Enhancing the thermal stability and fire retardancy of bio-based building materials through pre-biochar system.

• Biochar was used as an eco-friendly fire retardant that effectively blocks heat transfer. • Thermal stability at high temperature was improved as the content of biochar increased. • A fire-resistant building material was manufactured through the cone calorimeter test. • Post-biochar systems have successfully improved the fire performance of bio-building materials. In an environment that emphasizes ecological sustainability, there is increasing interest in the development of bio-building materials to achieve carbon neutrality. Among bio-building materials, plant-based materials must also consider improving fire resistance. In this study, we developed composite materials with improved fire resistance by adding 0 %, 5 %, and 10 % biochar to bio-materials. A clear improvement in fire resistance was observed in the composite material (CB10) added with 10 % biochar. Through TGA analysis, thermal stability was improved by about 27.6 %, and through cone calorimeter testing, it was confirmed that the peak heat release rate was reduced by 34.5 %. The time to reach the maximum value was also delayed from 25 s to 45 s. This study confirmed that biochar is an eco-friendly fire retardancy that acts as a barrier against heat and oxygen, and that bio-materials can also stably improve fire resistance. [ABSTRACT FROM AUTHOR]