Hydration kinetics of sulfoaluminate cement with different water/cement ratios as grouting material used for coal mines

In order to provide theoretical guidance for sulfoaluminate cement as grouting material used for coal mines, the purpose of this paper is to trace the hydration process and study the hydration kinetics of sulfoaluminate cement. The influence of the water/cement ratio (W/C) on the hydration exothermic characteristics of sulfoaluminate cement was studied by TAM air hydration microcalorimeter, Raman spectrum and compressive strength test, respectively. The results show that the rapid hydration of sulfoaluminate cement can be divided into three hydration processes: acceleration period, deceleration period and stability period. With the increase of W/C, the maximum heat release rate of cement decreases, while the cumulative heat release increases. In addition, increasing W/C can affect the microstructure of the cement paste, increase the porosity and further decrease the strength. Meanwhile, the Krstulović–Dabić model was used to analyse the hydration kinetics of sulfoaluminate cement with different W/C. The results show that the hydration mechanism of sulfoaluminate cement is not affected by increasing W/C. The hydration kinetics process can include three stages: nucleation and growth mechanism, phase boundary reaction and diffusion reaction.