Minimization of the volume of the wood-based barrier for 2-hour fireproof wooden beam: Bench-scale and full-scale furnace tests on fire-retardant barrier of japanese cedar glulam

In the 2-hour fireproof wooden beam composed of Japanese cedar, the minimization of wood-based fire protection barrier volume is studied to reduce the weight of elements. Through two types of bench-scale tests and one full-scale test, this study clarified that the optimum thicknesses of fire-retardant wood to ensure 2-hour fireproof performance in the condition of a 25mm thick sacrificial layer. The thicknesses at the vertical side part and the bottom part of the elements are 75 mm and 100mm, respectively. The target amount of the fire-retardant agent should be contained over 180 kg/m3.