• 제목/요약/키워드: profiled steel sheeting

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전단 지간의 변화에 따른 PSC 거더용 강-콘크리트 합성 바닥판의 역학적 거동 (Behavior of Steel-Concrete Composite Decks for PSC Girder Bridge with Various Shear Span Lengths)

  • 김태협;박준명;홍성남;박선규;김형렬
    • 콘크리트학회논문집
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    • 제19권3호
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    • pp.275-281
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    • 2007
  • 최근에 교량과 건축물의 건설에 강-콘크리트 합성 구조물이 광범위하게 적용되고 있다. 본 논문에서는 과거의 현장 타설 철근콘크리트 바닥판을 대체하기 위하여 새로운 형태의 강-콘크리트 합성 바닥판을 재안하였다. 유공판재형 전단 연결재는 성형 강판과 콘크리트 사이의 수평전단저항력을 제공하는데 유용하였다. 제안된 바닥판 시스템의 효과를 증명하기 위하여 PSC 거더용 바닥판을 8개 제작하였으며, 정적 하중 상태에서 바닥판의 수평전단저항력을 결정하기 위하여 4가지의 전단 지간을 적용하여 실험을 수행하였다. 또한 제안된 바닥판과의 비교를 위하여 2개의 철근콘크리트 바닥판을 제작하여 실험을 수행하였다. 그리고 제안된 바닥판 시스템의 수평전단저항력은 m-k 방법을 이용하여 산정되었다.

강-콘크리트 합성 바닥판용 전단연결재의 합성 거동 연구 (Composite Behavior of Perfobond Rib Shear Connector for Steel-concrete Decks)

  • 김형열;구현본
    • 대한토목학회논문집
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    • 제26권1A호
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    • pp.91-97
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    • 2006
  • 본 연구에서는 강-콘크리트 합성 바닥판용 유공판재형 전단연결재의 전단성능을 평가하기 위한 전단실험을 수행하고 그 실험결과를 고찰하였다. 전단 실험체는 절곡된 강판, 유공판재형 전단연결재, 철근, 콘크리트로 구성되었으며, 절곡된 강판과 콘크리트 사이에 작용하는 수평전단력에 저항할 수 있도록 다수의 구멍이 가공된 유공판재형 전단연결재가 적용되었다. 실험체설계에 적용된 변수는 구멍의 간격과 위치, 구멍관통 철근의 유무이며, 총 12개의 실험체를 제작하여 전단실험을 수행하였다. 제한적 범위 내에서 수행한 실험결과에 따르면 유공판재형 전단연결재가 강-콘크리트 합성 바닥판에 효과적으로 사용될 수 있을 것으로 판단된다.

Strengthening of steel-concrete composite beams with composite slab

  • Subhani, Mahbube;Kabir, Muhammad Ikramul;Al-Amer, Riyadh
    • Steel and Composite Structures
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    • 제34권1호
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    • pp.91-105
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    • 2020
  • Steel-concrete composite beam with profiled steel sheet has gained its popularity in the last two decades. Due to the ageing of these structures, retrofitting in terms of flexural strength is necessary to ensure that the aged structures can carry the increased traffic load throughout their design life. The steel ribs, which presented in the profiled steel deck, limit the use of shear connectors. This leads to a poor degree of composite action between the concrete slab and steel beam compared to the solid slab situation. As a result, the shear connectors that connects the slab and beam will be subjected to higher shear stress which may also require strengthening to increase the load carrying capacity of an existing composite structure. While most of the available studies focus on the strengthening of longitudinal shear and flexural strength separately, the present work investigates the effect of both flexural and longitudinal shear strengthening of steel-concrete composite beam with composite slab in terms of failure modes, ultimate load carrying capacity, ductility, end-slip, strain profile and interface differential strain. The flexural strengthening was conducted using carbon fibre reinforced polymer (CFRP) or steel plate on the soffit of the steel I-beam, while longitudinal shear capacity was enhanced using post-installed high strength bolts. Moreover, a combination of both the longitudinal shear and flexural strengthening techniques was also implemented (hybrid strengthening). It is concluded that hybrid strengthening improved the ultimate load carrying capacity and reduce slip and interface differential strain that lead to improved composite action. However, hybrid strengthening resulted in brittle failure mode that decreased ductility of the beam.

