高温喷水冷却后方钢管高强混凝土的界面黏结性能  

Interface Bond Behavior of High Strength Concrete Filled Square Steel Tube Subjected to High Temperature and Subsequent Water Cooling

作　　者：陈宗平[1,2] 周济 陈建佳 周星宇 CHEN Zongping;ZHOU Ji;CHEN Jianjia;ZHOU Xingyu(College of Civil Engineering and Architecture,Guangxi University,Nanning 530004,Guangxi,China;MOE Key Laboratory of Disaster Prevention and Structural Safety,Guangxi University,Nanning 530004,Guangxi,China)

机构地区：[1]广西大学土木建筑工程学院,广西南宁530004 [2]广西大学工程防灾与结构安全教育部重点实验室,广西南宁530004

出　　处：《华南理工大学学报（自然科学版）》2020年第9期20-33,共14页Journal of South China University of Technology(Natural Science Edition)

基　　金：国家自然科学基金资助项目(51268004);广西自然科学基金重点资助项目(2016GXNSFDA380032);八桂学者专项经费资助项目([2019]79号)。

摘　　要：为研究高温喷水冷却后方钢管高强混凝土界面间的黏结性能,设计22个试件进行静力推出试验,其中包括18个喷水冷却试件和4个自然冷却试件,主要考虑混凝土强度、历经最高温度、锚固长度、恒温时长和冷却方式的影响。通过试验揭示了高温喷水冷却后方钢管高强混凝土界面黏结失效机理,分析了各变化参数对其黏结性能的影响,并提出了高温喷水冷却后方钢管高强混凝土极限黏结强度和残余黏结强度的计算公式。结果表明:高温喷水冷却后方钢管高强混凝土加载端与自由端的荷载滑移曲线可分为两类典型曲线;高温喷水冷却后,试件的黏结强度随历经最高温度的升高先增大后减小,随混凝土强度的增大而增大,随锚固长度的增大而减小,且与恒温60 min试件相比,恒温90 min试件的黏结强度有所回升;与自然冷却试件相比,喷水冷却试件的极限黏结强度、残余黏结强度与剪切黏结刚度均较小,但界面耗能能力较大;运用文中所提出的黏结强度计算公式算得的结果与试验值吻合良好。To study the interface bond behavior of high strength concrete filled square steel tube(HSST)subjected to high temperature and subsequent water cooling,22 specimens were designed to carry out static push-out tests including 18 water cooling specimens and 4 natural cooling specimens,and the effects of concrete strength,maximum temperature,anchorage length,constant temperature and cooling mode were mainly considered.The interface fai-lure mechanism of the HSST subjected to high temperature and subsequent water cooling was revealed through experiments,and the influence of various parameters on the bond properties was analyzed.In addition,the formulas for calculating ultimate bond strength and residual bond strength of HSST subjected to high temperature and subsequent water cooling were put forward.The results show that the load-slip curves of the loading end and the free end of the specimen subjected to high temperature and subsequent water cooling can be divided into two kinds of typical curves.After high temperature and subsequent water cooling,the bond strength of the specimen increases first and then decreases with the increase of the maximum temperature,increases with the increase of the concrete strength,and decreases with the increase of the anchor length.Compared with that at holding time for 60 min,the bond strength of the specimen at holding time for 90 min rebounds.Compared with the natural cooling specimens,the ultimate bond strength,residual bond strength and bond shear stiffness of the specimens subjected to water cooling are smaller,and the interface energy dissipation capacity is larger.The results calculated by the calculation formula of the bond strength proposed agrees well with the experimental results.

关 键 词：方钢管 高强混凝土 高温喷水冷却 黏结强度 滑移性能 

分 类 号：TU398[建筑科学—结构工程]