In order to explore the feasibility of using waste concrete to dispose expansive soil and make it as roadbed filler, the waste concrete and expansive soil were mixed evenly according to the ratio of 96 : 4, 92 : 8, 88 : 12, 84 : 16, 80 : 20 and 76 : 24. The boundary moisture content, linear shrinkage rate, expansion force and compaction tests were carried out. The influence of curing time was considered in unconfined strength and CBR tests to explore the improvement effect of the selected materials. The experimental results show that the liquid limit and plastic index decrease first and then increase with the increase of waste concrete content, and the minimum value appears when the content is 12 %, while the plastic limit increases slowly. The linear shrinkage rate increases first and then decreases with the increase of dosage, and the linear shrinkage rate is the smallest when the dosage is 12 %. The expansion force under different curing periods decreases slowly with the incorporation of concrete. When the dosage is 12 %, the dry density of the treated expansive soil is greater than that of the plain soil, and the optimum moisture content is less than that of the plain soil. Considering various factors, 12 % is determined as the best dosage. Under this dosage, the unconfined compressive strength of the mixed soil can reach the peak value, and the bearing capacity of the treated soil is about 5 times that of the plain soil. The treated expansive soil can be used as roadbed filler.