Bricks

Elements of civil Engineering

1. Shroff S.R. Rotary Institute of Chemical Technology S R I C T GUIDED BY :- SHAHID SIR MADE BY ;- NAVED FRUITWALA (150990119006) UTKARSH GANDHI (150990119007) DIGVIJAYSINH GOHIL (150990119008) JAIMIN PRAJAPATI (150990119010) INTRODUCTION AND CONSTRUCTION OF BRICKS TOPIC :--

2. CONTENT INTRODUCTION USES OF BRICK TYPES OF BRICKS COMPOSITION OF CLAY BRICK STRENGTH OF BRICKS CLASSIFICATION OF BURNT CLAY BRICKS CLASSIFICATION BASED ON UTILITY PROPERTIES OF BURNT CLAY BRICKS SPECIAL BRICKS HOLLOW BRICKS FLY-ASH BRICKS

3. INTRODUCTION Bricks are made up of clay and chiefly employed in building construction. Easy availability , lightweight , cheapness , ease in handling are the main characteristics of bricks. According to Indian standards , the size of the brick without thickness of mortar join is 19 cm X 9 cm X 9 cm.

4. Clay bricks may be divided into ordinary bricks and firebricks. The ordinary bricks can be further be classified into 4 classes according to their qualities such as 1 st class, 2 nd class, 3 rd class and zhama bricks or 4 th class bricks or over burnt bricks. Firebricks are made up of pure fire clay or a mixture of fire clay and pure sand cemented with a small proportion of clay. Firebricks are capable of withstanding intense heat without melting or softening.

5. 1 st class brick :- Well burnt in kilns, table moulded ; rectangular with sharp edges. These bricks are very hard 2 nd class brick :- Burnt in clamps and ground moulded but with little bit irregular shape. These bricks are hard. 3 rd class bricks :- Ground moulded and burnt in clamps These bricks are slightly soft. 4 th class bricks :- These bricks are over burnt. These bricks are very hard.

6. FIRST CLASS BRICKS SECOND CLASS BRICKS THIRD CLASS BRICKS FOURTH CLASS BRICKS

7. USES OF BRICKS 1 st and 2 nd class bricks are used for all sort of sound work, especially of permanent nature like construction of building, Bridge piers etc. 1 st class are used in architectural compositions and face work of structures. 3 rd class bricks are used in temporary or less important works like compound wall. Zhama bricks are used as road metal and as aggregate in road concrete. Firebricks are used in acid plants, steel furnaces, cement kiln etc.

8. TYPES OF BRICKS Bricks can be classified into two parts :- Conventional Bricks : The dimensions of conventional bricks or traditional bricks vary from 21 to 25 cm in length, 10 to 13 cm in width and 7.5 to 10 cm in height in different parts of country. The commonly adopted size of conventional brick is 23*11.4*7.5 cm.

9. Standard Bricks :- In different parts of the country different size of bricks are used. Therefore to have a uniform size throughout the country, Indian Standard Institution (ISI) has suggested a uniform brick or modular brick. The nominal size of modular brick or standard brick is 20X10X10 cm and the actual size of brick is 19X9X9 cm. Frog size is 6X4X2 cm.

10. COMPOSITION OF CLAY BRICK Brick earth is a natural substance. In the preparation of bricks, brick earth is moulded to required shape and size and dried well and then burnt in clams or kilns. The main ingredients of a good brick earth are :- 1) Alumina : It is the chief ingredient of every clay. A good brick earth should contains 20 to 30 % if alumina. Alumina absorbs more water and imparts plasticity to the clay.

11. 2) Silica : Silica is added to clay in appropriate quantities. It prevents cracking, shrinking and warping of raw bricks. A good brick earth should contain about 50 to 60 % silica. 3) Lime : Small quantity of lime in the brick earth is desirable. It acts as a flux such that in enables the sand to fuse or to melt during burning and binds the particles of brick together. The excess of lime causes the brick to melt and lose its shape.

12. 4) Magnesia : It also acts as flux during burning. A very small amount of magnesia gives a yellow tint to the bricks and also decreases shrinkage. Excess of magnesia cause brick to decay. 5) Iron Oxide : It acts as a flux such that a very small amount of iron oxide helps to fuse the lime and the sand during burning. It also binds the particles of the brick together so that bricks become hard and strong. It also imparts red colour to bricks but excess of iron oxide makes bricks dark blue in colour .

13. STRENGTH OF BRICKS The bricks which are commonly used should have a minimum compressive strength or crushing strength of 3.5 N/mm². Second class bricks i.e. grade B bricks should have compressive strength not less than 7 N/mm². First class bricks i.e. grade A bricks should have compressive strength not less than 10.5 N/mm². Grade A-A bricks should have compressive strength not less than 14 N/mm². Bricks with compressive strength less than 3.5 N/mm² will fall in the category of grade C. When the bricks soaked in water the strength of a brick reduces by about 25%.

