Objective

For determination of efflorescence of bricks

ReferenceStandards

IS: 3495 – Part(3)-1992

Equipment & Apparatus

• Oven (300⁰c)

Procedure

1. A shallow flat bottom dish containing sufficient distilled water to completely saturate the specimens is used for the test. The ends of the bricks are placed in the dish, the depth of immersion in water being 25 mm.
2. The whole arrangement is placed in a warm (between 20⁰C and 30⁰C) well ventilated room until all the water in the dish is absorbed by the specimens and the surplus water evaporates.
3. The dish containing the brick is covered with a suitable glass cylinder so that excessive evaporation from the dish may not occur.
4. When the water has been absorbed and brick appears to be dry, a similar quantity of water is placed in the dish and it is allowed to evaporate as before. Examine the bricks for efflorescence after the second evaporation and the results are reported.

Reports

The liability to efflorescence shall be reported as ‘Nil’, ‘Slight’, ‘Moderate’, ‘Heavy’ or ‘Serious’ in accordance with the following definitions

(a)Nil: When there is no perceptible deposit of efflorescence

(b)Slight: When not more than 10 percent of the exposed area of brick is covered with a thin deposit of salts

(c)Moderate: When there is a heavier deposit than under ‘Slight’ and covering up to 50 percent of the exposed area of the brick surface but unaccompanied by powdering or flaking of the surface.

(d)Heavy: When there is a heavy deposit of salts covering 50 percent or more of the exposed area of the brick surface but unaccompanied by powdering or flaking of the surface.

(e)Serious: When there is a heavy deposit of salts accompanied by powdering and / or flaking of the exposed surfaces

Safety & Precautions

• Use hand gloves while removing containers from oven after switching off the oven.
• Thoroughly clean & dry the container before testing.
• Use apron & safety shoes at the time of testing.