纤维布加固混凝土方柱的改进约束强度模型
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摘要
为研究不同种类纤维布约束对混凝土方形截面柱力学性能和破坏模式的影响,针对混凝土约束效应区域,提出采用1/4圆弧替代传统二次抛物线划分有效约束区和弱约束区,基于此改进并统一了形状系数,实现对既有约束强度模型的改进。采用138组不同纤维布包裹柱试验数据对比了5种不同约束强度计算模型改进前后的效果,发现改进后模型计算值与试验数据吻合更好。为了拓展改进模型的应用范围,进一步通过8根BFRP布包裹柱试验,验证了所提出改进模型在BFRP加固混凝土柱承载力预测上的可行性。
In order to investigate the strengthening effects of different types of FRP sheets on the mechanical properties and failure modes of square concrete columns,1/4 arc was adopted to replace the traditional second-degree parabola to distinguish the effective confinement area from weak area.Then the shape coefficients were improved and unified into one for purpose of engineering application.The performance of the five strength models after improvement was evaluated based on the analysis of 138 experimental columns strengthened by different types of FRP sheets.Satisfactory agreements between the improved models and the experiments were found.In order to extend the application range of the improved models,8 BFRP jacketed concrete columns were further tested.Result shows the improved models is capable of predicting the bearing capacity of BFRP jacketed concrete column in predicting the load capacities of such columns was confirmed.
In order to investigate the strengthening effects of different types of FRP sheets on the mechanical properties and failure modes of square concrete columns,1/4 arc was adopted to replace the traditional second-degree parabola to distinguish the effective confinement area from weak area.Then the shape coefficients were improved and unified into one for purpose of engineering application.The performance of the five strength models after improvement was evaluated based on the analysis of 138 experimental columns strengthened by different types of FRP sheets.Satisfactory agreements between the improved models and the experiments were found.In order to extend the application range of the improved models,8 BFRP jacketed concrete columns were further tested.Result shows the improved models is capable of predicting the bearing capacity of BFRP jacketed concrete column in predicting the load capacities of such columns was confirmed.
引文
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[2]LI P D,WU Y F.Stress-strain model of FRP confined concrete under cyclic loading[J].Composite Structures,2015,134:60-71.
[3]LIN G,YU T,TENG J G.Design-oriented stressstrain model for concrete under combined FRP-steel confinement[J].Journal of Composites for Construction,2016,20(4):04015084.
[4]PAN Y,RUI G,LI H,et al.Study on stress-strain relation of concrete confined by CFRP under preload[J].Engineering Structures,2017,143:52-63.
[5]LAM L,TENG J G.Design-oriented stress-strain model for FRP-confined concrete in rectangular columns[J].Journal of Reinforced Plastics and Composites,2003,2213:1149-1186.
[6]ZHOU Y W,LI M L,SUI L L,et al.Effect of sulfate attack on the stress-strain relationship of FRP-confined concrete[J].Construction&Building Materials,2016,110:235-250.
[7]熊海贝,李奔奔,江佳斐,FRP约束混凝土圆柱应力-应变模型的适用性[J].浙江大学学报(工学版),2015,49(12):2363-2375.XIONG H B,LI B B,JIANG J F.Applicability of FRP confined concrete column stress-strain model[J].Journal of Zhejiang University(Engineering Science),2015,49(12):2363-2375.(in Chinese)
[8]梁猛,李明海,王伟,等,FRP约束混凝土圆柱应力-应变关系模型[J].建筑结构,2016,46(Sup1):934-940.LIANG M,LI M H,WANG W,et al.Stress-strain relationship model of FRP confined concrete[J].Building Structure,2016,46(Sup1):934-940.(in Chinese)
[9]YOUSSEF M N,FENG M Q,MOSALLAM A S.Stress-strain model for concrete confined by FRPcomposites[J].Composites Part B Engineering,2007,38(5/6):614-628.
[10]MIRMIRAN A,SHAHAWY M,SAMAAN M,et al.Effect of column parameters on FRP-confined concrete[J].Journal of Composites for Construction,1998,2(4):175-185.
[11]SHEHATA I A E M,CARNEIRO L A V,SHEHATA L C D.Strength of short concrete columns confined with CFRP sheets[J].Materials&Structures,2002,35(1):50-58.
[12]KUMUTHA R,VAIDYANATHAN R,PALANICHAMY M S.Behaviour of reinforced concrete rectangular columns strengthened using GFRP[J].Cement&Concrete Composites,2007,29(8):609-615.
[13]卢亦焱,史健勇,赵国藩.碳纤维布约束轴心受压混凝土方形柱承载力计算研究[J].工程力学,2004,21(4):22-27.LU Y Y,SHI J Y,ZHAO G F.Calculation of bearing capacity of concrete columns with confined axial compression of carbon fiber cloth[J].Engineering Mechanics,2004,21(4):22-27.(in Chinese)
[14]AL-SALLOUM Y A.Influence of edge sharpness on the strength of square concrete columns confined with FRP composite laminates[J].Composites Part B,2007,38(5/6):640-650.
[15]LLKI A,PEKER O,KARAMUK E,et al.FRPretrofit of low and medium strength circular and rectangular reinforced concrete columns[J].Journal of Materials in Civil Engineering,2008,20(2):169-188.
[16]部门四川省住房和城乡建设厅.混凝土结构加固设计规范[M].北京:中国建筑工业出版社,2013.Ministry of Housing and Urban and Rural Construction department of Sichuan Province.Code for design of reinforced concrete structures[M].Beijing:China Architecture&Building Press,2013.(in Chinese)
[17]SOUDKI K,ALKHRDAJI T.Guide for the design and construction of externally bonded FRP systems for strengthening concrete structures(ACI 440.2R-08)[C]//Structures Congress,New York USA,2005.
