InterPore2026

Multiphase porous bio-composite for green housing: experimental and numerical thermos-mechanical study

22 May 2026, 15:30

1h 30m

Poster Presentation (MS09) Pore-Scale Physics and Modeling Poster

Speaker

Mrs Kanto RASOLOARIJAONA (ITheMM, Université de Reims Champagne Ardenne)

Description

Keywords: Multiphase porous bio-composite, green housing, thermo-mechanical properties, X-ray tomography, FEM

Bio-based porous materials are gaining importance in construction sector owing to their ecological benefits, sustainability, energy performance and availability. The lightness and internal macro-porosity of biobased concretes – around 20% – offer them optimum thermo-mechanical properties for insulation applications.
However, this particularity remains poorly understood by the buildings professionals who deal with those multiphase – fibres, binder and pores – porous bio-composite.
The originality of this work is to run numerical simulations and predict the thermo-mechanical behaviour of biobased porous concretes to provide green housing buildings professionals with a decision support tool. This innovative numerical approach considers the actual geometrical characteristics and thermo-mechanical properties of each phase – fibres, binder and pores.
First, two biobased porous concretes were studied: lime-hemp concretes formulated with Tradical Thermo® (lime) and Technichanvre C020® (hemp shiv), and typha-clay composites, raw materials imported from Senegal (as part of partnership with the enterprises BioBuild Concept and BioBuild Africa). Both of the bio-based porous concretes were manufactured with identical mass proportions Binder/Fibres = 2.15 - Water/Binder = 0.85, a controlled compacting pressure and microporosity and macro-porosity are known.
After manufacturing, the thermal conductivities of our biobased porous concretes were evaluated using the hot wire and heat flow meter methods to highlight their insulating potential. We show up low thermal conductivity around 0.1 W.m-1.K-1, confirming the insulating properties of our biomaterials.
Then, a compression test coupled with digital image correlation (DIC) was conducted on our samples to determine their stiffnesses and Poisson's ratios, and to analyse the strain fields to target areas of potential failure of bio-based porous concretes. Experimental results indicate Young’s moduli around 30 MPa and a Poisson’s ratios near 0.2.
The numerical model tends to simulate the thermo-mechanical behaviour of the biobased porous concrete using the finite element method (FEM). The element types chosen were C3D4 for mechanical simulations and DC3D4 for thermal simulations.
To effectively execute the numerical study, X-ray tomography on a sample was performed to obtain the bio-based concretes’ three-dimensional structure considering the real macro-porosity of both lime hemp concrete and typha-clay concrete.
Thus, each main phase - fibres, binder and pores induced by the manufacturing process - is represented with its thermo-mechanical properties and actual geometrical features.
Finally, the three-dimensional multiphase porous bio-composite was meshed, and a FEM was conducted using Abaqus® software to simulate and predict its thermo-mechanical response under compression and heat flux.
The developed numerical model was fed with thermo-mechanical characteristics data of each constituent – fibres, binder and pores. Thermal and mechanical behaviour of the bio composite obtained from the numerical model were compared with experimental results.
The obtained results will enable the advancement of green housing by the development of a reliable decision support tool for the buildings professionals who use the multiphase porous bio-composite.