Characterization and utilization of sawdust waste generated from advanced manufacture for its application as a thermal insulation in sustainable buildings using the blowing technique

Abstract

The construction industry is vital for economic development, but it accounts for 40% of energy consumption and 45% of global greenhouse gas emissions. In this context, research has focused on reducing energy demand in homes, particularly through the development of insulation materials. Sawdust is a byproduct available annually in Chile in quantities exceeding 4.5 million tons. Therefore, the objective of this study was to characterize the physical and thermal properties of this waste to evaluate its use as a thermal insulation material. Stability and thermal conductivity tests, as well as density and moisture content measurements, were conducted on the sawdust. Additionally, to assess the functionality of this thermal insulator, the material was applied using the blowing technique in partitions, followed by physical tests. The results indicate that the proposed insulation material has thermal stability up to 270 °C. The thermal conductivity was comparable to conventional mineral wool and fiberglass (0.042–0.048 [W/mK]). The density ranged from 123.77 to 198.15 [kg/m³] depending on the filling time of the specimens but remained low compared to other organic materials. The moisture content was 11.31%, suitable for maintaining good thermal conductivity. This study concludes that sawdust is a viable alternative for thermal insulation, especially when applied through blowing. Its stability and thermal conductivity are comparable to conventional materials, while its thermal inertia is 200% higher than that of glass wool. Furthermore, the low moisture content suggests that there would be no proliferation of pathogens, making it a promising thermal insulator for sustainable construction development. Finally, it is mentioned that the material carbonizes within a limited time, leading to self-extinguishment of the flame.