FFT-Homogenization of Elastic and Thermo-elastic Properties of Concrete

Meso-scale homogenization of elastic and thermo-elastic properties of concrete is carried out using a semi-random sequential adsorption algorithm taking basis on properties of aggregate randomly distributed in a homogenized matrix (cement mortar). The aggregates are generated by the sequential reduction of a cuboid into a polyhedron with multiple faces. The original Moulinec-Suquet (1994) FFT-based algorithm was used for the homogenization of elastic properties subjected to quasi-static loading with periodic boundary conditions. For the homogenization of thermo-elastic properties, the original algorithm is modified for temperature loading. The model is validated by comparing the homogenization results with the commercial DIGIMAT software. The results were verified for spherical inclusion by varying the properties of the constituents (matrix and inclusion) and the volume fraction. The volume fraction of the inclusion was however kept within 30% for comparison due to the limitation of DIGIMAT. A good agreement between the numerical and DIGIMAT results was obtained. Later on, the same algorithm is applied to a computationally generated realistic concrete mesostructure RVE with a higher volume fraction to obtain the homogenized properties of the concrete mix.