United States Congressional serial set Volume 3217

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1895 Excerpt: ... and, as used in the work, at least 85 per cent of it must pass by its largest dimension a 2i-inch ring, and of the remaining 15 per cent no pieces shall have a larger dimension than 'A± inches. In hauling stone, sand, and cement upon the work the soil foundation shall be properly planked and protected from injury, and no materials will bedumped except on a proper plauking. Concrete.--The concrete shall be composed of the above materials, manipulated as follows: The mortar shall be composed of cement and sand in the proportion of 300 pounds of cement and 2 barrels of loose sand, thoroughly mixed dry, and a sufficient quantity of water added afterward to form as stiff a paste as it is practicable to work, the proportions given being intended to form a mortar in which every particle of sand shall he enveloped by cement, and this result, must be obtained to the satisfaction of the Engineer Commissioner and under his direction. Facilities shall be given the Engineer Commissioner and his representatives for weighing and measuring the;ement and sand, and they shall also be allowed to take such samples of materials as they may think necessary. Specifications For Roadway Pavements. STANDARD ASPHALT PAVEMENT ON CONCRETE BASE. To the mortar made as above tlie specified broken stone shall be added in such proportions that the resulting concrete shall contain, for every 300 pounds of cement and 2 barrels of loose dry sand, such a proportion of broken stone as to give a slight "surplus of mortar when rammed. This proportion, shall be regulated by the Engineer Commissioner or his representatives. The stone shall be thoroughly cleaned from dust and foreign substances and sprinkled before it is added to the mortar. Any material which would pass a No. 10 screen wi...