Composites based on Juncus maritimus fibers for building insulation

Juncus maritimus fibers present an interesting cellular porous microstructure useful for thermal insulating properties. The elaboration and experimental characterization of composite materials based on different Juncus maritimus fibers content (0, 2, 5, 7 and 10 by mass) are investigated. We show that optimized composite materials can be elaborated from a simple chemically treatment of fibers. The thermo-physical properties (thermal conductivity, thermal diffusivity, and density) of both mortar composites with the raw and chemically treated fibers, were evaluated experimentally. Also, the water absorption uptake and mechanical strengths were performed to evaluate the chemical surface modification effects on the performances of the composites. As a result, due to their porous cellular microstructure, the use of Juncus maritimus fibers enhances the thermal insulating and lightness performances of reference mortar but affects negatively its mechanical strengths. The moisture effect tests reveal that thermal conductivity and density of the saturated composites are two times higher than that in a dry state. The chemical surface modification of used Juncus maritimus fibers improves the flexural and compressive strengths, decreases the water uptake of resulting composites with a low water diffusion coefficient. Thus, these new treated bio-cellular fibers composites can be used as structural and insulating lightweight concrete.