配置碳纤维格栅的大保护层钢筋混凝土梁的裂缝试验研究
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摘要
为了解决水工结构中大保护层钢筋混凝土构件裂缝宽度较大、耐久性差的问题,提出了在保护层中配置纤维格栅,以降低裂缝宽度和改善其裂缝性能。共制作了12根大保护层钢筋混凝土梁进行四点弯曲试验,其中3根梁未配置碳纤维格栅、另外9根梁配有碳纤维格栅。试验研究了保护层厚度、纤维格栅尺寸、纤维格栅层数等参数对梁开裂过程中裂缝数量、裂缝间距和裂缝宽度的影响,然后在现有规范关于裂缝宽度计算理论的基础上,推导出配置纤维格栅的大保护层钢筋混凝土梁的裂缝宽度计算公式。试验结果表明,配置纤维格栅对限制大保护层钢筋混凝土梁的裂缝扩展具有良好效果,且随着纤维格栅网格尺寸的减小、层数的增加,梁的开裂荷载提高,且最大裂缝宽度和平均裂缝间距显著降低。提出的配置纤维格栅的大保护层钢筋混凝土梁的最大裂缝宽度验算公式的计算值与试验值吻合较好,为纤维格栅的应用提供设计依据。
In this study, a non-corrosive carbon fiber reinforced polymer(CFRP) grid is arranged in thick concrete cover to solve the problem of wide crack opening and poor durability of reinforced concrete components under service conditions in hydraulic structures. We conduct experimental tests on totally 12 simply supported thick-cover reinforced concrete beams under four-point monotonic loading-9 with CFRP grid and 3 without, and analyze influencing factors of crack spacing and width, such as concrete cover thickness and the size and number of CFRP grids. And we derive a formula for calculating crack width using the existing theory of concrete cracking and the models of concrete crack width. Results show that CFRP grids effectively control crack propagation in thick-cover reinforced beams. And either an increase in CFRP grid number or a decrease in CFRP grid size can increase cracking load and reduce the maximum crack width and average crack spacing. Calculations of the maximum crack width are in good agreement with test measurements, and thus our crack width formula helps the design of CFRP grid reinforced concrete covers.
In this study, a non-corrosive carbon fiber reinforced polymer(CFRP) grid is arranged in thick concrete cover to solve the problem of wide crack opening and poor durability of reinforced concrete components under service conditions in hydraulic structures. We conduct experimental tests on totally 12 simply supported thick-cover reinforced concrete beams under four-point monotonic loading-9 with CFRP grid and 3 without, and analyze influencing factors of crack spacing and width, such as concrete cover thickness and the size and number of CFRP grids. And we derive a formula for calculating crack width using the existing theory of concrete cracking and the models of concrete crack width. Results show that CFRP grids effectively control crack propagation in thick-cover reinforced beams. And either an increase in CFRP grid number or a decrease in CFRP grid size can increase cracking load and reduce the maximum crack width and average crack spacing. Calculations of the maximum crack width are in good agreement with test measurements, and thus our crack width formula helps the design of CFRP grid reinforced concrete covers.
引文
[1]何化南,黄承逵.钢衬钢纤维自应力混凝土压力管道裂缝宽度的计算[J].水利学报,2008,39(8):988-993.HE Huanan,HUANG Chengkui.Method for calculating crack widths of steel-lined steel fiber reinforced selfstressing concrete penstocks[J].Journal of Hydraulic Engineering,2008,39(8):988-993.(in Chinese)
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[11]Brückner A,Ortlepp R,Curbach M.Textile reinforced concrete for strengthening in bending and shear[J].Materials and Structures,2006,39(8):741-748.
[12]Zheng Y Z,Wang W W,Brigham J C.Flexural behavior of reinforced concrete beams strengthened with 9a composite reinforcement layer:BFRP grid and ECC[J].Construction and Building Materials,2016,115:424-437.
[13]李赫,徐世烺.纤维编织网增强混凝土(TRC)的基体开发和优化[J].水力发电学报,2006,25(3):72-76.LI He,XU Shilang.Development and optimization of cementitious matrices for textile reinforced concrete[J].Journal of Hydroelectric Engineering,2006,25(3):72-76.(in Chinese)
[14]荀勇,支正东,张勤.织物增强混凝土薄板加固钢筋混凝土梁受弯性能试验研究[J].建筑结构学报,2010,31(3):70-76.XUN Yong,ZHI Zhengdong,ZHANG Qin.Experimental research on flexural behavior of reinforced concrete beams strengthened with textile reinforced concrete sheets[J].Journal of Building Structures,2010,31(3):70-76.(in Chinese)
[15]潘永灿,荀勇,张勤.碳纤维织物网-聚合物砂浆加固混凝土梁受力性能研究[J].混凝土,2010(2):133-135.PAN Yongcan,XUN Yong,ZHANG Qin.Tests on concrete beams strengthened by carbon fiber textile mesh and polymeric mortar[J].Concrete,2010(2):133-135.(in Chinese)
[16]徐世烺,尹世平.纤维编织网联合钢筋增强混凝土梁受弯性能解析理论[J].中国科学:技术科学,2010(6):619-629.XU Shilang,YIN Shiping.Textile combined steel reinforced concrete beam flexural behavior analysis theory[J].Chinese Science:Technical Science,2010(6):619-629.(in Chinese)
[17]Yin S,Lv H,Xu S.Properties and calculation of normal section bearing capacity of RC flexural beam with skin textile reinforcement[J].Journal of Central South University,2013,20(6):1731-1741.
