Compressive strength and microstructure evolution of lime-treated silty soil subjected to kneading action

Abstract

Long-term improvement in behaviour of soil subjected to lime treatment depends on the mechanism of its implementation. In-situ lime-treated fine-grained soil is often subjected to ‘kneading action’ developed by Pad-foot roller. The mechanism underlying the effect of kneading on lime-treated soil remains less investigated. Unconfined Compressive Strength (UCS) and microstructural modification of the lime-treated soil subjected to kneading compaction are evaluated. Kneading action undergoes better lime-dispersion during compaction. This feature accompanied with available water favours the long-term pozzolanic-reactions and hence enhanced the UCS evolution, particularly in the kneaded soil compacted at Wet Moisture Content (WMC). Lime-treated kneaded soil compacted at WMC, which is slightly higher than the Optimum Moisture Content (OMC) is beneficial for enhanced UCS evolution in specimens subjected to longer and accelerated curing. The UCS evolution in the laboratory accelerated-cured kneaded soil is of a similar level as the average UCS measured in the in-situ 7 years atmospherically cured kneaded soil.