Comparative Study on the Combustion Characteristics of Korean Wood with Changes in the Radiant Heat

Due to the increasing demand for sustainable construction materials, wood has gained prominence owing to its renewable nature and carbon-storage capabilities. However, the flammability of wood presents critical safety concerns in its structural applications. This study investigates the combustion and charring characteristics of three Korean softwood species, namely Larix kaempferi, Pinus densiflora, and Pinus koraiensis, which were subjected to varying levels of radiant heat using cone calorimetry testing (ISO 5660-1). The fire performance was evaluated based on the peak heat release rate (HRR), total heat release (THR), surface ignition temperature, and char depth. The obtained results showed that Pinus densiflora exhibited rapid ignition and the highest THR (62.2 MJ/m2), indicating an aggressive burning behavior. Additionally, Pinus koraiensis recorded the highest peak HRR (241.6 kW/m2). In contrast, Larix kaempferi showed the most favorable fire-resistance profile, with the highest ignition temperature (~300 °C), lowest THR (31.8 MJ/m2), and shallowest char depth (7.5 mm), suggesting slower pyrolysis. These findings identify Larix kaempferi as the most fire-resilient species among those tested, making it a promising material for use in timber structures. This work offers practical insights for improving fire safety in wooden buildings and supports the strategic use of Korean wood in sustainable and fire-safe architecture.