ABSTRACT

For road construction on sulfate (saline) soil, whether cement stabilisation could be effectively used must be determined. This study improves understanding of strength reduction characteristics for cement-stabilised sulfate soil subjected to variations in water content, cement content, and curing time. A series of laboratory tests to examine soil properties and compressive strength characteristics of soil-cement mixtures in conjunction with microstructural observations were performed. The compaction curves of cement-stabilised sulfate bearing clay and cement-stabilised high plasticity clay (a benchmark material) were established as nearly identical. This indicated minor effects of sulfate on the compaction characteristics of soil. The experimental results also showed that the rate of compressive strength loss escalated with an increase in cement content and curing time. While producing test samples through the compaction process, a series of unconfined compressive strength (UCS) tests on both materials exhibited a bell-like relationship with a peak at the optimum moisture content (OMC). The UCS of both study materials while compacted with water content below the OMC was lower than that while compacted with water content higher than the OMC. The microstructure observations in this study also supported this characteristic.

摘要

在硫酸盐（盐）土上修路，必须确定水泥稳定剂能否有效利用。这项研究提高了对水泥稳定硫酸盐土壤在含水量、水泥含量和养护时间变化的影响下强度降低特性的理解。进行了一系列实验室测试，以结合微观结构观察来检查土壤-水泥混合物的土壤特性和抗压强度特性。水泥稳定的含硫酸盐粘土和水泥稳定的高塑性粘土（基准材料）的压实曲线几乎相同。这表明硫酸盐对土壤压实特性的影响很小。试验结果还表明，随着水泥掺量和养护时间的增加，抗压强度损失率增加。在通过压实过程生产测试样品时，对两种材料进行的一系列无侧限抗压强度 (UCS) 测试显示出在最佳含水量处具有峰值的钟形关系（OMC）。两种研究材料在压实含水量低于OMC时的 UCS低于压实含水量高于OMC 时的 UCS 。本研究中的微观结构观察也支持这一特征。