LAB TEST FOR DETERMINATION OF EFFLORESCENCE OF BRICKS

OBJECTIVE: To determine the efflorescence of common burnt clay building bricks.

APPARATUS: shallow flat bottom glass, porcelain or glazed stoneware dish of size 180mm*180mm*40 for square shaped and 200mm dia*40mm depth for cylindrical shaped.

PROCEDURE:

1.      Take a representative sample of 5 bricks.

2.      Place the end of the bricks in the dish up to 25mm depth.

3.      Place the whole arrangement in a warm (20-30 cel) well ventilated room until all the water in the dish is absorbed by the specimen and surplus water evaporates.

4.      Cover the dish containing the bricks with suitable glass cylinder so that excessive evaporation from the dish may not occur.

5.      When the water has absorbed and bricks appear to be dry, place a similar quantity of water in the dish and allow it to evaporate as before.

6.      Examine the bricks for efflorescence after the second evaporation and report the results.

7.      The liability of efflorescence shall be reported as:

8.      Nil-when there is no acceptable deposit of efflorescence.

9.      Slight-when not more than 10% of the exposed area of the brick is covered with a thin deposit of salts.

10.  Moderate: when there is a heavier deposit than under “slight” and covering up to 50% of the exposed area of the brick surface but unaccompanied by powdering or flaking of the surface.

11.  Heavy-when there is a heavy deposit of salts covering 50% or more of the exposed area of the brick surface but unaccompanied by powdering or flaking of the surface.

12.  Serious-when there is a heavy deposit of salts accompanied by powdering and/or flaking of the exposed surfaces.