钢骨超高强混凝土框架节点受剪承载力试验研究与理论分析
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摘要
为研究钢骨超高强混凝土框架节点核心区受力特征和受剪承载力,对12个节点试件进行了低周反复加载试验,分析受剪破坏模式、各加载阶段受力特征、箍筋和钢骨腹板应变以及轴压比、体积配箍率、钢骨形式对受剪承载力的影响。采用"四边加强的剪力墙"模型描述了节点核心区受剪机理,建立了受剪承载力计算式,对比分析了计算结果与试验结果。研究表明:开裂阶段节点核心区超高强混凝土承担的外荷载较多,达85%以上,箍筋和钢骨腹板承担的外荷载较少;试件屈服后,超高强混凝土承担的外荷载有所减少,而箍筋和钢骨腹板承担的外荷载明显增多,箍筋和钢骨腹板的应变增长较快,荷载-应变关系由最初近乎直线,发展为应变随荷载变化明显的曲线,且存在较大的残余应变;节点核心区受剪承载力随轴压比或体积配箍率的增加而增大;钢骨形式对受剪承载力影响不明显;受剪承载力计算结果与试验结果比值在0.94~1.02范围内,所提出的计算式具有较高的精度。
In order to study the mechanical characteristic and shear strength of steel reinforced ultra high strength concrete( SRUHSC) frame joint at the joint core,twelve specimens were tested under low cycle reversed loading. The shear failure pattern,mechanical characteristic at every loading stage,strain development of stirrup and steel web,and the influences of the test axial compression ratio,volumetric stirrup ratio and encased-steel shape on the shear strength,were analyzed. The four-side-reinforced shear wall model was adopted to describe the shear mechanism at the joint core. Based on the model,calculation methods on shear strength were presented,and the calculated results were compared with the experimental ones. Analysis results indicate that the ultra-high strength concrete carries most of the external load and the share reaches more than 85% at the cracking stage,but the stirrup and steel web bear the less.After specimen yields,the load that the ultra-high strength concrete bears decreases,while the load that stirrup and steel web bear increases obviously. At the same time,the strain of stirrup and steel web become larger. The relations of load and strain change from nearly linear proportional to nonlinear,and the larger residual strain appears. The shear strength of the joint core increases when the axial compression ratio or volumetric stirrup ratio increases. But the encased steel shapes have no influence on the shear strength. The ratios between the calculated values and test ones range from 0. 94 to 1. 02,and the precision of calculation method is better.
In order to study the mechanical characteristic and shear strength of steel reinforced ultra high strength concrete( SRUHSC) frame joint at the joint core,twelve specimens were tested under low cycle reversed loading. The shear failure pattern,mechanical characteristic at every loading stage,strain development of stirrup and steel web,and the influences of the test axial compression ratio,volumetric stirrup ratio and encased-steel shape on the shear strength,were analyzed. The four-side-reinforced shear wall model was adopted to describe the shear mechanism at the joint core. Based on the model,calculation methods on shear strength were presented,and the calculated results were compared with the experimental ones. Analysis results indicate that the ultra-high strength concrete carries most of the external load and the share reaches more than 85% at the cracking stage,but the stirrup and steel web bear the less.After specimen yields,the load that the ultra-high strength concrete bears decreases,while the load that stirrup and steel web bear increases obviously. At the same time,the strain of stirrup and steel web become larger. The relations of load and strain change from nearly linear proportional to nonlinear,and the larger residual strain appears. The shear strength of the joint core increases when the axial compression ratio or volumetric stirrup ratio increases. But the encased steel shapes have no influence on the shear strength. The ratios between the calculated values and test ones range from 0. 94 to 1. 02,and the precision of calculation method is better.
引文
[1]闫长旺.钢骨超高强混凝土框架节点抗震性能研究[D].大连:大连理工大学,2009:48-74.(YAN Changwang.Study on seismic performance of steel reinforced ultra high strength concrete frame connection[D].Dalian:Dalian University of Technology,2009:48-74.(in Chinese))
[2]Yan C W,Jia J Q.Seismic performance of steel reinforced ultra high-strength concrete composite frame joints[J].Earthquake Engineering and Engineering Vibration,2010,9(3):439-448.
