Influence of the diameter on the mechanical property of agave fibre and their concentration on the thermomechanical properties of the Gypsum/Agave biocomposite

A study on agave fibers shows a strong correlation between fiber diameter and the mechanical behavior of gypsum/agave biocomposites (GAB). The finest fibers (0.03 mm) demonstrate very high tensile strength (2853.03 MPa) and a significant elastic modulus (225.83 GPa), giving the composite great stiffness but also increased brittleness. When mixed into a gypsum matrix, agave fibers generally improve the material’s performance. However, under compression, adding fibers reduces strength (from 7.96 MPa to 1.69 MPa at 3 wt%) due to increased porosity and weak bonding between fiber and matrix. Using a moderate fiber content (1 wt%) enhances ductility and flexural strength (3.35 MPa), while also increasing flexibility (flexural strain of 3.98 × 10⁻² %) without harming cohesion. On the other hand, fiber contents of 2 wt% or more reduce stiffness (down to 168.48 MPa at 3 wt%) because of weaker adhesion and higher porosity, which leads to structural weakness. Thermal conductivity also varies with fiber content. Adding 1 wt% slightly raises it (0.4445 W/m•K), while 3 wt% significantly lowers it (0.3075 W/m•K), improving insulation through better fiber dispersion and porosity control. Overall, agave fibers present strong potential for sustainable biocomposites, offering a promising balance between mechanical strength and thermal performance.