Charring Properties of Korean Larch Structural Glue-Laminated Timber Beams Based on Cross-Sectional Area Ratios

Carbon emissions accelerate global warming and climate change, prompting the global development of strategies for carbon reduction. Wood, with its excellent carbon storage capacity, is a sustainable and environmentally friendly material. One cubic meter of timber can absorb 1 t of carbon dioxide and store 250 kg of carbon. This study aimed to conduct fire resistance tests on structural glue-laminated timber beams made from Korean larch (Larix kaempferi) and analyze their char properties. The specimens were fabricated with different cross-sectional shapes and areas and underwent load-bearing fire resistance tests. The results were analyzed in terms of char depth, char rate, and changes in char thickness based on the aspect ratio of the beams. In the smaller specimens, the char properties were influenced more by the width than by the length of the beam. Additionally, at a constant cross-sectional area, charring was deeper when the width was shorter than the height. The specimens did not exhibit significant differences in displacement behavior, with all specimens displaying displacements below the maximum permissible value, indicating suitable fire resistance. The findings of this study provide a foundation for research and development of fire resistance design standards for wooden structures utilizing Korean timber.