Speaker
Description
Bio-based materials, such as vegetal wools, are promising alternatives to conventional building materials due to their carbon sequestration potential and sustainability. However, their high flammability necessitates the application of fire-retardant treatments, which may alter their microstructure and, consequently, their acoustic properties. This study evaluates the impact of a recently developed bio-based fire-retardant treatment, based on phosphorus grafting onto the fibers, on the acoustic performance of loose fiber assemblies and thermobonded vegetal wool panels.An impedance tube with a three-microphone method was used to measure sound absorption and indirectly determine the characteristic parameters of the pore network. Additionally, self-consistent homogenization models (Tarnow and Umnova) were applied to estimate the equivalent fiber radius, providing insights into the treatment’s effect on fiber diameter.Results indicate that the phosphorus-based fire-retardant treatment increases the fiber radius, which correlates with a reduction in airflow resistivity, viscous dissipative effects, and overall acoustic absorption. These findings highlight the trade-offs between fire safety and acoustic performance in biosourced materials. The study opens perspectives for optimizing fire-retardant treatments to minimize their impact on the acoustic properties of vegetal wools, thereby enhancing their applicability in sustainable construction.