This specification covers gypsum, calcium sulfate combined with two molecules of water in crystalline form and
having the approximate chemical formula CaSO4·2H2O.
Physical Properties
Size—If necessary, gypsum shall be crushed or ground,
or both, to the size specified in the purchase order.
Sampling
Bulk—When gypsum is shipped in bulk, samples of
approximately 5 lb [2 kg] each shall be taken at regular
intervals during the complete loading or unloading of the
carrier, in such a way as to accumulate not less than 200 lb [90
kg] of material and to represent correctly the percentages of
both the coarse particles and the fines in the shipment. This
material shall be broken to pass a 1-in. [25.0-mm] sieve,
thoroughly mixed, and reduced by quartering to provide not
less than a 1-lb [0.5-kg] sample for the laboratory.
Packages—When gypsum is shipped in packages, not
less than 1 % of the packages shall be sampled. Samples shall
be taken from both the surface and the center of the packages.
These samples shall then be broken, mixed, and quartered in
accordance with
Laboratory Samples—Each laboratory sample shall be
placed immediately in an airtight container and shipped to the
laboratory for testing.
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