Numerical estimation of transport properties of cementitious materials using 3D digital images

摘要

A multi-scale characterisation of the transport process within cementitious microstructure possesses a great challenge in terms of modelling and schematization. In this paper a numerical method is proposed to mitigate the resolution problems in numerical methods for calculating effective transport properties of porous materials using 3D digital images. The method up-scales sub-voxel information from the fractional occupancy level of the interface voxels,i.e. voxels containing phase-boundary,to increase the accuracy of the pore schematization and hence the accuracy of the numerical transport calculation as well. The numerical identification of the subvoxels that is associated with their level of occupancy by each phase is obtained by increasing the pre-processing resolution. The proposed method is presented and employed for hydrated cement paste microstructures obtained from Hymostruc,a numerical model for cement hydration and microstructure simulation. The new method significantly reduces computational efforts,is relatively easy to implement,and improves the accuracy of the estimation of the effective transport property.