The contribution of microstructural investigation to the study of lime-treated soils

It is widely known that lime treatment of clayey soils enhances mechanical and hydraulic characteristics of soils. In soil-lime systems, this improvement is due to a sequence of chemical processes that results in reaction products detectable at meso- and micro-scale. Therefore the contribution of experimental techniques such as Scanning Electron Microscopy, Energy Dispersive X-ray Spectroscopy and Mercury Intrusion Porosimetry turns out to be essential to analyze the results of geotechnical tests and to understand the behaviour of soil-lime mixtures. After a brief review of literature on the microstructure of lime stabilized soil, the paper presents the results of research studies carried out on clayey soils treated with lime by means of the previous cited techniques.