• Title, Summary, Keyword: Prestressed concrete girder

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A Study on the Static Behavior of Connection for the Steel-Concrete Hybrid Girder (강-콘크리트 혼합거더 접합부의 정적 거동에 관한 연구)

  • Kim, Moon-Kyum;Lho, Byeong-Cheol;Kim, Jeong-Hoon;Park, Hyun-Chul
    • Proceedings of the Korea Concrete Institute Conference
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    • pp.426-429
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    • 2006
  • This paper focuses on the static behavior of prestressed and non-prestressed connections for the steel-concrete hybrid girder. Based on the experimental study, it is found that the girder with non-prestressed connection failed by local concrete failure at the connection area, and the studs are taken out from the concrete. In case of the girder with prestressed joint, the failure of the girder is initiated by the crack at the varying section area. The test results show that the girder with prestressed connection has higher load carrying capacity compare to the girder with non-prestressed connection by 12%. Therefore, the application of prestressing at the concrete-steel connection recommended for the more secure connection.

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Prestress and excitation force identification in a prestressed concrete box-girder bridge

  • Xiang, Ziru;Chan, Tommy H.T.;Thambiratnam, David P.;Nguyen, Andy
    • Computers and Concrete
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    • v.20 no.5
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    • pp.617-625
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    • 2017
  • Prestress force identification (PFI) is crucial to maintain the safety of prestressed concrete bridges. A synergic identification method has been proposed recently by the authors that can determine the prestress force (PF) and the excitation force simultaneously in prestressed concrete beams with good accuracy. In this paper, the ability of this method in the application with prestressed concrete box-girder bridges is demonstrated. A reasonable assumption is made to capture the similarity of the dynamic behavior of the prestressed concrete box-girder bridge and a beam under a certain loading scenario, and the feasibility of this method for application in a prestressed box-girder bridge is affirmed. A comprehensive laboratory test program is conducted, and the effects of PF, excitation, measuring time and uncertainties are studied. Results show that the proposed method can predict the PF and the excitation force in a prestressed concrete box-girder accurately and has a great robustness against uncertainties.

Camber calculation of prestressed concrete I-Girder considering geometric nonlinearity

  • Atmaca, Barbaros;Ates, Sevket
    • Computers and Concrete
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    • v.19 no.1
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    • pp.1-6
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    • 2017
  • Prestressed concrete I-girders are subject to different load types at their construction stages. At the time of strand release, i.e., detensioning, prestressed concrete girders are under the effect of dead and prestressing loads. At this stage, the camber, total net upward deflection, of prestressed girder is summation of the upward deflection due to the prestressing force and the downward deflection due to dead loads. For the calculation of the upward deflection, it is generally considered that prestressed concrete I-girder behaves linear-elastic. However, the field measurements on total net upward deflection of prestressed I-girder after detensioning show contradictory results. In this paper, camber calculations with the linear-elastic beam and elastic-stability theories are presented. One of a typical precast I-girder with 120 cm height and 31.5 m effective span length is selected as a case study. 3D finite element model (FEM) of the girder is developed by SAP2000 software, and the deflections of girder are obtained from linear and nonlinear-static analyses. Only geometric nonlinearity is taken into account. The material test and field measurement of this study are performed at prestressing girder plant. The results of the linear-elastic beam and elastic-stability theories are compared with FEM results and field measurements. It is seen that the camber predicted by elastic-stability theory gives acceptable results than the linear-elastic beam theory while strand releasing.

Nonlinear Analysis of Prestressed Concrete Box Girder Bridges Using Macro Element (매크로요소를 이용한 프리스트레스트 콘크리트 박스거더 교량의 비선형 해석)

  • Oh, Byung-Hwan;Lee, Myung-Kue
    • Magazine of the Korea Concrete Institute
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    • v.11 no.1
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    • pp.77-87
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    • 1999
  • The conventional design of prestressed concrete box girder bridges has been based on the linear elastic analyses using simplified geometric models. To overcome the restriction involved in the simplifications, a macro element for the rational analysis of prestressed concrete box girder bridges with variable cross sections is incorporated in the present analysis. Through the adoption of nonlinear material models, the behaviour of prestressed box bridges up to ultimate loading stage can be examined. The time dependent material models included in the present macro element code enable to predict the long term behaviour of prestressed concrete box girder bridges. The proposed macro element code with the nonlinear material models and time dependent routines can be efficiently used for the realistic analysis of prestressed concrete box girder bridges with arbitrary shapes.

Determination of minimum depth of prestressed concrete I-Girder bridge for different design truck

  • Atmaca, Barbaros
    • Computers and Concrete
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    • v.24 no.4
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    • pp.303-311
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    • 2019
  • The depth of superstructure is the summation of the height of girders and the thickness of the deck floor. In this study, it is aim to determine the maximum span length of girders and minimum depth of the superstructure of prestressed concrete I-girder bridge. For this purpose the superstructure of the bridge with the width of 10m and the thickness of the deck floor of 0.175m, which the girders length was changed by two meter increments between 15m and 35m, was taken into account. Twelve different girders with heights of 60, 75, 90, 100, 110, 120, 130, 140, 150, 160, 170 and 180 cm, which are frequently used in Turkey, were chosen as girder type. The analyses of the superstructure of prestressed concrete I girder bridge was conducted with I-CAD software. In the analyses AASHTO LRFD (2012) conditions were taken into account a great extent. The dead loads of the structural and non-structural elements forming the bridge superstructure, prestressing force, standard truck load, equivalent lane load and pedestrian load were taken into consideration. HL93, design truck of AASHTO and also H30S24 design truck of Turkish Code were selected as vehicular live load. The allowable concrete stress limit, the number of prestressed strands, the number of debonded strands and the deflection parameters obtained from analyses were compared with the limit values found in AASHTO LRFD (2012) to determine the suitability of the girders. At the end of the study maximum span length of girders and equation using for calculation for minimum depth of the superstructure of prestressed concrete I-girder bridge were proposed.

