Experimental Study on Mechanics and Water Stability of High Liquid Limit Soil Stabilized by Compound Stabilizer: A Sustainable Construction Perspective

Sustainable highway construction and operation are threatened by high-liquid-limit soil with low strength and poor water stability in Dongting Lake areas. In order to obtain a soil stabilizer that can effectively improve its strength and water stability, first the author selected inorganic materials (cement, quicklime and fly ash) and sulfonated oil (SO) as the main components of the composite soil stabilizer. Then, a series of single admixture tests were carried out to explore the strength and water stability mechanism of single admixture stabilized soil. Finally, a series of orthogonal experiments and cost analyses were carried out to obtain the formula of the composite stabilizer. According to the results of single doping, inorganic materials can significantly enhance the strength and stiffness of high-liquid-limit soil. The content of SO has a strong correlation with the water stability of high-liquid-limit soil. On a microscopic scale, X-ray diffraction patterns and scanning electron microscopy images explained this law. According to the orthogonal results, the formula of the composite soil stabilizer is: cement 4.5%, quicklime 1.5%, fly ash 2.5%, and SO 0.2%. This paper provides a method to improve high-liquid-limit soil, which is beneficial to sustainable construction and operation of the highway.