Manual of Reinforced Concrete

Front Cover
Constable, 1916 - 475 pages
 

Other editions - View all

Common terms and phrases

Popular passages

Page 1 - Portland cement is the product obtained by finely pulverizing clinker produced by calcining to incipient fusion an intimate and properly proportioned mixture of argillaceous and calcareous materials, with no additions subsequent to calcination excepting water and calcined or uncalcined gypsum.
Page 1 - The cement shall be manufactured by intimately mixing together calcareous and argillaceous and/or other silica, alumina or iron oxide bearing materials, burning them at a clinkering temperature and grinding the resulting clinker so as to produce a cement capable of complying with this specification.
Page 26 - Material which, subsequent to the above tests at the mills, and its acceptance there, develops weak spots, brittleness, cracks, or other imperfections, or is found to have injurious defects, will be rejected at the shop and shall be replaced by the manufacturer at his own cost.
Page 25 - At least one tensile and one bending test shall be made from each melt of steel as rolled. In case steel differing | in.
Page 65 - The cement shall be stored in such a manner as to permit easy access for proper inspection and identification of each shipment. 5. Every facility shall be provided by the contractor and a period of at least twelve days allowed for the inspection and necessary tests.
Page 7 - Fineness. — Only the extremely fine powder of cement called flour possesses appreciable cementing qualities and the coarser particles are practically inert. No sieve is fine enough to determine the flour in a cement, nor is there any other means of accurately and practically measuring the flour. Some cements grind easier than others, thus, although a larger percentage of one cement may pass the...
Page 25 - Chemical determinations of the percentages of carbon, phosphorus, sulphur and manganese shall be made by the manufacturer from a test ingot taken at the time of the pouring of each melt of steel, and a correct copy of such analysis shall be furnished to the engineer or his inspector. Check...
Page 3 - ... sound and satisfactory cement does not necessarily result from the above composition. It is probable that further investigation will give a clearer understanding of the constitution of Portland cement, but at present chemical analysis furnishes but little indication of the quality of the material. . Defective cement usually results from imperfect manufacture, not from faulty composition. Cement made from very finely ground material, thoroughly mixed and properly burned, may be perfectly sound...
Page 3 - ... from individual mills, but will furnish little or no indication of the quality of the material. Occasional analysis should, however, be made for record and to determine the quantity of sulphuric anhydride and magnesia present. The ground clinker as it comes from the mill is usually quick setting which requires correction. This is usually accomplished by the addition of a small quantity of more or less hydrated calcium sulphate either gypsum or plaster of Paris. Experience and practice have shown...
Page 7 - ... a smaller percentage of actual flour due to the difference in the hardness and the character of the clinker and the method used in grinding. Thus the cementing value of different cements can not be compared directly upon their apparent fineness through a 200-mesh sieve. With cement from the same mill, with similar clinker and grinding machinery, however, it is probable that the greater the percentage which passes the 200-mesh sieve the greater the percentage of flour in that particular cement.

Bibliographic information