ABSTRACT
Lime-cement stabilisation of clayey soils has been successfully used for many years. However, limited published studies have investigated the influence of varying mellowing period for two-stage lime-cement stabilisation on the secant elastic and resilient moduli of subgrade soils. The two-stage stabilisation starts with mixing the soil with lime, allow it to mellow for a specific period to improve soil's workability and reduce plasticity. Cement is mixed with the treated soil and compacted to ensure strength development. The effects of lime-cement stabilisation on compaction, bearing capacity, compressive strength, elastic modulus, and resilient modulus of a medium plasticity clayey soil were investigated. A continuous reduction in the E50 of soaked lime-cement stabilised specimens was observed with longer mellowing periods specimens with 24 h mellowing showed the highest ability to absorb energy under the applied load. Repeated load triaxial test showed that the resilient moduli were significantly improved after the two stages stabilisation, and mellowing the lime treated soil will considerably enhance the soil stiffness. The three-parameter regression model showed that the two-stages stabilised materials have a strain hardening property. Increasing the mellowing period beyond 48 h, before adding cement and compaction will reduce in compressive strength, elastic modulus, and resilient modulus.
Acknowledgements
The authors wish to acknowledge the support of the Iraqi government. The support of Vicroads, the road authority in Victoria, by providing the natural soil for this research project is also gratefully acknowledged.
Disclosure statement
No potential conflict of interest was reported by the author(s).