预应力碳纤维布加固混凝土圆柱预应力损失试验研究
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摘要
为了研究预应力碳纤维布加固圆柱的应力损失情况,在恒温恒湿条件下进行了为期30 d的预应力碳纤维布加固混凝土圆柱预应力损失试验。试验考虑的影响因素包括:圆柱的直径大小、预应力大小、柱表面处理情况。试验得到了预应力碳纤维布的摩擦损失量和长期的应力松弛损失量,分析了各因素对碳纤维布预应力损失的影响,得出了预应力损失的发展规律,并提出了减小碳纤维布预应力损失的措施。试验结果表明:当预应力越大、圆柱直径越小、圆柱表面越粗糙,则摩擦损失越大;持荷初期碳纤维布应力松弛发展较快,12 h松弛率可达30 d松弛率的51%以上,之后逐渐趋于稳定;碳纤维布表面涂胶情况下的预应力松弛量较不做处理的情况小;圆柱直径越大、预应力越大,碳纤维布应力松弛率越低。预应力碳纤维布的松弛量和有效应力随圆柱直径及预应力度的增大而增大。摩擦损失占预应力总损失76.4%以上,碳纤维布应力松弛损失相对较小,占总损失的9.9%~23.6%。对加固圆柱表面及碳纤维布表面涂胶可有效减少预应力损失。增大预应力度,可提高碳纤维布有效预应力。试验结果对预应力碳纤维布加固柱的设计及施工具有一定的指导意义。
For researching the prestress loss of concrete columns strengthened with prestressed CFRP sheets,an experiment of the prestress loss of the concrete columns for a period of 30 d under constant temperature and humidity conditions is conducted. The influencing factors of the test include diameter of cylinder,degree of prestressing and treatment of surface. The frictional loss and the long-term stress relaxation loss of the prestressed CFRP sheets are obtained,the influence of various factors on the prestress loss of the CFRP sheets is analyzed,the development law of prestress loss is obtained,and the measures to reduce the loss of prestressed CFRP sheets are put forward. The result shows that( 1) the greater the prestress is,the smaller the diameter is,the rougher the cylindrical surface is,the greater the friction loss becomes;( 2) the stressrelaxation of CFRP in the initial stage of loading is fast,the relaxation rate of 12 h can reach more than 51%of the 30 d relaxation rate,then it gradually stabilizes;( 3) the prestress relaxation of coated CFRP sheets is lower than the sheets without coating;( 4) the greater the prestress and diameter are,the lower the relaxation rate becomes;( 5) the relaxation and the effective stress of the prestressed CFRP sheets increase with the increase of the diameter of the cylinder and the degree of prestressing;( 6) the friction loss accounts for more than 76. 4% of the total prestress loss, the stress relaxation loss of CFRP sheets is relatively small,accounting for 9. 9% to 23. 6% of the total loss;( 7) the coating on the surface of reinforced cylinder and the surface of CFRP sheets can effectively reduce the prestress loss,and increasing the degree of prestressing can improve the effective prestress of CFRP sheets. The test result has a certain guiding significance for the design and construction of prestressed CFRP reinforced columns.
For researching the prestress loss of concrete columns strengthened with prestressed CFRP sheets,an experiment of the prestress loss of the concrete columns for a period of 30 d under constant temperature and humidity conditions is conducted. The influencing factors of the test include diameter of cylinder,degree of prestressing and treatment of surface. The frictional loss and the long-term stress relaxation loss of the prestressed CFRP sheets are obtained,the influence of various factors on the prestress loss of the CFRP sheets is analyzed,the development law of prestress loss is obtained,and the measures to reduce the loss of prestressed CFRP sheets are put forward. The result shows that( 1) the greater the prestress is,the smaller the diameter is,the rougher the cylindrical surface is,the greater the friction loss becomes;( 2) the stressrelaxation of CFRP in the initial stage of loading is fast,the relaxation rate of 12 h can reach more than 51%of the 30 d relaxation rate,then it gradually stabilizes;( 3) the prestress relaxation of coated CFRP sheets is lower than the sheets without coating;( 4) the greater the prestress and diameter are,the lower the relaxation rate becomes;( 5) the relaxation and the effective stress of the prestressed CFRP sheets increase with the increase of the diameter of the cylinder and the degree of prestressing;( 6) the friction loss accounts for more than 76. 4% of the total prestress loss, the stress relaxation loss of CFRP sheets is relatively small,accounting for 9. 9% to 23. 6% of the total loss;( 7) the coating on the surface of reinforced cylinder and the surface of CFRP sheets can effectively reduce the prestress loss,and increasing the degree of prestressing can improve the effective prestress of CFRP sheets. The test result has a certain guiding significance for the design and construction of prestressed CFRP reinforced columns.
