3D multi-scale modelling of mechanical behaviour of sound and leached mortar

A 3D multi-scale modelling of mechanical properties of cement-based materials approach is presented. The proposed approach provides a quantitative means to estimate and predict the mechanical properties of cement-based materials taking into account the eventual changes in the micro-structure. Two numerical tools are combined. First, the NIST's 3D model (CEMHYD3D) is used to generate a realistic 3D Representative Volume Element of cement-based materials at different scales. Then, multi-scale simulations are performed by using the FE software Abaqus for the calculation of the mechanical behaviour. The approach is then successfully applied to a specific mortar in order to determine firstly its mechanical behaviour under tensile and compression loadings and secondly the evolution of its Young's modulus under the leaching phenomenon. This evolution is a key parameter since the leaching may be critical for the mechanical integrity of concrete structures such as radioactive waste storage systems in which cement-based materials may be largely used. The numerical results of the modelling are consistent with the experimental ones.