Tensile Behaviour of Hollo-bolts Embedded in Concrete
-
摘要: 为了研究混凝土的粘结效应对盲眼螺栓抗拉性能的影响,采用抗拉装置,对预埋于钢管混凝土的盲眼螺栓进行了抗拉试验.首先得到各种工况下试件的破坏模式和荷载-位移关系曲线;其次对各种工况下试件的破坏模式和荷载-位移关系曲线进行比较分析,得到有无混凝土以及不同混凝土强度等级对盲眼螺栓初始刚度、强度和延性的影响;最后分析考虑混凝土粘结效应后盲眼螺栓的抗拉受力机理,并提出了改良盲眼螺栓的合理措施.研究结果表明:混凝土的粘结效应改变了盲眼螺栓的抗拉传力机理,使其整体受力从套管转移到中心螺杆,从而使其破坏模式由套管提前破坏失效转化成中心螺杆强度破坏;混凝土强度等级对盲眼螺栓刚度有显著影响,混凝土强度从C30提高至C50时,其初始刚度由15.1%提高至35.7%,其屈服后刚度也分别提高了1.27和1.64倍;盲眼螺栓的抗拉屈服强度和延性主要由套管的性质决定,抗拉极限强度则取决于中心螺杆的承载力,混凝土的强度等级对其无影响.Abstract: To examine the tensile response of Hollo-bolts considering the bonding effect of concrete, a new device to perform pullout tests was used to investigate the tensile behaviour of Hollo-bolts embedded in concrete. First, the tensile force-displacement relationships for all specimens under different experimental conditions were obtained. Then, the failure modes and the tensile force-displacement relationship curves were compared and analysed to examine the influence of the tested experimental variables, which include the concrete strength grade and tubular sections with or without concrete filling, on the initial stiffness, strength, and ductility of the structure. Finally, the tension loading-bearing mechanism of Hollo-bolts was analysed considering the bonding effect of concrete. In addition, reasonable measures to improve the tensile-behaviour of Hollo-bolts were subsequently suggested. The test results revealed that the bonding effect of concrete changes the tension loading-bearing mechanism of Hollo-bolts, as the load on the Hollo-bolt eventually shifts from the bolt sleeve to focus on the centre screw. Accordingly, the failure model of the Hollo-bolt changes from sleeve failure to centre screw failure. Furthermore, it was determined that the concrete strength grade significantly influences the stiffness of Hollo-bolts. When the concrete strength grade increased from C30 to C50, the initial stiffness increased from 15.1% to 35.7% and the post-yield stiffness improved 1.27 and 1.64 times compared to the specimens for which the bonding effect of concrete was not considered. However, the findings indicate that the yield tensile strength and ductility of Hollo-bolts are primarily determined by the capacity of the sleeve, while the ultimate tensile strength of Hollo-bolts is influenced by the capacity of the centre screw, as the concrete grade shows no significant effect on the tensile strength of Hollo-bolts.
-
Key words:
- Hollo-bolt /
- bonding effect /
- concrete grade /
- tensile behavior
-
YEOMANS N F. Rectangular hollow section column using the Lindapter Hollo Bolt[C]//Tubular Hollo Bolt Structures Ⅷ, Choo andvan der Vegte (eds). Balkerma:Rotterdam, 1998:559-566. BARNETT T, TIZANI W, NETHERCOT D. Blind bolted moment resisting connections to structural hollow sections[C]//Connections in Steel Structures Ⅳ:Steel Connections in the New Millennium. Roanoke:[s.n.], 2000:340-348. BARNETT T C, TIZANI W, NETHERCOT D A. The practice of blind bolting connections to structural hollow sections:areview[J]. Steel & Composite Structures, 2001, 1(1):1-16. TIZANI W, AL-MUGHAIRI A, OWEN J S, et al. Rotational stiffness of a blind-bolted connection to concrete-filled tubes using modified Hollo-Bolt[J]. Journal of Constructional Steel Research, 2013, 80(1):317-331. WANG Z Y, TIZANI W, WANG Q Y. Strength and initial stiffness of a blind-bolt connection based on the T-stub model[J]. Engineering Structures, 2010, 32(9):2505-2517. BS En. Eurocode 3:design of steel structures. part 1.8:design of joints[S].Brussels:European Committee for Standardization, 2005. ELGHAZOULI A Y, MÁAGA-CHUQUITAYPE C, CASTRO J M, et al. Experimental monotonic and cyclic