密肋复合墙板抗火性能研究  

Fire resistance performance of multi-ribbed composite walls

作　　者：王泽林 陈安 孙静[1,2] WANG Zelin;CHEN An;SUN Jing(School of Civil Engineering,Beijing Jiaotong University,Beijing 100044,China;Beijing’s Key Laboratory of Structural Wind Engineering and Urban Wind Environment,Beijing Jiaotong University,Beijing 100044,China)

机构地区：[1]北京交通大学土木建筑工程学院,北京100044 [2]北京交通大学结构风工程与城市风环境北京市重点实验室,北京100044

出　　处：《建筑结构学报》2024年第12期148-159,共12页Journal of Building Structures

基　　金：国家自然科学基金项目(52078037,52078032)。

摘　　要：为研究密肋复合墙板的抗火性能,对2个足尺密肋复合墙板分别进行了单面及双面受火工况下的抗火性能试验研究,得到了墙板的温度场变化、位移变化、耐火极限和破坏模式。试验结果表明:单面受火工况下的密肋复合墙板内部沿厚度方向形成明显的温度梯度,破坏时背火面加气混凝土砌块和肋梁、肋柱混凝土温度分别为90℃和109℃,墙板破坏模式表现为由热弯曲引起的压弯失稳破坏;双面受火工况下的密肋复合墙板在加气混凝土砌块厚度的中心处形成低温区域,破坏时该处温度为193℃,墙板破坏模式为由材料强度退化引起的轴压破坏;两种受火工况下墙板内加气混凝土砌块和肋梁、肋柱混凝土间存在不可忽略的温度梯度;加气混凝土砌块和肋梁、肋柱混凝土的界面开裂未影响墙板在火灾下的完整性;轴压比为0.5时,单面和双面受火工况下的密肋复合墙板分别在181 min和91 min时达到耐火极限。建立了密肋复合墙板的有限元模型,通过对轴压比及受火工况进行参数分析发现:随轴压比的不断增大,密肋复合墙板在受火过程中的热膨胀极值不断减小,且在轴压比和受火时间相同时,双面受火墙板较单面受火墙板的轴向热膨胀值更大。To investigate the fire resistance performance of multi-ribbed composite walls,two full-scale multi-ribbed composite walls were subjected to single-and double-sided fire tests,respectively.The temperature fields,displacements,fire resistances and failure modes of the walls were obtained.It is observed from the test that,under single-sided fire,a significant temperature gradient formed inside the wall along the thickness direction.When damaged,the temperatures of the autoclaved aerated concrete blocks and the concrete of the ribbed beams and ribbed columns on the surface unexposed to fire are 90℃and 109℃,respectively.The failure mode is compressive-bending instability caused by thermal bending.For the wall under double-sided fire,a low temperature area is formed at the center along the thickness of the autoclaved aerated concrete blocks.When the wall fails,the temperature in this area is 193℃.The failure mode is axial compression failure caused by material strength degradation.Therefore,there is a significant temperature gradient between the autoclaved aerated concrete blocks inside the wall and the concrete of the ribbed beams and ribbed columns under both fire conditions.The interfacial cracking between the autoclaved aerated concrete blocks and the concrete of ribbed beams and columns has a negligible effect on the integrity of the walls.Under an axial compression ratio of 0.5,the walls under single-and double-sided fire conditions reach the fire resistances of 181min and 91min,respectively.The finite element model of multi-ribbed composite wall was established and a parametric study was conducted considering the axial compression ratios and fire conditions.It is found that the peak of thermal expansion of the multi-ribbed composite wall decreases as the axial compression ratio increases.When subjected to the same axial compression ratio and fire time,the axial thermal expansion of the wall under double-sided fire is larger than that under single-sided fire.

关 键 词：密肋复合墙板 单面受火 双面受火 足尺火灾试验 有限元分析 抗火性能 

分 类 号：TU528.2[建筑科学—建筑技术科学]