[3]张士前,陈宗平,王妮,等.型钢混凝土十形柱空间节点受剪机理及抗剪强度研究[J].土木工程学报,2014,47(9):84-93.(ZHANG Shiqian,CHEN Zongping,WANG Ni,et al.Shear mechanism and shear strength of steel reinforced concrete(SRC)crossshape 3D column-beam joints[J].China Civil Engineering Journal,2014,47(9):84-93.(in Chinese))
[4]商效瑀,郑山锁,韩协,等.型钢高强混凝土节点核心区模型化方法[J].华中科技大学学报(自然科学版),2013,41(7):10-14.(SHANG Xiaoyu,ZHENG Shansuo,HAN Xie,et al.Joint core model method of steel reinforced high strength concrete joints[J].Journal of Huazhong University of Science and Technology(Natural Science Edition),2013,41(7):10-14.(in Chinese))
[5]Tao M X,Fan J S,Nie J G.Seismic behavior of steel reinforced concrete column-steel truss beam hybrid joints[J].Engineering Structures,2013,56(11):1557-1569.
[6]Chou C C,Uang C M.Cyclic performance of a type of steel beam to steel-encased reinforced concrete column moment connection[J].Journal of Constructional Steel Research,2002,58(5/6/7/8):637-663.
[7]Chen C C,Suswanto B,Lin Y J.Behavior and strength of steel reinforced concrete beam-column joints with single-side force inputs[J].Journal of Constructional Steel Research,2009,65(8/9):1569-1581.
[8]Chen C C,Lin K T.Behavior and strength of steel reinforced concrete beam-column joints with two-side force inputs[J].Journal of Constructional Steel Research,2009,65(3):641-649.
[9]Aitcin P C.Developments the application high performance concrete[J].Construction and Building Materials,1995,9(1):13-17.
[10]Flaga K.Advances in materials applied in civil engineering[J].Journal of Materials Processing Technology,2000,106(1/2/3):173-183.
[11]王元,张大利,陈翠红.沈阳皇朝万鑫大厦C100混凝土耐久性的研究[J].混凝土,2006(11):56-57.(WANG Yuan,ZHANG Dali,CHEN Cuihong.Study on durability of C100 concrete in Shenyang Royal WAN XIN Hotel[J].Concrete,2006(11):56-57.(in Chinese))
[2]Yan C W,Jia J Q.Seismic performance of steel reinforced ultra high-strength concrete composite frame joints[J].Earthquake Engineering and Engineering Vibration,2010,9(3):439-448.
[3]张士前,陈宗平,王妮,等.型钢混凝土十形柱空间节点受剪机理及抗剪强度研究[J].土木工程学报,2014,47(9):84-93.(ZHANG Shiqian,CHEN Zongping,WANG Ni,et al.Shear mechanism and shear strength of steel reinforced concrete(SRC)crossshape 3D column-beam joints[J].China Civil Engineering Journal,2014,47(9):84-93.(in Chinese))
[4]商效瑀,郑山锁,韩协,等.型钢高强混凝土节点核心区模型化方法[J].华中科技大学学报(自然科学版),2013,41(7):10-14.(SHANG Xiaoyu,ZHENG Shansuo,HAN Xie,et al.Joint core model method of steel reinforced high strength concrete joints[J].Journal of Huazhong University of Science and Technology(Natural Science Edition),2013,41(7):10-14.(in Chinese))
[5]Tao M X,Fan J S,Nie J G.Seismic behavior of steel reinforced concrete column-steel truss beam hybrid joints[J].Engineering Structures,2013,56(11):1557-1569.
[6]Chou C C,Uang C M.Cyclic performance of a type of steel beam to steel-encased reinforced concrete column moment connection[J].Journal of Constructional Steel Research,2002,58(5/6/7/8):637-663.
[7]Chen C C,Suswanto B,Lin Y J.Behavior and strength of steel reinforced concrete beam-column joints with single-side force inputs[J].Journal of Constructional Steel Research,2009,65(8/9):1569-1581.
[8]Chen C C,Lin K T.Behavior and strength of steel reinforced concrete beam-column joints with two-side force inputs[J].Journal of Constructional Steel Research,2009,65(3):641-649.
[9]Aitcin P C.Developments the application high performance concrete[J].Construction and Building Materials,1995,9(1):13-17.
[10]Flaga K.Advances in materials applied in civil engineering[J].Journal of Materials Processing Technology,2000,106(1/2/3):173-183.
[11]王元,张大利,陈翠红.沈阳皇朝万鑫大厦C100混凝土耐久性的研究[J].混凝土,2006(11):56-57.(WANG Yuan,ZHANG Dali,CHEN Cuihong.Study on durability of C100 concrete in Shenyang Royal WAN XIN Hotel[J].Concrete,2006(11):56-57.(in Chinese))