Artificial Materials (Bricks)
Artificial
Materials (Bricks)
Write short note on Bricks. Or write terminology of Bricks.
·
Each civil engg. Should be a good brick maker. He should be familiar
with its raw material used, process of manufacturing, and its properties of its
constituents.
·
With increasing in development of country and industrialization demand
of brick has increased.
·
Major problem is increasing prizes of bricks, production of bricks and
quality of bricks.
·
Quality of bricks is depends on raw materials used for production of
bricks.
There are mainly three types of soils used for brick
manufacturing.
Alluvial soil: In all over India this type
of soil is most popular for brick production.
Black Cotton soil: In Madhya Pradesh, Gujarat,
and some part of Maharashtra this type of soil is used for brick production.
Red soil: In Mysore, Assam, M.P.
region this type of soil is popular for brick manufacturing due to its
availability in large quantity.
All of above mentioned soil
type alluvial soil is most popular, because according to requirement of good
brick soil, it should be contain clay particle - 20to30% and silt particle
40to65%. And alluvial soil contain clay particle – 17%to20% and clay particle
30 to 40%
Brick Earth.
Brick earth is natural
substance which is used for brick manufacturing. It is obtained from
decomposition of soft rock. It is mixed with water and other raw materials of
brick and brick is produced. The good brick earth is consist alumina (20to30%)
and silica (50to60%). And other content like lime, iron oxide, magnesia, potash
and soda, etc.
What are the properties of constituents of brick earth?
Alumina: 1) It make clay plastic and
moldable paste.
2) Excess
alumina causes shrink(crack developed and change in volume due to removing
moisture content).
Silica: 1) It is hard cementing
material.
2) It avoid shrinkage of brick
during drying.
Iron Oxide: It gives red color to
brick.
Lime: 1) It avoid shrinkage of
brick during manufacturing process of brick.
2) Excess lime is responsible for brick
to spilt and crumble.
Magnesia, Potash and soda: presence of magnesia gives
yellowish tint to the brick.
What are harmful constituent in brick earth?
Pebbles of stone or gravels: 1) It avoid homogenous
mixing of clay.
2) Also it is responsible for un
uniformity of bricks.
Alkalies: 1) Causes brick twist and
warp.
2) Causes
efflorescence .
Lime stone: Causes brick to spilt and
crumble.
Iron Pyrite: It decompose, oxidize and
cause brick to spilt.
Soluble Salts: 1) Low quality brick.
2) Causes efflorescence.
What is conventional and standard
brick?
Conventional
Brick: The
dimensions of conventional bricks vary from 210mm to 250mm in length, 100mm to
130mm in width and 75mm to 100mm in thickness in various region of country. The
most common size of conventional brick used in construction field is 230mm x
114mm x 75mm
Standard
Brick: In
different countries of the world, different sizes of bricks are used. Hence, to
have uniform size in the county, Indian Standard has suggested a brick size
which is termed as Standard Brick. Size of Standard Brick is 190mm x 90mm x
90mm. Small depression is made on one side of brick which is called as frog.
The size of frog is 60mm x 40mm x 20mm.
Use
of Frog: 1)
Make key between courses of brick masonry. 2) For the trade name of manufacturer.
What the requirement of good Building
Bricks
1. It should be good shape and
size.
2. It should have uniform
colour.
3. It should be well burnt.
4. It should give a clear
metallic ringing sound when struck with each other.
5. It should not absorb more
than 20% water by weight.
6. It should not give any
impression on brick surface when scratched with finger nail.
7. It should not break when it
fall from height 1m on hard strata.
8. It should have low thermal
conductivity.
9. It should be good sound
insulating.
What are the classification of burnt
clay brick and Give its suitability
Brick
may be classified as
i.
By quality –
sand faced, rustic and multi coloured.
ii.
By manufacture
– hand made, machine made and moulded.
iii.
By utility
– common or building brick, firing brick, paving brick, hollow brick,
engineering brick,
Engg.
Brick further classified in various classes as mentioned as below-
Class
|
Nature
|
Hardness
|
Suitability
|
First Class
|
Sound, well burnt,
rectangular
|
Very hard
|
In face work of building.
|
Second Class
|
Well burnt but irregular
shape
|
Hard
|
Low cost housing.
|
Third Class
|
Under burnt
|
Soft
|
In buildings not subjected
to heavy rainfall.
|
Fourth Class
|
Over burnt
|
Very hard
|
Road pavement, Railway
ballast, foundation filling.
|
iv.
IS Classification: According to Indian Standard (IS) brick is classified as 300 grade
bricks, 250 grade bricks, 200 grade bricks, 150 grade bricks, 125 grade bricks,
100 grade bricks, 75 grade bricks, etc.
300
grade brick menace that brick having strength 300kg/cm2.
What do you mean by Special Brick?
The
brick which are made for special purposes, such as for chemical plant to resist acid
Acid resisting brick produced, for
furnaces to with stand large temperature some special type of brick
manufactured that is called as Special Brick.
