Brick of ADABOTO, Why Brick?

Building bricks are a mixture of clay and sand which is mixed with water to create the correct consistency. Sometimes the bricks also have added lime, ash or organic matter which speeds up the burning of the brick. The clay mixture is then formed in moulds to the desired specification ready to be dried then burnt in the kiln. Clay: The properties and quality of bricks depend on the type of clay used. The most common form of clay used for everyday bricks, is that with a sandy consistency, silicate or alumina, which usually contains small quantities of lime or iron oxide. Silica, when added to pure clay in the form of sand, prevents cracking, shrinking and warping. If there is a large proportion of sand used in the mixture the brick will be more textured and shapely. An excess of sand, however, renders the bricks too brittle and destroys cohesion. 25% of silica is said to be advantageous. Iron oxide in the clay enables the silica and alumina to fuse and adds considerably to the hardness and strength of the bricks. The iron content of the brick is evident in the colour of the brick and can be used to add the colour red into the bricks. However a clay which burns to a red colour will provide a stronger brick than clay which burns to a white or yellow brick. The lime content in a brick has two different effects. It stops the raw brick from shrinking and drying out, and it also acts as a flux during burning which causes the silica to melt and creates the bond which binds all the components of the brick together. However, too much lime can cause the brick to melt and loose shape. Any amount of quicklime within a brick is detrimental to its quality and can cause the brick to split into pieces. For the best qualities of pressed brick the clay is carefully selected both colour and composition. Clay from different sources is also often mixed together to create the desired mixture.