Study of high liquid limit clay improvement test

Through lab test, effect of improvement of high liquid limit clay by mixing of sand, Portland cement, quicklime and white lime were studied. Results show that compared with untreated soil, maximum dry density of high liquid limit clay improved by sand increase with the increase of mix-ratio of sand while optimum moisture content is decrease, but CBR value, swelling increment and soakage (after being immersed in water) of high liquid limit clay improved by sand change very little. Mixing of Portland cement can greatly increase CBR value of high liquid limit clay, and also lower swelling increment and soakage, but effect on optimum moisture content is very small and maximum dry density is only slightly increased. Mixing of lime can increase both optimum moisture content and CBR value of high liquid limit clay, and lower swelling increment and soakage at the same time. Through comprehensive comparison of effect of mixing of sand, Portland cement, quicklime and white lime on lowering moisture content of high liquid limit clay and effect on its optimum moisture content, CBR, swelling capacity, and soakage, mixing of quicklime has the best effect of improvement of high liquid limit clay.