English：

The application of recycled construction waste materials in road subgrade is an importantapproach to enabling large⁃scale resource utilization of construction waste and promoting the green andlow⁃carbon transformation of the road industry. Based on the Chengdu Third Ring Road reconstructionproject, this study conducted performance index design for recycled materials, investigated subgradefilling construction techniques, and implemented quality control and acceptance during construction, inorder to comprehensively evaluate the feasibility and field performance of recycled materials used insubgrade engineering. The results indicate that the recycled material achieved a California Bearing Ratio（CBR） exceeding 80%, demonstrating high strength and substantial strength reserve. When the fineaggregate proportion （particle size < 4.75mm） increased from 25.2% to 30. 8%, both the CBR and themaximum dry density increased, and field compaction became easier,which is beneficial for constructionquality control. After a series of procedures including spreading,watering, moisture conditioning, androlling compaction, both the degree of compaction and deflection met the design requirements, and theconstructed subgrade exhibited a uniform and smooth surface with overall good quality.