IS 2222:1991 is the Indian Standard (BIS) for burnt clay perforated building bricks. This standard lays down the specifications for dimensions, quality requirements, and testing of burnt clay perforated building bricks. It covers parameters like compressive strength, water absorption, efflorescence, and the specific geometry of perforations to ensure structural adequacy and thermal efficiency.
Specification for burnt clay perforated building bricks
| Parameter | IS Value | International | Source |
|---|---|---|---|
| Compressive Strength (Typical Class) | Class 10: Average strength ≥ 10.0 N/mm² | Declared mean compressive strength (e.g., 10 N/mm²). Not based on predefined classes. | BS EN 771-1 |
| Water Absorption (24h Cold Soak) | ≤ 20% by weight | No absolute limit specified; manufacturer must declare the value for design consideration. | BS EN 771-1 |
| Perforation Area | 15% to 50% of the gross area | Defined as a 'Hollow Brick' if voids are > 25% of the gross area. | ASTM C652 |
| Minimum Shell Thickness | 15 mm | Grade SW: 19 mm (3/4 in); Grade MW: 13 mm (1/2 in) for cells > 6.5 cm² (1 in²). | ASTM C652 |
| Efflorescence Test | Visual rating: 'Slight' or 'Moderate' acceptable | Categorized by soluble salt content (e.g., S1, S2), a quantitative measurement. | BS EN 771-1 |
| Dimensional Tolerance (on 190 mm length) | ± 6 mm | Tolerance Category 'Tm' (mean deviation from work size): ±2.5 mm for a 190mm brick. | BS EN 771-1 |
| Warpage | Maximum 3% of length (e.g., 5.7 mm on a 190 mm brick) | Type HBX: Max 1.6 mm (1/16 in.) on a nominal 200 mm (8 in.) brick. | ASTM C652 |