• Steel and Composite Structures
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• 제23권4호
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• pp.399-408
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• 2017

This paper experimentally studies the cyclic behavior of hybrid connections between steel coupling beams and concrete shear walls with embedded steel columns. Four beam-to-wall connection specimens with short and long embedded steel columns are tested under monotonic and cyclic loads, respectively. The influence of embedment length of columns on the failure mode and performance of connections is investigated. The results show that the length of embedded steel columns has significant effect on the failure mode of connections. A connection with a long embedded column has a better stiffness, load-bearing capacity and ductility than that of a short embedded column. The former fails due to the shear yielding of column web in the joint panel, while failure of the latter is initiated by the yielding of horizontal reinforcement in the wall due to the rigid rotation of the column. It is recommended that embedded steel columns should be placed along the entire height of shear walls to facilitate construction and enhance the ductility.

• 교육녹색환경연구
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• 제10권2호
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• pp.1-7
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• 2011

An experimental study to evaluate structural capacity of an embedded plate connected with prestressed concrete beam was performed. Embedded steel plates and prestressed concrete beam were connected with stud-bolts at the ends of concrete beam specimens. About 1,000 kN concentrated load was applied at 450mm away from the end of beam specimen. A 3,000 kN capacity static Oil-jack was used to direct concentrated load. The maximum strain of stud-bolt recorded $90{\times}10^{-6}$(mm/mm) and wide width cracks were not founded. Any falling failures of concrete and large deformations were not founded either between steel plate and prestressed concrete specimen. As a result, construction performance can be improved using this embedded steel plate connection system apply to large space educational facilities.

• Steel and Composite Structures
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• 제23권4호
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• pp.409-420
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• 2017

This paper theoretically studies the cyclic behavior of hybrid connections between steel coupling beams and concrete shear walls with embedded steel columns. Finite element models of connections with long and short embedded steel columns are built in ABAQUS and validated against the test results in the companion paper. Parametric studies are carried out using the validated FE model to determine the key influencing factors on the load-bearing capacity of connections. A close-form solution of the load-bearing capacity of connections is proposed by considering the contributions from the compressive strength of concrete at the interface between the embedded beam and concrete, shear yielding of column web in the tensile region, and shear capacity of column web and concrete in joint zone. The results show that the bond slip between embedded steel members and concrete should be considered which can be simulated by defining contact boundary conditions. It is found that the loadbearing capacity of connections strongly depends on the section height, flange width and web thickness of the embedded column. The accuracy of the proposed calculation method is validated against test results and also verified against FE results (with differences within 10%). It is recommended that embedded steel columns should be placed along the entire height of shear walls to facilitate construction and enhance the ductility. The thickness and section height of embedded columns should be increased to enhance the load-bearing capacity of connections. The stirrups in the joint zone should be strengthened and embedded columns with very small section height should be avoided.

• 콘크리트학회논문집
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• 제17권6호
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• pp.1065-1074
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• 2005

Due to lack of information, current design methods to calculate bearing strength of connections are tacit about cases in which hybrid coupled walls have connection details of stud bolts and horizontal ties. In this study, analytical study was carried out to develop model for calculating the connections strength of embedded steel section. The bearing stress at failure in the concrete below the embedded steel coupling beam section is related to the concrete compressive strength and the ratio of the width of the embedded steel coupling beam section to the thickness of the shear walls. Experiments were carried out to determine the factors influencing the bearing strength of the connection between steel coupling beam and reinforced concrete shear wall. The test variables included the reinforcement details that confer a ductile behavior in connection between steel coupling beam and shear wall, i. e., the auxiliary stud bolts attached to the steel beam flanges and the transverse ties at the top and the bottom steel beam flanges. In addition, additional test were conducted to verify the strength equations of the connection between steel coupling beam and reinforced concrete shear wall. The results of the proposed equations in this study are in good agreement with both our test results and other test data from the literature.

• Architectural research
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• 제7권1호
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• pp.27-38
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• 2005

No specific guidelines are available for computing the bearing strength of connection between steel coupling beam and reinforced concrete shear wall in a hybrid wall system. There were carried out analytical and experimental studies on connection between steel coupling beam and concrete shear wall in a hybrid wall system. The bearing stress at failure in the concrete below the embedded steel coupling beam section is related to the concrete compressive strength and the ratio of the width of the embedded steel coupling beam section to the thickness of the shear walls. Experiments were carried out to determine the factors influencing the bearing strength of the connection between steel coupling beam and reinforced concrete shear wall. The test variables included the reinforcement details that confer a ductile behavior in connection between steel coupling beam and shear wall, i.e., the auxiliary stud bolts attached to the steel beam flanges and the transverse ties at the top and the bottom steel beam flanges. In addition, additional test were conducted to verify the strength equations of the connection between steel coupling beam and reinforced concrete shear wall. The proposed equations in this study were in good agreement with both our test results and other test data from the literature.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2013년도 춘계 학술논문 발표대회
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• pp.19-20
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• 2013

Green Frame is a column-beam system constructed by composite precast column and beam connected by embedded steel of their. From when the precast concrete beam of Green Frame is installed, until the concrete of slab and connection joint is cured, the self load of beam shall be supported by the embedded steel of it. Therefore, the concrete of beam could be separated from the embedded steel if the shear connector of beam of Green Frame is designed by the code on Structural standard. So, this study suggest an equation for the shear connection of composite precast concrete beams of Green Frame. The result of this study will be used as the main equation of the calculation model for shear connectors of composite precast concrete beams.

