Experimental Study on Road Properties of High Liquid Limit Soil in Yunfu Highway

There are a large number of high liquid limit soil distributed in southern China. As one of the special soils commonly seen in highway construction, high liquid limit soil cannot be used in subgrade filling directly due to its special engineering properties. With the idea of saving engineering investment and protecting environment, high liquid limit soil must be improved to be qualified subgrade filling material. First, detailed laboratory tests are carried out to reveal the special properties of high liquid limit soil. Then, based on the characters of high liquid limit soil, the improving tests of liquid plastic limit, unconfined compressive strength, CBR and compaction are completed by adding different percentages of quicklime and white lime to the high liquid limit soil to study the change in the physical and mechanical properties and strength. The results show that, after being improved by lime, the high liquid limit soil can be used as subgrade filling of expressway as its liquid limit, plastic index being reduced, the strength increased and the value of CBR increased remarkably, and modified effectiveness of quicklime is better than that of white lime. Through comparison and analysis of the test results, it is found that high liquid limit soil with 5% quicklime can be used as subgrade filling material for highway since it is not only economical but also qualified to meet the requirement of improvement and strength.