Classification and Characteristics of Bricks as per IS 1077-197
Tests to determine the suitability of bricks for construction purposes typically include dimension and tolerance testing, compressive strength testing, water absorption testing, and efflorescence testing.
Dimension and tolerance testing involves checking the size and shape of bricks, as well as ensuring that they fall within acceptable tolerances specified by construction standards. This helps ensure that the bricks will fit together properly during construction and result in a structurally sound wall.
Compressive strength testing is conducted to determine the load-bearing capacity of bricks. This test involves applying a compressive force to a brick until it fails or cracks, and measuring the maximum force it can withstand. This helps assess the strength and durability of bricks, which is important for ensuring the stability and longevity of a building.
Water absorption testing is performed to determine the porosity of bricks, or their ability to absorb water. This test involves measuring the weight of a dry brick, soaking it in water, and then measuring its weight after a specified period of time. This helps assess the brick’s resistance to moisture and potential for water damage, which is important for preventing issues such as dampness or efflorescence in a building.
Efflorescence testing involves assessing the presence of salts on the surface of bricks. This test typically involves exposing bricks to moisture and then examining them for any visible signs of salt deposits. This helps determine the brick’s resistance to efflorescence, which is a white powdery deposit that can form on the surface of bricks and affect their appearance and durability.
Overall, these tests are crucial in evaluating the quality and suitability of bricks for building construction, ensuring that they meet the necessary standards for structural integrity, durability, and resistance to moisture-related issues.
1. Dimension and Tolerance Test on Bricks
To obtain 20 bricks from the available sample, it is important to ensure that the dimensions of these bricks fall within the specified limits. These limits have been predefined and must be adhered to in order to select the appropriate bricks. The dimensions of the 20 bricks should be carefully checked to ensure they meet the requirements set forth in the given guidelines. It is crucial to accurately measure and select the bricks that fall within the specified limits to ensure that they are suitable for the intended purpose. By carefully adhering to the provided dimensions, 20 bricks can be accurately chosen from the available sample.
| Class | Length | Width | Height |
| Class A | 380 +/- 12mm i.e. 368 to 392 mm | 180 +/- 6mm, i.e. 174 to 186 mm | 174 to 186 mm |
| Class B | 380 +/- 30mm, i.e. 350 t0 410 mm | 80 +/- 15mm, i.e. 165 to 195 mm | 165 to 95 mm |
2. Compressive Strength Test on Bricks
The compressive strength of a common brick is typically measured as 50 kg per square centimeter. This measurement reflects the ability of the brick to withstand compressive forces without breaking or crumbling. Compressive strength is an important property of bricks, as it determines their durability and suitability for various construction applications. Bricks with higher compressive strength are generally preferred for load-bearing structures, such as walls and columns, as they are capable of withstanding heavier loads without deformation. Conversely, bricks with lower compressive strength may be used for non-load-bearing applications, such as partition walls or decorative purposes. The compressive strength of bricks is typically tested in a controlled laboratory environment, following standardized procedures, to ensure accurate and consistent results.
3. Water Absorption Test on Bricks
The strength of a brick is inversely proportional to its water absorption capacity. If a brick has a higher water absorption capacity, its strength will be comparatively lower. For first class bricks, it is recommended that the water absorption capacity should not exceed 20% of its weight.
4. Efflorescence Test on Bricks
The test for alkaline matter in bricks involves the following procedure:
- Randomly select five bricks from the sample.
- Place each brick upright in a dish containing distilled water, ensuring that the brick is submerged to a depth of at least 2.5 cm.
- Keep the dish in a well-ventilated room with a temperature ranging from 20°C to 30°C.
- Allow the distilled water in the dish to evaporate completely.
- Once the water has evaporated, pour another 2.5 cm depth of distilled water into the dish and allow it to evaporate as well.
- Finally, examine the bricks for efflorescence, which is the presence of white deposits on the surface of the bricks.
| OBSERVATION | RESULT |
| No perceptible deposit | Nil – efflorescence |
| 10% are covered with deposit of salts | Slight – efflorescence |
| 50% area covered with deposits of salts without any powdering or flaking surface | Moderate – efflorescence |
| 50 % area covered with deposit of salts accompanied by flaking of surface | Heavy – efflorescence |
| Heavy deposits of salts accompanied by flaking of the surface | Serious – efflorescence |
Terra Cotta is a type of baked earth material that is made from a mixture of fine clay, crushed pottery, sand, powdered glass, and a desired coloring substance. The composition typically consists of 60% fine clay, 20% crushed pottery, 14% sand, and 6% powdered glass. This unique combination of materials results in a superior variety of clay that is highly durable and ideal for architectural and ornamental purposes in high-quality buildings, serving as a substitute for stones.
One of the key properties of Terra Cotta is its ability to act as a soundproofing material. Its dense composition helps to reduce noise transmission, making it a popular choice for applications where sound insulation is important. Additionally, Terra Cotta’s hollow blocks can help prevent dampness in the structure, making it an ideal material for areas where moisture may be a concern.
Terra Cotta has a wide range of uses in construction and design due to its versatility and aesthetic appeal. It is commonly used for architectural elements such as facades, cornices, and decorative moldings, as well as for ornamental details on buildings. Its natural earthy color and texture can add a touch of warmth and elegance to any structure.
In summary, Terra Cotta is a superior variety of clay that is made from a carefully formulated mixture of fine clay, crushed pottery, sand, powdered glass, and coloring substances. Its unique properties, including its durability, soundproofing capabilities, and resistance to dampness, make it a popular choice for architectural and ornamental applications in superior buildings. Its versatility and aesthetic appeal make it a favored material among designers and builders for its ability to add warmth and elegance to structures.