引文
[1]岳清瑞.我国碳纤维材料(CFRP)加固修复技术研究应用现状与展望[J].工业建筑,2000,30(4):23-26.YUE Qing-rui.Present Status of Research and Application of Strengthening and Repairing Technology with Carbon Fibre Reinforced Plastics(CFRP)and Its Outlook in China[J].Industrial Building,2000,30(4):23-26.
[2]TENG J G,CHEN J F,SMITH S T,et al.FRPstrengthened RC Structures[M].New York:John Wiley&Sons,2002:35-73.
[3]周长东,田腾,吕西林,等.预应力碳纤维条带加固混凝土圆墩抗震性能试验[J].中国公路学报,2012,25(4):57-66.ZHOU Chang-dong,TIAN Teng,LXi-lin,et al.Test on Seismic Performance of RC Circular Piers Strengthened with Pre-stressed CFRP Belts[J].Journal of China Highway,2012,25(4):57-66.
[4]周长东,田腾,吕西林,等.预应力碳纤维条带加固高轴压比混凝土圆柱抗震性能试验研究[J].建筑结构学报,2012,33(11):115-123.ZHOU Chang-dong,TIAN Teng,LXi-lin,et al.Experimental Study on Seismic Behavior of Circular RC Columns Strengthened with Pre-stressed CFRP Belts under High Axial Compression[J].Journal of Building Structures,2012,33(11):115-123.
[5]易亚敏.预应力CFRP布加固混凝土方柱轴心受压试验及有限元分析[D].哈尔滨:东北林业大学,2012.YI Ya-min.Test of Prestressed CFRP Reinforced Concrete Columns Subjected to Axial Compression and FEA[D].Harbin:Northeast Forestry University,2012.
[6]周长东,白晓彬,赵锋,等.预应力纤维布加固混凝土圆形截面短柱轴压性能试验[J].建筑结构学报,2013,34(2):17-26.ZHOU Chang-dong,BAI Xiao-bin,ZHAO Feng,et al.Experimental Study on Circular Concrete Short Columns Strengthened with Pre-stressed FRP under Axial Compression[J].Journal of Building Structures,2013,34(2):17-26.
[7]COSTA I,BARROS J.Prestress Losses in NSM-CFRP Flexurally Strengthened RC Beams[J].Strain,2015,51(4):276-287.
[8]江胜华,侯建国,何英明.考虑预应力损失的CFRP布加固钢筋混凝土梁正常使用极限状态可靠度研究[J].土木工程学报,2015(11):36-43.JIANG Sheng-hua,HOU Jian-guo,HE Ying-ming.Reliability Research of Serviceability Limit States for RC Beams Strengthened with Prestressed CFRP Sheets Considering Prestress Loss[J].China Civil Engineering Journal,2015(11):36-43.
[9]黄照南.CFRP修复震后严重破坏钢筋混凝土桥墩抗震性能试验研究[D].大连:大连理工大学,2009.HUANG Zhao-nan.Experimental Investigation on Seismic Behavior of Severe Earthquake-damaged RC Bridge Piers Repaired with Wrapped CFRP Sheets[D].Dalian:Dalian University of Technology,2009.
[10]杨建江,张雅琴.CFRP筋预应力损失研究进展[J].四川建筑科学研究,2016,42(4):30-35.YANG Jian-jiang,ZHANG Ya-qin.Research Progress of Prestress Loss of CFRP Bars[J].Sichuan Building Science,2016,42(4):30-35.