What are different types of Special
Bricks?
Acid
Resistant Brick, Engineering Brick, Silica Brick, Refractory Brick, Sand-lime
Brick, Blue Brick, Coloured Brick, Fire Brick, Modular Brick, etc.
What is the Acid Resistant Brick?
1. It is necessary for chemical
industry.
2. Alluvial soil is used for
manufacturing Acid Resisting Brick.
3. Brick Earth contain –silica
(near about 80%), iron (1.5%), Calcium oxide(less than 0.5%).
4. Due to increasing silica and
decreasing iron causes increase acid resistance.
5. Acid resisting capacity
depends on firing of brick.
6. It is fired up to 10500C.
7. Acid resisting brick absorb
water less than 1%.
What is Engineering Brick?
1. It vitrified than ordinary brick.
2. Less porous hence absorb
less water.
3. It have sufficient
resistance against abrasion.
4. Alluvial soil is used for manufacturing
of engg. Brick.
5. Strength and water
absorption depends on its firing and its compositions.
6. It is fired up to 10600C.
7. Soil contain more than
1%calcium is not suitable fro Engg. Brick.
What is Silica Brick?
1. It contain 95% silica.
2. It is easy to moulding. If
not easy to moulding then small contain of clay particles are increase.
3. Fired up to 12000C.
4. Compresive strength is near
about 150kg/cm2.
What is Refractory Brick?
1. It is used for various type
of furnaces.
2. This type of bricks possess
low thermal conductivity.
3. It resist high temp. and
action of gases.
4. It consist ore mixed with
fire clay and water.
5. Firing point at 17000C.
What is Sand-lime Brick?
1. It is strong and hard.
2. Produced by chemical action
and under pressure.
3. Sand used for manufacturing
should be clean and free from salts and organic matter.
4. Lime should be well burnt
and free from ash.
What is Blue Brick?
1. It is very hard and dense.
2. Containing 7 -10% Iron
Oxide.
3. Fired at 1250oC.
4. Used for heavy construction
work e.g. dams, bridges, etc.
What is Coloured Brick?
1. It is rarely used in India.
2. It is only used for
decoration purpose.
3. Some admixtures are mixed in
raw material and required colour will give.
·
Preparation of clay: in this step clay required for brick is
manufactured.
i.
For this firstly unsoiling is carried out i.e. removing all matter than
soil in field.
ii.
Then digging is carried out. It may be done by manually or mechanically
like JCB.
iii.
Then stone pebbles are collected from soil.
iv.
All raw materials like sand and chalk powder added after picking
stones.
v.
Then whole clay is tampered by manually or mechanically.
It
consist of one long arm. By rotating this arm hole mixture of clay is
thoroughly mixed. It also consist of near about 2m dia. pot which is inserted
in 1m below depth. It also consist of vertical shaft which having horizontal
shaft. After filling clay mixture up to required level this process of
tampering is started, by rotating long arm this whole parts are rotated and
clay of brick is tampered very well. It is very helpful to get clay of good
quality in short time when requirement of brick is more.
· Moulding: Moulding means giving shape
to the brick clay. For this there are three methods. i. by hand moulding – in
this method required size and shape of brick is given by means of hand. This is
very old fashion method and speed of production is very less than other method.
ii. by machine moulding –in this method required size and shape of brick is
given by means of machine. This is very latest method and speed of production
is very high than other method. ii. by use of
mould –in this method required size and shape of brick is given by means
of mould. This is very latest method and speed of production is normal as
compared to other method.
· Drying: After moulding brick is
required to dry. There are two main method of drying of brick i. Natural Drying
–in this method brick is dried in air. Moulded brick is placed in form of hips
to dry. ii Artificial Drying –in this
method brick is dried by using artificial sources.
· Burning –this is main and important
method in brick production. Brick is burned in two process
i. Clamp Burning –this old technique of brick burning. For this bricks
are placed in form of hips as shown in fig. and coal is filled in between gaps
of brick. And finally clamp is fired. This very long time process hence new
technique is developed for brick burning that is kiln burning.
ii. KILN BURNING –in this different types of furnaces are used for
brick burning like bull.
What are the field test of brick?
Sound test: In this test two bricks are
stacked on each other and it must be produce good metallic ringing sound.
Size and shape test: In this we check size and
shape of brick as per IS size or Conventional size requirement.
Strength test: In this test we fall brick
form height near about 1m. and it should not break.
Hardness test: In this test we scratch on
brick by finger nail, and it should not give any impression or any scratch on
its surface of brick if it produce any scratch on surface then reject the brick
for construction.
Water absorption test: In this test we wet brick
in water min for 24hrs. and finally its weight should not be greater than 20%.
For this we use following formula- (W2 – W1)/W1
Where, W1 –weight of brick before wet. And W2 –weight
of brick after wetting in 24hrs.
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1 comments
This is very informative post. It gives lot of information about Bricks
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