LAUSR

Abstract The particle size and apparent viscosity of cement slurry are the key factors that affect the grouting effect. However, the flocculation mechanism of cement slurry and its influence on the viscosity of macroscopic slurry are unclear. In this study, focused beam reflectance measurement system is used to investigate the in-situ particle characteristics of fresh cement slurry; the viscosity of the slurry is also measured. The results reveal that the water–cement ratio, cement fineness, and content of the water-reducing agent significantly affect the distribution of the chord size and number of flocculent particles. The aforementioned three factors have different influencing mechanisms and affect the viscosity by affecting the flocculation effect. The variation in the viscosity of the slurry is found to be proportional to the flocculation degree under different conditions. Finally, considering the flocculation effect, an effective volume fraction viscosity model based on the chord size and number of flocculent particles is established and verified.