Fire safety performance of radiata pine-magnesium-laminated (RML) board for building material,

In this study, the Radiata pine-magnesium-laminated (RML) board was proposed to develop wood materials with flame retardancy. The 45° flammability test, cone calorimeter test, gas toxicity test, single burning item (SBI) test, and Steiner tunnel test were performed to confirm the flame-retardant performance of RML. For RML with 80 to 150 g/m2 of flame retardant applied, the carbonized area in the flammability test was 44.3 to 35.0 cm2; in the cone calorimeter test, the total heat release (THR) was 5.4 to 6.2 MJ/m2, and the time to stopped behavior of white lab mice was 857s, which surpasses the standard for semi-noncombustible materials in Korea. The RML was Class A2 based on EN 13823 (2020) in the SBI test and Class A based on ASTM E84-21a (2022) in the Steiner tunnel test. In conclusion, RML showed excellent flame-retardant performance. The thin wood veneer absorbs the flame retardant easily, and the magnesium board is a semi-noncombustible material. Accordingly, it was confirmed that an RML board could be a commercial wood-based building material with satisfactory flame retardancy.