摘要
通过4组18根胶合木梁三面受火耐火极限的对比试验，研究截面尺寸、持荷比、阻燃涂料、木梁跨中受拉区是否存在指接对耐火极限的影响。研究结果表明，随着持荷比增加，三面受火胶合木梁耐火极限明显降低，当持荷比由30％增加到50％时，耐火极限降低5～29min；随着截面尺寸增加，耐火极限略有增加，当截面尺寸由100x200增加到150×300时，耐火极限增加1～12min；胶合木梁表面采用I型阻燃涂料涂抹后耐火极限提高4～6min，采用Ⅱ型阻燃涂料常温常压浸渍后耐火极限提高4～13min；纯弯段受拉区存在指接时，耐火极限降低4～25min。多数试件竖向炭化速度大于水平炭化速度，有阻燃涂料木梁的炭化速度略小于没有阻燃涂料木梁的炭化速度。
To learn about the effective factors of fire endurance, such as cross-section, load ratio, fire retardant coating and whether the finger joints existing in the tension zone of wooden beam cross section, 18 specimens in 4 series glulam beams exposed to three-side fire were experimentally studied. It is found that the fire endurance of glulam beams exposed to three-side fire decreased greatly with the increasing load ratio. When the load ratio increases from 30% to 50% , the fire endurance decreases 5-29rain; the fire endurance increases slightly with the increasing cross-section. When the cross-section increases from 100 × 200 to 150×300, the fire endurance increases 1-12min. The fire endurance increases 4-6min when painted the I type fire retardant coating over the beam surfaces; the fire endurance increases 4-13min by Ⅱ type fire retardant coating impregnation under normal pressure and normal temperature： The finger joints at the tension zone reduces the fire endurance about 4-25min. The vertical charring rate of most specimens is greater than the horizontal charring rate, and the charring rate of specimens with fire retardant coating is slightly smaller than the others without fire retardant coating.
作者
许清风
韩重庆
胡小锋
陈玲珠
冷予冰
Xu Qingfeng;Han Chongqing;Hu Xiaofeng;Chen Lingzhu;Leng Yubing(Shanghai Key Laboratory of Engineering Structure Safety, Shanghai Research Institute of Building Sciences, Shanghai 200032, China;Architects ＆ Engineers Co., Ltd. of Southeast University, Nanjing 210096, China;School of Civil Engineering. Southeast University. Naniint~ 210096. China~)
出处
《建筑结构》
CSCD
北大核心
2018年第10期73-78,97,共7页
Building Structure
基金
上海市科委标准项目(17DZ2202600)
上海市青年科技启明星计划项目(17QB1403400)
关键词
胶合木梁
阻燃涂料
三面受火
耐火极限
指接
glulam beam
fire retardant coating
exposed to three-side fire
fire endurance
finger joint
