Category: Bricks

Bricks are burnt in kilns after moulding and drying so as to impart hardness and strength and to increase the density of the brick so that it absorbs less quantity of water. Physical and chemical changes take place in burning of bricks. Heating brick earth up to about 640°C produces only physical changes. At this…

Moulded bricks can not be burnt directly as they may get cracked or distorted. Hence, before burning they are dried. Natural drying or artificial drying may be resorted to. The bricks are left to dry for about two weeks. 1. Natural Drying It is also called hack drying. It comprises placing moulded bricks in rows on…

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…

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…

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…

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…

The manufacturing of bricks involves four stages, viz., preparation of soil, moulding, drying and burning.

The following factors are to be considered in the selection of a site for 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…

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…