预张拉碳纤维布加固钢筋混凝土梁受弯性能研究  

Study on Bending Behavior of Reinforced Concrete Beams Strengthened by Pre-tensioned Carbon Fiber Composite Sheets

作　　者：顾祥林[1] 高鹏[1] 张伟平[1] 李翔[1] 

机构地区：[1]同济大学建筑工程系,上海200092

出　　处：《建筑材料学报》2009年第2期141-147,共7页Journal of Building Materials

基　　金：上海市科学技术委员会科研攻关项目(032112060)

摘　　要：采用自行开发的锚具和张拉加固施工工艺,对12根钢筋混凝土梁进行了预张拉碳纤维布加固和单调静力加载试验.通过试验,研究了加固梁的破坏模式和破坏机理,分析了持荷力水平、碳纤维布预张拉应变和加固量对构件受力性能的影响.结果表明,采用预张拉工艺加固钢筋混凝土梁,梁端锚具具有很好的锚固作用,能有效避免碳纤维布端部剥离;提高碳纤维布的工作应变,可使抗拉强度得到充分利用;增加碳纤维布预拉应变和碳纤维布用量可提高梁的承载力,改善梁的使用性能;对于极限状态下碳纤维布被拉断这一破坏模式,加固时梁上的持荷水平对预张拉碳纤维布加固梁的极限承载力影响不大.另外,给出了加固梁截面抗弯承载力的计算公式和加固设计建议.Using the new type of tensioning and anchoring system for carbon fiber composite sheets and corresponding construction techniques developed by ourselve,twelve reinforced concrete beams strengthened with pre-tensioned carbon fiber composite sheets were tested.The failure modes and mechanism of strengthening under monotonic load were studied and the influence of the pre-tensioned strain,the amount of carbon fiber composite sheets and initial load on the bending behavior of strengthened beams were analyzed and discussed.The results of the test show that the anchoring system can prevent the debonding of carbon fiber composite sheets at the end of the beam;the working strain of carbon fiber composite sheets is increased significantly and the tensile strength of fiber materials is fully used;both the flexural bearing capacity and the stiffness of the strengthened beams are enhanced with the increase of the pre-tensioned strain and the amount of carbon fiber cloth;for the failure mode of the breaking of carbon fiber composite sheets,the initial load on the beam will not much influence the ultimate capacity of the beam greatly.Based on the experiment results a calculation method of bending bearing capacity for strengthened beams and suggestions of strengthening design are proposed.

关 键 词：预张拉 碳纤维布 加固 钢筋混凝土梁 受弯性能 

分 类 号：TU528.571[建筑科学—建筑技术科学]