Tests on Bricks.pptx

Tests of Bricks by Ameer Murad Khan

1. Testing of Clay Bricks

2. Different Types of Tests on Bricks Various Tests of Bricks are as Follows, Water absorption test Crushing strength test Hardness test Shape and size test Soundness test Test for the presence of soluble salts

3. Water Absorption Test of Bricks Water absorption test for bricks can be performed by using two methods, ( i ) 24-hour immersion cold water test (ii) 5-hour boiling water test 24-hour Immersion Cold Water Brick Test: The dry specimen is put in an oven maintained at a temperature of 105+5 C, till it attains substantially constant mass. After cooling the specimen at room temperature weight of the specimen was recorded as W1. The dry specimen is then immersed completely in the water at a temperature of 27 ± 2 C for 24 hours. Take out specimens from the water and wipe all water from its surface with a wet cloth.

4. Water Absorption Test of Bricks (Cont.) Complete weighing of the specimen, 3 minutes after the specimen has been removed from the water. Let this weight be W2. Water absorption  after 24 hours of immersion in cold water is given by (W2 – W1) x 100 / W1

5. Water Absorption Test of Bricks (Cont.) 5-hour Boiling Water Brick Test: The brick sample is dried in an oven at 105 to 115 C till it attains constant mass. Cool the brick sample at room temperature and record its weight (W1). The brick is immersed in boiling water for 5 hours. With brick immersed in water is allowed to cool at 27 ± 2 C. The brick sample is taken out and wiped with a damp cloth. Complete the weighing of the specimen in three minutes. Let it be W3. Water absorption, percent by mass, is given by (W3 – W1) x 100 / W1

6. Efflorescence

7. Efflorescence Test Soluble salt available in brick causes efflorescence. The presence of such salts can be determined as follows. Place one end of the bricks in a 25 mm depth of water in a dish with a minimum diameter of 150 mm and depth of 30 mm. The dish is made of porcelain, glass, or of glazed stonework. The experiment is performed in a well-ventilated room between 20 to 30 degrees C till all the water in the dish is either absorbed by the specimen or evaporated. After the specimen has dried, add a similar quantity of water to the dish and let it be absorbed by the specimen for efflorescence after the second evaporation.

8. Efflorescence Test Efflorescence in brick is denoted by nil, slight, moderate, heavy, or serious as defined below: Nil: When a salt deposit is imperceptible, then it is said to be Nil. Slight:  When efflorescence does not cover more than 10% of the exposed area of the bricks, it is said to be slight. Moderate: When the deposit of  efflorescence   is heavier than slight and does not cover more than 50 percent of the exposed area of the brick surface. There should not be powder or flake on the brick-exposed surfaces. Heavy: When the deposit covers an area of 50 percent or more of the exposed area of the brick surface. Then it is said to be efflorescence salts are heavy. There should not powder or be flaking of the brick-exposed surfaces. Serious:   Heavy deposits of salts accompanied by flaking of the surface.

9. Compressive Test on Brick For this test well brunt clay brick is selected. The top and bottom faces of bricks are ground to provide a smooth and even surface for the test. The brick sample is then placed in water at room temperature. Clean top flogs of brick and fills them with cement mortar (1 part cement and 1 part clean coarse sand of grade 3 mm and down), store under damp jute bags for 24 hours, and then immerse in clean water for 3 days. Take out the brick sample and clean the extra water from the surface. Place brick sample between two plywood sheets, each 3 mm thick, with flat faces horizontal and mortar-filled faces facing upwards.

10. Compressive Test on Brick (Cont.) The brick sample between plywood sheets is carefully set in the center of the compression testing machine. Fix the gauge of the machine and tighten it and start applying the axial load at a uniform rate of 140 kg/cm2 per minute till failure. The maximum load on the dial gauge at the failure of the brick sample is noted. Compressive strength =  maximum load at failure/ Base are of Brick.

11. Compressive Test on Brick (Cont.) First Class Brick:  The brick which has a compressive strength of 10N/mm2 is called as a First class brick Second Class Brick:  The brick with compressive strength of 7N/mm2 is called as a Second class brick Building brick:  The brick which we use for building has a compressive strength of 3.5N/mm2 Sundried Brick:  The sun dried brick has a compressive strength of 1.5N/mm2 to 2.5N/mm2

12. Hardness Test on Brick The Hardness Test of Brick can be judged with the help of the scratch of the fingernail. Try to scratch the figure on the brick, if no scratch is left on the surface of the brick, it is considered to be having sufficient hardness.

13. Shape and Size Test The shape of bricks should be truly rectangular and should have standard sizes per the relative code of regulation.

14. Soundness Brick Test A soundness brick test is conducted by striking two bricks together. The striking of brick should emit a ringing sound. It can be tested by the fall of brick. A good quality brick should not break, when made to fall flat on hard ground, from a height of about 1 m.

15. Conclusion In conclusion the 7 brick test serves as a comprehensive and reliable method for evaluating the durability of brick and quality of brick, this test which include dimension, compressive strength, efflorescence, soundness, hardness, presence of soluble salts and water absorption. By Subjecting the bricks to this rigorous examinations, engineers and builders can make informed decision regarding their usage, ensuring and the safety and longevity of structure.

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