钢与混凝土组合结构与钢筋混凝土结构过渡构件的抗震性能研究展望

在组合结构中底部数层采用型钢混凝土结构,上部采用钢筋混凝土结构,这样在两种结构的转换层就产生了底部为型钢混凝土结构上部为钢筋混凝土结构的非常规柱,这种非常规过渡柱的抗震性能与型钢混凝土柱及钢筋混凝土柱存在显著差别。目前关于这种非常规柱的研究主要集中在通过改变型钢的长度比例、纵向钢筋的配置方法,过渡部位的处理进行。另外目前的研究还包括对两端为钢与混凝土组合结构中部为钢筋混凝土结构的混合柱的抗震性能试验研究,通过在中部钢筋混凝土段设置与两端型钢焊接的交叉钢筋实现良好的连接,使得这种组合构件在循环荷载的作用下在构件的两端形成塑性铰,当混合梁构件的构造合理交叉钢筋的与型钢焊接后实现良好锚固时,构件的极限抗弯强度要高于普通的型钢混凝土梁。     

论某高层民用建筑钢骨混凝土施工技术

高层民用建筑采用型钢混凝土组合结构,可缩小结构构件截面尺寸,增大使用空间,但对型钢构件的制作、安装以及与钢筋工程的配合提出了更高的要求。本文介绍了复杂型钢混凝土组合结构施工的施工工艺和技术控制措施．以及施工中应解决的有关关键技术问题。     

型钢混凝土梁柱节点梁钢筋与型钢连接的施工技术

威海九龙城休闲购物广场工程主楼采用型钢混凝土组合结构,工程层高高、梁柱节点复杂,通过节点部位钢筋排列、连接方式的深化处理,解决了施工中的关键技术问题,采用腹板打孔穿过钢筋、套筒焊接予翼板连接、钢板焊接予翼板连接等方式形成了型钢混凝土组合结构节点部位梁钢筋与型钢连接的施工技术。     

高层民用建筑钢骨混凝土施工技术

高层民用建筑采用型钢混凝土组合结构,可缩小结构构件截面尺寸,增大使用空间,但对型钢构件的制作、安装以及与钢筋工程的配合提出了更高的要求。本文介绍了复杂型钢混凝土组合结构施工的施工工艺和技术控制措施,以及施工中应解决的有关关键技术问题。     

多向杆件相交的清水型钢混凝土组合结构节点施工技术研究

结合成都来福士广场工程实例,详细介绍了型钢混凝土组合结构节点深化设计的方法,提出了包括钢筋绕过型钢、钢筋伸至型钢边弯锚、钢筋穿过型钢腹板、钢筋与型钢通过连接板焊接连接、钢筋与型钢通过焊接套筒连接五种解决方法,并以工程典型节点为例详细说明了五种方法的选取过程。同时,结合工程施工实施情况,对型钢混凝土组合结构施工进行了总结。     

倒T形型钢-混凝土组合结构受弯性能试验研究

为了研究倒T形型钢 混凝土组合结构 (地下组合墙体系统 ,即CBS)的抗弯受力性能 ,以剪切连接度、U形补助连接钢筋、栓钉长度、受拉钢筋及墙体厚度作为主参变量 ,进行了 1 1根两跨型钢 混凝土组合梁的试验研究。研究结果发现U形补助连接钢筋及栓钉的附加长度明显地改善了结构的延性 ,墙体厚度及受拉钢筋的增大提高了结构的刚度和强度。并且验证了倒T形型钢 混凝土组合结构的跨中极限抗弯承载力计算可以直接利用一般型钢 混凝土组合梁的抵抗负弯矩极限承载力的计算公式     

石狮明昇凯悦酒店型钢混凝土结构钢骨架施工关键技术

当前,由型钢、钢筋为骨架与混凝土形成整体的型钢混凝土结构已逐渐成为综合性高层建筑经常采用的一种结构形式,而在施工中控制好钢骨架的施工工艺对型钢混凝土结构整体施工质量至关重要。文章以石狮明昇凯悦酒店工程为例,详细介绍了型钢混凝土转换层型钢的吊装、连接,型钢与钢筋连接等关键施工技术。     

重庆来福士广场型钢混凝土组合伸臂结构施工关键技术

以T4N塔楼为依托,针对型钢混凝土组合伸臂结构工序复杂、钢筋预埋困难、钢筋与型钢冲突、后合龙时间不易确定等施工重难点,在综合考虑型钢混凝土组合伸臂结构施工影响因素的基础上,结合有限元模拟及信息化技术,首次总结出超高层型钢混凝土组合伸臂结构后合龙施工、纵向钢筋预留预埋及钢混复杂节点优化技术,同时详细阐述了组合伸臂钢结构及混凝土结构施工过程及要点。     

