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.

摘要

石灰水泥稳定粘土已成功使用多年。然而，有限的已发表研究调查了两阶段石灰水泥稳定的不同熟化期对路基土的割线弹性和弹性模量的影响。两阶段稳定首先将土壤与石灰混合，使其成熟一段时间以改善土壤的可加工性并降低可塑性。水泥与处理过的土壤混合并压实以确保强度发展。研究了石灰水泥稳定化对中等塑性粘土的压实度、承载力、抗压强度、弹性模量和回弹模量的影响。E _{50的持续减少}对浸泡过的石灰水泥稳定试样进行了观察，其熟化期较长，熟化 24 小时的试样在外加载荷下吸收能量的能力最高。重复荷载三轴试验表明，两阶段稳定后，弹性模量显着提高，石灰处理后的土体软化将显着提高土体刚度。三参数回归模型表明两阶段稳定材料具有应变硬化特性。在加入水泥和压实之前将熟化期延长到 48 小时以上会降低抗压强度、弹性模量和回弹模量。