Effect of bio-fillers on the mechanical, thermal, and fire properties of gypsum composites

Gypsum composites are prepared using three different bio-fillers at various mass fractions separately to investigate the mechanical, thermal, and fire behavior in order to assess the suitability of the resulting materials in building applications. The mechanical test results showed that the obtained gypsum composites are well compatible with existing gypsum composites in the literature as well as with the relevant standard. The ranges of compressive and flexural strength found are 9.04-14.25 MPa and 3.21-4.47 MPa for a density range of 1.08-1.20 g/cm3 respectively. The thermal conductivity and diffusivity range lies within 0.42-0.53 W/m-K and 0.35-0.62 mm2/s respectively. The lowest thermal conductivity and diffusivity are found for composites with highest filler content indicating that the thermal conductivity is lower for a high bio-filler content. The wood dust- and bamboo powder-filled samples showed a good thermal insulation considering the thermal parameters i. e., thermal conductivity and specific heat capacity. Under an exposure of 50 kWm- 2 heat flux for 20 minutes, the average mass loss rate (MLR) fluctuated around 0.026 g/s. Overall, the investigation of bio-filled gypsum composites shows promising results and may be utilized in building interiors. This research shows that the utilization of various biomass in producing gypsum composite may be an effective way of biomass consumption to uphold circular economy and sustainability.