Properties of Bricks

PROPERTIES OF BRICKS

Good quality bricks should consists of the following properties:

 ❖ Colour: Brick should have a uniform and bright red colour.

❖ Shape: Brick shapes should ideally be rectangular, with well-defined, sharp edges and an even surface.

❖ Size: As prescribed by codes bricks should be of standard sizes.

❖ Texture: They should represent fine, dense and uniform texture and should not possess fissures, cavities, loose grit or any unburnt lime.

❖ Soundness: When struck with another brick or a hammer, metallic sound should be heard

❖ Hardness: Scratching should not cause any impression on the brick's surface.

❖ Strength: Compressive strength of brick should not be less than 3.5 N/mm². The brick should not break into pieces, when dropped from a height of 0.9 m to 1.0 mm on a hard ground.

❖ Durability: Effectively manufactured bricks are incredibly durable, often lasting many years.

❖ Water Absorption: When immersed in water for 24 hours, water absorption should not be more than 20% by weight of the brick. For Ist class bricks this limit is 15%.

❖ Efflorescence: When immersed in water for 24 hours and then allowed to dry in shade, bricks should not show white patches. Due to the presence of sulphate of calcium, magnesium and potassium, these white patches are formed. Efflorescence keeps the masonry permanently in damp and wet conditions.

❖ Thermal Conductivity: Bricks should have low thermal conductivity, so that buildings built with them are cool in summer and warm in winter.

❖ Sound Insulation: Light weight and hollow bricks provide good sound insulation, while heavier bricks are poor insulators of sound.

❖ Fire Resistance: Bricks have good fire resistance. Even they are used to encase steel columns to protect them from fire.