- 摘 要
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（1 上海交通大學船舶海洋與建筑工程學院， 上海 200240; 2 上海市建筑科學研究院 上海市工程結(jié)構(gòu)安全重點實驗室， 上海 200032）
［摘要］通過5根膠合竹梁的耐火極限試驗，對三面受火膠合竹梁的升溫規(guī)律和耐火極限進行了研究，試驗參數(shù)包括截面和荷載比。研究表明：未受火對比膠合竹梁經(jīng)歷彈性階段、彈塑性階段后，發(fā)生脆性斷裂破壞；跨中截面應(yīng)變符合平截面假定。耐火極限試驗試件各測點溫度隨受火時間的增加而升高，且停火之后溫度下降較慢；測點離膠合竹截面表面距離越近，溫度越高；不同試件距邊緣相同距離測點的溫度隨受火時間變化規(guī)律基本相似。相同截面膠合竹梁耐火極限隨荷載比增大而減小，相同荷載比膠合竹梁耐火極限隨截面尺寸增大而增加。100×225截面膠合竹梁荷載比為0-2，0-35，0-5時，耐火極限分別為30，22，10 min。
［關(guān)鍵詞］膠合竹梁； 三面受火； 耐火極限； 跨中撓度
中圖分類號：TU366-1， TU352-5文獻標識碼：A文章編號：1002-848X(2018)10-0103-05
Experimental study on fire endurance of laminated bamboo beams exposed to three-side fire
Leng Yubing1,2, Chen Lingzhu2, Xu Qingfeng2, Zhao Jincheng1, Chen Xi2
(1 School of Naval Architecture, Ocean and Civil Engineering, Shanghai Jiao Tong University, Shanghai 200240, China; 2 Shanghai Key Laboratory of Engineering Structure Safety, Shanghai Research Institute of Building Sciences, Shanghai 200032, China)
Abstract:The temperature development law and fire endurance of laminated bamboo beams exposed to three-side fire were studied through fire endurance tests of 5 laminated bamboo beams. The parameters included cross-section and load ratio. Results show that the control specimen experiences elastic phase and elastic-plastic phase before brittle rupture. The strain distribution across the mid-span cross-section is basically conformed to plane cross-section assumption. Temperature of thermocouples set in specimens increases with the increase of fire exposure time and decreases very slowly after the fire is stopped. The closer the thermocouples to the surface of laminated bamboo beam are, the higher their temperature is. For the thermocouples at different specimens with the same distance to the surface of laminated bamboo beam, temperature varies similarly with the fire exposure time. It is observed that for the laminated bamboo beams with the same cross-section, the fire endurance decreases with the increase of load ratios, while for the laminated bamboo beams subjected to the same load ratios, the fire endurance increases with the increase of cross-section. The fire endurance of laminated bamboo beams with the 100×225 cross-section tested under the load ratio of 0-2, 0-35 and 0-5 are 30, 22 and 10 min respectively.
Keywords:laminated bamboo beam; three-side fire; fire endurance; mid-span deflection
*“十三五”重大科技專項課題（2017YFC0703503），上海市科委技術(shù)標準項目（17DZ2202600）。
通訊作者：許清風，博士，教授級高級工程師，Email: xuqingfeng73@163.com。
