Random Dispersion Model and Simulation of Model Pore Structure of Cementitious Materials

doi:10.16183/j.cnki.jsjtu.2023.037

Abstract

Abstract:

In order to investigate the evolution of pore structures in cementitious materials, a statistical model is proposed by taking the cement paste as a random dispersion system of two-phase medium. Simultaneously, the μic platform is employed to simulate the cement hydration. The results obtained from the simulation and the disperse models are compared with each other, and further analysis on calculation conditions and parameters of the disperse models are conducted. The pore size distribution obtained from polydisperse hard sphere model is very close to the simulation in completely dispersion condition. Taking into account the cross and agglomeration effects of hydrated products, the calculation results of the monodisperse concentric-shell model are more consistent to the simulations. Considering the flocculation of cement particles in initial state, the monodisperse hard model is closer to the simulation results. This paper offers a new insight from the viewpoints of mathematics and physics to understand and describe the pore structures of cementitious materials.

Key words: two-phase media, randomly disperse models, μic simulation platform, pore structure, pore size distribution

CLC Number:

TU528

CHEN Nü, XU Wenhao, WU Biao, CHEN Xiaowen, HOU Dongwei. Random Dispersion Model and Simulation of Model Pore Structure of Cementitious Materials[J]. Journal of Shanghai Jiao Tong University, 2024, 58(11): 1745-1752.

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反应物/产物	密度/ (g·cm^-3)	k₁/h^-3	k_diff/ (μm²·h^-1)
C₃S	3.15	1.14×10^-5	1.0
C₂S	3.28	1.14×10^-4	1.0
C₃A	3.03	1.14×10^-2	1.0
内层C-S-H	2.2		0.04
外层C-S-H	2.2		1.0
CH	2.2		1.0

α	<r>/ μm	<r²>/μm²	<r³>/μm³	ϕ_w
0	4.12	18.88	105.88	0.63
0.3	3.70	15.09	72.67	0.48
0.6	4.29	19.83	103.67	0.35
0.9	4.57	22.50	123.50	0.24