高空大跨度型钢混凝土组合结构模板支撑体系施工技术

高层、超高层建筑大跨度连体或悬挑结构支模的特点是:跨度大、高度高、施工荷载大、施工工艺要求高、难度大。财智广场(赣州书城)项目B幢主楼21层悬空结构梁模板支撑体系采用工字钢或型钢搭建轻型操作平台,楼板采用钢筋桁架自承式楼板。提出了型钢混凝土组合梁自承重支模体系与钢筋桁架自承式楼板的有效连接、轻型斜拉钢平台拆除技术、型钢混凝土组合结构梁自承重技术、节点设计,成功解决了高空大跨度型钢混凝土组合结构施工技术难题。     

型钢混凝土柱底板节点预制构件定位施工方法

型钢混凝土柱兼具钢结构与混凝土结构两者的性能,型钢和混凝土两者的弹性模量相近,这种组合结构能够充分发挥材料的特性,显著改善结构的抗震性能,在建筑结构适用性方面具备着独特的优势。本文针对型钢混凝土柱的底板节点和梁柱节点的设计要点,采用BIM技术进行可视化模型的制作,预制定位构件(地脚螺栓与纵向钢筋的一体化定位器),确保型钢混凝土柱底部施工的精准度。     

Strength of slender concrete filled high strength steel box columns

The use of thin walled steel sections coupled with concrete infill has been used on various building projects with great advantage. The currently available international standards for composite structures are limited to the design of concrete filled steel columns with compact sections. However, there is limited research work in the literature available which is concerned with slender concrete filled thin-walled steel columns. This paper presents a comprehensive experimental study of thin walled steel sections utilising high strength steel of a thin walled nature and filled with normal strength concrete. A numerical model is developed herein in order to study the behaviour of slender concrete filled high strength steel columns incorporating material and geometric non-linearities. For this analysis, the equilibrium of the member is investigated in the deformed state, using the idealised stress–strain relationships for both the steel and concrete materials, considering the elastic and plastic ranges. This paper presents both an experimental and theoretical treatment of coupled local and global buckling of concrete filled high strength steel columns sometimes termed interaction buckling. The experimental results of columns with high strength steel casings conducted herein by the authors are used for comparison. The effect of the confined concrete core is also addressed and the method shows good agreement with the experimental results of concrete filled steel columns with compact sections. The behaviour of concrete filled steel slender columns affected by elastic or inelastic local buckling is also investigated and compared with relevant experimental results. The paper then concludes with a design recommendation for the strength evaluation of slender composite columns using high strength steel plates with thin-walled steel sections, paying particular attention to existing codes of practice so as not to deviate from current design methodologies.     

Analytical behavior of frames with steel beams to concrete-filled steel tubular column

This paper reports the mechanism of composite frames with steel beams connected to concrete-filled square hollow section (SHS) columns. Detailed analysis was carried out on longitudinal stress in steel beams, axial stress distribution in concrete, and concrete stress along the column height and at the connection panel. Parametric studies were conducted to investigate the influence of axial load level, beam-to-column linear stiffness ratio on the structural behavior of composite frames. Simplified hysteretic lateral load (P) versus lateral displacement (Δ) models are proposed for such composite frames.     

体外索钢箱-混凝土组合梁力学性能研究

对一种新型的体外索钢箱-混凝土组合梁与普通的钢箱-混凝土组合梁进行对比试验,研究这两种钢箱-混凝土组合梁受力过程中的应变分布、界面滑移、刚度、极限强度等力学性能的差异。试验证实,体外索钢箱-混凝土组合梁比普通的钢箱-混凝土组合梁的刚度提高54．15％,极限强度提高27．72％。由于体外索的作用,减少了钢箱-混凝土组合梁的脆性破坏程度,提高了结构的强度与刚度,使钢箱-混凝土组合梁的应变分布和增长更为合理。因此,体外索钢箱-混凝土组合梁具有更好的力学性能。试验表明,截面应变沿宽度方向呈非线性分布,剪力滞效应随荷载的增加而变化,并不是常量。研究还发现,体外索应力与混凝土翼板最大压应变有密切的关系。在试验研究基础上,建立了截面非线性分析模型和体外索钢箱-混凝土组合梁极限强度计算公式,计算的极限强度与试验结果符合很好,这为体外索钢箱-混凝土组合梁极限强度的理论分析和工程实际应用提供了有意义的参考和研究途径。     

