• Title/Summary/Keyword: Prestressed

Search Result 1,178, Processing Time 0.046 seconds

Behavior of Prestressed Concrete Panels under Blast Load (폭발하중을 받는 프리스트레스트 콘크리트 패널의 거동)

  • Jo, Eunsun;Kim, Min Sook;Park, Jong Yil;Lee, Young Hak
    • Journal of the Computational Structural Engineering Institute of Korea
    • /
    • v.27 no.2
    • /
    • pp.113-120
    • /
    • 2014
  • This paper showed the behavior of the material four members under blast load, and are trying to demonstrate the effectiveness of the prestress. The prestressed concrete structures are on the rise, but there is little research in this regard explosion. Concrete panels, Reinforced concrete panels, the prestressed concrete panels, and the prestressed reinforced concrete panels was set variables. TNT 500 kg was an explosion in the distance 3m. Analysis, concrete and reinforced concrete members after an explosion occurred continuously deformed, but the including prestressed panel deformation occurs only at the beginning of the explosion were able to see the results. That is, the including prestressed member is prestressed against blast load cracking and destruction can be seen that control.

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
    • /
    • 1997.04a
    • /
    • pp.436-441
    • /
    • 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.

  • PDF

Design of Expansion Segment of Precast Prestressed Concrete Segmental Box Girder bridges Using Strut and Tie Model (스트럿 타이 모델을 이용한 프리캐스터 프리스트레스 콘크리트 세그멘탈 박스 거더 교량의 신축이음 세그멘트이 설계기법 연구)

  • 오병환;이형준;김익현;한승환
    • Proceedings of the Korea Concrete Institute Conference
    • /
    • 1995.04a
    • /
    • pp.268-273
    • /
    • 1995
  • In recent years, precast prestressed concrete segmental box girder bridges have been increasingly constructed Expansion disphragm segment of this type bridge transfers forces from the superstructure onto bearing or column, and plays an important roll of anchorage zone for longitudinal prestressed forces. Non-linear stresses occur inside of diaphragms by these extensive concentrated forces. In this study, the strut-and-tie models are proposed to design an expansion segment rationally. A formula to determine the effective transverse prestressed forces is proposed on the basis of these models. The present study is expected to provide an effective tool to design expansion segment of prestressed concrete bridges rationally.

  • PDF

An Equivalent Fatigue Load Model for Prestressed Concrete Bridges Girders (프리스트레스트 콘크리트 교량거더의 등가피로하중모델)

  • 김지상
    • Magazine of the Korea Concrete Institute
    • /
    • v.6 no.2
    • /
    • pp.148-158
    • /
    • 1994
  • The goal of this study is to develop an equivalent fatigue load model for prestressed concrete composite girder bridges in Korea. To meet this goal, the probabilistic characteristics of traffics which cause fatigue damage in bridges are properly modeled. An equivalent fatigue load inodel for prestressed concrete composite girder bridges with constant. amplitude and frequency is established. The model proposed in this paper is very simple to use and gives fairly good results.

Flexural behaviour of reinforced concrete beams strengthened with NSM CFRP prestressed prisms

  • Liang, Jiong-Feng;Yu, Deng;Xie, Shengjun;Li, Jianping
    • Structural Engineering and Mechanics
    • /
    • v.62 no.3
    • /
    • pp.291-295
    • /
    • 2017
  • The behaviour of reinforced concrete beams strengthened with near surface mounted (NSM) CFRP prestressed prisms was experimentally investigated. Five RC beams were tested under four point bending. All beams were made with dimensions of 300 mm in width, 2000 mm in length and 150 in depth. The effects of presstress level of CFRP prestressed prisms and prism material type were studied. The failure mode, load capacity, deflection, CFRP strain, steel strain and ductility of the tested beams were all analyzed. The results showed that the behavior of the reinforced concrete beams strengthened with NSM CFRP prestressed prisms showed a significant increase in the load-carrying capacity and the deformation capacity. The NSM CFRP prestressed prisms strengthening technique could be considered as an effective method for repairing RC structures.

PCA-based filtering of temperature effect on impedance monitoring in prestressed tendon anchorage

  • Huynh, Thanh-Canh;Dang, Ngoc-Loi;Kim, Jeong-Tae
    • Smart Structures and Systems
    • /
    • v.22 no.1
    • /
    • pp.57-70
    • /
    • 2018
  • For the long-term structural health monitoring of civil structures, the effect of ambient temperature variation has been regarded as one of the critical issues. In this study, a principal component analysis (PCA)-based algorithm is proposed to filter out temperature effects on electromechanical impedance (EMI) monitoring of prestressed tendon anchorages. Firstly, the EMI monitoring via a piezoelectric interface device is described for prestress-loss detection in the tendon anchorage system. Secondly, the PCA-based temperature filtering algorithm tailored to the EMI monitoring of the prestressed tendon anchorage is outlined. The proposed algorithm utilizes the damage-sensitive features obtained from sub-ranges of the EMI data to establish the PCA-based filter model. Finally, the feasibility of the PCA-based algorithm is experimentally evaluated by distinguishing temperature changes from prestress-loss events in a prestressed concrete girder. The accuracy of the prestress-loss detection results is discussed with respect to the EMI features before and after the temperature filtering.

A Study on the Design of the Prestressed Precision Cold Forging Die (예압된 정밀 냉간단조 금형설계에 관한 연구)

  • Yeo, H. T.;Choi, Y.;Hur, K. D.
    • Proceedings of the Korean Society of Precision Engineering Conference
    • /
    • 2000.11a
    • /
    • pp.377-380
    • /
    • 2000
  • The dimensional accuracy of the cold forged part is depended on the elastic characteristics of the die. To obtain the high stiffness of the prestressed die, the first stress ring of the tungsten carbide material is considered. For the design, Lam 's equation is used. The design of the prestressed die has been compared with the conventional that. For the comparison, the FE-analysis using ANSYS has been performed. The results indicate that the prestressed die with the high stiffness can be obtained by the using the high stiffness material as the first stress ring.

  • PDF

A Study for Structural Capacity Evaluation of Embedded Steel Plate Connected with Prestressed Concrete Beam to Build Large Space Educational Facilities (대공간 교육시설 축조를 위한 프리스트레스트 보에 사용되는 접합 강재의 성능평가에 대한 연구)

  • Lee, Kyoung-Hun
    • The Journal of Sustainable Design and Educational Environment Research
    • /
    • v.10 no.2
    • /
    • pp.1-7
    • /
    • 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.

Theoretical Determination of Transfer Length in Pretensioned Members Using Thick Cylinder Theory

  • Oh, Byung-Hwan;Kim, Eui-Sung
    • KCI Concrete Journal
    • /
    • v.12 no.2
    • /
    • pp.31-43
    • /
    • 2000
  • The extensive usage of pretensioned prestressed concrete component in modem construe- tion as structural members mandates precise understanding of its mechanism. Especially, an adequate transfer of prestressing force from steel tendons to concrete around the end regions of the member is a critical issue. Due to the importance of the topic, several investigators have formulated equations modeling the transfer bond length based on various bonding mechanism between steel and concrete. However, the existing models are still inadequate in predicting the bond development in pretensioned prestressed concrete members. Therefore, this study presents a model of transfer bond length based on rational theory that can simulate experimental results. The model is developed into solid mechanics based structural analysis computer program. The program is validated by comparing the analysis results with experimental results of bond stress distribution, concrete strain profiles, and transfer length in pretensioned prestressed concrete members. The proposed analytical procedure in this study can be utilized as a useful tool for realistic evaluation of transfer length in pretensioned prestressed concrete members.

  • PDF