寒冷环境纳米高岭土增强预应力FRP-混凝土梁承载能力研究
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摘要
基于插层后的纳米高岭土改性环氧树脂胶,并对4根混凝土基准梁、4根预应力CFRP-混凝土梁进行0、50、150、300次冻融循环,通过三点弯曲试验,研究了冻融循环对预应力CFRP-混凝土梁的承载能力的影响。研究结果表明:基于改性的环氧树脂胶的预应力CFRP-混凝土梁可以明显改善CFRP-混凝土界面性能,强化界面黏结应力,开裂荷载、极限荷载分别提高6～12、8～16倍不等;150次冻融循环内,融循环对预应力CFRP-混凝土梁的质量和弹性模量认为变化不大;预应力CFRP-混凝土梁可以明显增强结构整体韧性,减少跨中挠度损失约20%。
Based on intercalating about nano kaolin modified epoxy resin,and the four concrete beam and four prestressed CFRP-concrete beams were made,adopting 0,50,150,300 times of freeze-thaw cycles,using three point bending test,the freeze-thaw cycle influence the bearing capacity of the prestressed CFRP-concrete beam was studied.The results show that based on the modification of epoxy resin adhesive the prestressed CFRP-concrete beam can obviously improve the interfacial performance between CFRP and concrete,strengthen the interfacial bond stress,cracking load,ultimate load increase by 6 to 12 times,8 to 16 times respectively.freeze-thaw cycle influences little on the mass and elastic modulus of prestressed CFRP-concrete beam within 150 times cycles,cycle in the quality of CFRP and concrete beam and elastic modulus think little change.Prestressed CFRP-concrete beam can significantly enhance the structural ductility,and reduce the midspan deflection lost about 20%.
Based on intercalating about nano kaolin modified epoxy resin,and the four concrete beam and four prestressed CFRP-concrete beams were made,adopting 0,50,150,300 times of freeze-thaw cycles,using three point bending test,the freeze-thaw cycle influence the bearing capacity of the prestressed CFRP-concrete beam was studied.The results show that based on the modification of epoxy resin adhesive the prestressed CFRP-concrete beam can obviously improve the interfacial performance between CFRP and concrete,strengthen the interfacial bond stress,cracking load,ultimate load increase by 6 to 12 times,8 to 16 times respectively.freeze-thaw cycle influences little on the mass and elastic modulus of prestressed CFRP-concrete beam within 150 times cycles,cycle in the quality of CFRP and concrete beam and elastic modulus think little change.Prestressed CFRP-concrete beam can significantly enhance the structural ductility,and reduce the midspan deflection lost about 20%.
引文
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[4]牛雪莉,EP/OMMT纳米改性基体GFRP的研制及耐久性研究[D].哈尔滨:哈尔滨工业大学,2011(6).
[5]李知兵.预应力CFRP板加固混凝土结构的力学性能及温差与冻融影响研究[D].长沙:湖南大学,2014(5).
[6]王兴国,周朝阳,曾宪桃,等.外贴预应力GFRP板加固混凝土梁抗弯试验研究[J].哈尔滨工业大学学报,2005,37(3):351-354.
[7]曾磊.预应力CFRP板加固混凝土梁试验与理论研究[D].上海:同济大学,2005.
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[9]薛魏辰,曾磊,谭园.预应力CFRP板加固混凝土梁设计理论研究[J].建筑结构学报,2008,29(4),127-133.
[10]普通混凝土长期性能和耐久性能试验方法标准:GB/T 50082-2009[S].
[2]EL-HACHA R,WIGHT R G,GREEN M F.Innovative system for prestressing fiber-reinforced polymer sheets[J].ACI StructuralJournal,2003,100(3):305-313.
[3]XUE W C,ZENG L,TAN Y.Experimentalstudieson bond behavior of high strength CFRP plates[J].Composites,Part B:Engineering,2008,39(4):592-603.
[4]牛雪莉,EP/OMMT纳米改性基体GFRP的研制及耐久性研究[D].哈尔滨:哈尔滨工业大学,2011(6).
[5]李知兵.预应力CFRP板加固混凝土结构的力学性能及温差与冻融影响研究[D].长沙:湖南大学,2014(5).
[6]王兴国,周朝阳,曾宪桃,等.外贴预应力GFRP板加固混凝土梁抗弯试验研究[J].哈尔滨工业大学学报,2005,37(3):351-354.
[7]曾磊.预应力CFRP板加固混凝土梁试验与理论研究[D].上海:同济大学,2005.
[8]薛伟辰.现代预应力结构设计[M].北京:中国建筑工业出版社,2003.
[9]薛魏辰,曾磊,谭园.预应力CFRP板加固混凝土梁设计理论研究[J].建筑结构学报,2008,29(4),127-133.
[10]普通混凝土长期性能和耐久性能试验方法标准:GB/T 50082-2009[S].