[11]杨勇新,李庆伟,岳清瑞.预应力碳纤维布加固混凝土梁预应力损失试验研究[J].工业建筑,2006,36(4):5-8.YANG Yong-xin,LI Qing-wei,YUE Qing-rui.Experimental Research on Prestress Loss in Technique of Concrete Structure Strengthened with Prestressed CFRP Sheets[J].Industrial Construction,2006,36(4):5-8.
[12]黄金林,黄培彦,郑小红.预应力碳纤维板加固钢筋混凝土梁预应力损失试验研究[J].建筑结构学报,2015,1(36):85-91.HUANG Jin-lin,HUANG Pei-yan,ZHENG Xiao-hong.Experimental Study of Prestress Losses of RC Beams Strengthened with Prestress FRP[J].Journal of Building Structures,2015,36(1):85-91.
[13]邓朗妮,张鹏,杨帆,等.预应力碳纤维板加固混凝土钢结构预应力损失研究[J].工业建筑,2012,42(9):71-74.DENG Lang-ni,ZHANG Peng,YANG Fan,et al.Study of Prestress Loss of Steel Structure Strenghthened with Prestress CFRP Plates[J].Industrial Construction,2012,42(9):71-74.
[14]许晓,艾军,潘建伍,等.预应力纤维布加固钢筋混凝土小梁工艺及预应力损失试验研究[J].工业建筑,2013,43(12):129-132.XU Xiao,AI Jun,PAN Jian-wu,et al.Experimental Research on Technique of Reinforced Concrete Beam Strengthened with Prestressed FRP Sheets and Prestress Loss[J].Industrial Construction,2013,43(12):129-132.
[15]朱永祥,王文炜.预应力碳纤维布加固混凝土梁预应力长期损失的增量微分法[J].重庆大学学报,2015,38(4):61-66.ZHU Yong-xiang,WANG Wen-wei.Incremental Differential Model for Long-term Prestress Losses of Reinforced Concrete Beams Strengthened with Prestressed CFRP Sheets[J].Journal of Chongqing University,2015,38(4):61-66.
[16]王文炜,戴建国,张磊.后张预应力碳纤维布加固钢筋混凝土梁预应力损失试验及计算方法研究[J].土木工程学报,2012(11):88-94.WANG Wen-wei,DAI Jian-guo,ZHANG Lei.Experimental Study and Analytical Modeling of Prestress Losses of Reinforced Concrete Beams Strengthened with Post-tensioned CFRP Sheets[J].China Civil Engineering Journal,2012(11):88-94.
[17]何初生,王文炜,杨威,等.预应力CFRP布加固钢筋混凝土梁疲劳性能试验研究[J].东南大学学报:自然科学版,2011,41(4):841-847.HE Chu-sheng,WANG Wen-wei,YANG Wei,et al.Experimental Study on Fatigue Behavior of Reinforced Concrete Beams Strengthened by Prestressed CFRP Sheets[J].Journal of Southeast University:Natural Science Edition,2011,41(4):841-847.
[18]黄侨,万世成,侯旭.桥梁预应力碳纤维板加固中的参数取值及损失计算方法研究[J].公路交通科技,2016,33(9):52-57.HUANG Qiao,WAN Shi-cheng,HOU Xu.Study on Study on Parameter Determination and Calculation Method of Prestress Loss of Prestressed CFRP Plates in Bridge Reinforcement[J].Journal of Highway and Transportation Research and Development,2016,33(9):52-57.
[19]江胜华,侯建国,何英明.考虑预应力损失的CFRP布加固钢筋混凝土梁正常使用极限状态可靠度研究[J].土木工程学报,2015(11):36-43.JIANG Sheng-hua,HOU Jian-guo,HE Ying-ming.Reliability Research of Serviceability Limit States for RC Beams Strengthened with Prestressed CFRP Sheets Considering Prestress Loss[J].China Civil Engineering Journal,2015(11):36-43.