[18]徐世烺,尹世平,蔡新华.纤维编织网增强混凝土加固钢筋混凝土受弯梁的抗裂性能研究[J].水利学报,2010,41(7):833-840.XU Shilang,YIN Shiping,CAI Xinhua.Investigation on crack resistance of flexural RC beam strengthened with textile-reinforced concrete[J].Journal of Hydraulic Engineering,2010,41(7):833-840.(in Chinese)
[19]刘德军,岳清瑞,黄宏伟,等.TRC加固水工偏心受压结构的抗裂性能初探[J].水利学报,2016,47(1):101-109.LIU Dejun,YUE Qingrui,HUANG Hongwei,et al.Preliminary discussion on crack resistanceof eccentric compression hydraulic structure based on TRC[J].Journal of Hydraulic Engineering,2016,47(1):101-109.(in Chinese)
[20]管俊峰,赵顺波,黄承逵.钢筋混凝土梁裂缝分布受保护层厚度影响试验研究[J].大连理工大学学报,2010,50(5):723-728.GUAN Junfeng,ZHAO Shunbo,HUANG Chengkui.Experimental study of crack distribution of reinforced concrete beams influenced by thickness of concrete cover[J].Journal of Dalian University of Technology,2010,50(5):723-728.(in Chinese)
[21]水工混凝土结构设计规范:DL/T 5057—2009[S].北京:中国电力出版社,2009.Code for design of hydraulic concrete structures:DL/T5057—2009[S].Beijing:China Electric Power Press,2009.(in Chinese)
[22]郑乔文.FRP筋混凝土梁设计理论研究[D].上海:同济大学,2006.ZHENG Qiaowen.Studies on design theory for concrete beams reinforced with FRP rebars[D].Shanghai:Tongji University,2006.(in Chinese)
[23]胡志海.内嵌式纤维板条—混凝土粘结本构模型及其应用研究[D].长沙:中南大学,2007.HU Zhihai.Study on near-surface mounted CFRP reinforcement bond constitutive model and its application[D].Changsha:Zhongnan University,2007.(in Chinese)
[2]何化南,杨嫚嫚,贡金鑫.不同保护层厚度下微锈蚀钢筋混凝土粘结性能梁式试验研究[J].水利与建筑工程学报,2016,14(4):25-30,35.HE Huanan,YANG Manman,GONG Jinxin.Influence of cover thickness on bond behaviors between concrete and slight corroded bars[J].Journal of Water Conservancy and Building Engineering,2016,14(4):25-30,35.(in Chinese)
[3]Cao C,Cheung M M,Chan B Y.Modeling of interaction between corrosion-induced concrete cover crack and steel corrosion rate[J].Corrosion Science,2013,69:97-109.
[4]杨灵江.钢筋锈蚀引起的混凝土保护层开裂过程及影响因素分析[D].杭州:浙江大学,2007.YANG Lingjiang.Analysis on the crack process and effect factors of concrete cover induced by steel corrosion[D].Hangzhou:Zhejiang University,2007.(in Chinese)
[5]混凝土结构设计规范:GB 50010—2010[S].北京:中国建筑工业出版社,2011.Code for design of concrete structures:GB 50010—2010[S].Beijing:China Architecture&Building Press,2011.(in Chinese)
[6]童保全.大保护层钢筋混凝土受弯构件裂缝开展的试验研究[J].水运工程,1985(6):52-55.TONG Baoquan.Experimental study on crack development of reinforced concrete flexural memberswith thick concrete cover[J].Water Transport Engineering,1985(6):52-55.(in Chinese)
[7]宁喜亮,丁一宁.钢筋钢纤维自密实混凝土梁裂缝宽度试验研究[J].工程力学,2017,34(4):116-124.NING Xiliang,DING Yining.Experimental research on crack width of steel fibers reinforced self-consolidating concrete beams[J].Engineering Mechanics,2017,34(4):116-124.(in Chinese)
[8]Deluce J R,Vecchio F J.Cracking behavior of steel fiberreinforced concrete members containing conventional reinforcement[J].ACI Structural Journal,2013,110(3):481-490.
