Abstract: In order to achieve the resource utilization of engineering muck and solve the problems of high carbon emission and poor solidification of traditional cement solidified materials, the composite binders composed of industrial solid waste and cement was used to carry out solidifying treatment of engineering muck. Comparative analysis of cement-ground granulated blast furnace slag (OPC-GGBS), cement-phosphogypsum, cement-fly ash three kinds of composite binder curing performance, preferred working performance of the composite binder combinations and proportion parameters, and further combined with the fluidity test, field emission scanning electron microscope (FSEM) test to explore the initial water content, binder content and the water-cement ratio of the influence rule of the workability of the fluid solidified soil. The result shows that: the mechanical properties of OPC-GGBS fluid solidified soil are relatively excellent, with an optimal mass ratio of OPC to GGBS of 50∶50. The effect of binder content on the fluidity of the fluid solidified soil at the early stage of the process is relatively low. With the increase of the initial water content or the decrease of binder content, the strength of the OPC-GGBS fluid solidified soil decreases significantly, while the flow value shows the opposite trend. The correlation fitting functions for the strength and flow value of OPC-GGBS fluid solidified soil with respect to water-cement ratio are established. With increasing water-cement ratio, the strength decreases in a power function trend, while the flow value increases linearly. FSEM image analysis shows that reducing the initial water content or increasing binder content can increase the production of cementitious materials, such as calcium silicate (aluminate) hydrate (C-(A)-S-H), in the fluid solidified soil, and reduce the pore volume.

Key words: solidified soil, engineering muck, industrial solid waste, soil binder, flow value, unconfined compressive strength