Bulletin - United States, Office of Public Roads, Issues 45-48

Front Cover
 

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 2 - ... inch in diameter. Gravel shall be of hard sound durable material equal in quality to that specified for broken stone. It shall be clean and of the sizes herein specified for broken stone. Class B concrete 59. Class B concrete shall be made of 1 part of cement, 2^ parts of sand and 5 parts of broken stone or gravel. Broken stone, gravel and sand for Class B concrete shall in all respects comply with the requirements specified for the same materials for Class A concrete. Class C concrete 60. Class...
Page 18 - The stiffness of oil-mixed concrete appears to be but little different from that of plain concrete. "(6) Elasticity. — Results of tests for permanent deformation indicate that no definite law is followed by oil-mixed concrete. "(7) Absorption. — Oil-mixed mortar and concrete containing 10 per cent, of oil have very little absorption, and under low pressures both are waterproof. "(8) Permeability. — Oil-mixed mortar containing 10 per cent, of oil is absolutely watertight under pressures as high...
Page 32 - Cement shall be delivered in sacks of 94 pounds net weight, and each sack shall be considered as having a volume of 1 cubic foot. Cement which contains lumps or has been damaged in any way by exposure to the weather or by other cause shall be rejected. Sand. The sand shall consist of dry, clean, sharp quartz grains, and shall not contain more than 5 per cent of clay, loam, or other foreign materials. The grains shall be well graded and of such size that all will pass a %-inch mesh screen, and not...
Page 3 - The blocks used had a cube of 33 tons each, and were composed of Portland cement, stone, and sand, in the proportions of 1 part of cement to 2 parts of sand and 3 parts of broken stones. After being made they were allowed to remain for three months to harden, and were then conveyed in waggons to the tip-head.
Page 3 - ... then to add water and mix to a mortar of the desired consistency. The required quantity of oil is then added to this mortar and mixed until it entirely disappears. The oil-mortar thus formed is then added to the previously moistened coarse aggregate and the mass is turned until thoroughly mixed. Ten per cent of oil based on the weight of cement in the mixture is all that is required to produce a concrete with very small water absorption and 5 per cent of oil is nearly as efficient. Roughly speaking,...
Page 32 - Not more than 75 per cent shall be retained on a 1% -inch mesh screen, and not more than 75 per cent shall pass such a screen. Mixing. The cement and sand shall first be thoroughly mixed dry in the proportions specified, on a proper mixing platform. Sufficient clean water shall then be admixed to produce a pasty mortar. To the mortar thus prepared shall be added the proper proportion of coarse aggregate previously drenched with water, and the whole shall be mixed until every particle of the coarse...
Page 32 - ... by machinery, the mixing shall be done in a batch mixer, approved by the engineer. If by hand, the sand and cement shall be first mixed dry in proper proportions until the mixture shows a uniform color; to the mixture thus prepared shall be added the proper proportion of broken rock which has been previously drenched with water, and the whole shall be mixed until every piece of the rock is coated with mortar. Sufficient water shall...
Page 27 - ... the United States Department of Agriculture made an exhibit of road models for the first time at the Alaska-Yukon-Pacific Exposition. The aim was to put on view such striking examples in miniature of model roads that visitors would not only appreciate the beneficent effects of improved highways^ but would, at the same time, be able to understand the methods of their construction. Since the Alaska- Yukon-Pacific Exposition closed the exhibit of the Office of Public Roads has been displayed at...
Page 10 - This road was treated with 0.5 gallon of heavy asphaltic oil in two applications of 0.25 gallon each. The average haul was two miles for the oil and two and one-half miles for the sand. No allowance is made in the detailed statement...
Page 2 - ... exposed. The acid solution should be left on not longer than half an hour, when it should be removed completely with clean water. The surface then should be brushed with a wire or stiff scrubbing brush to remove any particles of sand that may have become loosened because of the dissolving of the cement. To strengthen the bond it will be well to apply a wash of grout, made by mixing cement with water to the consistency of cream. All large holes or openings must be filled with cement mortar. A...

Bibliographic information