Properties of Bricks

The required properties of good bricks are following:

A.   Color: Color should be bright and uniform.

B.   Shape: Bricks should have plane faces. They should have true and sharp right angled corners.

C.   Size: Bricks should have standard sizes as prescribed by codes.

D.   Texture: They should possess dense, fine and uniform texture. They should not possess cavities, fissures, loose grit and unburnt lime.

E.   Soundness: When struck with hammer or another brick, it should generate metallic sound.

F.    Hardness: Finger scratching should not produce any notion on the brick.

G.   Strength: Crushing strength of brick will not be less than from3.5 N/mm2. A field test for strength is that while dropped from a height of range 0.9 m to 1.0 mm on a hard ground, the brick will not break into pieces.

H.   Water Absorption: In water after immersing the brick for 24 hours, water absorption might not be more than 20 %by weight. For class-I works this restrict is 15 %.

I.      Efflorescence: Bricks should not indicate white patches when soaked in water for 24 hours and then permitted to dry in shade. White patches are due to the existence of sulphate , magnesium , calcium and potassium. They keep the masonry permanently in wet and damp conditions.

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

K.   Sound Insulation: Heavier bricks are poor insulators of sound whenever light weight and hollow bricks provide good sound insulation.

L.    Fire Resistance: Fire resistance of bricks is generally good. In fact bricks are utilized to encase steel columns to protect them from fire.