Soil-cement base course

Abstract

Scope of Study: Soil-cement was first used in road construction in the U.S.A. in 1935 and since then has been used on an increasing scale. The ways in which soil-cement may be used successfully is treated in this study. The structure and factors influencing the physical properties of soil-cement mixtures are discussed as well as sampling .and testing of the raw or natural soil and the interpretation of the test results in connection with the design of the mixtures. Construction methods and necessary equipment to accomplish the job are also discussed. Included in this study is a specification to help project engineers in the construction procedure, Materials used are mainly the results of research studies conducted by the Highway Research Board, Portland Cement Association, American Association of State Highway Officials, and American Road Builders' Association.

Findings and Conclusions: Soil type, cement content, compaction and method of mixing are the chief factors which affect the quality of soil-cement. Most soils with clay contents not exceeding about 30 per cent can be successfully processed while soils containing organic matter or deleterious chemicals are generally unsuitable. The moisture content of the processed soil affects both the uniformity of mixing and the compaction obtained. Good compaction is essential to obtain high quality soil-cement mixtures. Moisture content necessary for cement hydration and satisfactory compaction of the mixture are approximately the same and should not exceed.