双端张拉CFRP布加固大直径RC圆柱的预应力损失  

Study on the prestress loss of CFRP reinforced large diameter RC cylinder by double-ended tensioning CFRP fabric

作　　者：卢春玲[1,2,3,4] 袁国华 王强 陈建通[1] Lu Chun-ling;Yuan Guo-hua;Wang Qiang;Chen Jian-tong(College of Civil Engineering,Guilin University of Technology,Guilin 541004,China;Guangxi Key Laboratory of New Energy and Building Energy Saving,Guilin 541004,China;Guilin University of Technology,Collaborative Innovation Center for Exploration of Hidden Nonferrous Metal Deposits and Development of New Materials in Guangxi,Guilin 541004,China;Guangxi Engineering Research Center of Intelligent Structural Material,Guilin 541004,China)

机构地区：[1]桂林理工大学土木与建筑工程学院,广西桂林541004 [2]广西建筑新能源与节能重点实验室,广西桂林541004 [3]桂林理工大学广西有色金属隐伏矿床勘查及材料开发协同创新中心,广西桂林541004 [4]广西壮族自治区智慧结构材料工程研究中心,广西桂林541004

出　　处：《工程抗震与加固改造》2023年第4期138-147,169,共11页Earthquake Resistant Engineering and Retrofitting

基　　金：国家自然科学基金项目(51568015);广西创新驱动发展专项(桂AA20302006);广西建筑新能源与节能重点实验室基金项目(22-J-21-10);广西重大科技创新基地建设项目(2018-242-G02)。

摘　　要：针对单端张拉碳纤维(Carbon Fibre Reinforced Plastics,CFRP)布加固大直径RC圆柱持荷过程中损失较大的问题。本文提出增设一套张拉锚固装置的双端张拉施工方法对其进行改善,对12组预应力CFRP布加固RC柱进行了预应力损失试验研究。考虑了单/双端张拉、柱直径大小、柱表面粗糙度、是否二次张拉对预应力损失的影响,分析了张拉过程的摩擦损失和持荷过程的预应力损失。建立了CFRP布预应力损失理论计算公式。试验结果表明,张拉过程中CFRP布与柱表面的相对滑动造成的摩擦损失是CFRP布预应力损失的主要部分,双端张拉较单端张拉可有效降低CFRP布的最大摩擦损失和CFRP布总预应力损失,其降幅高达53.9%和46.7%。在柱面涂胶可降低CFRP布的摩擦损失率和回缩引起的预应力损失率,二次张拉可有效降低CFRP布回缩引起的预应力损失率。基于试验结果建立了预应力损失计算公式,为CFRP布预应力损失计算提供参考。To solve the problem of large losses during the load-holding process of large-diameter RC columns reinforced with single-end tensioned Carbon-Fiber Reinforced Polymers(CFRP)fabric,a double-end tensioning construction method with an additional set of tensioning anchorage devices is proposed to improve it,and a test study on prestress losses is conducted on 12 groups of prestressed CFRP fabric reinforced RC columns.Experimental variables include single/double-end tensioning method,column diameter,surface treatment,prestress level,and one-off/repeated tensioning.The prestress losses due to friction during the tensioning process and the prestress losses in CFRP fabric during load-holding are analyzed.The test results show that the friction loss caused by the relative sliding of CFRP fabric and column surface during the tensioning process is the main part,and the double-end tensioning can effectively reduce the maximum friction loss of CFRP fabric and the total prestress of CFRP fabric by up to 53.9%and 46.7%compared with the single-end tensioning.Applying to epoxy coating to the column surface can reduce the friction loss ratio and the prestress losses ratio caused by CFRP fabric retraction,while repeated tensioning can effectively reduce the prestress losses ratio caused by CFRP fabric retraction.Based on the test results,the calculation formula of prestress losses is established,which provides a reference for the calculation of prestress losses of CFRP fabric.

关 键 词：预应力损失 CFRP布 大直径RC圆柱 双端张拉 试验研究 

分 类 号：TU375.3[建筑科学—结构工程] TU502.6