- 摘 要
-
（同濟(jì)大學(xué)建筑工程系，上海 200092）
［摘要］采用外貼U形碳纖維布條的方法對12根低強(qiáng)度（fcu≤15MPa）混凝土梁進(jìn)行了抗剪加固試驗。結(jié)果表明，外貼碳纖維布能夠明顯改善低強(qiáng)度混凝土梁的抗剪性能，梁破壞主要源于纖維布剝離，如果布條端部設(shè)置壓條，加固梁破壞前有明顯先兆?；跀嗔蚜W(xué)模型，由拉剪粘結(jié)試驗確定碳纖維布剝離時所能承受的有效拉力；利用平面桁架模型，提出加固梁外貼U形碳纖維布條剝離時抗剪承載力的計算方法。計算和試驗結(jié)果的比較分析表明，所提方法可用于低強(qiáng)度混凝土梁的抗剪加固設(shè)計。
［關(guān)鍵詞］碳纖維布；低強(qiáng)度混凝土梁；加固；抗剪性能；剝離
Shearing behavior of low strength reinforced concrete beams strengthened with carbon fiber composite sheets
Li Xiang，Gu Xianglin，Zhang Yuefang (Deparment of Building Engineering, Tongji University, Shanghai 200092，China)
Abstract:Low strength reinforced concrete beams (the cubic strength of concrete fcu≤15MPa) were strengthened by gluing carbon fiber composite U type strips across the beam section to enhance the shearing behavior of beams, and corresponding tests for 12 strengthened beams were done in the lab. Test results show that the method can be applied to improve the shear behavior of low strength reinforced concrete beams. Using the additional anchoring sheets at the end of U type strips, shearing capacity and deformation ability of reinforced concrete beams can be improved obviously. With the help of fracture mechanics and bond strength test, the effective pulling force between carbon fiber composite sheets and concrete was calculated. Based on the plane truss model, the calculation method to determine the shearing bearing capacity of low strength reinforced concrete beams was proposed when sheets debonded. Verified by the test results, it can be concluded that the proposed method can be used in the shearing strengthening design of low strength reinforced concrete beams.
Keywords:carbon fiber composite sheet； low strength reinforced concrete beam； strengthening； shearing behavior； debonding
國家科技支撐計劃（2006BAJ03A07）；上海市科學(xué)技術(shù)委員會科研攻關(guān)項目（032112060）聯(lián)合資助。
作者簡介：李翔，博士，講師，Email:lixiang@mail.#edu.cn。
參考文獻(xiàn)
［1］吳剛，安琳，呂志濤．碳纖維布用于鋼筋混凝土梁抗剪加固的試驗研究［J］．建筑結(jié)構(gòu)，2000，30(7)：16-20.
［2］匡志平，劉成偉，王皓波．無腹筋混凝土梁的碳纖維抗剪加固試驗研究［J］．同濟(jì)大學(xué)學(xué)報，2004，32(5)：575-579.
［3］ZHANG ZHICHAO，THOMAS HSU CHENG TZU．Shear strengthening of reinforced concrete beams using carbon-fiber-reinforced polymer laminates［J］．ASCE Journal of Composites for Construction，2005，9(2)：158-169.
［4］GB50367—2005 混凝土結(jié)構(gòu)加固設(shè)計規(guī)范［S］. 北京：中國建筑工業(yè)出版社，2005.
［5］ACI Committee 440.2R-02．Guide for the design and construction of externally bonded FRP systems for strengthening concrete structures［S］．Farmimington Hill，USA：ACI，July 2000.
［6］NEUBAUER U， ROSTASY F S．Design aspects of concrete structures strengthened with externally bonded CFRP plates［C］∥Proc．7th International Conference on Structural Faults and Repair．2，ECS Publications，Edinburgh，Scotland，1997：109-118.
［7］劉麗梅．碳纖維與混凝土粘結(jié)性能及其耐久性研究［D］．上海：同濟(jì)大學(xué)，2006.
［8］CHAJES M J， FINCH W W， JANUSZHA T F，et al．Bond and forcetransfer of composite material plates bonded to concrete［J］．ACI Structural Journal，1996，93(2)：208-218.
