The Process of Creating Bricks.
Bricks have been used in construction for thousands of years. Originally, bricks were made of pressed mud that was baked in the sun. It was later discovered that bricks which had been fire-cured were much better at resisting weather damage. Fired bricks also had the advantage of absorbing heat throughout the day to be released at night, helping to better control the temperature in the structure. With fired bricks, buildings became more permanent, and because of these factors their popularity grew and they are still used commonly today.
Brick is the second most commonly used material in building, only beat by wood. The bricks of today are still kiln fired in a similar manner, but the materials and process have been thoroughly refined throughout the years.
The Manufacturing Process
Bricks today are manufactured by combining a mixture of natural clay and shale, and some additives like barium carbonate are added to increase strength and resistance to the elements. Depending on the clay being used, occasionally sand or grog, which is often recycled scrap brick, is added to the mix. Bricks can be coloured by adding manganese or other additives.
The brick mixture is shaped, often with a process known as extrusion. In this process, the mixture is fed through a machine that cuts it into pre-determined amounts that are fed through a chamber that removes the air from the mixture, usually by creating a vacuum. Removing the air is important because it helps to keep the brick from cracking or other various defects caused by air pockets. After the air is removed a high-pressure cylinder presses the mix and it is pressed into a special mould to shape the brick into the desired dimensions.
Once the mixture has been extruded and shaped, the newly formed bricks must be laid out to dry. If excess moisture is not allowed to evaporate prior to firing the bricks, it will burn too quickly and cause significant cracking to occur. The bricks are often laid on large racks that can be wheeled into dryer rooms.
After they have been thoroughly dried, the bricks are fired at extremely high temperatures in large kilns that have been specially developed to burn at a specific temperature for a carefully calculated time to provide the highest strength, and overall best quality concrete possible.
Bricks have been a common building material for thousands of years. Although the methods for constructing them have been refined, it is still essentially the same process that has been used for almost as long as bricks have existed.