There are various types of bricks used in masonry.
1. Common Burnt Clay Bricks
2. Sand Lime Bricks (Calcium Silicate Bricks)
3. Concrete Bricks
4. Fly ash Clay Bricks
5. Fire Clay Bricks
Common Burnt Clay Bricks
Clay bricks are fired bricks. These are formed by pressing in moulds or by an extrusion and wire cutting process. Then these bricks are dried and fired in a kiln.
Sand Lime Bricks (Calcium Silicate Bricks)
These bricks are mixtures of sand and hydrated lime pressed in moulds and cured in a high-pressure steam autoclave.
Concrete bricks are mixtures of cement, sand and aggregates vibrated in moulds and steam cured.
Fly ash Clay Bricks
Fly ash is used along with clay in these bricks. Fly ash is obtained from boilers of thermal power stations.
Fire Clay Bricks
Fire clay exists at much depth below the surface and is usually mined. Generally, Fire clays contain metallic oxides less than surface clays and have more uniform chemical and physical properties.
Recommended Bricks for Construction
Common burnt clay bricks are recommended for construction of a house. The bricks should be burnt in kiln thoroughly so that they become hard and durable. The two bricks should give a hard ringing sound when they are struck together. The bricks should have rectangular shapes with sharp corners and uniform colors. The bricks should be free from cracks, chips and warp ages, large particles of lime and organic matter. First class bricks are suitable for construction of a building.