Strength formation mechanism and composition design of fly-ash and carbide-slag-stabilized mine solid waste road base

To achieve effective utilization of large-scale solid waste, this study prepared subgrade materials using mine waste, fly ash, and carbide slag as raw materials. The effects of the basic structure and composition ratio of the three raw materials on the performance of the subgrade materials were investigated. The mechanisms and strength enhancement effects of fly ash, carbide slag, and fly ash–carbide slag composite-stabilized mine solid waste were analyzed. The optimal mixing ratio of the subgrade materials was determined. When the mass ratio of carbide slag to fly ash was 1:4 and the total addition amount was 20%, the subgrade material had an optimal moisture content of 16.8%, maximum dry density of 1.70 g/cm3, and 90-day compressive strength of 8.51 MPa. This fully solid waste inorganic binder-stabilized subgrade material can effectively utilize large quantities of solid waste and meet the performance requirements of subgrade materials, thereby providing a good technical solution for large-scale solid waste disposal.