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 180 mm x 180 mm x 40 for square shaped and 200 mm dia x 40 mm depth for cylindrical shaped.
PROCEDURE:
OBJECTIVE:
To determine the efflorescence of common burnt clay building bricks.
APPARATUS:
shallow flat bottom glass, porcelain or glazed stoneware dish of size 180 mm x 180 mm x 40 for square shaped and 200 mm dia x 40 mm depth for cylindrical shaped.
PROCEDURE:
- Take a representative sample of 5 bricks.
- Place the end of the bricks in the dish up to 25 mm depth.
- 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.
- Cover the dish containing the bricks with suitable glass cylinder so that excessive evaporation from the dish may not occur.
- 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.
- Examine the bricks for efflorescence after the second evaporation and report the results.
- The liability of efflorescence shall be reported as:
- Nil-when there is no acceptable deposit of efflorescence.
- Slight-when not more than 10% of the exposed area of the brick is covered with a thin deposit of salts.
- 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.
- 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.
- Serious-when there is a heavy deposit of salts accompanied by powdering and/or flaking of the exposed surfaces.
