Impact of initial state on the fabric and permeability of a lime-treated silt under long-term leaching

Abstract

The long-term performance of lime-treated soil is still in question, especially in the case of the use of such soils to build earthen structures in permanent contact with water (i.e., dams, river levees, etc.) Indeed, water circulation may induce significant alteration of the improvements brought by the lime treatment. In this context, the main objective of this work is to study the long-term behaviour (durability) of lime-treated soils submitted to water circulation as well as to determine the most favourable initial soil compaction in terms of lime-treated soil durability. First, the impact of lime addition on soil microstructure is investigated with mercury intrusion porosimetry tests. This was done to highlight the effect of curing time, lime dosage, and compaction on soil initial permeability, a critical parameter in terms of long-term behaviour of the lime-treated soil. Then, lime-treated soil samples were submitted to an accelerated circulation of water over a period of 150 days. The obtained results show that soil permeability did not fluctuate with circulation time. This has been confirmed by the results obtained on the samples’ microstructure that remained stable throughout the experiments.