Contribution à la formulation et à la caractérisation d'un écomatériau de construction à base d'agroressources

The main aim of this work was to contribute to the development of an innovative building material that complies with legislations and users actual requirements concerning environmental and health impacts as well as thermal or hygroscopic comfort. An original pozzolanic matrix has been formulated while conventional admixtures, reinforcement fibres and aggregates were substituted by renewable raw materials. Hardening mechanisms and long term behaviour of that binder (mix of metakaolin and hydraulic lime) have been explored. The benefits of incorporating two organic admixtures on early age properties and long term behaviour of the pozzolanic binder have been explained by the identification of interaction mechanisms between mineral and organic species. A comparative study has been realised on flexural reinforcement of this matrix by vegetable fibres of flax, hemp and yucca and on the durability of these different composites. Finally, the compatibility of this matrix with vegetable aggregates (hemp chenevotte and sunflower stem pith) has been checked and demonstrated in order to formulate self-supporting insulation ecomaterial.