A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
A novel lattice model to predict chloride diffusion coefficient of unsaturated cementitious materials based on multi-typed pore structure characteristics
Abstract This paper develops a novel lattice diffusive model to quantitatively study the chloride diffusion coefficient in unsaturated cementitious materials, in which the pore voxels are redistributed to make a better representation of a real microstructure of hardened cement paste. Considering the hierarchical microstructure and different drying-wetting cycles, water distributions in multiscale pore structures are modelled and the structure characteristics of water-filled pores, including water connectivity, water tortuosity and effective porosity, are computationally extracted based on that. A lattice diffusion network is established to predict relative chloride diffusion coefficient by combining the effect of both water saturation degree and pore structure characteristics. The predicted results are validated against experimental data, and a concise analytical equation is proposed to predict the relative chloride diffusion coefficient. The equation indicated that the relative chloride diffusion coefficient is proportional to water connectivity but inversely proportional to the square of water tortuosity. Besides, the lattice model's quantitative results reveal that the water connectivity and water tortuosity are highly related to pre-water loading processes, and influenced by the gel pore fraction, which in turn will affect the relative chloride diffusion coefficient. Compared with existing equations and non-redistributed models, the present model could improve the prediction accuracy significantly.
Highlights The unsaturated pore structure is computationally generated and redistributed to better represent the real microstructure of cement paste. Water distributions in pores structure are simulated considering the hierarchical microstructure and different drying-wetting cycles. A novel lattice network is developed to predict the relative chloride diffusivity and validated against third-party experimental data. An analytical equation is proposed to describe the relationship between multiple pore structure features and chloride diffusivity efficiently. The existing and proposed model are further compared to evaluate the accuracy of the present model based on the quantitative results.
A novel lattice model to predict chloride diffusion coefficient of unsaturated cementitious materials based on multi-typed pore structure characteristics
Abstract This paper develops a novel lattice diffusive model to quantitatively study the chloride diffusion coefficient in unsaturated cementitious materials, in which the pore voxels are redistributed to make a better representation of a real microstructure of hardened cement paste. Considering the hierarchical microstructure and different drying-wetting cycles, water distributions in multiscale pore structures are modelled and the structure characteristics of water-filled pores, including water connectivity, water tortuosity and effective porosity, are computationally extracted based on that. A lattice diffusion network is established to predict relative chloride diffusion coefficient by combining the effect of both water saturation degree and pore structure characteristics. The predicted results are validated against experimental data, and a concise analytical equation is proposed to predict the relative chloride diffusion coefficient. The equation indicated that the relative chloride diffusion coefficient is proportional to water connectivity but inversely proportional to the square of water tortuosity. Besides, the lattice model's quantitative results reveal that the water connectivity and water tortuosity are highly related to pre-water loading processes, and influenced by the gel pore fraction, which in turn will affect the relative chloride diffusion coefficient. Compared with existing equations and non-redistributed models, the present model could improve the prediction accuracy significantly.
Highlights The unsaturated pore structure is computationally generated and redistributed to better represent the real microstructure of cement paste. Water distributions in pores structure are simulated considering the hierarchical microstructure and different drying-wetting cycles. A novel lattice network is developed to predict the relative chloride diffusivity and validated against third-party experimental data. An analytical equation is proposed to describe the relationship between multiple pore structure features and chloride diffusivity efficiently. The existing and proposed model are further compared to evaluate the accuracy of the present model based on the quantitative results.
A novel lattice model to predict chloride diffusion coefficient of unsaturated cementitious materials based on multi-typed pore structure characteristics
Tong, Liang-yu (author) / Xiong, Qing Xiang (author) / Zhang, Zhidong (author) / Chen, Xiangsheng (author) / Ye, Guang (author) / Liu, Qing-feng (author)
2023-10-16
Article (Journal)
Electronic Resource
English
| British Library Online Contents | 2019
| British Library Online Contents | 2019