[9]柯开展,周瑞忠.掺短切碳纤维活性粉末混凝土的力学性能研究[J].水力发电学报,2007,26(1):90-96.KE Kaizhan,ZHOU Ruizhong.Researches on mechanical properties of carbon fiber reactive powder concrete[J].Journal of Hydroelectric Engineering,2007,26(1):90-96.(in Chinese)
[10]叶列平,冯鹏.FRP在工程结构中的应用与发展[J].土木工程学报,2006,39(3):24-36.YE Lieping,FENG Peng.Applications and development of fiber-reinforced polymerin engineering structures[J].China Civil Engineering Journal,2006,39(3):24-36.(in Chinese)
[11]Brückner A,Ortlepp R,Curbach M.Textile reinforced concrete for strengthening in bending and shear[J].Materials and Structures,2006,39(8):741-748.
[12]Zheng Y Z,Wang W W,Brigham J C.Flexural behavior of reinforced concrete beams strengthened with 9a composite reinforcement layer:BFRP grid and ECC[J].Construction and Building Materials,2016,115:424-437.
[13]李赫,徐世烺.纤维编织网增强混凝土(TRC)的基体开发和优化[J].水力发电学报,2006,25(3):72-76.LI He,XU Shilang.Development and optimization of cementitious matrices for textile reinforced concrete[J].Journal of Hydroelectric Engineering,2006,25(3):72-76.(in Chinese)
[14]荀勇,支正东,张勤.织物增强混凝土薄板加固钢筋混凝土梁受弯性能试验研究[J].建筑结构学报,2010,31(3):70-76.XUN Yong,ZHI Zhengdong,ZHANG Qin.Experimental research on flexural behavior of reinforced concrete beams strengthened with textile reinforced concrete sheets[J].Journal of Building Structures,2010,31(3):70-76.(in Chinese)
[15]潘永灿,荀勇,张勤.碳纤维织物网-聚合物砂浆加固混凝土梁受力性能研究[J].混凝土,2010(2):133-135.PAN Yongcan,XUN Yong,ZHANG Qin.Tests on concrete beams strengthened by carbon fiber textile mesh and polymeric mortar[J].Concrete,2010(2):133-135.(in Chinese)
[16]徐世烺,尹世平.纤维编织网联合钢筋增强混凝土梁受弯性能解析理论[J].中国科学:技术科学,2010(6):619-629.XU Shilang,YIN Shiping.Textile combined steel reinforced concrete beam flexural behavior analysis theory[J].Chinese Science:Technical Science,2010(6):619-629.(in Chinese)
[17]Yin S,Lv H,Xu S.Properties and calculation of normal section bearing capacity of RC flexural beam with skin textile reinforcement[J].Journal of Central South University,2013,20(6):1731-1741.
[18]徐世烺,尹世平,蔡新华.纤维编织网增强混凝土加固钢筋混凝土受弯梁的抗裂性能研究[J].水利学报,2010,41(7):833-840.XU Shilang,YIN Shiping,CAI Xinhua.Investigation on crack resistance of flexural RC beam strengthened with textile-reinforced concrete[J].Journal of Hydraulic Engineering,2010,41(7):833-840.(in Chinese)
[19]刘德军,岳清瑞,黄宏伟,等.TRC加固水工偏心受压结构的抗裂性能初探[J].水利学报,2016,47(1):101-109.LIU Dejun,YUE Qingrui,HUANG Hongwei,et al.Preliminary discussion on crack resistanceof eccentric compression hydraulic structure based on TRC[J].Journal of Hydraulic Engineering,2016,47(1):101-109.(in Chinese)
[20]管俊峰,赵顺波,黄承逵.钢筋混凝土梁裂缝分布受保护层厚度影响试验研究[J].大连理工大学学报,2010,50(5):723-728.GUAN Junfeng,ZHAO Shunbo,HUANG Chengkui.Experimental study of crack distribution of reinforced concrete beams influenced by thickness of concrete cover[J].Journal of Dalian University of Technology,2010,50(5):723-728.(in Chinese)
[21]水工混凝土结构设计规范:DL/T 5057—2009[S].北京:中国电力出版社,2009.Code for design of hydraulic concrete structures:DL/T5057—2009[S].Beijing:China Electric Power Press,2009.(in Chinese)
[22]郑乔文.FRP筋混凝土梁设计理论研究[D].上海:同济大学,2006.ZHENG Qiaowen.Studies on design theory for concrete beams reinforced with FRP rebars[D].Shanghai:Tongji University,2006.(in Chinese)
[23]胡志海.内嵌式纤维板条—混凝土粘结本构模型及其应用研究[D].长沙:中南大学,2007.HU Zhihai.Study on near-surface mounted CFRP reinforcement bond constitutive model and its application[D].Changsha:Zhongnan University,2007.(in Chinese)