A brick is building material used to make walls, pavements and other elements in masonry construction. Traditionally, the term brick referred to a unit composed of clay, but it is now used to denote any rectangular units laid in mortar. A brick can be composed of clay-bearing soil, sand, and lime, or concrete materials. Bricks are produced in numerous classes, types, materials, and sizes which vary with region and time period, and are produced in bulk quantities.
Categorization of Bricks
1. Unburnt Bricks
- Unfired bricks, also known as mudbricks, are made from a wet, clay-containing soil mixed with straw or similar binders.
- The heat generated from sun light is used to dry these bricks as soon as the moulding process is completed.
- The bricks are mostly found in temporary and low-priced construction work.
2. Burnt Bricks
- Modern, fired, clay bricks are formed in one of three processes – soft mud, dry press, or extruded. Depending on the country, either the extruded or soft mud method is the most common, since they are the most economical.
- Once moulding and drying process are finished, these bricks are burnt in a clamp or kiln.
- These bricks are solid, strong, long lasting and applicable in permanent construction works.
- These Bricks divided into 4 categories:- a) First Class Brick, b) Second Class Brick, c)Third Class Brick, d)Fourth Class Brick.
a) First Class Brick
- The bricks are moulded through table
- Properly burnt and regular in shape and size.
- Edges are piercing and properly demarcated.
- Consistent in colour.
- Water absorption capacity should not surpass 20%
- Lowest crushing strength is similar to 0.5 N/mm2.
Applications of First Class Brick
- For pointing and uncovered face work.
- Flooring and reinforced brick work.
b) Second Class Brick
- These are moulded in ground
- Perfectly burnt and the shape and size are uneven.
- Edges are neither straight nor properly demarcated.
- Inconsistent in colour.
- Water absorption capacity does not surpass 22%
- Lowest crushing strength=7 N/mm2.
Applications of Second Class Brick
- Concealed masonry work enclosed with plaster.
- Centering of reinforced brick work.
c) Third Class Brick
- It is moulded in ground
- Under-burnt and shape and size are inconsistent.
- Light yellowish The colour is light yellow.
- Edges are asymmetrical.
- Water absorption capacity does not surpass 25%
- Lowest crushing strength is 3.5 N/mm2.
Applications of Third Class Brick
- usually used for temporary building structure.
d) Fourth Class Brick
- Burnt excessively.
- Uneven in shape and size.
- Colour is gloomy.
- Solid and well-built.
Applications of Fourth Class Brick
- Ballast of such bricks are applied for foundation and floor.