This standard outlines the specifications for burnt clay hollow bricks intended for use in walls and partitions, detailing their dimensions, physical characteristics, and performance standards. It is intended for producers, engineers, and inspectors to ensure that the bricks achieve the necessary strength, water absorption, dimensional accuracy, and resistance to efflorescence, thereby providing durable and thermally efficient masonry units suitable for construction across India.
Overview
This standard outlines the specifications for burnt clay hollow bricks intended for use in walls and partitions, detailing their dimensions, physical characteristics, and performance standards. It is intended for producers, engineers, and inspectors to ensure that the bricks achieve the necessary strength, water absorption, dimensional accuracy, and resistance to efflorescence, thereby providing durable and thermally efficient masonry units suitable for construction across India.
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Frequently Asked
The standard specifies nominal brick sizes such as 190x190x90 mm, 290x90x90 mm, and 290x140x90 mm. Dimensional tolerances are checked over a sample of 20 bricks with overall length, width, and height measurements required to fall within designated minimum and maximum limits to ensure uniformity. For instance, the total length for 20 bricks measuring 290 mm each must be between 5680 mm and 5920 mm. These tolerances promote consistent masonry work and reduce mortar usage.
Bricks are required to meet a minimum average crushing strength, typically not less than 35 N/mm² for first-class bricks. The crushing strength is calculated by dividing the maximum load sustained during testing by the cross-sectional area of the brick face under load. Testing involves bedding bricks in mortar and subjecting them to axial loads at a controlled rate. The average strength is computed from six specimens to represent the batch quality.
The water absorption test involves drying six brick samples at 110-115°C until they reach a constant weight, cooling them to ambient temperature, then soaking them fully in water at 27 ± 2°C for 24 hours. After soaking, bricks are surface-dried and weighed within three minutes. Water absorption percentage is calculated using the increase in mass relative to the dry mass. The average absorption for the six specimens must not exceed 20% by mass to ensure durability.
The standard applies to hollow bricks made from burnt clay specifically designed for walls and partitions. These bricks feature vertical perforations perpendicular to the bearing surface that run completely through the brick. The standard does not cover solid bricks or bricks with perforations oriented differently. It ensures bricks meet prescribed size, strength, and quality criteria for both load-bearing and non-load-bearing applications.
Each brick must carry the manufacturer's identification mark or initials to ensure traceability. Additionally, bricks may bear the Bureau of Indian Standards (BIS) Standard Mark, signifying compliance with the standard and quality assurance under BIS supervision. Use of the Standard Mark requires a license from BIS and assures ongoing inspection, testing, and conformity monitoring to uphold product quality.
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