[18]MIYAUCHI K,INOUE S,KURODA T,et al.Strengthening effects of concrete column with carbon fiber sheet[J].Transactions of the Japan Concrete Institute,2000,21:143-150.
[19]PARVIN A,WANG W.Behavior of FRP jacketed concrete columns under eccentric loading[J].Journal of Composites for Construction,2001,5(3):146-152.
[20]徐竞雄.FRP加固矩形混凝土柱研究[D].武汉:华中科技大学,2011.XU J X.Study on FRP Reinforced rectangular concrete columns[D].Wuhan:Huazhong University of Science and Technology,2011.(in Chinese)
[21]WU Y F,WANG L M.Unified strength model for square and circular concrete columns confined by external jacket[J].Journal of Structural Engineering,2009,135(3):253-261.
[2]LI P D,WU Y F.Stress-strain model of FRP confined concrete under cyclic loading[J].Composite Structures,2015,134:60-71.
[3]LIN G,YU T,TENG J G.Design-oriented stressstrain model for concrete under combined FRP-steel confinement[J].Journal of Composites for Construction,2016,20(4):04015084.
[4]PAN Y,RUI G,LI H,et al.Study on stress-strain relation of concrete confined by CFRP under preload[J].Engineering Structures,2017,143:52-63.
[5]LAM L,TENG J G.Design-oriented stress-strain model for FRP-confined concrete in rectangular columns[J].Journal of Reinforced Plastics and Composites,2003,2213:1149-1186.
[6]ZHOU Y W,LI M L,SUI L L,et al.Effect of sulfate attack on the stress-strain relationship of FRP-confined concrete[J].Construction&Building Materials,2016,110:235-250.
[7]熊海贝,李奔奔,江佳斐,FRP约束混凝土圆柱应力-应变模型的适用性[J].浙江大学学报(工学版),2015,49(12):2363-2375.XIONG H B,LI B B,JIANG J F.Applicability of FRP confined concrete column stress-strain model[J].Journal of Zhejiang University(Engineering Science),2015,49(12):2363-2375.(in Chinese)
[8]梁猛,李明海,王伟,等,FRP约束混凝土圆柱应力-应变关系模型[J].建筑结构,2016,46(Sup1):934-940.LIANG M,LI M H,WANG W,et al.Stress-strain relationship model of FRP confined concrete[J].Building Structure,2016,46(Sup1):934-940.(in Chinese)
[9]YOUSSEF M N,FENG M Q,MOSALLAM A S.Stress-strain model for concrete confined by FRPcomposites[J].Composites Part B Engineering,2007,38(5/6):614-628.
[10]MIRMIRAN A,SHAHAWY M,SAMAAN M,et al.Effect of column parameters on FRP-confined concrete[J].Journal of Composites for Construction,1998,2(4):175-185.
[11]SHEHATA I A E M,CARNEIRO L A V,SHEHATA L C D.Strength of short concrete columns confined with CFRP sheets[J].Materials&Structures,2002,35(1):50-58.
[12]KUMUTHA R,VAIDYANATHAN R,PALANICHAMY M S.Behaviour of reinforced concrete rectangular columns strengthened using GFRP[J].Cement&Concrete Composites,2007,29(8):609-615.
[13]卢亦焱,史健勇,赵国藩.碳纤维布约束轴心受压混凝土方形柱承载力计算研究[J].工程力学,2004,21(4):22-27.LU Y Y,SHI J Y,ZHAO G F.Calculation of bearing capacity of concrete columns with confined axial compression of carbon fiber cloth[J].Engineering Mechanics,2004,21(4):22-27.(in Chinese)
[14]AL-SALLOUM Y A.Influence of edge sharpness on the strength of square concrete columns confined with FRP composite laminates[J].Composites Part B,2007,38(5/6):640-650.
[15]LLKI A,PEKER O,KARAMUK E,et al.FRPretrofit of low and medium strength circular and rectangular reinforced concrete columns[J].Journal of Materials in Civil Engineering,2008,20(2):169-188.
[16]部门四川省住房和城乡建设厅.混凝土结构加固设计规范[M].北京:中国建筑工业出版社,2013.Ministry of Housing and Urban and Rural Construction department of Sichuan Province.Code for design of reinforced concrete structures[M].Beijing:China Architecture&Building Press,2013.(in Chinese)
[17]SOUDKI K,ALKHRDAJI T.Guide for the design and construction of externally bonded FRP systems for strengthening concrete structures(ACI 440.2R-08)[C]//Structures Congress,New York USA,2005.
[18]MIYAUCHI K,INOUE S,KURODA T,et al.Strengthening effects of concrete column with carbon fiber sheet[J].Transactions of the Japan Concrete Institute,2000,21:143-150.
[19]PARVIN A,WANG W.Behavior of FRP jacketed concrete columns under eccentric loading[J].Journal of Composites for Construction,2001,5(3):146-152.
[20]徐竞雄.FRP加固矩形混凝土柱研究[D].武汉:华中科技大学,2011.XU J X.Study on FRP Reinforced rectangular concrete columns[D].Wuhan:Huazhong University of Science and Technology,2011.(in Chinese)
[21]WU Y F,WANG L M.Unified strength model for square and circular concrete columns confined by external jacket[J].Journal of Structural Engineering,2009,135(3):253-261.