Introduction for Tests on Brick
Bricks are commonly used in the construction of various types of Structures. Bricks are one of the basic materials which are commonly used for the construction of walls.
Bricks should be checked and tested on-site before using them for construction purposes. It is very necessary that the bricks should pass all the required criteria given by the Indian Standards.
As a civil engineer, you should know the various tests on bricks that are used to check the quality of bricks. In this article, we will go through the various tests on bricks.
Bricks are artificially constructed with the help of clay. It is very important that bricks should go through various tests to know their suitability for construction work. There are basically two types of tests conducted on the bricks, which are laboratory tests and field Tests.
The Laboratory Tests are those which are carried out in the lab with the help of various instruments and types of machinery. A detailed report is made on the tests which are carried out in the laboratory.
The Tests which are carried out in the lab are the crushing strength test on bricks, water absorption test, porosity test on bricks, efflorescence test on bricks, and the dimensional stability test.
Field Tests also play an important role which is very helpful in checking the brick’s quality present on the site. The one best part of the field test on the bricks is that it gives faster results.
Tests on Brick
Here, two different parts divided the brick test. One part is a lab test on bricks, and the second part considers a field test on bricks.
- Laboratory Tests on Brick.
- Water Absorption Test on Brick.
- Crushing Strength Test on Brick.
- Efflorescence Test on Brick.
- Dimensional Stability Test on Brick.
- Field Tests on Brick.
- Hardness Test on Brick.
- Soundness Test on Brick.
- Impact Test on Brick.
- Shape and size Test on Brick.
- Structure Test on Brick.
All types of tests on a brick in full detail and specification are as follows.
1. Laboratory Tests on Brick.
Inside lab test on brick, various types of test on bricks like Water absorption test, crushing strength test, efflorescence test, and dimensional stability test.
1.1. Water Absorption Test on Brick.
The water absorption test on bricks is the measure of the quantity of water that is absorbed by the bricks when it is immersed in water. In the water absorption test, the brick is weighed at room temperature when bricks are completely dry.
Let its weight be W. The bricks are soaked in water for 24 hours at room temperature and then weighed. Let its Weight be W1
The percentage of water absorption of bricks = (W1 – W)/ W x 100
As per Indian standards, the amount of water that is absorbed by the bricks should not be more than 20% of their Dry weight.
As per IS: 1077 and 1237, the water absorption for various grades of bricks is as follows.
Class 1 Brick: The water absorption for class 1 brick should not be more than 20% of its Dry weight.
Class 2 Brick: The water absorption for class 2 brick should not be greater than 22% of its Dry weight.
Class 3 Brick: The water absorption for class 3 brick should not be more than 25% of its Dry weight.
1.2. Crushing Strength Test on Brick.
The crushing strength of brick is determined by using a compression testing machine in the laboratory. The bricks are pressed under the compression testing machine till It Breaks or is just on the point of crushing.
All the values of the readings at the point of crushing or note down indicate the crushing strength of the bricks. The minimum compressive strength of brick is 5 N/mm2.
The grade A brick for the 1st class brief has a crushing strength value ranging between 7 to 14 N/mm2.
1.3. Efflorescence Test on Brick.
In the Efflorescence test, the presence of soluble salts is determined. It is very necessary to identify the soluble salts present in the bricks because they will cause efflorescence on the surface of the bricks.
In this test, the brick is soaked or immersed in water for 24 hours and then taken out and allowed to dry completely. After the bricks are completely dry, the proper observation of the bricks is done.
If there is no grey or white deposit present on the surface of the bricks, then it indicates the absence of soluble salts. If there is any white deposit present on the surface of the brick, then there will be efflorescence, and it is necessary that the brick should be treated before being used in construction.
There are various results are analyzed, and the bricks are classified as follows according to the area of bricks affected by efflorescence. When 10% of the exposed area of the bricks is covered with a thin deposit of salt, then the difference is Slight.
When there is a heavy deposit of salt that covers up to 50% of the area of the brick surface, then the Efflorescence will be moderate. When the exposed surface of the brick is more than 50% affected by the heavy deposit of salt, then the bricks are in the Heavy Efflorescence condition.
If there is a heavy deposit of salt present on the surface of the brick, or there is flaking of the exposed surface, then the bricks are in the Serious Efflorescence condition.
1.4. Dimensional Stability Test on Brick.
In the dimensional stability test, the bricks are wetted, and there is a change in volume and linear dimension. The resistance to change of volume is called Dimensional.
The bricks are saturated with water, indicating 0.02% linear expansion, which is normal. The bricks which undergo more linear expansion are not good for construction work, and it indicates that they are burnt. Bricks should also show dimensional stability when they are heated.
2. Field Tests on Brick.
Field Tests are also one of the most important which are carried out on-site during the construction. The Field test is very helpful in determining the quality of bricks on the site.
2.1. Hardness Test on Brick.
The hardness test of bricks is used to determine the resistance of bricks to abrasion in the hardness test of the bricks or scratches made on the exposed surface of the brick by a fingernail.
After making scratches on the surface of the bricks, if there is any impression left on the brick, then the brick is not sufficiently hard to wear. There should not be any impression left on the brick after scratching it with nails.
2.2. Soundness Test on Brick.
The soundness test is also one of the most important tests, which are commonly used to check the quality of the bricks on the construction site. The soundness test is one of the simple and easy tests which anyone can do on the site.
In the soundness test, the two bricks are struck with each other. The brick should not break while it was struck with each other, but it should you a metallic ringing sound. The metallic ringing sound of the bricks indicates the good quality of the bricks.
2.3. Impact Test on Brick.
In the impact test of the bricks, the brick is allowed to drop flat from a height of 1 meter on the ground. After dropping the brick on the ground, it should not break your crush into pieces.
If the brick gets cracked or crushed into pieces, then it indicates the best quality of the brick.
2.4. Shape and Size Test on Brick.
The shape and size of the brick should be uniform and standard size. The shape of the standard brick should be rectangular. The bricks should have a uniform color, and their edges should be straight.
Check whether the bricks should be well burnt. The bricks should have a copper color or reddish color, and they should be free from cracks and should have sharp edges. All the above characteristics show that the brick is of good quality.
2.5. Structure Tests of Brick.
The structure of the brick should be compact, homogeneous, and free from holes and lumps. The bricks should not be broken. It is necessary that you should observe the overall structure of the bricks so that you can understand the condition and the quality the bricks.