Manufacturing Process of Brick and Constituent of Brick

What are the constituents of brick and Manufacturing Process of Brick

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Welcome to our blog again

So , most of us does not know the constituents of brick as a civil engineering student and manufacturing process of brick.

So let's begin ...

CONSTITUENTS OF BRICK

1) Allumina or clay : 20-30% by weight

2) Silica or sand. : 35 - 50 % by weight

3) Silt : 20-25% by weight

And Other ingredients such as

1) Iron oxide

2) Magnesia

3) Lime

4) Sodium potash

FUNCTIONS OF THIS IN BRIEF

1) Allumina or clay : This is the main constituent. This imparts plasticity so that it can me moulded. If it is in excess quantity, it leads to shrinkage and wrapping during the drying and burning

2) Silica or Sand : It exist in free sand or combined form of as a silicate of allumina. It prevents cracking, shrinking, and wrapping of rock brick, so that it provides uniform shape to the brick , also it increases the hardness durability and resistance to it. Excess silica removes removes cohesion between the particles and make the brick brittle.

3) Lime : It unable the silica to melt during burning and bind the particle together. Lime should be in powdered form otherwise lumps of lime are converted into thin line (calcium oxide ) after burning and this quick like slakes and expand in the presence of moisture and results in splitting of the brick in two pieces. Excess like causes the brick to melt too readily and the shape will be lost.

4) Iron Oxide : It is act as in flux and help the grains of sand to melt and bind the particles of the clay. Also it provide red colour to the brick and improve durability of brick. Excess quantity of it makes the brick dark blue or blackish and less quantity of it makes the brick yellowish in colour

5) Magnesia : A small quantity of it provides yellow tint and decreases shrinkage . Excess of magnesia causes decay of bricks

now,

Manufacturing Process of BRICK

Site selection for manufacturing of bricks

For the manufacturing of bricks, the site should be selected based on some important considerations such as:

The ground should be of plain surface.
The site should be connected with communicating roads for transporting materials etc.,
Good brick earth should be easily available.
The site should offer all facilities to the workers.

Manufacturing process involves four stages

1) Preparation of soul .

2) Moulding .

3) Drying .

4) Burning.

1) Preparation of Soil :-

(a) Removal of soil :- First remove the loose materials at the top of ground about 200mm as it contains lot of impurities so this material is not use for the preparation of bricks.

(b) Digging and Spreading :- The earth Earth is dug out 200mm, after that ,the soil is spread on the ground and making the hips of clay about 600 to 1200mm

(c) Cleaning :- The soil spread on the ground should be clean from stones , pebbles , Vegetable matters, and all lumps of the soil should be broken into powdered form.

(d) Weathering :- The soil is exposed to the atmosphere for softening and the period may be last for few weeks depending upon the nature of soil. This provides plasticity and strength to the soil.

(e) Blending :- To increase the quality of brick (soil) , additional soil such as sand or calcareous clay that may be added in suitable proportion with small quantity of holes. This whole mass is placed properly .

(f) Tempering :- It is the process of kneading the soil sample under the caddle after the necessary quantity of water in order to make the soil stiff and homogeneous. Generally soft plastic plane could be prepared by using above 25 to 30% of water. This procedure is adopted for majority of common hand made bricks And for making superior bricks on larger scale . The Earth is tempered in pug Mill

2) Moulding :-

A brick mould is rectangular box of steel or wood . The inside dimensions of would (20×10×10) in cm . Moulding of brick is carried out by either

(a) Hand moulding - Two ways

Ground moulding & Table moulding

(b) Machine moulding

Hand molding of bricks

If manufacturing of bricks is on a small scale and manpower is also cheap then we can go for hand molding. The molds are in rectangular shape made of wood or steel which are opened at the top and bottom. The longer sides of molds are projected out of the box to serve it as handles. If we take durability in consideration steel molds are better than wooden molds. In hand molding again there are two types and they are

Ground molded bricks
Table-molded bricks

Ground molded bricks

In this process of ground molding, first level the ground and sand or ash is sprinkled over it.
Now place the wet mold in the ground and filled it with tempered clay and press hard to fill all corners of the mold. Extra clay is removed with metal strike or wood strike or with wire.
The mold is then lifted up and we have raw brick in the ground. And again wet the mold by dipping it in water and repeat the same process. The process of dipping mold every time to make bricks is called slop molding.
Sometimes, the inside surface of mold is sprinkled with sand or ash instead of dipping in water this is called sand molding
Frog mark of bricks are made by using a pair of pallet boards. Frog mark means the mark of depth which is placed on raw brick while molding. The depth may be 10mm to 20mm.
Frog mark stats the trademark of manufacturing company and also it is useful to store mortar in it when the bricks is placed over it.

Table molded bricks

This process is similar to ground molding process, but here the bricks on molded on the table of size 2m x 1m.
Ground molding is economical when compared to table molding.

Machine molding of bricks

The bricks required are in large quantity, then machine molding is economical and also saves more time. Here also we are having two types of machines,

Plastic clay machines
Dry clay machines

Plastic clay machines This machines contain an opening in rectangular shape and when we place the tempered clay in to this machine it will come out through this opening. Now, the rectangular strips coming out the opening are cut by wires to get required thickness of brick. So, these are also called wire cut bricks. Now these raw bricks are ready for the drying process. Dry clay machines Dry clay machines are more time saving machines. We can put the blended clay into these machines directly without tempering. Means tempering is also done in this machine by adding some water. When the required stiffness is obtained the clay is placed in mold and pressed hard and well-shaped bricks are delivered. These are called pressed bricks and these do not require drying they may directly sent to burning process.

3) Drying Of bricks :-

Moulded bricks are not directly kept for burning as they may crack or distorted and hence before burning they are dried .

The bricks are dried for about two weeks

It is carried out by :-

(a) Natural drying . (b) Artificial Drying

In natural drying , the air and sun drying bricks are strong .

4) Burning of bricks :-

Burning of bricks

In the process of burning, the dried bricks are burned either in clamps (small scale) or kilns (large scale) up to certain degree temperature. In this stage, the bricks will gain hardness and strength so it is important stage in manufacturing of bricks.
The temperature required for burning is about 1100oC. If they burnt beyond this limit they will be brittle and easy to break. If they burnt under this limit, they will not gain full strength and there is a chance to absorb moisture from the atmosphere.
Hence burning should be done properly to meet the requirements of good brick.

Thank you guys for reading this and will come up with some more manufacturing process of different materials. Follow us for more .

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Some points are from https://theconstructor.org/building/manufacturing-of-bricks-methods-and-process/11972/