Finite element modelling of the shear behaviour of profiled composite walls incorporating steel-concrete interaction

  • Anwar Hossain, K.M.;Wright, H.D.
    • Structural Engineering and Mechanics
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    • 제21권6호
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    • pp.659-676
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    • 2005
  • The novel form of composite walling system consists of two skins of profiled steel sheeting with an in-fill of concrete. The behaviour of such walling under in-plane shear is important in order to utilise this system as shear elements in a steel framed building. Steel sheet-concrete interface governs composite action, overall behaviour and failure modes of such walls. This paper describes the finite element (FE) modelling of the shear behaviour of walls with particular emphasis on the simulation of steel-concrete interface. The modelling of complex non-linear steel-concrete interaction in composite walls is conducted by using different FE models. Four FE models are developed and characterized by their approaches to simulate steel-concrete interface behaviour allowing either full or partial composite action. Non-linear interface or joint elements are introduced between steel and concrete to simulate partial composite action that allows steel-concrete in-plane slip or out of plane separation. The properties of such interface/joint elements are optimised through extensive parametric FE analysis using experimental results to achieve reliable and accurate simulation of actual steel-concrete interaction in a wall. The performance of developed FE models is validated through small-scale model tests. FE models are found to simulate strength, stiffness and strain characteristics reasonably well. The performance of a model with joint elements connecting steel and concrete layers is found better than full composite (without interface or joint elements) and other models with interface elements. The proposed FE model can be used to simulate the shear behaviour of composite walls in practical situation.

Finite element model for the long-term behaviour of composite steel-concrete push tests

  • Mirza, O.;Uy, B.
    • Steel and Composite Structures
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    • 제10권1호
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    • pp.45-67
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    • 2010
  • Composite steel-concrete structures are employed extensively in modern high rise buildings and bridges. This concept has achieved wide spread acceptance because it guarantees economic benefits attributable to reduced construction time and large improvements in stiffness. Even though the combination of steel and concrete enhances the strength and stiffness of composite beams, the time-dependent behaviour of concrete may weaken the strength of the shear connection. When the concrete loses its strength, it will transfer its stresses to the structural steel through the shear studs. This behaviour will reduce the strength of the composite member. This paper presents the development of an accurate finite element model using ABAQUS to study the behaviour of shear connectors in push tests incorporating the time-dependent behaviour of concrete. The structure is modelled using three-dimensional solid elements for the structural steel beam, shear connectors, concrete slab and profiled steel sheeting. Adequate care is taken in the modelling of the concrete behaviour when creep is taken into account owing to the change in the elastic modulus with respect to time. The finite element analyses indicated that the slip ductility, the strength and the stiffness of the composite member were all reduced with respect to time. The results of this paper will prove useful in the modelling of the overall composite beam behaviour. Further experiments to validate the models presented herein will be conducted and reported at a later stage.

An innovative system to increase the longitudinal shear capacity of composite slabs

  • Simoes, Rui;Pereira, Miguel
    • Steel and Composite Structures
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    • 제35권4호
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    • pp.509-525
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    • 2020
  • Steel-concrete composite slabs with profiled steel sheeting are widely used in the execution of floors in steel and composite buildings. The rapid construction process, the elimination of conventional replaceable shuttering and the reduction of temporary support are, in general, considered the main advantages of this structural system. In slabs with the spans currently used, the longitudinal shear resistance commonly provided by the embossments along the steel sheet tends to be the governing design mode. This paper presents an innovative reinforcing system that increases the longitudinal shear capacity of composite slabs. The system is constituted by a set of transversal reinforcing bars crossing longitudinal stiffeners executed along the upper flanges of the steel sheet profiles. This type of reinforcement takes advantage of the high bending resistance of the composite slabs and increases the slab's ductility. Two experimental programmes were carried out: a small-scale test programme - to study the resistance provided by the reinforcing system in detail - and a full-scale test programme to test simply supported and continuous composite slabs - to assess the efficacy of the proposed reinforcing system on the global behaviour of the slabs. Based on the results of the small-scale tests, an equation to predict the resistance provided by the proposed reinforcing system was established. The present study concludes that the resistance and the ductility of composite slabs using the reinforcing system proposed here are significantly increased.

