Rheological characteristics of cement-sodium silicate grout in its fluid–solid phase transition process

The rheology of quick-setting grout during the phase transition from fluid to solid is a key factor for consideration in grouting diffusion design. In this paper, cement-sodium silicate grout (C[sbnd]S grout) was used in the experiment as a typical quick-setting grout. The rheological properties of quick-setting grout during the entire phase transition period, including phase transition time, grout viscosity, and yield stress, were investigated. The influences of water-cement mass ratio (W/C mass ratio) and cement-sodium silicate ratio (C/S volume ratio) on rheological properties of quick-setting grout were analyzed. Results show that gel reaction process of C[sbnd]S grout can be divided into three stages: fluid phase, fluid–solid phase, and solid phase. Among them, shear stress of C[sbnd]S grout increased rapidly with phase transition from fluid to fluid–solid state. The rheological constitutive relation of C[sbnd]S grout always belonged to the Bingham model with W/C mass ratio ranging from 0.8 to 2.0 and C/S volume ratio ranging from 1 to 3. A rheological model of C[sbnd]S grout was presented, among which the relationship between rheological parameters and reaction time is expressed by exponential functions.