Wet Compaction and Lime Stabilization to Mitigate Volume Change Potential of Swelling Clayey Soils

Abstract

In this study, the possibility of wet compaction method to reduce swelling potential of high plasticity (active) clayey soils has been investigated and compared with lime stabilization method. Swell (and shrink) potential tests were performed using an oedometer apparatus on sand-bentonite mixtures which were compacted immediately after mixing with water. Tests were then repeated on different samples of the same composition after allowing 3-day free swelling prior to compaction. This method of sample preparation is herein referred to as “wet compaction”. Additional tests conducted on lime stabilized samples with and without wet compaction enabled comparison of the wet compaction and lime stabilization methods. Test results showed that wet compaction reduces the swelling potential of sand-bentonite mixtures and can thus work as a mitigation technique to reduce swelling potential of high plasticity (active) soils. However, as expected, lime treatment was found to be superior, especially if the dose corresponded to or was higher than lime fixation point. In addition, the volumetric change of both untreated and treated samples after drying at 40°C in an oven (during drying, shrinkage deformations were measured) as well as the effect of cyclic wetting and drying on the unconfined compression strength (UCS) of lime-stabilized samples were investigated.