Prevention of rainwater infiltration and suppression of infiltration rainwater to improve durability of wooden structural members-exposed wall construction

Research Project

Project/Area Number	17K06659
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Multi-year Fund
Section	一般
Research Field	Building structures/Materials
Research Institution	Waseda University
Principal Investigator	Koshiishi Naoyuki 早稲田大学, 理工学術院, 教授 (00257213)
Project Period (FY)	2017-04-01 – 2020-03-31
Project Status	Completed (Fiscal Year 2019)
Budget Amount *help	¥3,640,000 (Direct Cost: ¥2,800,000、Indirect Cost: ¥840,000) Fiscal Year 2019: ¥520,000 (Direct Cost: ¥400,000、Indirect Cost: ¥120,000) Fiscal Year 2018: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000) Fiscal Year 2017: ¥1,820,000 (Direct Cost: ¥1,400,000、Indirect Cost: ¥420,000)
Keywords	木造 / 真壁 / 小舞土壁 / ラスモルタル / 雨仕舞 / 防水 / 送風散水 / 吸水速度 / 吸水 / 壁土 / モルタル / 左官材料 / 小舞壁 / 毛管上昇高 / 毛管空隙 / 散水 / 雨水浸入 / 内部結露 / 腐朽
Outline of Final Research Achievements	This study is to confirm the superiority of the wooden structural members-exposed wall construction in terms of long-term use of wooden houses. First, a material test was performed on each material used, and characteristic values such as a water absorption rate were obtained. Next, wind and water spray experiment were conducted on element specimens with different details and flashing, and the effect of preventing rainwater infiltration and the behavior of infiltrated rainwater were confirmed. Then, numerical analysis was performed using the water absorption rate measured in the material test, and the experimental results were analyzed. Although the analytical model in this study is simple, the behavior of rainwater infiltration and infiltration rainwater were could be roughly expressed.
Academic Significance and Societal Importance of the Research Achievements	真壁を構成する各材料の吸水特性と、真壁構法における軸組と壁面との取合い部および壁面からの雨水の浸入や浸入後の雨水の挙動を実験により確認した。そして数値解析によって実験結果の検証を試みた。その結果は途中段階であるものの、木造住宅の長期使用に向けた材料選定、雨仕舞、納まりなどの検討に有用ないくつかの知見が得られた。