Bulletin, Edição 4

Capa
The Survey, 1913

No interior do livro

Outras edições - Ver tudo

Palavras e frases frequentes

Passagens conhecidas

Página 260 - Significance. — The object of this test is to determine the time which elapses from the moment water is added until the paste ceases to be fluid and plastic (called the "initial set"), and also the time required for it to acquire a certain degree of hardness (called the "final
Página 252 - EXECUTIVE ORDER. It is hereby ordered that all Portland cement that may hereafter be purchased by any department, bureau, office, or independent establishment of the Government, or that may be used in construction work connected with any of the aforesaid branches of the Government service, shall conform in every respect to the specification for Portland cement adopted by the departmental conference at the meeting held at the Bureau of Standards on February 13, 1912, and approved by the heads of the...
Página 75 - This term is applied to the finely pulverized product resulting from the calcination to incipient fusion of an intimate mixture of properly proportioned argillaceous and calcareous materials, and to which no addition greater than 3 per cent has been made subsequent to calcination.
Página 89 - ... consequently about 700 pounds of such a mixture would be required to make one barrel of finished cement. With marls the loss on drying and burning is much greater. Russell states...
Página 260 - ... centering, tend to lower the breaking strength. The load should not be applied too suddenly, as it may produce vibration, the shock from which often breaks the briquette before the ultimate strength is reached.
Página 77 - In a paper read before the Association of Portland Cement Manufacturers, at Atlantic City, NJ, June 15, 1904, Dr.
Página 260 - Tensile tests.— -Consistent results can only be obtained by exercising great care in molding and testing the briquets. The correct method of filling the mold [is illustrated in the circular]. In testing, the sides of the briquet and the clips should be thoroughly cleaned and free from grains of sand or dirt, which would prevent a good bearing, and the briquet should be carefully centered in the clips so as to avoid cross strains. It may be considered good laboratory practice if the individual briquets...
Página 75 - By a Portland cement is meant the product obtained from the heating or calcining up to incipient fusion of intimate mixtures, either natural or artificial, of argillaceous with calcareous substances, the calcined product to contain at least 1.7 times as much of lime, by weight, as of the materials which give the lime its...
Página 254 - The right is reserved to reject any cement which has not established itself as a high-grade Portland cement and has not been made by the same mill for two years and given satisfaction in use for at least one year under climatic and other conditions at least equal in severity to those of the work proposed. Packages. — 12. The cement shall be delivered in sacks, barrels, or other suitable packages (to be specified by the engineer), and shall be dry and free from lumps. Each package shall be plainly...
Página 76 - Portland cement is an artificial product obtained by finely pulverizing the clinker produced by burning to semi-fusion an intimate mixture of finely ground calcareous and argillaceous material, this mixture consisting approximately of one part of silica and alumina to three parts of carbonate of lime (or an equivalent amount of lime oxide.) Composition and Constitution.

Informação bibliográfica