behaviour of blind-bolted angle connections[J]. Engineering Structures, 2009, 31(11):2540-2553. LIU Y, MÁAGA-CHUQUITAYPE C, ELGHAZOULI A Y. Behaviour of open beam-to-tubular column angle connections under combined loading conditions[J]. Steel and Composite Structures, 2014, 16(2):157-185. LIU Y, MÁAGA-CHUQUITAYPE C, ELGHAZOULI AY, Behaviour of beam-to-tubular column angle connections under shear loads[J]. Engineering Structures, 2012, 42:434-456. TIZANI W, PITRAKKOS T, PITRAKKOS T. Performance of T-stub to CFT joints using blind bolts with headed anchors[J]. Journal of Structural Engineering, 2015, 141(10):1-12. ELISON S, TIZANJ W. Behaviour of blind bolted connections to concrete filled hollow sections[J]. Structural Engineer, 2004, 82(22):16-17. AGHESHLUI H, GOLDSWORTHY H, GAD E, et al. Tensile behavior of groups of anchored blind bolts within concrete-filled steel square hollow sections[J]. Journal of Structural Engineering, 2016, 142(2):125-132. 王静峰,郭水平,陈莉萍. 带肋薄壁钢管混凝土框架梁柱端板连接节点试验研究[J]. 建筑结构学报,2011, 32(10):69-78. WANG Jingfeng, GUO Shuiping, CHEN Liping. Experimental study on behavior of beam-column endplate joints of concrete-filled thin-walled steel tube frame with ribs[J]. Journal of Building Structures, 2011, 32(10):69-78. GARDNER A P, GOLDSWORTHY H M. Experimental investigation of the stiffness of critical components in a moment-resisting composite connection[J]. Journal of Constructional Steel Research, 2005, 61(5):709-726. YAO H, GOLDSWORTHY H, GAD E. Experimental and numerical investigation of the tensile behavior of blind-bolted T-stub connections to concrete-filled circular columns[J]. Journal of Structural Engineering, 2008, 134(2):198-208. 李德山,陶忠,王志滨. 钢管混凝土柱-钢梁单边螺栓连接节点静力性能试验研究[J]. 湖南大学学报:自科版,2015(3):43-49. LI Deshan, TAO Zhong, WANG Zhibin. Experimental investigation of blind-bolted joints to concrete filled steel columns[J]. Journal of Hunan University:Natural Sciences, 2015(3):43-49. BS En. ISO 898-1 Mechanical properties of fasteners made of carbon steel and alloy steel. part 1:bolts, screws and studs with specified property classes-coarse thread and fine pitch thread[S]. London:BSI, 2009. 李久林,高振英. GB/T2975-1998钢及钢产品力学性能试验取样位置及式样制备[J]. 冶金标准化与质量,1999(5):35-37. LI Jiulin, GAO Zhenying. GB/T2975-1998 Steel and steel products-location and preparation of samples and test pieces for mechanical testing[J]. Metallurgical Standardization and Quality, 1999(5):35-37. 国家质量监督检验检疫总局. GB6379-86金属拉伸试验试样[S]. 北京:中国计划出版社,1986. 国家质量监督检验检疫总局. GB/T228-2010金属材料室温拉伸试验方法[S]. 北京:中国计划出版社,2010. MÁAGA-CHUQUITAYPE C, ELGHAZOULI A Y. Component-based mechanical models for blind-bolted angle connections[J]. Engineering Structures, 2010, 32(10):3048-3067. LIU Y, MÁAGA-CHUQUITAYPE C, ELGHAZOULI A Y. Response and component characterisation of semi-rigid connections to tubular columns under axial loads[J]. Engineering Structures, 2014, 41(3):510-532. PITRAKKOS T, TIZANI W. Experimental behaviour of a novel anchored blind-bolt in tension[J]. Engineering Structures, 2013, 49(2):905-919. XU Y. Experimental study of bond-anchorage properties for bundle of bars[J]. Building Structure, 1996, 15(3):275-291. 王海龙,李朝红,徐光兴. 带肋钢筋与混凝土粘结性能的细观数值模拟[J]. 西南交通大学学报,2011,46(3):365-372. WANG Hailong, LI Chaohong, XU Guangxing. Mesoscopic numerical simulation of bond behavior of ribbed bars and concrete[J]. Journal of Southwest Jiaotong University, 2011, 46(3):365-372. 淡丹辉,王庆霖. 钢筋混凝土结构锈胀裂缝的计算机模拟[J]. 西南交通大学学报,2000,35(5):484-487. DAN Danhui, WANG Qinglin. Computer simulation of corrosive cracks on RC members[J]. Journal of Southwest Jiaotong University, 2000, 35(5):484-487.
点击查看大图
计量
- 文章访问数: 458
- HTML全文浏览量: 73
- PDF下载量: 83
- 被引次数: 0