正交胶合木-混凝土组合楼板单面受火耐火极限试验研究  

Experimental study on fire endurance of CLT-concrete composite slabs exposed to one-side fire

作　　者：冷予冰 王明谦 许清风 陈玲珠 郭雪媛 陈溪 LENG Yubing;WANG Mingqian;XU Qingfeng;CHEN Lingzhu;GUO Xueyuan;CHEN Xi(Shanghai Key Laboratory of Engineering Structure Safety,Shanghai Research Institute of Building Sciences Co.,Ltd,Shanghai 200032,China)

机构地区：[1]上海市建筑科学研究院有限公司、上海市工程结构安全重点实验室,上海200032

出　　处：《建筑结构学报》2024年第3期52-59,100,共9页Journal of Building Structures

基　　金：国家自然科学基金面上项目(51978402);上海市优秀技术带头人计划(22XD1432100);上海市自然科学基金项目(23ZR1454400)。

摘　　要：为研究正交胶合木-混凝土组合楼板的耐火极限,设计并制作了4个正交胶合木-混凝土组合楼板试件和2个正交胶合木楼板对比试件,分别进行常温下受弯加载试验、持荷耐火极限试验和数值模拟。结果表明:常温下正交胶合木楼板的破坏模式主要包括底部规格材的顺纹受拉断裂破坏、上下两层规格材之间横纹劈裂破坏和中部规格材的滚剪破坏;常温下正交胶合木-混凝土组合楼板的破坏模式包括现浇混凝土层与正交胶合木板的界面发生剪切破坏和底部规格材顺纹受拉断裂破坏;常温下正交胶合木-混凝土组合楼板的初始刚度和受弯承载力比正交胶合木楼板的分别提高了237.8%和60.1%。受火后,正交胶合木板底发生了明显炭化,正交胶合木-混凝土组合楼板发生了明显的受弯变形。在荷载比相同的条件下,正交胶合木-混凝土组合楼板的耐火极限比正交胶合木楼板的提高了335.3%;随着荷载比由0.20增加至0.50时,试件耐火极限由74.1 min降低至30.6 min。正交胶合木-混凝土组合楼板耐火极限的数值模拟精度误差在14.1%以内,满足工程精度要求。To investigate the fire endurance of CLT-concrete composite slabs in fire,four CLT-concrete composite slab specimens and two CLT slab control specimens were designed and tested at normal temperature and in fire,respectively.Numerical simulation of the specimens was also conducted.The test results indicate that the failure modes of the CLT slab specimen at normal temperature basically include tensile failure along the grain of the bottom dimension lumbers,transverse grain splitting failure between the two adjacent layers of dimension lumbers,and rolling shear failure of the middle dimension lumbers.The failure modes of CLT-concrete composite slab specimen at normal temperature include shear failure at the interface between the cast-in-place concrete layer and the CLT panel,and tensile fracture failure of the bottom dimension lumbers along the grain.The initial stiffness and bending capacity of the CLT-concrete composite slab specimen at normal temperature are 237.8%and 60.1%higher than those of the CLT slab specimen.After being exposed to fire,there are obvious charring layers in the CLT panels,and the composite slab specimens have obvious bending deformations.Under the same load ratio,the fire endurance of the CLT-concrete composite slab specimen is 335.3%higher than that of the CLT slab specimen.With the load ratio increasing from 0.20 to 0.50,the fire endurance decreases from 74.1min to 30.6 min.The finite element model provides good prediction accuracy for the fire endurance of the CLT-concrete composite slab specimens,and the modelling errors are within 14.1%,which can satisfy the engineering accuracy requirements.

关 键 词：正交胶合木-混凝土组合楼板 荷载比 单面受火试验 数值模拟 耐火极限 

分 类 号：TU366.3[建筑科学—结构工程] TU317.1