Experimental study of bonded steel concrete composite structures

This paper deals with the experimental analysis of the mechanical behaviour of bonded steel-concrete composite structures. The steel girder and the concrete slab are assembled by adhesives. The effect of the main parameters, such as the adhesive nature and the irregular thickness of the adhesive joint, on mechanical performance and ultimate load is studied. Two adhesives are used in this work. The results show that the connection between the steel girder and the concrete slab ensured by epoxy adhesive is perfect and without any slip in the steel-concrete interface. In the case of the composite beam interface ensured by polyurethane, the connection is flexible. The influence of the variation in adhesive thickness, 2 mm in the transverse direction and 4 mm in the longitudinal direction, on the mechanical behaviour and ultimate force is not important. The first cracks in the concrete slab appear in the transverse direction. The experimental results show that it is possible to realise a steel concrete composite structure bonded by adhesive.     

Enhancing the fire resistance of composite floor assemblies through the use of steel fiber reinforced concrete

This paper presents a strategy for achieving the required fire resistance in composite floor systems through the use of steel fiber reinforced concrete (SFRC). Both experimental and numerical studies were carried out to evaluate the fire performance of floor systems comprising unprotected steel beams and concrete/SFRC deck slabs. The results from these studies show that SFRC composite deck slabs develop significant tensile forces (through tensile membrane action) that transfer load from fire-weakened steel beams to other cooler parts of the structure. Preliminary results indicate that the combined effect of composite construction, tensile membrane action, and the improved properties of SFRC under realistic fire, loading, and restraint conditions can provide sufficient fire resistance in steel beam-concrete deck slabs without the need for external fire protection on the floor assembly.     

型钢混凝土组合结构安装施工技术

本文结合工程实例介绍型钢混凝土组合结构安装技术     

Headed steel stud anchors in composite structures, Part I: Shear

The formula in the 2005 American Institute of Steel Construction Specification to compute the strength of headed steel stud anchors (shear connectors) in composite steel/concrete structures has been used in the United States since 1993, after being proposed based primarily on the results of push-out tests. In the past several decades, the range of members used in composite structures has increased significantly, as has the number of tests in the literature on the monotonic and cyclic behavior of headed studs in composite construction. This paper reviews 391 monotonic and cyclic tests from the literature on experiments of headed stud anchors and proposes formulas for the limit states of steel failure and concrete failure of headed stud anchors subjected to shear force without the use of a metal deck. Detailing provisions to prevent premature pryout failure are also discussed. This paper also reviews proposals from several authors and provides recommended shear strength values for the seismic behavior of headed studs. The limit state formulas are proposed within the context of the 2005 AISC Specification, and comparisons are made to the provisions in the ACI 318-08 Building Code, the PCI Handbook, 6th Edition, and Eurocode 4. The scope of this research includes composite beam-columns [typically concrete-encased steel shapes (SRCs) or concrete-filled steel tubes (CFTs)], concrete-encased and concrete-filled beams, boundary elements of composite wall systems, composite connections, composite column base conditions, and related forms of composite construction.     

Fire resistance of axially loaded concrete filled steel tube columns

The behaviour of axially loaded square and circular concrete-filled steel tube (CFST) columns when exposed to elevated temperatures is investigated in this paper. The fire resistance of this kind of composite tubes is calculated. Comparison of the square and circular columns in the fire resistance shows that, for columns with the same steel and concrete cross-section areas, the circular column has slightly better fire resistance than the square column.     

钢与混凝土组合梁的发展、研究和应用

本文简要介绍了钢与混凝土组合梁的发展史,阐述了四类钢与混凝土组合梁的研究现状并提出了有待进一步解决的问题,列举了其在国内部分工程上的应用.     

Development of Brazilian steel construction

This article presents a concise short overview of the development of the steel industry in Brazil, with the emphasis on civil construction. The relatively rapid increase in the application of steel structures for both low and tall buildings and the modern bridges in Brazil are the results of an extensive effort of the steel producers and the improvement of steel courses and research programmes in several universities and institutions during the last two decades. The steel industry in collaboration with the universities, which have provided the results of their recent studies, contributed to the improved steel technologies and composite construction. Data, supplied by the Brazilian Institute of Metallurgy, IBS, is presented on the actual steel production and fabrication with regard to application in civil engineering. Case studies of steel structures, such as multi-storey buildings, space structures, light gauge steel construction and bridges, are presented and commented on. Further, steel structures subjected to corrosion or to fire, as well as steel and composite semi-rigid joints, are mentioned and finally the Brazilian experience with steel architecture is introduced.