BRICK INFORMATION PART 1

COMPOSITION OF BRICK-  There is various ingredients are presents in good earth brick.Following compositions are -

 1.Silica(50-60%)- It is responsible for shape,hardness,strength of the brick. silica prevent shrinkage and cracking. If it is in excess quantity the brick will tends to brittle and weak.

2.Alumina-(20-30%)-This ingredient give plastic quality in the brick so it can easily moulded. High alumina makes bricks refractory. 

3.Lime(͖≯ 5%)-It causes silica to fuse during burning and bind the particles together and it also prevent shrinkage while drying. In the form of lumps it cause disintegrate and shape of the brick is lost.

4.Magnesia(<1%)-It impart yellow color when in small quantity and it is also prevent the shrinkage effect.

5.Iron oxide(5-6%)- this is act as flux.Provide Strength and hardness.The most important thing is that it is provide cheery red color in presence of oxygen and dark brown in insufficient availability of oxygen.

SIZE,WEIGHT AND UNIT WEIGHT OF BRICKS:-

• Size of modular brick or standard brick is 19 x 9 x 9 cm.
• Brick with mortar it will become 20 x 10 x 10 cm.
• On an average the weight of Modular brick should  3 Kg.
• In our country the bricks are generally non Standardize or it call traditional size of  9'' x 4.5'' x 3'' or 23 cm x  11.4 cm x 7.6 cm.

Typical diagram of standard size of brick(All the dimensions are in "mm")

• Unit weight of brick is generally 19-20 Kn/㎥

CLASS OF BRICKS:-  

(A) 1st class brick:-  Compressive strength of this brick 10.5 Mpa and water absorption limit after 24 hrs is 20%. 

(B)2nd class brick:-Compressive strength of this brick 7.0 Mpa and water absorption limit after 24 hrs is 22%.

(C)3rd class brick:-Compressive strength of this brick 5 Mpa and water absorption limit after 24 hrs is 23%.

(D) Common building brick:-Compressive strength of this brick 3.5 Mpa and water absorption limit after 24 hrs is 25%.

TYPE OF CLOSER AND BAT  IN BRICK:-  

                            

1.Queen Closer 

2.Queen Closer (Quarter)

3.Bevelled Closer

4. King closer

5.Mitred closer 

6.Half bat

7.Three quarter bat

8.Bavelled bat

 MANUFACTURING OF BRICKS:-  

Manufacturing of bricks is conduct in four major operation-

1. Preparation of clay
2. Moulding 
3. Drying 
4. Burning 

A. Preparation of clay:- Preparation of clay is carried out in following sequence

• Unsoiling:- Soil is thrown from top up to 200 mm and it is not use for preparation of bricks due to consist of impurities.
• Digging:- In this process the soil is dig out and thrown over the level field and proceed for the next step.
• Cleaning:- In this process the impurities like stone,pebble,vegetative matter or organic matter are remove from brick earth.
• Weathering:- It is the process which cleaned clay is expose to the open atmosphere for few week to few months to carry out it's softening/ripening or weathering.
• Blending:- In this process Various ingredients are spread over the weathered clay for required property.
• Tempering:-In this stage the plasticity property is induced in the brick earth so it can ready for the next operation. Tempering is done in Pug mill.

Pug mill

B. Moulding :- In this operation the brick is get his proper shape and size.Moulding is done by mould which may be of wood or steel.

• Hand Moulded Bricks

1. Ground moulded brick
2. Table Moulded brick

• Machine Moulded bricks

1. Plastic clay moulded bricks
2. Dry clay moulded brick

C. Drying:- Moulded bricks are not directly burn without drying because of cracking and disintegration due to loss of moisture from it. Before the burning drying is done moisture content reduce up to 2%. Drying is done naturally or artificially. During this stage the brick never placed along their face but they are always place along the edge to increase the rate of evaporation.

D. Burning:- Burning of brick is required to induce strength and hardness to make it dense and durable. Burning of brick is done by clamp or kiln.

      (a) Clamps:- 

 

       

        (b)Kiln:-

1. Intermittent type;
2. Continuous type.

 1.Intermittent type :- This is also two type 1.Up - drought 2. Down- drought.

2.Continuous type :-  This is also 3 type

 1. Bull trench kiln, 2. Hoffmen kiln, 3 Tunnel type kiln.

1. Bull trench kiln

            

        Today                                  Tomorrow 

1.  loading                               Heating
2.  Empty                                 Loading 
3. Unloading                           Empty 
4. cooling                                 Uncooling 
5. Burning                              Cooling 
6. Heating                               Burning              

 Hoffmen kiln