Products in Fibre Reinforced Cement - Long Corrugated or Asymmetrical Section Sheets and Fittings for Roofing and Cladding
2000 الطبعة

Per the standard and corresponding tables, minimum breaking load values differ according to sheet category and class, which are determined based on thickness and corrugation height. For instance, Category A sheets with corrugation heights between 15 and 55 mm require minimum breaking loads ranging from 600 to 1400 N/m depending on class. Categories B, C, and D specify higher minimum breaking loads correlating with increased thickness and load classes, commonly with Category B and C sheets at Class 7 requiring at least 3300 N/m. Testing follows detailed procedures to verify these load capacities.

Dimensional tolerances are specified with precise limits for length, overall width, effective width, corrugation height, and thickness. Corrugation height tolerances vary by height range, such as ±2 mm for 15 to 45 mm height, and asymmetrical tolerances for larger heights. Measurements involve laying sheets flat on a surface with valleys touching, taking multiple readings at specified points along length and width, and averaging measurements of corrugation height across selected corrugations. Effective width is measured by overlapping two sheets and assessing the overlap distance at edges. This methodology ensures compliance with the standard's dimensional accuracy.

The frost resistance evaluation involves subjecting samples conditioned for seven days in laboratory atmosphere to 25 freeze-thaw cycles. Each cycle includes cooling to approximately -20°C and thawing at ambient temperature, with specimens arranged to allow free circulation of air and water. Post-testing, samples are inspected visually for cracks, delamination, or other defects that could impair performance. For fittings, smaller specimens undergo identical cycling. Passing this test ensures the product maintains integrity under freezing conditions as per the standard.

The standard permits inorganic hydraulic binders including Ordinary Portland Cement grades 33, 43, and 53 (referencing appropriate IS codes), Portland Pozzolana Cement with fly ash or calcined clay bases, Rapid Hardening Cement, and Portland Slag Cement. Fly ash used must conform to relevant specifications. Importantly, no additional pozzolanic or slag materials are to be added beyond those contained within these cements. Pigments compatible with fibre cement may be incorporated. This ensures the products meet durability and compatibility requirements.

Each sheet and fitting must bear a permanent marking that includes the manufacturer's identification, manufacturing date, product type, category, class, size, and thickness. If the product is frost resistant, the inscription "FROST RESISTANT" must be included. Optionally, products may carry the BIS Standard Mark in compliance with regulatory guidelines. These markings facilitate traceability, quality assurance, and proper application of the products.