Improving the performance of superfine-tailings cemented paste backfill with a new blended binder

Abstract

To improve the performance of the superfine-tailings cemented paste backfill (SCPB) and thus improve the utilization rate of superfine tailings, a blended binder (BB, containing high-volume mineral admixtures) and superplasticizer (SP) were employed. BB was designed based on the proposed model that coupled wet packing method and compressible packing model (CPM). The fluidity, the mechanical and microstructure properties of SCPB with various dosages of BB and SP were evaluated. Moreover, the coupling mechanism of BB and SP on the fluidity of fresh SCPB was also discussed. The results showed that the proposed coupling model could accurately predict the packing density of the multi-mixed cementitious system. The addition of BB and SP can improve the fluidity and strength of SCPB, and the coupling mechanism that affects the fluidity mainly by changing water film thickness (WFT). Therefore, using BB and SP is an effective method for improving the performance of SCPB.