A dual-porosity SWRC model for lime-treated soils upon curing

The pore structure of lime-treated soils changes due to short-term particle flocculation and long- term pozzolanic reactions, which affect the soil-water retention curve (SWRC) and pore size distribution with curing time. In this study, an improved SWRC model was proposed for lime-treated soils, allowing the impact of pore structure evolution with curing time on water retention properties to be described by incorporating the proportions of macro-pores and micro-pores and the effect of curing time. Comparison between the experimental data and model prediction revealed the performance of the proposed model. In particular, the results show that the ratio of macro-pores decreases while the ratio of micro-pores increases during curing. The air entry values of both macro-pores and micro-pores increase and the subsequent slopes of SWRCs become steeper with curing time, indicating a reduction in pore diameter and more concentrated pore distribution of lime-treated soils due to the formation of cementitious compounds. The proposed model constitutes a useful tool for describing the water retention property of treated soil and further the hydraulic and mechanical behaviour.