干湿循环作用下超高层建筑桩基础混凝土耐久性分析  

Durability Analysis of Concrete Pile Foundation of Super Tall Building Under Dry-wetting Cycle

作　　者：李振生 LI Zhen-sheng(China Railway 19 th Bureau Group Fifth Engineering Co.,Ltd.,Dalian Liaoning 116600,China)

机构地区：[1]中铁十九局集团第五工程有限公司,辽宁大连116600

出　　处：《兰州工业学院学报》2021年第4期19-23,共5页Journal of Lanzhou Institute of Technology

摘　　要：针对超高层建筑桩基础混凝土在干湿循环作用下的耐久性问题,以辽宁某在建超高层建筑为工程依托,对该建筑桩基础混凝土进行干湿循环试验及三轴加载试验,分析加载前后试样的各物理参数的变化特征随干湿循环次数n的分布规律.结果表明:随着干湿循环次数n的逐渐增多,超高层建筑桩基础混凝土试样加载前的动弹模量呈先增大再减小变化趋势,质量损失率与之相反,呈先减小再增大趋势,二者均在n=2时出现极值,在n=9时变化幅度开始减小;随着干湿循环次数的逐渐增加,应力-应变曲线的弹性阶段逐渐缩短,试样的峰值强度、峰值应变、弹性模量、泊松比及抗剪强度参数黏聚力和内摩擦角均呈逐渐递减变化趋势,且干湿循环对混凝土试样各特征参数的影响程度不同,其中受干湿循环影响最大的是峰值应变.In view the problem of the high-rise building pile foundation of the durability of the concrete under dry-wet circulation,based on the engineering support of a tall building under construction in Liaoning,the building pile foundation concrete under dry-wet cycling test and triaxial loading test are carried out to analyze load characteristics of various physical parameters of sample along with the distribution of dry-wet circulation times.The results showed that:with the increasing of the number of wetting and drying cycles,the dynamic modulus of concrete samples for pile foundation of super high-rise building increases first and then decreases before loading.On the contrary,the mass loss rate decreases first and then increases.Both of them show a maximum value when the wetting and drying cycles n=2,and the variation range begins to decrease when the wetting and drying cycles n=9.As dry-wet cycles increase gradually,gradually shorten the stress-strain curve of elastic stage,the sample of the peak strength,peak strain,elastic modulus,Poisson ratio,shear strength parameters are in diminishing the cohesion and internal friction angle change trend,dry-wet circulation characteristic parameters of concrete were investigated and the influence degree of different,one of the biggest influenced by dry-wet circulation was peak strain.

关 键 词：房屋建筑 桩基混凝土 干湿循环 动弹模量 三轴加载试验 

分 类 号：TU525[建筑科学—建筑技术科学]