Effects of concrete strength on structural behavior of holed-incrementally prestressed concrete (H-IPC) girder

  • Han, Man Yop;Kim, Sung Bo;Kang, Tae Heon
    • Advances in concrete construction
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    • v.3 no.2
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    • pp.113-126
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    • 2015
  • Holed-Incrementally Prestressed Concrete (H-IPC) girders are designed using the following new design concepts. At first, web openings reduce the self-weight of the girder, and also diffuse prestressing tendon anchorages. The reduced end anchoring forces decrease the web thickness of the end sections. Additionally, precast technology help to improve the quality of concrete and to reduce the construction period at the site. For experimentally verification, two 50 m full-scale H-IPC girders are manufactured with different concrete strength of 55 MPa and 80 MPa. The safety, stiffness, ductility, serviceability and crack development of H-IPC girder are measured and compared with each other for different strengths. Both girders show enough strength to carry live load and good stiffness to satisfy the design criteria. The experimental result shows the advantages of using high strength concrete and adopting precast girder. The test data can be used as a criterion for safety control and maintenance of the H-IPC girder.

Shrinkage and Creep Effects on Continuous Prestressed Concrete Girder Bridges (연속 프리스트레스트 콘크리트 거더교에서 건조수축과 크리프의 영향)

  • Cho, Sun-Kyu;Youn, Seok-Goo;Lee, Jong-Min;Choi, Yun-Wang;Chung, Jee-Seung
    • Proceedings of the Korea Concrete Institute Conference
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    • pp.417-420
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    • 2004
  • The Prestressed concrete girder bridges(PSC girder bridges), consisting of prestressed concrete girders and cast-in-place deck slabs, are sensitive to creep and shrinkage of concrete. Shrinkage and creep produce additional internal forces md deformations in PSC girder bridges. The long-term behavior of the PSC girder bridges depends on time-dependent properties of materials, amount of prestressing, methods and sequences of construction and age at loading. The purpose of this study is to predict the long-term behavior of PSC girder bridge. For this purpose, Computer program for Time-dependent analysis of PSC girder bridge has been developed. thereafter, Time-dependent analysis using developed computer program was carried out about 3-span continuous PSC girder bridges. Various construction timing sequences were used for parametric study.

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Wireless Impedance Sensor with PZT-Interface for Prestress-Loss Monitoring in Prestressed Concrete Girder

  • Nguyen, Khac-Duy;Lee, So-Young;Kim, Jeong-Tae
    • Journal of the Korean Society for Nondestructive Testing
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    • v.31 no.6
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    • pp.616-625
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    • 2011
  • Ensuring the designed prestress force is very important for the safety of prestressed concrete bridge. The loss of prestress force in tendon could significantly reduce load carrying capacity of the structure. In this study, an automated prestress-loss monitoring system for prestressed concrete girder using PZT-interface and wireless impedance sensor node is presented. The following approaches are carried out to achieve the objective. Firstly, wireless impedance sensor nodes are designed for automated impedance-based monitoring technique. The sensor node is mounted on the high-performance Imote2 sensor platform to fulfill high operating speed, low power requirement and large storage memory. Secondly, a smart PZT-interface designed for monitoring prestress force is described. A linear regression model is established to predict prestress-loss. Finally, a system of the PZT-interface interacted with the wireless sensor node is evaluated from a lab-scale tendon-anchorage connection of a prestressed concrete girder.

Development of Macro Element for the Analysis of Prestressed Concrete Box Girder Bridges (프리스트레이트 콘크리트 박스거더교량 해석을 위한 매크로요소의 개발 및 유한요소 정식화(1))

  • 오병환;이명규
    • Proceedings of the Korea Concrete Institute Conference
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    • pp.436-441
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    • 1997
  • A Formulation based on macroelement concept is developed to analysis the prestressed concrete box girder bridges. The proposed method enables to model the arbitrary shapes and boundary conditions of prestressed concrete box girder bridges. The validity of the algoriyhm is demonstrated through comparisons with other results.

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Experimental Study for the Development of Steel-Confined Prestressed Concrete Girder (강재로 구속된 프리스트레스트 콘크리트 합성거더의 개발을 위한 실험연구)

  • Kim, Jung Ho;Park, Kyung Hoon;Hwang, Yoon Koog;Choi, Young Min;Cho, Hyo Nam
    • Journal of Korean Society of Steel Construction
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    • v.14 no.5
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    • pp.593-602
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    • 2002
  • A new type of bridge superstructures referred to as Steel-Confined Prestressed Concrete Girder (SCP Girder) was developed, which is composed of concrete, steel plate, and prestressing tendon. The girder may maximize structural advantages of these components; thus, long span bridges with low height girder may be constructed. For the effective design and fabrication of the gilder, the design software program was developed and the process of fabrication established. The experimental girder designed using the program was manufactured in actual size to confirm the fabric ability of the girder. Propriety of design, structural safety, and applicability of the gilder were verified through the load test.