Brick / Block Masonry

Bricks are small modular units of fired clay (or cement, fly ash) used for masonry walls, partitions, and infill. Indian Standards: IS 1077:1992 (common burnt clay bricks), IS 13311 (testing), IS 2212 (mortar for brickwork), IS 2185 (concrete masonry units). Standard Indian brick (modular): 190 × 90 × 90 mm (with 10 mm mortar joint = 200 × 100 × 100 mm); traditional brick: 230 × 115 × 75 mm. Brick classes by compressive strength: Class A (70 kg/cm² = 7 MPa), Class B (50 kg/cm²), Class C (30 kg/cm²) per IS 1077.

Brick types in Indian construction: (a) Common burnt clay (CBR) — most widely used; produced by firing molded clay at 1000-1200°C in kilns. (b) Fly ash brick (FAB) — IS 12894:2002; 10-20% lighter than CBR, higher compressive strength (10-15 MPa vs 7 MPa for Class A CBR), lower water absorption. Increasingly used for sustainable construction. (c) Concrete blocks — IS 2185 Part 1; 200 × 200 × 400 mm typical; lower fire resistance but faster construction. (d) AAC blocks — IS 6041 + IS 2185 Part 3; lightweight, thermally insulating; replacing brick in non-load-bearing applications.

Brick procurement: visual inspection, dimensional check, and 24-hour water absorption test (≤ 20% by mass per IS 1077). Sound brick rings on tapping; broken brick shows uniform colour throughout (over-burnt or under-burnt is brittle). Indian brick sources: small kilns concentrated in clay-rich regions (Uttar Pradesh, Bihar, West Bengal), supplying local markets. Recent Indian regulations against polluting kilns (CPCB orders 2020-2024) have shifted demand toward fly ash bricks and concrete blocks. The most-overlooked brick quality issue: under-burnt bricks (ring dull) absorb >20% water and crumble within 5-10 years; over-burnt bricks (rings hollow) are brittle and crack under load. Both must be rejected.