STABILIZATION OF BLACK COTTON SOIL WITH LIME AND STONE DUST

Abstract

Ankur Mudgal: Geotechnical Engineering, DTU Page | 18 ABSTRACT Black cotton soil have the tendency to swell when their moisture content is increased and shrink when their moisture content is decreased. The moisture may come from rain flooding, leaking water or sewer lines or from reduction in surface evapotranspiration when an area is covered by a building or pavement. To achieve the economy and for proper performance of structures it is necessary to improve the geotechnical properties of expansive soil. Due to the for construction purpose, rubble and aggregates are high demanded rubble quarries and aggregate crushers are very common. Out of the different quarry wastes, quarry dust is one, which is produced in abundance. About 20–25% of the total production in each crusher unit is left out as the waste material-stone dust. Bulk utilization of this waste material is possible through geotechnical applications like embankments, back-fill material, sub-base material and the like. Lime treatment of soils is a proven method to save time and money on construction projects. Lime drying of wet soils minimizes weather-related construction delays and permits the return to work within hours. Lime modification chemically transforms clay soils into friable, workable, compactable material. Lime stabilization creates long-term chemical changes in unstable clay soils. For our project work we collected Black cotton soil sample from shivpuri (M.P). About 125 Kg soil sample was brought by us to soil mechanics lab for carrying out our project work. In this project the results of an experimental program undertaken to investigate the effect of stone dust & lime combined at different percentage with expansive soil, the test results such as X-ray diffraction analysis, scanning electronic microscopic, index properties, Proctors compaction, differential free swelling test and unconfined compression strength, California bearing ratio obtained on expansive clays mixed at different proportions of lime and stone dust admixture are presented and discussed. From the results, it is observed that at optimum percentages, i.e., 6% lime +25 % stone dust , it is found that the swelling of expansive clay is almost controlled and also noticed that there is a marked improvement in the other properties of soil. The conclusion drawn from this investigation is that the combination of equal proportion of stone dust and lime is more effective than the addition of stone dust/lime alone to the expansive soil in controlling the swelling behavior