Three-dimensional numerical prediction of elastic modulus of concrete as a three-phase composite with asymptotic homogenization

In this study, the elastic modulus of a concrete material was predicted using three-dimensional (3D) numerical models based on asymptotic homogenization. A novel meshing method was developed to discretize the mesoscale model of concrete with an arbitrary thickness of the interfacial transition zone (ITZ), offering a low computational cost with accurate ITZ representation. A practical implementation of asymptotic homogenization using ABAQUS was presented. Numerical models were verified by comparison with theoretical predictions, published numerical results, and experimental data. The results prove that the proposed numerical model is adequate to offer an accurate estimate of the elastic modulus of concrete. A systematic parametric study was conducted to investigate the effects of the mesostructural characteristics on the elastic modulus of concrete. The results indicate that the aggregate shape has a slight influence on the elastic modulus of concrete. The effect of the ITZ thickness is small owing to its much lower volume fraction compared with that of the aggregate and mortar. Moreover, the elastic moduli of concrete predicted by the 3D numerical models using random configurations exhibit negligible dispersion. A significant difference between the 3D and 2D numerical results demonstrates that 3D numerical models offer a more accurate and reliable prediction of the elastic modulus of concrete.