SPECIFICATION FOR HEAVY DUTY BURNT CLAY BUILDING BRICK ( IS: 2180 )

HEAVY DUTY BURNT CLAY BUILDING BRICKS

QUALITY

1) These bricks should have uniform texture and colour. 

2) The surface of these bricks should be smooth and rectangular, with parallel, sharp and straight edges and square corners.

3. Heavy duty bricks should be free from flaws, cracks and stones.

4) No impression should be left on the heavy duty bricks when a scratch is made by a finger nail.

5) When broken fractured surface of the brick shall show a uniformly dense structure, free from large voids and lime particles.

6) Water absorption of these bricks should be 10% of its dry weight when immersed in cold water for

24 hours.

7) A metallic or ringing sound should come when two bricks are struck against each other.

SPECIFICATION

Water Absorption

Water absorption of these brick should not be more than 10 per cent after 24 hours immersion in water.

Efflorescence 

Should be nil

Bulk Density

Shall not be less than 2500 kg/m3.

Compressive Strength

Heavy duty bricks are classified into two categories on the basis of compressive strength namely class 40 and class 45 each one have their different specification.

a) CLASS 40

Minimum average compressive strength of heavy duty burnt clay bricks of class 40 should not be less than 40 N/mm2 and not greater than 45N/mm2. When tested for any individual brick, shall not fall below the minimum average compressive strength specified for the corresponding class of brick by more than 20%.

b) CLASS 45

Minimum average compressive strength of heavy duty burnt clay bricks of class 45 should not be less than 45 N/mm2. When tested for any individual brick, shall not fall below the minimum average compressive strength specified for the corresponding class of brick by more than 20%.

DIMENSION AND TOLERANCE

Class 40 (40-45 N/mm2)

Dimension

Length- 190 mm 

Width- 90 mm

Height- 90 mm (40 mm for no frog brick)

Class 45 (45 N/mm2)

Dimension

Length- 190 mm

Width- 90 mm

Height- 90 mm( 40 mm for no frog brick)

Heavy duty burnt clay brick of class 45 further subdivided into subclasses A and B based on tolerance.

Tolarence 

Subclass A  a) length- 6 mm (less or more)

                   b) width- 3 mm (less or more)

Subclass B  a) length- 15 mm (less or more)

                   b) width- 7 mm(less or more)