Bricks
It is one of the the kind of structure cube or a block which is utilised to construct walls, payments and other construction works.
Formally the term brick can be called cube developed from dried clay.
Composition of Good Brick Earth
Following are the constituents of brick earth:
1. Alumina
It is the main ingredient of every type of clay.
20 to 30% of alumina should contain in the good brick Earth. Elasticity can be increased with the the alumina resulting in moulding for any shape.
2 Silica
50 to 60% of silica ingredients should be content in the good Earth brick. Shrinking cracking wrapping of raw materials can be prevented by silica.
Which is resulted by uniform shape of the brick while on the other hand too much of silica can be e dangerous for the brick resulting in less cohesion between particle and bricks which is reason for brittle bricks.
3. Lime
Lime should be exist in a powdered state which should be fine.
Shrinkage of raw bricks can be prevented by lime, sand is alone infusible but it moderately boils at Kiln temperature when lime is present.
Chunk of lime transferred into quicklime following burning and presence of moisture enlarge this quicklime slake. Extra presence of lime in the the brick causes liquify and loose its shape.
4.Oxide of Iron
Oxide of iron is one of the most important ingredients for brick earth and it is about 5 to 6% desirable for mix.
it is useful for lime to fuse sand, red colour for bricks is imported buy oxide of iron while on the other hand surplus oxide of iron will bring black ok and dark blue colour.
5. Magnesia
Yellow tint colour is proclaimed by I just small quantity of magnesia in a brick and decrease a shrinkage. Surplus magnesia resulting in decay of bricks.
Harmful Ingredients in Brick Earth
1. Lime
Unsoundness in brick is caused by existence of lime in the brick.
2. Iron pyrites
At the time of of burning if the the iron pyrites are present then bricks are han disintegrated and crystallized.
3. Alkalies
Soda and potash are the form of alkaloids which is very harmful for the brick.
4. Pebbles
Pebbles are one of the chief factors which should not be or which is undesirable in the brick Earth . As pebbles or grit will not allow the original material clay to be mixed uniformly and which will result in in weak bricks.
5. Organic Matter
Organic matter assist brick Earth while burning, but in case if the matter is not completely burnt it will cause porus in the brick.
Manufacture of bricks
1. Preparation of clay
Clay of bricks is prepared in the following order:
(i) Unsoiling
(ii) Digging
(iii) Cleaning
(iv) Weathering
(v) Blending
(vi) Tempering
2. Moulding
1 Hand Moulding
2 Machine Moulding
A)Plastic Clay Machine
B)Dry Clay Machine
3. Drying
4. Burning: Burning of bricks is done either in incinerate or kiln.
(a) Clamps: Trapezoidal is the shape generally in the plan. The clamp is build in a such way that it's shorter and is slightly in the excavation and wider end is elevated at an angle of 15 degree from the ground.
(b) Kilns: A kiln is a large oven which is used to burn bricks. The kiln which are used in the manufacture of bricks are of the following :-
(i) Intermittent kilns
(ii) Continuous kilns
Intermittent Kiln: This can be classified as underground aur ground kilns.
They are classified in two ways:
(a) Intermittent up-drought kilns.
(b) intermittent down-drought kilns
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