Author: haroonkhan
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Machine Moulding
Moulding machines are used when a large number of bricks are to be manufactured within a short time. Machine-moulded bricks are heavier and stronger than the hand-moulded ones. These bricks have a sharp regular shape and size, a smoother surface and sharp edges. There are two types of machine moulding, viz., plastic method and dry…
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Hand Moulding
Two types of hand moulding, viz., ground moulding and table moulding, are adopted in India. In hand moulding, bricks are moulded manually. This is preferred in areas where the manpower is cheap and available readily and where only a small quantity of bricks is needed. (i) Ground Moulding The process of moulding bricks on the…
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Moulding of Bricks
Bricks are made in traditional size (in inch) and in metric size (cm) as prescribed by the Bureau of Indian Standards. Metric size bricks are called modular bricks. Nominal size of bricks is the size including thickness of the mortar. Hence, the actual size of modular bricks is 19 cm × 9 cm × 9…
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Preparation of Soil
1. Removal of Top Soil The preparation of soil involves first renewal of loose materials at the top of the ground for a depth of about 200 mm. As it contains a lot of impurities, this material is not used for the preparation of bricks. 2. Digging and Spreading The earth is dug out 200…
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MANUFACTURING OF BRICKS
The manufacturing of bricks involves four stages, viz., preparation of soil, moulding, drying and burning.
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SELECTION OF SITE FOR BRICK EARTH
The following factors are to be considered in the selection of a site for brick earth:
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Field Testing of Brick Earth
Brick earth in the field has to be tested for consistency, moulding properties and shrinkage. In order to test for the first property, a handful of soil sample is taken and formed into a ball. The ball is dried in the sun and then examined. Crumbling of the dried ball shows the presence of excess…
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Harmful Ingredients in Brick Earth
Naturally available soil may contain ingredients other than those required for making quality bricks, which are discussed below. 1. Alkalis Alkalis in the form of soda and potash lower the fusion point of clay, and cause bricks to fuse, twist and warp during burning. Alkalis present in bricks absorb moisture from the atmosphere and create…
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Desirable Chemical Composition of Brick Earth
The desirable chemical composition of brick earth for good quality bricks are given below (IS: 1077, 1976):
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Functions of Constituents of Brick Earth
1. Alumina This is the main constituent of every kind of brick earth. This imparts plasticity to the earth so that it can be moulded. If alumina is present in excess, it leads to shrinking and warping during drying and burning. This can be prevented by the addition of sand. 2. Silica It exists in…