Portland cement

Front Cover
Offices of the Stone Trades Journal, 1904 - Portland cement - 138 pages
0 Reviews
 

What people are saying - Write a review

We haven't found any reviews in the usual places.

Other editions - View all

Common terms and phrases

Popular passages

Page 69 - From what has been stated above it will be seen that the sensory cells of the eye belong to a somewhat different category from those of the other sense organs.
Page 130 - That it is resolved that all government contracts should contain such conditions as will prevent abuses which may arise from the subletting of such contracts, and that every effort should be made to secure the payment of such wages as are generally accepted as current in each trade for competent workmen in the district where the work is carried out...
Page 120 - Gravity: The specific gravity of the cement shall be at least 3.09, and shall not exceed 3.25 for fresh cement; the term "fresh" being understood to apply to such cements as are not more than two months old. (3) Tests: The cement shall be subjected to the following tests: (a) Blowing...
Page 94 - Ibs. is indicated on the dial.) When in this position there should be about half an inch between the under side of knife edge H, and the buffer or recoil spring I. Having seen that the pinion K is in gear with the wheel L, turn the handle M until the briquette breaks. The loose pointer will show on the dial the strain in Ibs. at which the briquette broke. To RETURN TO ZERO. — Throw the pinion K out of gear with the wheel L by...
Page 41 - ... Intermittent kilns 15 to 30 barrels. Continuous shaft kilns 40 to 80 Rotary kilns 120 to 150 " While the rotary kiln is wasteful of fuel, it shows a great saving in labor and a marked increase in daily capacity, and by further improvements the cost cf fuel will be decreased. Temperature of Burning. — The proper degree of burning is indicated by the formation of a dense greenish-black clinker. Underburned clinker is brownish and soft, while the overburned clinker is fused and slag-like. Long...
Page 119 - The whole of the cement is to be well-burned pure Portland cement, of the best quality, free from free-lime, slag, dust, or other foreign material. (1) Fineness : The cement shall be ground so fine that residue on a sieve of 10,000 meshes to the square inch...
Page 60 - Before this ie quite completed the vessel may be corked, and the contents shaken to remove any small air-bubbles that may be entangled in the cement. The height of the column of liquid remaining in the pipette determines the specific gravity, which can be at once read off on the graduated stem. It is manifest that the denser the substance operated upon, the less liquid will be displaced in the smaller vessel, and therefore the less will remain in the pipette, and vice versa. In reading the accompanying...
Page 120 - ... added, when the briquettes are to be formed in suitable moulds. After remaining in a damp chamber for 24 hours, the briquettes shall be immersed in water, and briquettes made in the proportion of one of cement to three of sand by weight, shall bear a tensib stress of 125 Ib.
Page 131 - The cement, when tested with sand, is to be gauged with three times its weight of dry sand, which has passed through a sieve of 400, and been retained upon one of 900 meshes to the square inch. The cement and sand having been well mixed dry, about 10 per cent, of their weight of water is to be added, and briquettes formed in moulds of one inch sectional area at the weakest parts.
Page 95 - The loose pointer will show on the dial the strain in pounds at which the briquette broke. To Return to Zero. — Throw the pinion K out of gear with the wheel L by removing the pin and pushing it to the left ; turn the wheel L from left to right until the quadrant A has returned to its normal position, with the chain B. slack ; put the loose pointer back to zero ; release the...

Bibliographic information