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arXiv · 2301.11834

Gas Diffusion in Cement Pastes: An Analysis using a Fluctuating Diffusivity Model

Fumiaki Nakai·Takato Ishida
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Abstract

This work propose an application of the concept of fluctuating diffusivity to the diffusion of gas molecules in cementitious materials, particularly through a two-state fluctuating diffusivity (2SFD) model. The 2SFD model is utilized to investigate the diffusion of oxygen in cement pastes. The analysis provides a reasonable description of the diffusion coefficient of oxygen in cement pastes, and highlights the presence of non-Gaussian diffusion, which can be attributed to the heterogeneous microstructure. The presence of non-Gaussianity in the probability density of the molecule's displacement, characterized by heavier tails than those of the Gaussian distribution, may have a significant impact on the durability assessments of concrete structures.

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Fumiaki Nakai, Takato Ishida. 2023-01-27. Gas Diffusion in Cement Pastes: An Analysis using a Fluctuating Diffusivity Model. https://doi.org/10.1016/j.conbuildmat.2023.133411

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