[20]江胜华,侯建国,何英明.预应力碳纤维布加固钢筋混凝土梁的抗弯性能试验研究[J].建筑结构学报,2008,29(增1):10-14.JIANG Sheng-hua,HOU Jian-guo,HE Ying-ming.Experimental Study on Flexural Behavior of RC Beams Strengthened with Prestressed CFRP Sheets[J].Journal of Building Structures,2008,29(S1):10-14.
[21]尚守平,张宝静,吕新飞.预应力碳纤维板加固梁桥长期徐变性能的试验研究[J].公路交通科技,2015,32(5):68-74.SHANG Shou-ping,ZHANG Bao-jing,LXin-fei.Experimental Study on Long-term Creep Behavior of Beam Bridge Strengthened with Prestressed CFRP Plate[J].Journal of Highway and Transportation Research and Development,2015,32(5):68-74.
[22]WANG W W,DAI J G,HARRIES K A,et al.Prediction of Prestress Losses in RC Beams Externally Strengthened with Prestressed CFRP Sheets/Plates[J].Journal of Reinforced Plastics&Composites,2014,33(8):699-713.
[23]周长东,李季,吕西林.预张拉纤维布约束混凝土圆柱预应力损失试验[J].同济大学学报:自然科学版,2012,40(12):1760-1765.ZHOU Chang-dong,LI Ji,LXi-lin.Experimental Research on Pre-stress Loss of Concrete Circular Columns Confined with Post-tensioned FRP[J].Journal of Tongji University:Natural Science Edition,2012,40(12):1760-1765.
[24]李季.纤维复合材料自锁式锚具设计及其性能研究[D].北京:北京交通大学,2011.LI Ji.Study on Design and Performance of Self Locking Anchorage for Fiber Composite[D].Beijing:Beijing Jiaotong University,2011.
[25]周长东,李季,朱万旭,等.碳纤维复合材料自锁式锚具设计及力学性能研究[J].建筑结构学报.2013,34(2):141-148.ZHOU Chang-dong,LI Ji,ZHU Wan-xu,et al.Design of Self-locking Anchor System of FRP and Research on Mechanical Properties[J].Journal of Building Structures,2013,34(2):141-148.
[26]张建伟,张瑞云,杜修力.芳纶纤维布松弛性能试验[J].建筑科学与工程学报,2010,27(1):73-77.ZHANG Jian-wei,ZHANG Rui-yun,DU Xiu-li.Experiment of Relaxation Performance of AFRP Sheets[J].Journal of Architecture and Civil Engineering,2010,27(1):73-77.
[2]TENG J G,CHEN J F,SMITH S T,et al.FRPstrengthened RC Structures[M].New York:John Wiley&Sons,2002:35-73.
[3]周长东,田腾,吕西林,等.预应力碳纤维条带加固混凝土圆墩抗震性能试验[J].中国公路学报,2012,25(4):57-66.ZHOU Chang-dong,TIAN Teng,LXi-lin,et al.Test on Seismic Performance of RC Circular Piers Strengthened with Pre-stressed CFRP Belts[J].Journal of China Highway,2012,25(4):57-66.
[4]周长东,田腾,吕西林,等.预应力碳纤维条带加固高轴压比混凝土圆柱抗震性能试验研究[J].建筑结构学报,2012,33(11):115-123.ZHOU Chang-dong,TIAN Teng,LXi-lin,et al.Experimental Study on Seismic Behavior of Circular RC Columns Strengthened with Pre-stressed CFRP Belts under High Axial Compression[J].Journal of Building Structures,2012,33(11):115-123.
[5]易亚敏.预应力CFRP布加固混凝土方柱轴心受压试验及有限元分析[D].哈尔滨:东北林业大学,2012.YI Ya-min.Test of Prestressed CFRP Reinforced Concrete Columns Subjected to Axial Compression and FEA[D].Harbin:Northeast Forestry University,2012.
