High calcium lime is commonly used to improve subgrades made of fine-grained soils. Different forms of lime can be applied in various ways. A study found that the type of lime used doesn't affect soil moisture-density relationship much. Adding enough lime for stabilization is crucial for strength. Mixing well above optimum moisture levels leads to stronger subgrades. Multiple passes during mixing and re-compaction improve strength. Lime dust can be released into the air during application.