Study on effect of laboratory roller compaction on unconfined compressive strength of lime treated soils

Abstract

Expansive soils are problematic due to their swell—shrinkage behavior and low compressive strength. They are modified generally with additives such as lime, fly ash, and various other inorganic and organic materials. Chemical stabilization treatments can improve expansive soil properties for its reuse in geotechnical applications. The present study investigates the properties of two types of subgrade soil treated with Lime and compacted by three different methods in the laboratory. The study is mainly focused to bring out the effect of different methods of compaction on the unconfined compressive strength of Lime treated soils and untreated soils. Laboratory investigation included pH, Atterberg limits, cation exchange capacity (CEC), compaction, unconfined compression strength (UCS), California Bearing Ratio (CBR), Scanning Electron Micrographs (SEM) and EDAX before and after lime treatment. Tests were performed on lime treated soils (2, 4, 6 and 8% of lime). The soil samples for unconfined compressive strength test were prepared by static, dynamic and roller compaction methods in the laboratory. Roller compaction was performed using indigenously fabricated Roller compactor cum Rutting Analyzer (RCRA). The results indicate that dry unit weight and UCS of roller compacted lime treated soil is lower than that of dynamic compacted soil. However, dry unit weight and UCS of lime treated roller compacted soil are closer to that of statically compacted soil. Cation exchange capacity of both soils before and after treatment with lime were examined, CEC reduced with increase in lime content.