Machine learning-based probabilistic predictions of shear resistance of welded studs in deck slab ribs transverse to beams

  • Vitaliy V. Degtyarev;Stephen J. Hicks
    • Steel and Composite Structures
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    • 제49권1호
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    • pp.109-123
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    • 2023
  • Headed studs welded to steel beams and embedded within the concrete of deck slabs are vital components of modern composite floor systems, where safety and economy depend on the accurate predictions of the stud shear resistance. The multitude of existing deck profiles and the complex behavior of studs in deck slab ribs makes developing accurate and reliable mechanical or empirical design models challenging. The paper addresses this issue by presenting a machine learning (ML) model developed from the natural gradient boosting (NGBoost) algorithm capable of producing probabilistic predictions and a database of 464 push-out tests, which is considerably larger than the databases used for developing existing design models. The proposed model outperforms models based on other ML algorithms and existing descriptive equations, including those in EC4 and AISC 360, while offering probabilistic predictions unavailable from other models and producing higher shear resistances for many cases. The present study also showed that the stud shear resistance is insensitive to the concrete elastic modulus, stud welding type, location of slab reinforcement, and other parameters considered important by existing models. The NGBoost model was interpreted by evaluating the feature importance and dependence determined with the SHapley Additive exPlanations (SHAP) method. The model was calibrated via reliability analyses in accordance with the Eurocodes to ensure that its predictions meet the required reliability level and facilitate its use in design. An interactive open-source web application was created and deployed to the cloud to allow for convenient and rapid stud shear resistance predictions with the developed model.

Experimental investigation of shear connector behaviour in composite beams with metal decking

  • Qureshi, Jawed;Lam, Dennis
    • Steel and Composite Structures
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    • 제35권4호
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    • pp.475-494
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    • 2020
  • Presented are experimental results from 24 full-scale push test specimens to study the behaviour of composite beams with trapezoidal profiled sheeting laid transverse to the beam axis. The tests use a single-sided horizontal push test setup and are divided into two series. First series contained shear loading only and the second had normal load besides shear load. Four parameters are studied: the effect of wire mesh position and number of its layers, placing a reinforcing bar at the bottom flange of the deck, normal load and its position, and shear stud layout. The results indicate that positioning mesh on top of the deck flange or 30 mm from top of the concrete slab does not affect the stud's strength and ductility. Thus, existing industry practice of locating the mesh at a nominal cover from top of the concrete slab and Eurocode 4 requirement of placing mesh 30 mm below the stud's head are both acceptable. Double mesh layer resulted in 17% increase in stud strength for push tests with single stud per rib. Placing a T16 bar at the bottom of the deck rib did not affect shear stud behaviour. The normal load resulted in 40% and 23% increase in stud strength for single and double studs per rib. Use of studs only in the middle three ribs out of five increased the strength by 23% compared to the layout with studs in first four ribs. Eurocode 4 and Johnson and Yuan equations predicted well the stud strength for single stud/rib tests without normal load, with estimations within 10% of the characteristic experimental load. These equations highly under-estimated the stud capacity, by about 40-50%, for tests with normal load. AISC 360-16 generally over-estimated the stud capacity, except for single stud/rib push tests with normal load. Nellinger equations precisely predicted the stud resistance for push tests with normal load, with ratio of experimental over predicted load as 0.99 and coefficient of variation of about 8%. But, Nellinger method over-estimated the stud capacity by about 20% in push tests with single studs without normal load.