摘要
为研究正交胶合木(CLT)楼板耐火极限计算中的零强度层厚度取值,分别进行了三层、五层CLT楼板常温极限承载力试验和耐火极限试验,并基于国内外木结构设计规范,结合忽略横纹层层板的弹性模量、仅考虑其厚度对组合截面惯性矩贡献的简化计算方法与剩余截面法,得到了一种适用于CLT楼板高温下零强度层厚度取值的计算方法,分析了CLT楼板零强度层厚度随炭化深度的变化规律,比较了CLT楼板高温下抗弯承载力在文中零强度层厚度取值下的结果和欧洲规范EN1995-1-2中的结果.研究结果表明:文中计算方法下的计算值与试验值吻合较好.当CLT楼板的炭化层到达横、顺纹层胶缝处时,零强度层厚度变化连续;而当炭化深度到达顺、横纹层的胶缝处时,零强度层厚度发生急剧突变.本文计算方法得到的高温下CLT楼板抗弯承载力相较于欧洲规范EN1995-1-2更合理,对于工程中的CLT楼板抗火设计具有更好的参考价值.
In order to study the thickness evaluation of zero-strength layer in the calculation of fire resistance for Cross-Laminated Timber(CLT)floor,the ultimate load-carrying capacity test and fire test of the CLT floors with three and five layers were carried out,respectively.Based on the domestic and foreign wood structure design codes,com-bined with the simplified design method that ignores the elastic modulus of laminated laminates and only considers the thickness contribution to the moment of inertia of composite sections as well as the reduced cross-section method,a suitable method for the CLT floor was obtained.The variation law of zero-strength layer thickness of CLT floor with charring depth was analyzed.The flexural capacity of CLT floor under high temperature based on the thickness of ze-ro-strength layer in this paper and the results based on EN1995-1-2 were compared.The results showed that the val-ues by the calculation method agreed well with the experimental values.When the charred layer of the CLT floor reached the glue line between cross and longitudinal-layer,the thickness of the zero-strength layer changed continu-ously;and when the charring depth reached the glue line between longitudinal and cross-layers,the thickness of the zero-strength layer changed sharply.The bending capacity of CLT floor under high temperature obtained by the cal-culation method in this paper was more reasonable than the prediction of EN1995-1-2,which had better reference value for the fire resistance design of CLT floor in practice.
作者
张晋
陆川
梅方
王卫昌
李维滨
ZHANG Jin;LU Chuan;MEI Fang;WANG Weichan;LI Weibin(Key Laboratory of Concrete and Prestressed Concrete Structures of Ministry of Education,Southeast University,Nanjing 211189,China;CIFI Holdings(Group)Co Ltd,Shanghai 201106,China)
出处
《湖南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2020年第3期73-81,共9页
Journal of Hunan University:Natural Sciences
基金
国家重点研发计划项目(2017YFC0703503)
国家自然科学基金资助项目(51778143)。
关键词
正交胶合木(CLT)
零强度层
耐火极限
炭化深度
剩余截面法
抗火设计
Cross-Laminated Timber(CLT)
zero-strength layer
fire resistance
charring depth
reduced crosssection method
fire resistant design
作者简介
通讯联系人:张晋(1974-),男,安徽巢湖人,东南大学教授,工学博士,E-mail:zhangjin@seu.edu.cn。
