Development of microscopic rheological model of cementitious suspension containing attapulgite based on water film thickness and bonding strength coefficient

Abstract

Based on the theoretical framework of water film thickness (WFT) and bonding strength coefficient (ζ), the motion and collision laws of particles in shear flow field were analyzed by using continuum mechanics, particle collision mechanics, fluid mechanics, thermodynamics and hydration dynamics, and the microscopic rheological model of cementitious suspension containing attapulgite (BGA and GBA) was established to predict the rheological parameters. The results indicated that the error range of rheological parameters predicted by the microscopic rheological model based on WFT-ζ and the experimental values was 0.09%–8.66%. The model can well predict the influence of BGA and GBA on rheological parameters. In addition, ζ has been proved to be closely related to the net force of four microscopic forces in the cementitious suspension, including gravity, van der Waals force, electrostatic double repulsion force and adhesion force caused by hydration product formation, which can characterize the bonding strength between particles.