14. CLASSIFICATION OF BURNT CLAY BRICKS By Quality Sand faced Rustic multicolored By Manufacture Hand moulded Machine moulded By Utility 1 st class 2 nd class 3 rd class 4 th class

15. CLASSIFICATION BASED ON UTILITY 1 st class brick (Grade A) Sound, well burnt in kilns, table moulded ; rectangular with sharp edges Surface is clean smooth and no cracks These bricks are very hard Mainly used for face-worked structure or used for superior work . 2 nd class brick (Grade B) Burnt in clamps and ground moulded but with little bit irregular shape Surface is rough and have spots These bricks are hard Mainly used for ordinary structures and also used at places where brickwork is to be provided with plaster coat.

16. CLASSIFICATION BASED ON UTILITY 3 rd class bricks (Grade C) Ground moulded and burnt in clamps Surface is rough and have distorted edges These bricks are slightly soft Used for unimportant and temporary structure and at places where rainfall is not heavy. 4 th class bricks (Grade D) These bricks are over burnt Surface is irregular and have dark colour These bricks are very hard Used as metal or aggregates for concrete in foundation, floors, roads, etc.

17. PROPERTIES OF BURNT CLAY BRICKS The bricks should be well burnt, copper coloured or reddish in colour , free from cracks and with sharp edges Its colour should be uniform and bright throughout The bricks should be uniform in shape and with standard size The burnt clay bricks should be free from voids When two bricks are struck with each other, then it should give a clear metallic ringing sound

18. When the burnt clay bricks are soaked in water, it should not absorb water more than 20% of its dry weight. When the burnt clay bricks are dropped flat on hard ground from a height of 1 m, it should not crash into pieces. The burnt clay bricks should be hard. When it is scratched with finger nail, no impressions should be left on brick surfaces. Burnt clay brick should be sound proof and should have low thermal conductivity. When the bricks are soaked for 24 hours , no white salt deposits should be seen after drying. Burnt clay brick should have crushing strength more than 5.5 N/m².

19. HOLLOW BRICK OR HOLLOW BLOCK These bricks are also termed as cavity bricks or cellular bricks. It has wall thickness about 20mm to 25mm and is prepared from special homogeneous clay. They are light in weight. They also reduces the transmission of heat, sound & damp. They used in construction work of brick partitioning.

20. SPECIAL BRICKS Acid Resistant Brick:- They are specially made for chemical plant. It is made from mixture of refractory clay and silica. Engineering bricks :- They are those which are more vitrified than common clay building brick; These bricks are used for paving purpose in the construction work. These bricks are very hard.   Silica Brick:- These bricks contain a very high percentage of silica to the extent of about 95 to 97%. A small quantity of lime about 1 to 2% is added to work as a binding material. Silica bricks can stand a high temperature up to about 2273 K.

21. Refractory bricks:- It can stand a temperature up to 1973k. Hence these bricks are much employed in the construction of lime flue, hearths and various classes of furnaces used in metallurgical process. Sand lime brick : - These bricks are very strong and hard bricks manufactured by a process involves a chemical reaction and not a mere mechanical mixture under pressure. These bricks are much stronger than clay bricks and are uniform in colour and texture with sharp edges Hence these bricks are used for ornamental work due to its line texture and uniform colour .

22. Blue bricks : - These bricks are very hard and dense. It makes from a clay containing 7 to 10 % iron oxide. These bricks are fired at a temperature of 1250°C. Blue bricks are very much used for heavy engineering constructional work such as bridges etc. Coloured bricks: This type of bricks are rarely used in India. These bricks are used for decoration work only. Any sort of colour bricks can be produced by mixing some admixtures. Fire bricks :- This type of bricks are used for the construction of hearth, furnaces and chimney where the bricks are required to resist very high temperature.

23. Perforated bricks: This type of bricks contain cylindrical holes throughout their thickness . These are light in weight and require less quantity of clay for their preparation.   These bricks are mainly used in the construction of bricks panels for light weight structures and multi- storeyed framed structure.

24. FLY-ASH BRICKS The fly-ash is a fine powder thrown out as a waste material in large quantities at the thermal power station. Fly-ash resembles like a pozzolana . Fly-ash is acidic in nature and its main constituents are silica, aluminium oxide and ferrous oxide. The process of making fly-ash bricks involves the use of fly-ash. lime, sand and a small quantity of magnesium chloride as chemical accelerator.

25. The fly-ash. sand and lime are mixed together approximately in the ratio of 80: 13 : 7. The hydraulic press is used for making these bricks. Semi-dried bricks are cured in a steam chamber at appropriate pressure and temperature. The fly—ash bricks are more superior to the conventional burnt bricks in shape. technical specifications. compressive strength and impermeability. These bricks are light in weight and 10 to 15 % cheap as compared to the conventional bricks.

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