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The Pamphlet Collection of Sir Robert Stout: Volume 73

Sand Tests

Sand Tests.

From a Manufacturer's standpoint this form of testing is inadmissible since in this country a "Standard Sand" is not obtainable.

From an Engineer's point of view it does not seem a desirable test.

Mr. Faija, M. Inst. C.E., and an eminent authority on cement, in a paper prepared for the "International Engineering Congress" of the Columbian Exposition, 1893, writes:

page 12

"The sand test consists in gauging the cement with 3 parts of sand, [unclear: which] should be of approved quality sifted to a certain size and properly washed [unclear: and] cleansed, but the difficulties of carrying out this test are many. Variations [unclear: in] the form of hardness of the grain of sand materially affect the result of [unclear: this] test, and the difficulties of the manipulation and of making solid [unclear: briquette] render it an altogether undesirable test to adopt—irrespective of which [unclear: the] test is a long one. The briquettes not being tested for 28 days after [unclear: gauging] and it is needless to say that in very many cases it would be impossible [unclear: t] wait that length of time to know the value of the material which it is [unclear: required] to use. In the author's opinion cement should be tested by itself, not [unclear: only] because the manipulation is considerably simpler, but because it is unwise [unclear: to] introduce into a test extraneous matters and complications which are [unclear: in] themselves open to considerable variations. If it is desired to ascertain [unclear: the] strength of a mortar compounded with any particular cement, then let [unclear: the] cement be gauged with those aggregates and sand which are to be used on [unclear: the] work; by this means some definite information may be obtained as to [unclear: the] strength and binding power of the mortar which is to be used; but to test [unclear: a] cement with what it is pleased to call a normal or standard sand, [unclear: gives] practically no information in this direction, and simply tends to [unclear: complicate] and confuse an otherwise simple test."