Compatibility of Sophistication of Wooden Fire-Resistant Structural Members and Cross-Section Control - Toward High-Rise Wooden Buildings

2022 Fiscal Year Final Research Report

• Project/Area Number: 21K20466
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Multi-year Fund
• Review Section: 0304:Architecture, building engineering, and related fields
• Research Institution: Waseda University
• Principal Investigator: Hokibara Tomoyo 早稲田大学, 理工学術院, 専任講師 (70908061)
• Project Period (FY): 2021-08-30 – 2023-03-31
• Keywords: 高層木造 / 火災 / 燃え止まり / 材積 / 軽量化 / 3時間耐火 / 耐火構造

Outline of Final Research Achievements

Regarding the relationship between the fire resistance performance necessary for building a high-rise building entirely in wood and the cross-sectional dimensions of members, the following results were obtained for wooden structural members using flame-retardant treated wood as a barrier layer.(1) A cross-sectional structure that ensures fire resistance performance for 3 hours, which enables construction of 15 stories or more, was clarified.(2) It was clarified that the depth of charring can be reduced by making the lamina direction of the barrier layer the direction in which lamina shrinkage and cracking do not easily occur and by using flame-retardant treated wood equivalent to noncombustible materials for the barrier layer.(3) It was clarified that the effect of reducing the charring depth by increasing the amount of flame retardant agent is greater during cooling than during heating, and it can be one of the methods that contributes to the weight reduction of the coating layer.

Free Research Field

建築学

Academic Significance and Societal Importance of the Research Achievements

既に開発済みの2時間耐火部材の被覆層厚さ程度で、3時間耐火性能を確保する部材断面構成を明らかにしたことは、耐火被覆厚さによって、同一建築物内で階によって部材断面寸法が大きく異なるというような設計計画上の制約を軽減できる成果である。更に、同じ被覆層厚さの中で、加熱面側の燃え止まり層の難燃薬剤量を低減できる見通しが立ったことで、更なる部材重量の軽量化や、建築計画上の納まりやコストによって建物全体での柱・梁の断面が選択可能となる設計手法の確立に寄与すると考える。