预应力CFRP片材抗剪加固钢筋混凝土T梁试验研究  

Experimental study on T-section RC beams shear-strengthened with prestressed CFRP sheets

作　　者：周畅[1] 王文炜[1] 石劭阳 Zhou Chang;Wang Wenwei;Shi Shaoyang(Southeast University,Nanjing 211189,China;Zhuhai Da Hengqin Investment Co.,Ltd.,Zhuhai 519000,China)

机构地区：[1]东南大学,江苏南京211189 [2]珠海大横琴集团投资有限公司,广东珠海519000

出　　处：《土木工程学报》2020年第9期68-76,84,共10页China Civil Engineering Journal

基　　金：国家自然科学基金(51578135,51878156)。

摘　　要：针对外贴FRP片材抗剪加固钢筋混凝土梁存在材料利用率低、易发生剥离破坏等问题,开发了用于抗剪加固的CFRP片材预应力张拉和锚固系统,给出了相应的施工工艺和方法。为验证提出系统的有效性,进行了预应力CFRP片材抗剪加固钢筋混凝土T型截面梁试验。基于CFRP片材断裂的破坏模式,提出了预应力CFRP片材加固钢筋混凝土梁的抗剪承载力计算公式。结果表明,该文开发的预应力张拉和锚固系统能有效地对CFRP片材施加预应力,减少预应力损失。预应力CFRP片材抗剪加固梁均发生以受压区混凝土压碎为标志的受弯破坏模式,锚固装置能够确保CFRP片材在断裂之前不发生剥离破坏。预应力CFRP片材对混凝土梁斜裂缝的产生和发展有明显的抑制作用,加固后钢筋混凝土梁的抗剪承载力得到大幅提升。计算结果与试验值吻合较好,验证了加固梁抗剪承载力模型的有效性。Due to low utilization of high-strength properties and easy peeling failure of CFRP sheets,performance improvement of RC beams strengthened with non-prestressed CFRP sheets is usually limited.To ensure effective bonding,a tensioning and anchorage system of prestressed CFRP sheet was developed and the corresponding construction technology was also given.In order to verify the feasibility of the proposed system,experiments on T-section reinforced concrete(RC) beams strengthened with prestressed CFRP sheets were carried out.Based on the failure mode for the rupture of CFRP sheets,an analytical model was presented to predict the shear capacity of RC beams strengthened with prestressed CFRP sheets.The results demonstrate that the tensioning and anchorage system can produce the reliable prestressing forces for CFRP sheets and reduce the loss of prestress.Flexural failure signified by concrete crushing in compression zone was witnessed in tested beams strengthened with prestressed CFRP sheets,but anchorage device can prevent the peeling failure of CFRP sheet before the rupture of CFRP sheets.The prestressed CFRP sheets can significantly restrain the initiation and development of concrete cracks,and the shear capacity of strengthened beams can be greatly improved.The calculated results agree well with the experimental ones,indicating that the analytical model is effective in predicting the shear capacity of RC beams strengthened with prestressed CFRP sheets.

关 键 词：预应力 CFRP片材 抗剪加固 剥离破坏 抗剪承载力 

分 类 号：TU375.1[建筑科学—结构工程]