An iterative micromechanical modeling to estimate the thermal and mechanical properties of polydisperse composites with platy particles: Application to anisotropic hemp and lime concretes

- An iterative multiscale modeling technique including FE simulations is developed.
- It allows to account for the shape and spatial distribution of platy hemp shives.
- Thermal conductivity & mechanical properties of hempcretes (HLC) are estimated.
- Special attention is paid to the anisotropy of both hemp shives and compacted HLC.
- The evolution of HLC porosity throughout compaction process is also accounted for.

This work aims at providing a multi-scale model to estimate the effective properties of hemp and lime concretes. The microstructures of such materials are characterized by a relatively high filling rate, platy orthotropic particles distributed on a wide range of spatial directions, and a high level of porosity at meso and micro scales. An iterative micromechanical modeling is here enhanced with some numerical features allowing to deal with the shape and orientation of the particles and with the resulting effective anisotropy of concretes. The model thus constructed is first put into practice to identify the properties of hemp shives and air-slaked lime for various compaction degrees. The results obtained are then used as input data to estimate the thermal and mechanical properties of both a collection of moderately compacted concretes, and a set of concretes with several compaction degrees. Simulations results are eventually confronted with experimental data from the literature.