The IS 8272:1984 standard defines the specifications and testing procedures for gypsum plaster utilized in producing fibrous plaster boards. It establishes criteria including setting time, compressive strength, fineness, permissible impurities, and packaging to guarantee product consistency and quality for manufacturers and end-users in dry construction environments.
Overview
The IS 8272:1984 standard defines the specifications and testing procedures for gypsum plaster utilized in producing fibrous plaster boards. It establishes criteria including setting time, compressive strength, fineness, permissible impurities, and packaging to guarantee product consistency and quality for manufacturers and end-users in dry construction environments.
Audience
Contents
Structure
Frequently Asked
Per IS 8272, the initial setting time for gypsum plaster should range from 20 to 35 minutes, measured from the moment water and plaster are mixed until an incision in the plaster remains fully open. This test ensures the plaster achieves proper workability and hardening suitable for construction applications, with timing determined by repeated incisions at one-minute intervals until stiffening occurs.
IS 8272 outlines that compressive strength testing involves preparing standard cubic specimens from homogenized plaster samples. These specimens are cured and then subjected to compression until failure occurs, with the strength calculated by dividing the maximum load by the specimen's cross-sectional area. Testing is performed on multiple specimens, averaging results while discarding outliers differing by more than ±15% from the mean to ensure accuracy.
The standard permits up to 10% by mass of impurities insoluble in ammonium acetate, determined by treating the plaster sample with ammonium acetate solution, filtering, drying, and weighing the residue (Appendix A). Chloride content, expressed as sodium chloride, must not exceed 0.2% by mass, measured via a titrimetric method using silver nitrate solution as detailed in Appendix B. These controls maintain the plaster’s quality and suitability for manufacture.
According to IS 8272, gypsum plaster should be packaged dry and free from lumps in moisture-proof bags or containers. Each package must be clearly marked with the manufacturer's name, plaster classification, and manufacturing date. Prior to sampling for quality tests, contents should be homogenized, and samples stored in clean, dry, airtight containers to preserve integrity for laboratory evaluation.
The standard testing consistency is established by mixing gypsum plaster with water and placing the mixture in a ring mould with an internal diameter of 35 mm and height of 50 mm. The spread diameter of the mixture is measured after lifting the mould, and the average of the maximum and minimum spreads must fall within 100 ± 3 mm. The water volume required per 100 g of plaster to achieve this spread defines the standard consistency, ensuring uniformity in subsequent testing.
Ask AI about any clause, requirement, or provision in IS 8272. Get instant, clause-cited responses powered by our indexed library.
Free tier includes 150 queries (50 AI + 100 Reference) · No credit card required