Mechanical Characterization and Literature-Based Thermal Review of Typha Australis Fiber-Reinforced Earth Composites for Ecological Building Construction

This study investigates the valorization potential of Typha australis fibers in earth-based composites intended for ecological building construction in sub-Saharan Africa. The composite specimens were prepared by progressively substituting laterite with Typha australis fibers at dosages ranging from 0% to 7% by mass in a multicomponent earth matrix comprising laterite, kaolin, limestone (calcaire), and dune sand. Specimens were compacted using the Standard Proctor method and subjected to uniaxial compressive strength (UCS) tests after a 7-day curing period. The results demonstrate that the addition of Typha fibers significantly influences the mechanical performance of the composite. Compressive strength increased progressively from 2.15 MPa (0% Typha) to a maximum of 2.86 MPa at a 4% fiber dosage, representing a 33% improvement. Beyond this threshold, mechanical strength declined. The thermal behavior of the composites is discussed on the basis of measurements performed on pure Typha specimens and literature data on Typha-based composites; direct thermal conductivity measurements on Proctor-compacted earth-Typha specimens are recommended in future work. The mean thermal conductivity of Typha australis alone was measured at 0.045 W/m·K, confirming its excellent insulating potential. Physical and geotechnical characterization of raw materials—including particle size distribution, Atterberg limits, specific Gravity, and bulk density—revealed suitable properties for composite formulation. These findings suggest that an optimum Typha fiber content of 4% maximizes mechanical performance under the reported laboratory conditions, while higher contents (5% - 7%) are expected to favor thermal insulation, enabling tailored composite design for structural or insulating applications. This work contributes to the promotion of locally sourced, low-carbon building materials in tropical regions.