Water Absorption test on brick is conducted to determine the moisture absorbed by the bricks when subjected to extreme conditions. The absorption test can be used as an indicator of the durability properties of bricks such as quality, degree of burning and behaviour of bricks in weathering. The test can be briefly explained as follows:
APPARATUS AND SPECIMEN REQUIRED
1. A ventilated oven
2. A weighing balance with a sensitivity of less than 0.1%
3. Sample of whole bricks
The procedure for the absorption test on bricks includes the following series of steps:
i. The brick specimen is first dried in the ventilated oven at a temperature ranging from 105 degree Celsius to 115 degree Celsius until the specimen attains a constant mass.
ii. The heated specimen is then allowed to cool at room temperature.
iii. The specimen is weighed and its mass is recorded ( M1).
iv. Then, the specimen is immersed in water at a temperature of about 27 degree Celsius for a period of 24 hours.
v. The brick specimen is taken out from the water and wiped with a clean cloth to remove the traces of water that may be present.
vi. The specimen thus obtained is then weighed (M2).
Calculation of Water Absorption of Bricks
Water absorption by the brick specimen is given by the formula,
The average result shall be reported.
M2 = Wet Weight of brick after immersion of brick in water for 24 hours
M1 = Dry Weight after oven drying of brick at 105-110 deg. C
Water absorption of the given bricks = ………….%
Water Absorption Test on Brick – Table
After the water absorption test on brick; the obtained value should not be more than 20% for first-class brick, 22% for second-class brick and 25% for third-class brick.
|S.N.||Brick Class||The maximum water absorption percentage|
|4.||Heavy-duty machine made bricks||5%|