Soutenance de thèse de Haichuan LIU

Hemp concrete is a promising bio-based material for low-carbon building envelopes, offering thermal insulation, moisture regulation, and reduced environmental impact. However, its wider application is still limited by weak mechanical performance, moisture-induced deformation, durability concerns, and the difficulty of predicting anisotropic hygrothermal properties. This thesis addresses these challenges through a multiscale framework linking microstructure, formulation, modeling, and aging.
X-ray computed tomography was used to characterize early-age microstructural evolution, while digital image correlation was applied to investigate moisture-induced deformation under service-like hygric conditions. Based on these insights, an interface-oriented formulation strategy using bio-based polymers was developed to improve the balance between mechanical performance and hygrothermal function. A 3D numerical homogenization model was then established from real XCT-reconstructed microstructures, explicitly incorporating hemp shiv orientation and intrinsic anisotropy to predict thermal conductivity and water vapor permeability. Finally, service-relevant accelerated aging protocols were designed by combining classical aging theories, climatic data, hygrothermal cycling, carbonation, and fungal risk assessment.
Overall, this work provides new theoretical insights and methodological support for formulation optimization, property prediction, and durability assessment, thereby offering guidance for the practical application of hemp concrete and related bio-aggregate composites.

 

Composition du Jury :

• M. Philippe COUSSO, Professeur des Universités, Université Gustave Eiffel, Laboratoire Navier,    Rapporteur
• M. Karim BENZARTI, Directeur de Recherche, Université Gustave Eiffel, Laboratoire Navier    Rapporteur
• M. Ouali  AMIRI    Professeur des Universités, Nantes Université, Examinateur
• Mme Anne-Lise BEAUCOUR, Professeure des Universités, CY Cergy Paris Université, Examinatrice