Towards a realistic morphological model for the meso-scale mechanical and transport behavior of cementitious composites

In this work, we investigate the mechanical and transport properties of cementitious composites using a realistic morphological 3D matrix-inclusion-ITZ model for the mesoscale behavior. Assuming a compression damaged plasticity-based behavior for the matrix phase under quasi-static loading, the model is used to determine the effect of inclusion (aggregate) shape, volume fraction and segregation on the mechanical response of the composite specimen under uniaxial loading. We then use the model to evaluate the effect of the previously mentioned variables as well as aggregate intrinsic permeability on the macroscopic permeability of the same composite specimen using a series of non-conforming FE meshes and level set functions to monitor the heterogenities. The model is then applied to a self-compacting concrete (SCC) with a higher volume of cement paste in order to flow more freely and be formed into complex shapes without shaking. However, this elevated fluidity predisposes SCCs to a higher risk of segregation, i.e. separation between the suspending phase and coarse aggregates, which can affect the mechanical behavior of the composite.