• Steel and Composite Structures
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• 제21권5호
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• pp.981-997
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• 2016

To avoid the cracks of cast-in-place concrete in shear pockets and seams in the traditional composite beam with precast decks, this paper proposed a new type of prefabricated steel truss-concrete composite beam (ab. PSTC beam) with pre-embedded shear studs (ab. PSS connector). To study the initial cracking load of concrete deck, the development and distribution laws of the cracks, 3 PSTC beams were tested under hogging moment. And the crack behavior of the deck was compared with traditional precast composite beam, which was assembled by shear pockets and cast-in-place joints. Results show that: (i) the initial crack appears on the deck, thus avoid the appearance of the cracks in the traditional shear pockets; (ii) the crack of the seam appears later than that of the deck, which verifies the reliability of epoxy cement mortar seam, thus solves the complex structure and easily crack behavior of the traditional cast-in-place joints; (iii) the development and the distribution laws of the cracks in PSTC beam are different from the conventional composite beam. Therefore, in the deduction of crack calculation theory, all the above factors should be considered.

• KIEAE Journal
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• 제7권6호
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• pp.107-112
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• 2007

Recently hybrid beam system is widely used because it has many structural advantages such as short construction period and low story height etc. Generally steel wide flange beam exposure type and embedded type hybrid beams are constructed. Even though exposure hybrid beam is easily constructed, the fire proofing protection process is necessary because steel wide flange beam cannot resist to fire itself. Story height reduction type hybrid beam, which is introduced hybrid beam in this paper, does not need fire proofing protection process because it is constructed as a fully embedded type hybrid beam. Developed construction process and actual construction cases of story height reduction type hybrid beam were introduced in this study.

• 한국방재학회 논문집
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• 제10권5호
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• pp.27-33
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• 2010

본 연구에서는 2,000 kN 용량의 actuator를 이용, 12 m 경간의 실물 크기로 제작된 프리스트레스트 콘크리트 보의 구조성능 평가를 위한 실험을 수행하였다. 보의 양 단에는 접합을 위한 강판을 매립하였으며 시험체는 별도로 제작된 철골 보에 고력볼트접합 방식으로 세팅되었다. 프리스트레스트 콘크리트와 슬래브 콘크리트의 설계기준강도는 각각 50 MPa와 24 MPa이며, 인장 철근으로 사용된 2-HD25 철근은 매립강판의 구성요소 중 하나인 수직강판에 용접하였다. 실험은 변위제어법에 의하여 수행되었으며 10 mm의 변위를 증가시키며 loading과 unloading을 반복적으로 가력하였다. 실험결과를 살펴보면, 탄성거동구간에서는 약 88.34%, 비탄성거동구간에서는 약 86.97% 그리고 소성거동구간에서는 약 66.83%의 프리스트레싱에 의한 변위복원능력을 나타냄을 알 수 있었다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2008년도 추계 학술발표회 제20권2호
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• pp.301-304
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• 2008

본 연구에서는 싱글 플레이트 전단접합에 앵글을 접합한 새로운 방식의 철골 커플링보를 개발하여 여러 가지 구조적 성능을 평가하고자 한다. 주요 변수는 앵글유무, 콘크리트 보강 유무, 매립길이, 결손단면이다. 실험은 커플링 보의 가운데 지점을 2,000kN Actuator를 이용하여 횡방향 반복가력을 가하여 구조물의 전체적인 거동을 알아본다. 실험결과 싱글 플레이트 전단 접합부로 이루어진 실험체보다 앵글을 접합한 실험체가 강도, 변형능력, 강성, 에너지 소산 능력 등 전반적인 구조적 성능이 훨씬 우수한 것으로 나타났다. 매립된 철골보 주위에 전단철근을 보강하지 않은 경우 PC벽체의 조기 지압파괴로 인해 그 성능이 현저히 떨어지는 것으로 나타났다. 그러나 전단철근이 배근이 된 경우 철골 커플링 보의 전단 항복이 발생할 때까지 PC벽체의 파괴가 충분히 지연되는 것으로 나타났다. 앵글이 접합된 경우 매립길이가 작아도 그 성능이 떨어지지 않았다. 결손 단면이 있을 경우 강도는 작게 나타났으나 접합부 전단 강도보다 훨씬 작도록 설계된 관계로 PC벽체의 파괴가 발생하기 전에 충분히 전단 거동을 통해 우수한 성능을 발휘하였다. 이러한 결과는 시공성과 경제성 향상을 위해 앵글을 접합한 철골 커플링 보 방식이 매우 유용할 것으로 사료된다.