Bricks

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How It's Made Bricks!

Bricks which are blocks of ceramic material that used mostly in construction, where there usually laid using different kinds of mortar. It has been known as one of the longest lasting and strongest building materials used throughout the history. Bricks are also the only man-made building materials that testify to their use since the early human civilization.

There are few types of clays where it occured in three principal forms, all of which have similar chemical compositions but different physical characteristics.

1.      Surface Clays. 

Surface clays may be the upthrusts of older deposits or of more recent sedimentary formations. Asthe name implies, they are found near the surface of the earth.

            2.      Shales.  

            Shales are clays that have been subjected to high pressures until they have nearly hardened into slate.

           3.      Fire Clays.  

           Fire clays are usually mined at deeper levels than other clays and have refractory qualities.

Surface and fire clays have a different physical structure from shales but are similar in chemical composition. Allthree types of clay are composed of silica and alumina with varying amounts of metallic oxides. Metallic oxides act as fluxes promoting fusion of the particles at lower temperatures. Metallic oxides (particularly those of iron, magnesium and calcium) influence the colour of the fired brick. The manufacturer minimizes variations in chemical composition and physical properties by mixing clays from different sources and different locations in the pit. Chemical composition varies within the pit, and the differences

are compensated for by varying manufacturing processes. As a result, brick from the same manufacturer will have slightly different properties in subsequent production runs. Further, brick from different manufacturers that have the same appearance may differ in other properties.