مهندسی عمران شریف (Feb 2018)
THE INVESTIGATION OF THE EFFECTS OF LIME PROPERTIES AND THE MANNER OF COMBINATION ON STABILIZATION OF EXPANSIVE SOILS
Abstract
Expansive soils are generally found in many parts of the world, especially in arid and semi-arid areas. Because of the ability of volumetric changes in response to seasonal fluctuations of moisture content, these soils are known as a harmful phenomenon in geotechnical engineering. Such soils swell when the moisture content is increased and shrink when the moisture content is decreased. Consequently, expansive soils cause detrimental damage to the structures founded on them. Clay soil can be stabilized by the addition of small percentages, by weight, of lime, thereby enhancing many of the engineering properties of the soil and producing an improved construction material.In this study, in order to find an optimum percentage of the lime to stabilization of expansive soil, the expansive soil was stabilized with various amounts of dolomite quick lime. Next, in order to find the effective type of lime to reduce the swelling potential, the expansive soil was stabilized with two types of lime such as Dolomite lime and Calcite lime that are used as quick lime and hydrated lime. Finally, in the last step, the soil was stabilized with lime by different methods to find the best method of adding lime to the soil.The results show that the optimum percentage of adding lime is 3\% of the total weight of expansive soil. However, the results indicate that the use of calcite quick lime shows a lower free swell, but a higher swelling pressure than the use of dolomite quick lime. It is also expressed that stabilization of expansive soils with hydrated lime has higher free swell and lower swelling pressure, in comparison to the stabilization with quick lime. The experimental results also show that adding lime in the optimum moisture of soil is the most effective method of stabilization of expansive soil.
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