Bricks

BRICKS.

Bricks are obtained by moulding good clay into a block, which is dried and then burnt. Bricks are the oldest building block to replace stone. Bricks manufacturing started with hand moulding, sun drying and burning in clamps. A considerable amount of technological development has taken place with better  knowledge about to properties of raw materials, better machinaries and improved techniques of moulding drying and burning.

DIFFERENT SIZE OF BRICKS.

The size of bricks are;

1. 190 mm × 190 mm × 90 mm

2. 190 mm × 90 mm × 40 mm

*Considering mortar joints of 10mm, the size of the above mentioned bricks are taken as;

1. 200 mm × 100 mm × 100 mm

2. 200 mm × 100 mm × 50 mm

PROPERTIES OF BRICKS.

Good bricks required the following properties;

1. Colour: The colour of bricks have to be uniform and bright.

2. Shape: Bricks must have a plane surface. Corners of the brick have to be sharp and right angled.

3. Size: Bricks have to be of standard and uniform sizes as prescribed by codes.

4. Texture: Bricks have to be of fine, dense and uniform texture. They should not possess

fissures, cavities, loose grit and unburnt lime.

5. Hardness: Bricks must be hard and should not produce marks when it is scratched using finger nails.

6. Soundness: It should produce a metallic sound when two bricks are banged with each other.

7. Strength: Crushing strength of brick should not be less than 3.5 N/mm2.

When a full piece of brick is dropped freely on a hard surface from a height of 0.9 meters to 1 meter, it should not break into pieces.

8. Sound Insulation: Heavier solid bricks are poor insulators of sound while hollow bricks provide better sound insulation.

9. Fire Resistance: Bricks should be fire resistant, as they are usually used to encase steel sections such as columns, beams etc... to protect them from fire.

10. Water Absorption: After immercing the brick in water for 24 hours, water absorption should not be more than 20 percent by weight.

11. Efflorescence: Bricks should not show white patches, after soaking it in water for 24 hours and then allowing it to dry in shade.

12. Thermal Conductivity: Bricks must have low thermal conductivity, such that the walls remain cool in hot weather and warm cold weather.