CFRP加固钢筋混凝土梁裂缝基部剥离界面剪应力分析  

Debonding interfacial shear stress near crack of RC beam strengthened with CFRP

作　　者：刘泽军[1] 李艳[1] 

机构地区：[1]河南理工大学土木工程学院,河南焦作454003

出　　处：《混凝土》2009年第5期43-47,共5页Concrete

基　　金：国家自然科学基金项目(50574037);河南省教育厅自然科学研计划资助项目(2007560005);河南理工大学青年骨干教师资助项目(649042)

摘　　要：CFRP的剥离是抗弯加固钢筋混凝土梁经常会出现一种早期破坏模式,这种破坏主要是由于裂缝基部附近的界面剪应力与正应力所造成。通过8根碳纤维板材抗弯加固钢筋混凝土梁的试验,主要研究裂缝基部纤维片材发生剥离时的界面剪应力。研究结果表明:在跨中等弯矩区,受拉区垂直裂缝的发生,导致裂缝基部的CFRP与混凝土间产生界面剪应力而剥离,其剪应力分布类似于钢筋与混凝土之间的锚固黏结应力分布,且最大剪应力位置逐步向远离裂缝转移的过程大致与CFRP剥离过程相一致,剪应力最大值与纤维层数、混凝土强度有关。Debonding of CFRP is a main premature failure of RC members strengthened by means of externally bonded plate, which is mainly due to both shear and normal stress induced near crack.By the experiment of 8 RC beam strengthened with CFRP,the interfacial shear stress is studied.The results of research show that in the constant moment region at mid-span, vertical flexural cracks led to the debonding between CFRP and concrete substrate because of the interfacial shear stress,whose distribution pattern was similar to that of bond-anchorage stress.The distribu- tion region of maximum interracial shear is similar to the debonding extending of CFRP.The main influence parameters on the maximum interfa- cial shear stress include the amount of FRP and the concrete strength.

关 键 词：CFRP 剥离 裂缝 界面剪应力 

分 类 号：TU528.01[建筑科学—建筑技术科学]