Types of Tests on Bricks for Building Construction Works
How To Check Quality Of Bricks:
Bricks are widely used in masonry construction and it is crucial to ensure the use of good quality bricks for durable structures. In this article, we will focus on important brick tests that help determine the quality of bricks. These tests are conducted to assess various properties of bricks and ensure they meet the required standards. By performing these tests, builders and engineers can make informed decisions about the suitability of bricks for construction projects. Let’s explore these brick tests in detail to understand their significance in ensuring the quality and reliability of brickwork.
brick tests
The common brick tests performed on the field as well as in the laboratory are described below.
1. Compressive Strength Test:
2. Water Absorption Test:
3. Efflorescence Test:
4. Impact Test:
5. Dimension Tolerance Test:
6. Soundness Test Of Bricks:
7. Hardness Test:
8. Structure Test:
Brick Tests:
1. Compressive Strength Test:
This test is conducted to determine the compressive strength of bricks, also known as the crushing strength test of bricks.
Typically, five samples of bricks are selected and transported to the laboratory for testing.
A brick sample is placed on the crushing machine, and then pressure is gradually applied in an axial direction until it breaks.
The maximum pressure at which the brick starts to crack is recorded.
The test is repeated with all five brick samples, one by one, and the average result is considered as the compressive strength or crushing strength of the bricks.
This test helps assess the ability of the bricks to withstand compressive loads, ensuring their suitability for construction purposes.
2. Water Absorption Test:
In this test, bricks are first weighed in dry condition (W1), and then they are fully submerged in water for 24 hours.
After the 24-hour immersion, the bricks are collected and weighed again in wet condition (W2).
The difference in weight between the dry and wet conditions represents the water absorbed by the bricks.
The amount of water absorption is then calculated as a percentage.
Water absorption (%) = [(W2 – W1) / W1] * 100
A lower percentage of water absorption indicates higher quality bricks.
A brick is considered to be of good quality if its water absorption does not exceed 20% of its own weight.
3. Efflorescence Test:
To determine the presence of soluble salts in bricks, the following procedure can be followed:
Take a dish with a minimum diameter of 150 mm and a depth of 30 mm.Fill the dish with water to a depth of 25 mm.Place one end of the bricks in the water, ensuring that they are immersed to a depth of 25 mm.
The dish used for the test should be made of porcelain, glass, or glazed stonework. These materials are suitable for containing the water and the bricks during the testing process.
The experiment is conducted in a well-ventilated room with a temperature between 20 to 30 degrees Celsius. During the experiment, the dish with the bricks and water is left undisturbed until all the water in the dish is either absorbed by the specimen or evaporated.
After the specimen has dried, pour a similar amount of water into the dish and allow it to be absorbed by the specimen. After the second evaporation, observe for any signs of efflorescence.
Efflorescence in brick is denoted by nil, slight, moderate, heavy, or serious as defined below:
Nil:
When there is no visible salt deposit or efflorescence present, it is categorized as nil. The brick surface appears clean and unaffected by soluble salts.
Slight:
When the efflorescence covers less than 10% of the exposed area of the bricks, it is categorized as slight. The salt deposit is minimal and does not significantly affect the appearance or performance of the bricks.
Moderate:
When the deposit of efflorescence is heavier than slight and covers less than 50 percent of the exposed area of the brick surface, it is classified as moderate. There may be a noticeable accumulation of salts, but there should not be any powder or flakes on the exposed surfaces of the bricks.
Heavy:
When the deposit of efflorescence covers 50 percent or more of the exposed area of the brick surface, it is classified as heavy. The presence of efflorescence salts is more pronounced, but there should not be any powder or flaking on the exposed surfaces of the bricks.
Serious:
Efflorescence is classified as serious when there is visible powdering or flaking of salt on the exposed surface of the bricks. This indicates a significant presence of efflorescence salts and requires immediate attention for proper remediation.
4. Impact Test:
In this test, a few bricks are dropped from a height of 1 meter. If the bricks break upon impact, it indicates a low impact value and they are not suitable for construction work. On the other hand, good quality bricks do not break at all during the test.
5. Dimension Tolerance Test:
In this test, 20 bricks are randomly collected and arranged in a straight line. This is done to observe and assess the variation in shape, size, and color compared to the standard bricks. The purpose is to ensure that the collected bricks meet the required standards for uniformity and consistency in their physical characteristics.
6. Soundness Test Of Bricks:
In this test, two randomly selected bricks are firmly tapped against each other. If they produce a clear metallic sound and remain unbroken, it indicates that they are of good quality. This test helps to assess the hardness and strength of the bricks.
7. Hardness Test:
This test is conducted to assess the hardness of bricks. It involves making scratches on the surface of the brick using a hard object. If the scratches do not leave any impression on the brick surface, it indicates that the bricks are of good quality.
8. Structure Test:
In this test, a brick is intentionally fractured and thoroughly examined. If any flaws, holes, or cracks are observed inside the broken brick, it indicates that the brick is of poor quality.