CFRP加固混凝土梁蠕变特性的研究  

Research on Creep Characteristics of CFRP Reinforced Concrete Beams

作　　者：李延超[1] 聂智鹏 曹平[3] LI Yanchao;NIE Zhipeng;CAO Pin(Hunan Urban Construction College,Xiangtan Hunan 411101,China;Hunan Institute of Engineer-ing,Xiangtan Hunan 411104,China;Central South University,Changsha Hunan,410083,China)

机构地区：[1]湖南城建职业技术学院,湖南湘潭411101 [2]湖南工程学院,湖南湘潭411104 [3]中南大学,湖南长沙410083

出　　处：《保山学院学报》2023年第5期82-87,共6页JOURNAL OF BAOSHAN UNIVERSITY

基　　金：湖南省教育厅资助科研项目“基于价值系数和系统评价方法基坑支护成本优化的研究”(项目编号:22C0765)。

摘　　要：针对碳纤维增强塑料(CFRP)物理力学特性,探讨了混凝土梁式构件加固中碳纤维增强塑料筋材与锚固剂黏结应力的非线性特征、荷载传递和黏弹塑非线性蠕变模型问题。通过添加M-C塑性元件,建立反映黏结界面三阶段的非线性蠕变模型,推导了蠕变本构方程,获得了加速蠕变时CFRP筋材与锚固剂界面黏结应力的门槛值和加速蠕变的破坏时间。通过室内实验验证:加载初期筋材出现了瞬时的轴向变形及轴向应力,随着时间延续筋材中间点a位置的轴向位移、位移速率及轴向应力较测点b位置均有增加的传递特性。经五级加载后,最大轴向位移和最大轴向应力分别达到9.52 mm和240 MPa,在加载持续62.2 h后,首先在筋材中间产生加速变形,紧接着向两侧迅速延伸发生脱黏而破坏。Based on the physical and mechanical properties of carbon fiber reinforced plastic(CFRP),this paper explores the nonlinear characteristics,load transfer,and viscoelastic plastic nonlinear creep model of the bond stress between carbon fiber reinforced plastic reinforcement and anchorage agent in the reinforcement of concrete beam members.By adding M-C plastic elements,a nonlinear creep mod⁃el reflecting the three stages of bonding interface was established,and the creep constitutive equation was derived.The threshold value of bonding stress at the interface between CFRP reinforcement and an⁃choring agent during accelerated creep and the failure time of accelerated creep were obtained.Through indoor experiments,it was verified that there was instantaneous axial deformation and axial stress in the reinforcement during the initial loading stage.Over time,the axial displacement,displacement rate,and axial stress at point a in the middle of the reinforcement increased compared to point b in the measure⁃ment.After five levels of loading,the maximum axial displacement and maximum axial stress reached 9.52 mm and 240 MPa,respectively.After loading for 62.2 hours,accelerated deformation first oc⁃curred in the middle of the reinforcement,followed by rapid extension to both sides,leading to debond⁃ing and failure.

关 键 词：碳纤维增强塑料 物理力学特性 混凝土加固 蠕变模型 破坏 

分 类 号：TU502[建筑科学—建筑技术科学]