![]() ![]() Gypsum plaster is mixed with clean water in recommended proportion at site to make a consistent slurry. ![]() sum of soluble sodium and magnesium salts expressed as percentages of sodium oxide (Na2O) and Magnesium oxide (MgO) by mass.Ībove tests are conducted at regular intervals for all Saint Gobain Gyproc Plasters by authorised third party agencies. ![]() Part II deals with Gypsum Plaster containing premixed “lightweight aggregates” and necessarily complying to IS: 2547 (Part 1).Ī. This method covers the tests determining Normal consistency (%), setting time (minutes), compressive strength (N/mm2), transverse strength (N/mm2), soundness, expansion (%), freedom from coarse particles (residue on 150micron mesh) & bulk density (kg/M3). Part I deals with all Gypsum Plasters with or without “light weight aggregates”. Gypsum Plasters are tested on the basis of their physical and chemical properties. Gypsum Plasters in India is governed and adopted by Indian Standards Institution (IS:2547), drafted by Gypsum Building Materials sectional committee and finalized by the Civil Engineering Division Council. Gypsum plaster sets and hardens by chemical recombination of the gypsum with water to provide a levelled surface that is ready for painting. This plaster is suitable for plastering and is commercially called Gypsum plaster. Gypsum plaster is formed when stucco or POP is mixed with special retarders and special additives to enhance its performance in terms of setting time, finish and coverage. Because of this fast setting the Plaster of Paris (POP) has very high wastage and tends to develop shrinkage cracks and hence is not suitable for use in plastering. This product typically has a very fast setting time of between 3 minutes and 6 minutes. This is commonly referred to as Plaster of Paris (POP) or Stucco. This process converts the dihydrate gypsum into a hemi-hydrate (CaSO4.1⁄2H2O) with three quarters of the water removed. Gypsum rock is converted into gypsum plaster by heating it at a temperature between 120☌ and 160☌ for a period of time to drive off some of the chemically combined water. ![]()
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