Improving discrete particle packing models for the microstructural formation simulation of Portland cement

Abstract

The 3D solid-phase spatial distribution strongly influences the electrical, mechanical and chemical properties of Portland cement microstructure. The commonly applied random sequential addition (RSA) method in cement microstructure formation simulation is causing over-computation of volume expansion due to the unrealistic initial geometry condition. However, it is difficult to search for a suitable model to represent the initial 3D pore structure with sufficient pore density range and compatibility with existing 3D cement microstructure models. An approach is proposed based on introducing a pseudo-contact mechanics analysis step to the RSA-discrete particle packing simulation scheme. The key control parameter to obtained specific pore density is identified to be the coefficient of friction after adjusting relative velocity distribution, lattice elastic constant and particle/domain size ratio. The proposed method enables the generation of random 3D pore structure with the same lattice configuration of major discrete cement microstructure formation models and Lattice Boltzmann Method (LBM), allowing more realistic 3D structure input and coupled modelling.