Lime is widely used to stabilize fine-grained subgrades beneath pavements. The procedure used to apply lime and the effectiveness of the mixing stage can have a significant impact on the quality of the stabilized subgrade. For this study, lime was applied to two test sections in slurry and quicklime forms and samples were taken at various stages of mixing. Strength values were determined for field- and laboratory-mixed samples. Strength and stiffness of the subgrades were tracked for up to 33 days by using the dynamic cone penetrometer and soil stiffness gauge. Results showed that additional mixing reduced average lump size, particularly when conducted after a mellowing stage, and significantly improved the subgrade for up to at least four passes. Strengths also increased substantially with time for the stabilized soil, and long-term strengths were highest for soils mixed wet of optimum moisture.
Abstract