[6]周长东,白晓彬,赵锋,等.预应力纤维布加固混凝土圆形截面短柱轴压性能试验[J].建筑结构学报,2013,34(2):17-26.ZHOU Chang-dong,BAI Xiao-bin,ZHAO Feng,et al.Experimental Study on Circular Concrete Short Columns Strengthened with Pre-stressed FRP under Axial Compression[J].Journal of Building Structures,2013,34(2):17-26.
[7]COSTA I,BARROS J.Prestress Losses in NSM-CFRP Flexurally Strengthened RC Beams[J].Strain,2015,51(4):276-287.
[8]江胜华,侯建国,何英明.考虑预应力损失的CFRP布加固钢筋混凝土梁正常使用极限状态可靠度研究[J].土木工程学报,2015(11):36-43.JIANG Sheng-hua,HOU Jian-guo,HE Ying-ming.Reliability Research of Serviceability Limit States for RC Beams Strengthened with Prestressed CFRP Sheets Considering Prestress Loss[J].China Civil Engineering Journal,2015(11):36-43.
[9]黄照南.CFRP修复震后严重破坏钢筋混凝土桥墩抗震性能试验研究[D].大连:大连理工大学,2009.HUANG Zhao-nan.Experimental Investigation on Seismic Behavior of Severe Earthquake-damaged RC Bridge Piers Repaired with Wrapped CFRP Sheets[D].Dalian:Dalian University of Technology,2009.
[10]杨建江,张雅琴.CFRP筋预应力损失研究进展[J].四川建筑科学研究,2016,42(4):30-35.YANG Jian-jiang,ZHANG Ya-qin.Research Progress of Prestress Loss of CFRP Bars[J].Sichuan Building Science,2016,42(4):30-35.
[11]杨勇新,李庆伟,岳清瑞.预应力碳纤维布加固混凝土梁预应力损失试验研究[J].工业建筑,2006,36(4):5-8.YANG Yong-xin,LI Qing-wei,YUE Qing-rui.Experimental Research on Prestress Loss in Technique of Concrete Structure Strengthened with Prestressed CFRP Sheets[J].Industrial Construction,2006,36(4):5-8.
[12]黄金林,黄培彦,郑小红.预应力碳纤维板加固钢筋混凝土梁预应力损失试验研究[J].建筑结构学报,2015,1(36):85-91.HUANG Jin-lin,HUANG Pei-yan,ZHENG Xiao-hong.Experimental Study of Prestress Losses of RC Beams Strengthened with Prestress FRP[J].Journal of Building Structures,2015,36(1):85-91.
[13]邓朗妮,张鹏,杨帆,等.预应力碳纤维板加固混凝土钢结构预应力损失研究[J].工业建筑,2012,42(9):71-74.DENG Lang-ni,ZHANG Peng,YANG Fan,et al.Study of Prestress Loss of Steel Structure Strenghthened with Prestress CFRP Plates[J].Industrial Construction,2012,42(9):71-74.
[14]许晓,艾军,潘建伍,等.预应力纤维布加固钢筋混凝土小梁工艺及预应力损失试验研究[J].工业建筑,2013,43(12):129-132.XU Xiao,AI Jun,PAN Jian-wu,et al.Experimental Research on Technique of Reinforced Concrete Beam Strengthened with Prestressed FRP Sheets and Prestress Loss[J].Industrial Construction,2013,43(12):129-132.
[15]朱永祥,王文炜.预应力碳纤维布加固混凝土梁预应力长期损失的增量微分法[J].重庆大学学报,2015,38(4):61-66.ZHU Yong-xiang,WANG Wen-wei.Incremental Differential Model for Long-term Prestress Losses of Reinforced Concrete Beams Strengthened with Prestressed CFRP Sheets[J].Journal of Chongqing University,2015,38(4):61-66.
[16]王文炜,戴建国,张磊.后张预应力碳纤维布加固钢筋混凝土梁预应力损失试验及计算方法研究[J].土木工程学报,2012(11):88-94.WANG Wen-wei,DAI Jian-guo,ZHANG Lei.Experimental Study and Analytical Modeling of Prestress Losses of Reinforced Concrete Beams Strengthened with Post-tensioned CFRP Sheets[J].China Civil Engineering Journal,2012(11):88-94.
