Insights into pore tortuosity and diffusivity of cement paste via hydration model with superovoidal cement particles

Abstract

Pore tortuosity, as being influenced by the pore micro-geometry, is an important physical quantity to understand the effect of sinuous transport paths on diffusivity of cement paste. This work develops a microstructure-guided model for investigating the influence of cement particle shape on the pore tortuosity and diffusivity during cement hydration process. There are three important components of the model: (1) a continuum-based hydration model with superovoidal cement particles for characterizing microstructure evolution; (2) a Dijkstra algorithm-based transport path searching model for measuring the pore tortuosity; (3) a lattice Boltzmann method for acquiring the diffusivity of cement paste. The results indicate that the pore tortuosity increases with enlarging squareness parameter m and tapering parameter T of superovoidal cement particle, which further induces the decrease of diffusivity.