空间约束钢-混凝土组合楼盖抗火性能试验研究  

Experimental study on behavior of steel-concrete composite floor with spacial restraints subjected to fire

作　　者：张大山[1] 张建春 王慧青 董毓利[1] 王卫华[1] 李艳艳 ZHANG Dashan;ZHANG Jianchun;WANG Huiqing;DONG Yuli;WANG Weihua;LI Yanyan(College of Civil Engineering,Huaqiao University,Xiamen 361021,China;College of Architecture and Civil Engineering,Xiamen Institute of Technology,Xiamen 361021,China;Henan Zhongyuan Highway Survey and Design Company,LTD,Puyang 457000,China)

机构地区：[1]华侨大学土木工程学院,福建厦门361021 [2]厦门工学院建筑与土木工程学院,福建厦门361021 [3]河南中原公路勘察设计有限公司,河南濮阳457000

出　　处：《建筑结构学报》2022年第2期52-64,共13页Journal of Building Structures

基　　金：国家自然科学基金项目(51778250);福建省自然科学基金项目(2019J01051);福建省中青年教师教育科研项目(JAT190949);厦门工学院校级科研项目(KYT2019011)。

摘　　要：整体结构中钢-混凝土组合楼盖的抗火性能和与其直接相连的周边部件提供的约束力关系密切,但以往研究中却难以获得约束力的真实大小。为此,设计了空间约束钢框架,用以模拟真实结构中钢-混凝土组合楼盖的边界条件,同时可测得约束力的大小。通过开展带空间约束框架的钢-混凝土组合楼盖的受火试验,获得了组合楼盖的裂缝发展过程、破坏特征、温度场、竖向位移、水平位移、板边转角和边界约束力等。研究表明:组合楼盖受火时间为300 min时,混凝土板的表面温度升高幅度超过180℃,失去隔热性;组合楼盖的板中最大竖向变形(105.8 mm)为短跨跨度的1/34,且停火后产生明显的回弹(恢复率达到47.8%),这多归因于降温段板底次梁的强度恢复;组合楼盖板角的约束力较为显著,主要包括板角约束弯矩和翘曲力;在升温和降温阶段,板角的翘曲力变化均较为明显并且反向,因此对上下相邻两层的承重柱有潜在的安全隐患。Fire resistance of steel-concrete composite floor in an overall structure has a direct relationship to its restraint forces provided by the surrounding structural elements,but it is very difficult to measure the corresponding restraint forces.In order to simulate the real edge restraint condition and to obtain the value of restraint forces,a new device,mainly composed of a spatial steel-frame structure,was designed and fabricated with the steel-concrete composite floor in this paper.A fire test was conducted on the steel-concrete composite floor with spatial restraints to observe the development of cracks and to explore the final failure modes.In addition,the temperature field,vertical and horizontal displacements,rotational angle and restraint forces at the corner of the slab,were all collected during the test.It is shown that the fire-resistance time of the steel-concrete composite floor is 300 min,at which moment the temperature on the slab surface reaches 180℃,so indicating that thermal insulation is compromised.The testing data indicated that the maximum vertical displacement,105.8 mm,is approximately 1/34 of the length of the shorter span.A strong displacement-recover phenomenon occurrs at the cooling stage,with a ratio of as high as 47.8%,and this phenomenon is due to the strength recovery of the steel secondary beam under the slab.The effect of restraint forces at the corner of steel-concrete composite floor is obvious,and the restraining action includes the restraint moments and warping forces.The warping forces are significant and have an inverse variation range at the elevated and cooling stage,and it could be a potential hazard to the columns at the adjacent storey.

关 键 词：钢-混凝土组合楼盖 空间约束 受火试验 翘曲力 抗火性能 

分 类 号：TU398.9[建筑科学—结构工程] TU317.1