CLASSIFICATION AND CHARACTERISTICS OF BRICKS



CLASSIFICATION AND CHARACTERISTICS OF BRICKS AS PER IS-1077 – 1973

Tests for the acceptance of bricks for building construction

  1. Dimension and tolerance test
  2. Compressive strength test
  3. Water absorption test
  4. Efflorescence test

1. Dimension and Tolerance Test

Take 20 bricks out of given sample. The dimensions of 20 bricks should be within the following limits.

 

Class

Length

Width

Height

Class A

12 – 380 + 12

368 to 392 mm

6 – 180 + 6

174 to 186 mm

174 to 186 mm

Class B

30 – 380 + 30

350 t0 410 mm

15 – 180 + 15

165 to 195 mm

165 to `95 mm

 

2. Compressive Strength Test:

Click on above to get the procedure of the test.

The compressive strength of a common brick should be 50 kg/sq.cm

3. Water Absorption Test:

If the water absorption capacity of a brick is more, its strength will be comparatively low.

Click on above link to get the procedure.

For first class bricks, the water absorption capacity should not be more than 20% by weight.

4. Efflorescence Test

This test is performed to know the presence of of any alkaline matter in the bricks.

Procedure:

  1. Take five bricks at random from the given sample.
  2. Place each brick on end in a dish containing distilled water ensuring depth immersion at least 2.5cm.
  3. Keep the dish in a ventilated room (temperature 20 deg to 30 deg C) till the whole of distilled water in the dish evaporates.
  4. Again pore 2.5 cm depth of distilled water in the dish and keep it till whole of water gets evaporated.
  5. Now examine the bricks for efflorescence as detailed below:

 

OBSERVATION

RESULT

No perceptible deposit

Nil – efflorescence

10% are covered with deposit of salts

Slight – efflorescence

50% area covered with deposits of salts without any powdering or flaking surface

Moderate – efflorescence

50 % area covered with deposit of salts accompanied by flaking of surface

Heavy – efflorescence

Heavy deposits of salts accompanied by flaking of the surface

Serious – efflorescence

 

Terra Cocta made from a mixture of fine clay 60%, crushed pottery 20%, while sand 14% and powdered glass 6% with a quantity of desired colouring substance. It is baked earth of superior variety of clay. Terra-cocta is used for architectural and ornamental parts of superior building as a substitute for stones. It is used as sound proof material and its hollow blocks prevent dampness in the structure.