<p>A large amount of expansive soils were distributed along Yiyang-Loudi Expressway situated in Hunan Province, China. Due to the fact that these expansive soils cannot be directly used as subgrade fillers, it will lead to a significant increase in the land for the discarded soil heap and a large number of borrowing soils. In addition, many quarries have been built along the project, a large amount of stone chips during the gravel production are produced as by-products simultaneously, but most of them become solid wastes that have potential environmental impacts. Experimental tests were conducted for possible replacement of stone chips in expansive soils solving a dual problem including the treatment of expansive soils and disposal of stone chips in this paper. These tests aimed to study the engineering properties of expansive soil improved by stone chips at different percentages (0%, 5%, 10%, 15%, 20%, and 25% by dry soil weight) via measuring the grain-size composition, compaction characteristics, consistency limits, shear strength parameters, and swelling-shrinkage behavior. The optimal stone chips content added to expansive soils was recommended as 15% based on the experimental results. The results indicated that by adding 15% stone chips to expansive soils, the percentage of reduction in the clay content, the maximum dry density, Plasticity Index, activity were 25.9%, 4.49%, 61.9%, 48.6%, respectively. The free swelling rate, load-free swelling rate, total ratio of swell-shrink, and standard moisture absorption decreased noticeably, and the reduction percentages were 49.0%, 56.6%, 89.1%, and 69.8% respectively. The reduction percentages of the linear shrinkage ratio, volumetric shrinkage ratio, shrinkage limit, and shrinkage coefficient are 34.2%, 43.7%, 20.7%, and 31.1% respectively compared to untreated soil. Overall, these results indicated that the stone chips could be effectively used to stabilize the expansive soils, improve its swelling-shrinkage behavior for the application in subgrades.</p>