Shrinkage behaviour of a compacted lime-treated clay

Shrinkage of expansive soils may cause serious problems to geotechnical and geo-environmental structures. In this study, the shrinkage behaviour of compacted clay treated with 4% lime was investigated. The samples of compacted clay without lime treatment were also tested for comparison. Besides, changes in the microstructure were analysed by mercury intrusion porosimetry tests on both treated and untreated samples. The results showed that the shrinkage curve of untreated sample is close and almost parallel to the saturation line, prior to approaching the compacted shrinkage limit (shrinkage limit for compacted soils). By contrast, the shrinkage curve of lime-treated soil is located leftwards and exhibits a higher compacted shrinkage limit, evidencing a clear microstructure effect. Further analysis showed that large aggregates with large pores are formed by lime treatment and these large pores play an important role in the shrinkage behaviour of soils. In addition, the curing time effect seems to be insignificant on the shrinkage behaviour of lime-treated soil.