Performance and mix proportion of industrial residue-cement fluid solidified shield muck

The performance and mix ratio of industrial residue-cement fluid solidified shield muck were studied for promoting the utilization of urban solid wastes. The shield muck collected in Wuhan city were solidified by cement and industrial residues, including blast furnace slag, carbide slag, phosphogypsum, rice husk ash, fly ash and silica fume. The effects of water-cement ratio, cement-soil ratio, industrial residue type and replacement ratio on sample fluidity, shrinkage deformation and strength were discussed. Results indicate that sample fluidity is determined by the water-cement and cement-soil ratios. As the fly ash replacement ratio increases, sample fluidity continuously increases. With increasing replacement ratios of other industrial residues, sample fluidity gradually decreases. The order of reduction is silica fume > rice husk ash > phosphogypsum > slag > carbide slag. The shrinkage deformation mainly occurs within 3~28 d, and the shrinkage rate is significantly reduced when the industrial residue replaces the cement. Sample strength depends on the water-cement ratio and the cement-soil ratio. A low water-cement ratio enhances long-term sample strength, while a high cement-soil ratio boosts early strength. Blast furnace slag and phosphogypsum in the industrial residue promote long-term strength development. Finally, a design method of fluid solidified soil mix ratio based on the theory of slurry rheology and strength development is proposed, providing reference for subsequent construction.