Brick is a building material that consists of clay molded into oblong blocks and fired in a kiln or baked in the sun. It is one of the oldest and most durable construction materials. It has been used in building for thousands of years and remains a common form of construction in many countries throughout the world.
There are thousands of types of brick named for their use, size, forming method, origin, quality and texture. In the United States, they are largely made from clay with a proportion of calcium silicate (also known as cement sand) added to prevent them from cracking or shrinking. They are a hard, durable and fireproof substance that can last for hundreds of years.
Historically, bricks were used to construct a variety of structures, including houses, walls and foundations, roads and railways. They are a strong and durable material with compressive strengths of about 7 to 103 MPa (1,000 to 15,000 lbf/in2), although they will vary according to the purpose for which they are intended.
The compressive strength of a brick will depend on its composition and the amount of water that is added during the forming process. In addition, the quality of the raw materials and the manufacturing methods affect their final strength.
A brick is usually made by using a mechanical hydraulic press, or by manually levering a mixture of clay, water and a small amount of a cement binder into a mold. The block is then compressed to create a brick with a uniform thickness and consistent shape.
Some types of bricks are extruded, while others are shaped by being forced through an opening in a steel die. The extruded type is more consistent in size and shape than the sand-struck or wood-mold types, but it can take longer to produce. The extruded types tend to have perforations or core holes in the bed of the brick, which reduces energy used for drying and firing.
The extruded type of brick can be manufactured in a number of ways, the most common being to place the clay into an extrusion head which forces it into a continuous column of material in the desired width and depth. This column is then cut into bricks of the required length by row wires.
Brick production is a major industry in many parts of the world, with Bangladesh, India, and Nepal accounting for 20% of global brick production [2]. The sector is also an important employment source in these countries, employing millions of people and supporting their economies.
In Bangladesh, the brick sector is dominated by migrants from various regions in the country. These workers often work for short periods of time and are not highly skilled.
They can make a lot of money and are not required to have any training in the brick making process. Besides, the wages are good and they enjoy social security benefits.
The process of brick making consists of six steps: a) collecting the clay, b) mixing the clay, c) preparing a dough, d) molding it inside a mold, e) drying it, and f) removing excess clay from the mold. The resulting bricks are then ready for delivery and can be applied in construction projects.