Precast Reinforced Concrete Door and Window Frames
1983 Edition

The standard specifies that single shutter doors should have cross-sectional dimensions of either 60 mm by 100 mm or 70 mm by 75 mm, while double shutter doors should measure 60 mm by 120 mm. Overall frame width is measured as the total horizontal length from outer edge to outer edge, and height is taken from the bottom of the lowest vertical member (for three-piece frames) or the outer edge of the lower horizontal member (for four-piece frames) up to the top horizontal edge. Modifications to cross-section shape are permitted, such as grooves for plastering, provided the overall size remains unchanged. Reinforcement includes 3 mm diameter mild steel wire ties spaced at 300 mm centers, 6 mm diameter mild steel bars, and holdfasts consisting of 10 mm diameter bolts or rods embedded and bent post-casting.

Materials should comply with relevant Indian Standards including Ordinary Portland Cement (IS 269, IS 8112), Portland Slag Cement (IS 455), Portland Pozzolana Cement (IS 1489), rapid-hardening Portland cement, and high-strength OPC. Aggregates must conform to IS 383 standards for coarse and fine aggregates. The concrete mix should be designed to achieve at least M20 grade strength, dense compaction, and a surface free from visible coarse aggregate and voids, as per IS 456 and IS 516. Reinforcement steel should meet IS 432 (Part I), IS 1786, and IS 1139 requirements.

Longitudinal reinforcement bars, typically 6 mm diameter mild steel, should be continuous and embedded in both vertical and horizontal members. These bars must be tied securely using 3 mm diameter mild steel wire at intervals not exceeding 300 mm center-to-center. Holdfasts for anchoring frames to masonry consist of 10 mm diameter bolts or rods embedded in concrete and bent after casting. Additionally, mild steel flats measuring 30 mm by 5 mm by 70 mm are embedded for fixture attachments. Proper alignment and support are essential during casting and curing to maintain plumb and level frame members.

Hinges can be affixed by welding them to mild steel flat plates (30 mm by 5 mm by 70 mm) embedded within the reinforced concrete frame, with gas welding being the recommended technique. Alternatively, L-type flap hinges may be bolted directly to the RCC frame using 6 mm mild steel bolts. Other purchaser-approved methods may also be utilized, provided they ensure secure and durable attachment. The standard mandates suitable arrangements for hinge fixing, and manufacturers may supply frames with hinges pre-fixed if required.

Yes, the standard incorporates optional provisions under the ECO Mark scheme managed by the Bureau of Indian Standards. While the ECO Mark is voluntary, products must meet additional environmental criteria beyond the ISI Mark to qualify. Eligible products may display a combined ISI and ECO Mark symbol. Requirements include making the frames from reinforced cement concrete, obtaining relevant environmental clearances, and providing documentation to BIS. This promotes sustainable building practices by encouraging the use of durable and environmentally conscious materials.