高温喷水冷却后圆钢管高强混凝土的界面黏结性能试验研究  

Experimental Study on Interface Bond Behavior of High Strength Concrete Filled Circle Steel Tube after Elevated Temperatures and Water Cooling

作　　者：陈宗平[1,2] 周济 陈建佳 班茂根 CHEN Zongping;ZHOU Ji;CHEN Jianjia;BAN Maogen(College of Civil Engineering and Architecture,Guangxi University,Nanning 530004,China;Key Laboratory of Disaster Prevention and Structural Safety of Ministry of Education(Guangxi University),Nanning 530004,China)

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

出　　处：《湖南大学学报（自然科学版）》2021年第3期75-87,共13页Journal of Hunan University:Natural Sciences

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圆钢管高强混凝土界面间的黏结性能,设计22个圆钢管试件进行高温喷水冷却处理后的静力推出试验,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圆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,并提出高温喷水冷却后圆钢管高强混凝土黏结强度的计算公式.结果表明:高温喷水冷却后试件加载端与自由端的荷载滑移曲线变化趋势基本相似,并可将其分为三类典型曲线;推出试验中钢管外表面应变与距加载端的距离呈指数关系分布;高温喷水冷却后,试件的黏结强度随混凝土强度的增大变化较小,与锚固长度成反比,恒温时长大于60 min后基本稳定,随历经最高温度的升高,极限黏结强度先增大后减小再增大,残余黏结强度先增大再减小;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,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.In order to study the interface bond behavior of high strength concrete filled circle steel tube(HCST)after elevated temperatures and water cooling,22 specimens were designed to be subjected to static push-out tests,and the effects of concrete strength,maximum temperature,bonded length,constant temperature and cooling mode were mainly considered.The interface failure mechanism of the HCST after elevated temperatures and water cooling was revealed through experiments,the influence of various parameters on the bond properties was analyzed,and the formulas for calculating the ultimate bond strength and residual bond strength of HSST after elevated temperatures and 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 elevated temperatures and water cooling are basically similar,and they can be divided into three typical curves.The longitudinal stress-strain distribution on the outer surface of the steel tube in the test is exponential.After elevated temperatures and water cooling,the bond strength of specimens changes little with the increase of concrete strength,and is inversely proportional to the bonded length.It is basically stable after the constant temperature reaching 60 minutes.With the increase of the maximum temperature,the ultimate bond strength first increases,then decreases,and finally increases,and the residual bond strength first increases and then decreases.Compared with the natural cooling specimens,the ultimate bond strength,residual bond strength and shear bond 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 in this paper agree well with the experimental values.

关 键 词：高温喷水冷却后 圆钢管 高强混凝土 黏结强度 滑移性能 

分 类 号：TU398[建筑科学—结构工程]