LABORATORY STUDY ON BEHAVIOUR OF LIME STABILIZED EXPANSIVE SOILS FOR HIGHWAY PAVEMENTS

Abstract

The peculiar behaviour that is heavy swelling and shrinkage with variation in moisture content is the unique property of expansive soils. The construction of roads and embankments in expansive soils poses a lot of problems due to its unique behaviour. This type of behaviour of soil particles is due to the mineralogical composition, electrical properties, shapes and orientation of soil particles, the nature and properties of soil water and its ionic composition and the interaction forces betw-eon soil particles, soil water and their absorption complexes. Under the present investigation the optimum and economical value of lime is evaluated which is necessary for desired impro-vement in index properties and strength characterstics of expan-sive soils. The compaction test is per formed for the evaluation of maximum dry density and optimum moisture content with different percentages of lime mixed with expansive soils. The improvement in index properties is evaluated by using different percentages of lime to the soils. The triaxial tests are performed with different lime percentage and the variation in strength is evaluated for different proportions of lime con-tent. The strength parameter is evaluated by performing soaked and unsoaked CBR tests with different percentages of lime. The durability of lime soil mixes has been evaluated by freeze-thaw tests and the optimum proportion of lime has been determined. From the unconfined compressive tests for different percentages of lime change in compressive strength has been studied with the change of lime percentage. On the basis of strength characteristics of lime soil stabilized mixes established from the laboratory tests i.e. compressive strength, durability tests, C.B.R. value and tri. axial testa the suitability of expansive soils from Patna for pavement construction has been determined