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Show NEW IDEA IN ROAD BUILDING Cement Mixed With Certain Types of Soil to Alter Characteristics Being Tried. (Prenared by the United States Department of Agriculture.) Mixing cement with certain types of soil to alter the characteristics of the soils and make them more suitable for road surfacing and subgrades is an experiment ex-periment recently conducted by the bureau of public roads, United States Department of Agriculture, which is now proving its value in actual use. The treatment was first suggested and tried out at the Arlington experimental experi-mental station of the bureau. Results warranted a field test, and it was arranged ar-ranged with the California state highway high-way department te try it on the adobe soil there. A part of the federal-aid project in Solano county was selected for the test. The dry soil was well broken up and harrovd to a depth varying from G to 12 Inches and mixed with cement in the proportions of 1 part cement to 10 parts soil and 1 part cement to 20 parts soil. It was intended to water and roll the surface but rain prevented. One section was allowed to remain untreated for purposes of comparison. A recent Inspection showed that the untreated section was badly broken up, due to the usual shrinkage cracks characteristic of adobe soils. The treatment is not intended to make a hard surface like concrete, but to alter the properties of the soil so that it will be stable and lessen the effects of moisture. California plans to conduct additional addition-al experiments, which will be observed ob-served in detail by the bureau and cost data obtained. |