stronger than even first class
11. SPECIAL TYPES:
Bricks are made in a wide range of
shapes and to suit the requirements
of the location where they are to be
Squint Bricks: These bricks are
made in a variety of shapes.
Bull Nosed Bricks: These bricks are
used to form rounded quoins.
13. BRICK SOAKED IN WATER,
Wetting of bricks removes any dirt, sand and dust from
Soaked bricks prevents suction of water from the wet
mortar. If dry bricks are used then it will absorb water from
mortar and mortar will become dry and cannot attain any
But not too much water can be used because There will
not be proper adhesion between mortar and brick and Brick
may slip over the mortar creating difficulty in ensuring
plumbness of the wall.
14. WATER ABSORBTION OF BRICKS.
The water absorption of brick is the quantity of water
absorbed by the brick when submerged under water for 24 hrs
expressed as % of its dry weight.
brick is normally porous so absorbs water. It should be prevented after
longtime construction to protect the structure.
Mass increases after absorbtion of water.
water absorption not more than 20% for 24 hours at room temperature.
Water absorption, percent by mass after 24 hours immersion in cold
water is given by the following formula.
15. WATER ABSORPTION OF BRICKS AFTER 24
First class bricks—20%,
Second class bricks—22 %,
Third class bricks—25%.
Heavy duty machine made bricks should not absorb
more than 5% of their weigh
16. COMPRESSIVE /CRUSHING STRENGTH OF
Brick strength is deﬁned as resistance to load per unit area and
is expressed in mega Pascals (MPa).
is the capacity of a material or structure to withstand loads
tending to reduce size.
Measured by universal testing machine. UTM
17. Compressive /Crushing strength of bricks are very variable, and may
vary from 30 kg/sq. cm to 150 kg/sq. cm for hand-made burnt bricks,
while Crushing strength of heavy duty bricks machine pressed (also
called engineering bricks) may have compressive strength as high
as 450kg/sq. cm, and even 500 kg/sq. cm.
The minimum crushing / compressive strengths of burnt bricks tested
flat-wise prescribed are:
(i) Common building bricks—35 kg/sq. cm,
(ii) Second class bricks—70 kg/sq. cm,
(iii) First class bricks— 105 kg/sq. cm.
(iv) Crushing strength of bricks not less than 140 kg/sq. cm are graded
as AA class.
19. INITIAL RATE OF ABSORPTION
The Initial Rate of Absorption (IRA) is a property describing the
absorption of a brick, in a limited time, of water primarily
through the bed face of the brick unit.
In the laboratory test, the dry unit is set in a pool of water to a
constant 1/8” depth, and the IRA is the weight gain of the unit in
grams in one minute to a corrected bed area of 30 square
The correction to a bed area of 30 square inches is a means of
placing the one-minute absorption on a per unit area basis for
exposed surface, and it reflects a former era when bricks
exhibited a gross bed of about 30 square inches.
22. RECENT PRICES .
N = 10 rs
burnt well with rubber, coal etc.
33= 9 rs
not relatively well burnt.
8= 8 rs.
Different prices of different brickswith respect
to quality design etc.
23. BRICK PLANTS :
Niazi Bricks is Pakistan’s largest brick manufacturer, with 10
manufacturing (units) facilities in 5 different cites throughout Pakistan.
We produce 1.5 billion brick each year.
Butt brick company and meher brick company in lahore are also
Plants in various major cities ex: mardan,peshawar, rawalpindi, swat .
In peshawar plants are in pabbo area, badda bair area and other
24. QUALITIES OF GOOD BRICK:
Bricks should be table moulded, well burnt in kilns, copper coloured,
free from cracks and with sharp and square edges.
Bricks should be uniform shape and should be of standard size.
Bricks should give clear ringing sound when struck each other.
Bricks when broken should show a bright homogeneous and compact
structure free from voids.
Bricks should not absorb water more than 20 percent by weight for first
class bricks and 22 percent by weight for second class bricks, when
soaked in coldwater for a period of 24 hours.
Bricks should be sufficiently hard no impression, should be left on
brick surface, when it is scratched with finger nail.
Bricks should be low thermal conductivity and they should be sound
Bricks should not break when dropped flat on hard ground from a height
of about one meter.
Bricks, when soaked in water for 24hours, should not show deposits of
white salts when allowed to dry in shade.
No brick should have crushing strength below 55kg/cm2