A new approach to estimate ionic diffusivity of hydrating cement paste

作者：Liu, Lin; Sun, Wei^*; Ye, Guang; Chen, Huisu; Van Breugel, Klaas

来源：Journal of the Chinese Ceramic Society, 2010, 38(11): 2159-2166.

• Cement paste
• Effective diffusion coefficients
• Hydrating cement pastes
• Ionic diffusivities
• Macroscopic and microscopic
• Representative volume element (RVE)
• Self-avoiding random walks
• Virtual microstructures

In order to estimate the ionic diffusivity of cement-based material which will be used in the research on durability and prediction of service life, the macroscopically observed phenomenon of diffusion is proposed to link with the Brown motion of ionic species at microscopic via Einstein-Smoluchowski equation. In order to validate the new approach, a virtual microstructure of cement paste is first generated based on a numerical model HYMOSTRUC3D. Then the effective diffusion coefficient of cement paste is predicted by use of self-avoiding random walk algorithm. In this study, the size of the representative volume element (RVE) of cement paste is determined by a statistical method. The simulations are validated on the RVE by use of chloride diffusion data from literatures. The results obtained by the newly developed approach in this paper show a good agreement with that from experiments. Finally, the influences of hydration degree and water-cement ratio are discussed by use of this new approach.

• 出版日期2010-11
• 单位东南大学