Reinforced Concrete: Mechanics and Elementary Design

Cover
McGraw-Hill Book Company, 1911 - 220 Seiten
 

Andere Ausgaben - Alle anzeigen

Häufige Begriffe und Wortgruppen

Beliebte Passagen

Seite 7 - Pats of neat cement about three inches in diameter, one-half inch thick at the center, and tapering to a thin edge, shall be kept in moist air for a period of twenty-four hours.
Seite 143 - When work is resumed, concrete previously placed should be roughened, thoroughly cleansed of foreign material and laitance, drenched and slushed with a mortar consisting of one part Portland cement and not more than two parts fine aggregate. The faces of concrete exposed to premature drying should be kept wet for a period of at least seven days.
Seite 7 - Another pat is kept in water maintained as near 70° F. as practicable, and observed at intervals for at least 28 days. (c) A third pat is exposed in any convenient way in an atmosphere of steam, above boiling water, in a loosely closed vessel for five hours. These pats, to satisfactorily pass the requirements, shall remain firm and hard and show no signs of distortion, checking, cracking, or disintegrating.
Seite 6 - 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 three per cent has been made subsequent to calcination.
Seite 138 - June 11, 1903, by the adoption of the following resolution: "It is the sense of this meeting that a Special Committee be appointed to take up the question of concrete and steel-concrete, and that such committee co-operate with the American Society for Testing Materials, and the American Railway Engineering and Maintenance of Way Association.
Seite 151 - The general effect of closely spaced hooping is greatly to increase the "toughness" of the column and its ultimate strength, but hooping has little effect on its behavior within the limit of elasticity. It thus renders the concrete a safer and more reliable material and should permit the use of a somewhat higher working stress. The beneficial effects of "toughening...
Seite 7 - SAND 7 days (1 day in moist air, 6 days in water) 150-200 " 28 days (1 day in moist air, 27 days in water) 200-300
Seite 6 - It shall leave by weight a residue of not more than 8 per cent on the No. 100, and not more than 25 per cent on the No. 200 sieve.
Seite 154 - Compression in Extreme Fiber. The extreme fiber stress of a beam, calculated on the assumption of a constant modulus of elasticity for concrete under working stresses, may be allowed to reach 32.5 per cent. of the compressive strength at 28 days, or 650 Ib. per sq. in. for 2000-Ib. concrete. Adjacent to the support of continuous beams, stresses 15 per cent. higher may be used.
Seite 7 - Mortars composed of one part Portland cement and three parts fine aggregate by weight when made into briquettes shall show a tensile strength of at least 70 per cent of the strength of 1 :3 mortar of the same consistency made with the same cement and standard Ottawa sand.

Bibliografische Informationen