[17]何初生,王文炜,杨威,等.预应力CFRP布加固钢筋混凝土梁疲劳性能试验研究[J].东南大学学报:自然科学版,2011,41(4):841-847.HE Chu-sheng,WANG Wen-wei,YANG Wei,et al.Experimental Study on Fatigue Behavior of Reinforced Concrete Beams Strengthened by Prestressed CFRP Sheets[J].Journal of Southeast University:Natural Science Edition,2011,41(4):841-847.
[18]黄侨,万世成,侯旭.桥梁预应力碳纤维板加固中的参数取值及损失计算方法研究[J].公路交通科技,2016,33(9):52-57.HUANG Qiao,WAN Shi-cheng,HOU Xu.Study on Study on Parameter Determination and Calculation Method of Prestress Loss of Prestressed CFRP Plates in Bridge Reinforcement[J].Journal of Highway and Transportation Research and Development,2016,33(9):52-57.
[19]江胜华,侯建国,何英明.考虑预应力损失的CFRP布加固钢筋混凝土梁正常使用极限状态可靠度研究[J].土木工程学报,2015(11):36-43.JIANG Sheng-hua,HOU Jian-guo,HE Ying-ming.Reliability Research of Serviceability Limit States for RC Beams Strengthened with Prestressed CFRP Sheets Considering Prestress Loss[J].China Civil Engineering Journal,2015(11):36-43.
[20]江胜华,侯建国,何英明.预应力碳纤维布加固钢筋混凝土梁的抗弯性能试验研究[J].建筑结构学报,2008,29(增1):10-14.JIANG Sheng-hua,HOU Jian-guo,HE Ying-ming.Experimental Study on Flexural Behavior of RC Beams Strengthened with Prestressed CFRP Sheets[J].Journal of Building Structures,2008,29(S1):10-14.
[21]尚守平,张宝静,吕新飞.预应力碳纤维板加固梁桥长期徐变性能的试验研究[J].公路交通科技,2015,32(5):68-74.SHANG Shou-ping,ZHANG Bao-jing,LXin-fei.Experimental Study on Long-term Creep Behavior of Beam Bridge Strengthened with Prestressed CFRP Plate[J].Journal of Highway and Transportation Research and Development,2015,32(5):68-74.
[22]WANG W W,DAI J G,HARRIES K A,et al.Prediction of Prestress Losses in RC Beams Externally Strengthened with Prestressed CFRP Sheets/Plates[J].Journal of Reinforced Plastics&Composites,2014,33(8):699-713.
[23]周长东,李季,吕西林.预张拉纤维布约束混凝土圆柱预应力损失试验[J].同济大学学报:自然科学版,2012,40(12):1760-1765.ZHOU Chang-dong,LI Ji,LXi-lin.Experimental Research on Pre-stress Loss of Concrete Circular Columns Confined with Post-tensioned FRP[J].Journal of Tongji University:Natural Science Edition,2012,40(12):1760-1765.
[24]李季.纤维复合材料自锁式锚具设计及其性能研究[D].北京:北京交通大学,2011.LI Ji.Study on Design and Performance of Self Locking Anchorage for Fiber Composite[D].Beijing:Beijing Jiaotong University,2011.
[25]周长东,李季,朱万旭,等.碳纤维复合材料自锁式锚具设计及力学性能研究[J].建筑结构学报.2013,34(2):141-148.ZHOU Chang-dong,LI Ji,ZHU Wan-xu,et al.Design of Self-locking Anchor System of FRP and Research on Mechanical Properties[J].Journal of Building Structures,2013,34(2):141-148.
[26]张建伟,张瑞云,杜修力.芳纶纤维布松弛性能试验[J].建筑科学与工程学报,2010,27(1):73-77.ZHANG Jian-wei,ZHANG Rui-yun,DU Xiu-li.Experiment of Relaxation Performance of AFRP Sheets[J].Journal of Architecture and Civil Engineering,2010,27(1):73-77.