Basic of Water Absorption of Brick
Bricks are dry and porous; therefore, it has the ability to release and absorb moisture inherently from the weather/mortar/concrete. If the brick dry, absorbs moisture from water when laid, the mortar will become weak and poor. It fails to make the bond between bricks and mortar due to insufficient water for the hydraulic reaction of cement in the mortar and overall reduces the strength of construction.
Also, if the brick absorbs more water than the recommended result, it gives adverse effects on the strength of brick as well as the durability of the structure. The porous bricks will allow absorption of rainwater thereby giving rise to dampness in the wall. Even it cannot be grouted like concrete. So, water absorption of bricks is a significant and useful property of bricks. Water absorption is found out by the water absorption test of bricks.
Standard Guidelines
- IS 3495 (Part 2) 1992
- ASTM C 67
- BS 3921:1985
Water Absorption Test of Bricks as Per IS 3495 (Part 2) 1992
24-hours Immersion Cold Water Test
Apparatus:
- Oven
- Weight balance
- Tray
Water Absorption Test of Bricks
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The Procedure of Water Absorption Test of Bricks
Preparation of Test Specimens:
- Take any five random bricks from a lot of brick as a specimen.
- Dry the specimen in a ventilated oven at a temperature of 105°C to 115°C till it achieves considerably constant mass.
- Cool the specimen to room temperature and take its weight (M1).
Testing:
- When the specimen is completely dry, then immerse it in the clean water at the room temperature (27 ±2°C) for 24 hours.
- Remove the specimen from the water after 24 hours and wipe out water with a damp cloth and weigh the specimen.
- Take the weight (M2) of the specimen after 3 minutes of removing from the water.
Points to be Taken Care:
- When you take M1, If the Specimen is warm while touching, it shall not be used for the test. Test it when you feel it cool.
Result:
- Note down the M1 and M2.
- Percentage of Water absorption of brick by its mass, after 24-hour immersion in cold water is calculated by the following formula
- (M2-M1)/M1*100
Acceptance Criteria of Water Absorption Test of Bricks
Test result recommendation is as follows:
- For first class bricks, should not more than 15 %
- For second class bricks, it should not more than 20 %
- For third class bricks, it should not more than 25 %
Water Absorption of Bricks
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What should You do When Result is not in Range of Acceptance Criteria?
If the water absorption test of bricks has failed, obvious reasons are poor manufacturing and clay composition, insufficient burning etc. and If brick fails in water absorption than never ever use such bricks because you can’t resolve the problem by any treatment or remedies in future. Hence be careful.
Quantity Needed for Water Absorption Test of Bricks
Nos of bricks sample required to water absorption test of bricks are as follows:
- Lot Size of bricks 2001-10000 per 05 Nos bricks
- Lot Size of bricks 10001-35000 per 10 Nos bricks
- Lot Size of bricks 35001-50000 per 15 Nos bricks
- If the lot size of brick contains 2000 or less than 2000 bricks, ask your engineer for the required test samples.
Cost of Water Absorption Test of Bricks
Cost of water absorption test of bricks is around Rs. 300 to 500. Price may generally change according to many factors, an i.e. area where a test is performed, relation with the client, the urgency of test results, numbers of the testing, etc.
Frequency of Water Absorption Test of Bricks
Water absorption test of bricks is performed at the use of every 50000 bricks or test when the source of brick, the class of brick and the type of brick are changed.