• Structural Engineering and Mechanics
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• 제76권6호
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• pp.737-749
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• 2020

A hybrid bridge deck is proposed, which includes steel bars, concrete and glass-fiber-reinforced-polymer (GFRP) plates with channel sections. The steel bar in the negative moment region can increase the flexural stiffness, improve the ductility, and reduce the GFRP ratio. Three continuous decks with different steel bar ratios and a simply supported deck were fabricated and tested to study the mechanical performance. The failure mode, deflection, strain distribution, cracks and support reaction were tested and discussed. The steel bar improves the mechanical performance of continuous decks, and a theoretical method is proposed to predict the deformation and the shear capacity. The experimental results show that all specimens failed with shear failure in the positive moment region. The increase of steel bar ratio in the negative moment region can achieve an enhancement in the flexural stiffness and reduce the deflection without increasing GFRP. Moreover, the continuous deck can achieve a yield load, and the negative moment can be carried by GFRP plates after the steel bar yields. Finally, a nonlinear analytical method for the deflection calculation was proposed and verified, with considering the moment redistribution, non-cracked sections and nonlinearity of material. In addition, a simplified calculation method was proposed to predict the shear capacity of GFRP-concrete decks.

• Steel and Composite Structures
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• 제4권5호
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• pp.385-402
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• 2004

Nearly 400 composite railway bridge decks of a new kind belonging to the trough type with U-shaped cross section have been constructed in Belgium over the last fifteen years. The construction of these bridge decks is rather complex with the preflexion of precambered steel girders, the prestressing of a concrete slab and the addition of a 2nd phase concrete. Until now, they have been designed with a classical computation method using a pseudo-elastic analysis with modular ratios. Globally, they perform according to the expectations but variability has been observed between the measured and the computed camber of these bridge decks just after the transfer of prestressing and also at long-term. A statistical analysis of the variability of the relative difference between the measured camber and the computed camber is made for a sample of 36 bridge decks using no less than 10 variables. The most significant variables to explain this variability at prestressing are the ratio between the maximum tensile stress reached in the steel girders during the preflexion and the yield strength and the type of steel girder. For the same sample, the long-term camber under permanent loading is computed by two methods and compared with measurements taken one or two years after the construction. The camber computed by the step-by-step method shows a better agreement with the measured camber than the camber computed by the classical method. The purpose of the paper is to report on the statistical analysis which was used to determine the most significant parameters to consider in the modeling in order to improve the prediction of the behaviour of these composite railway bridge decks.

• 대한토목학회논문집
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• 제32권6D호
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• pp.579-586
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• 2012

본 연구의 목적은 장경간 강바닥판 교량의 교면포장 재료로서 에폭시 아스팔트 혼합물을 평가하고, 현장에 적용하는 것에 있다. 에폭시 아스팔트 혼합물의 국내 적용을 위한 골재입도를 제시하였고, 실내 공용성 실험을 수행한 결과 내구성능 면에서 매우 우수함을 알 수 있었다. 또한, 온도에 따른 회복탄성계수와 전단부착강도 시험결과를 활용하여 구조해석을 실시 후 전단응력 검토결과 전단부착강도의 9%로도 충분한 접착 성능을 확보할 수 있는 것으로 나타났다. 에폭시 아스팔트 교면 포장에 발생하는 인장응력의 경우 중국에 시공되어 검증된 난징대교 실내시험결과와 비교 시 유사하거나 작은 값을 나타내어 충분한 공용 성능을 확보할 수 있는 것으로 나타났다. 결과적으로 에폭시 아스팔트 혼합물은 일반 아스팔트에 비해 매우 우수한 내구성능을 확보할 수 있는 것으로 나타났다. 하지만 현장에서 장경간 강바닥판 교량의 교면포장 재료로서 에폭시 아스팔트 혼합물을 적용할 경우 온도와 양생기간에 따른 강도발현에 차이가 있을 수 있으므로 현장 적용 시, 생산 시료로 제작한 혼합물에 대한 평가가 이루어져야 한다.

• 콘크리트학회논문집
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• 제14권4호
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• pp.556-565
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• 2002

콘크리트 교량 바닥판은 건조수축 및 온도변화 등에 의하여 초기 일차균열이 발생하고, 사용기간 동안 반복되는 차량하중의 크기와 철근 간격 등에 의하여 초기 균열이 이방향 균열로 점차 진전하게 된다. 바닥판의 거동을 효율적으로 향상시키기 위해서는 보강방향에 대한 고려가 필수적이다. 따라서 본 연구에서는 탄소섬유쉬트를 보강재로 사용한 경우의 보강된 바닥판에 대한 비선형 유한요소해석을 실시하였으며, 해석의 정확성을 높이기 위하여 보강된 바닥판의 경계조건과 재료성질을 시험조건과 부합될 수 있도록 모사하였다. 보강방향과 보강량에 대한 해석결과는 시험결과와 비교, 분석함으로써 정확성을 검증하였으며, 이와 함께 보강된 바닥판의 효율성을 검증하기 위하여 보강재량, 폭과 두께 등과 같은 보강변수에 의한 보강후의 구조적 효율성을 고찰하였다.

• Advances in concrete construction
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• 제10권1호
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• pp.21-34
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• 2020

Precast deck joints have larger crack width than cast-in-place concrete decks. The initial crack typically occurs at the maximum moment but cracks on precast joints are significant and lead to failure of the deck. The present crack equation is applied to cast-in-place decks, and requires correction to calculate the crack width of precast deck joints. This research aims to study the crack width correction equation of precast decks by performing static tests using high strength and normal strength concrete. Based on experimental results, the bending strength of the structural connections of the current precast deck is satisfied. However it is not suitable to calculate and control the crack width of precast loop connections using the current design equation. A crack width calculation equation is proposed for crack control of precast deck loop joints. Also included in this paper are recommendations to improve the crack control of loop connections.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2008년도 정기 학술대회
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• pp.276-281
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• 2008

Glass-fiber reinforced polyester(GFRP) composite material is a promising alternative to existing construction materials such as steel, concrete and wood. One of passible applications of GFRP composite material is to build temporary bridges by assembling GFRP composite decks. In this paper, we develop a system of temporary arch bridges that can be built by easy assembling of GFRP composite decks. For this purpose, several types of temporary arch bridges are suggested and verified by FE analysis.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2008년도 정기 학술대회
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• pp.282-287
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• 2008

Since glass-fiber reinforced composite decks have high-strength, light-weight and high durability, many researchs on the composite decks for bridges are currently performed and many composite decks are developed. In this paper, a composite deck with snap-fit connection for pedestrian bridge is developed and studied. A study on behavior of snap-fit connection of composite deck for pedestrian bridge during assembling or disassembling is performed by analysis and experiment.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2001년도 봄 학술발표회 논문집
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• pp.81-86
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• 2001

The concrete bridge decks are in need of replacement and rehabilitation due to decreasing load carrying capacity. In this study, to propose a strengthening technique that improves usability and structural performance of the bridge deck and to propose an efficient strengthening design technique which satisfies both the strength End serviceability of the bridge deck, this paper shows the failure characteristics of the strengthened bridge decks and proposes an empirical yield criterion. Therefore, strengthening efficiency was proposed based on the experiment and yield line analysis result. The yield line theory which adopts the modified criteria of Johansen is considered to predict the ultimate strength about all strengthening material(Carbon Fiber Sheet, Carbon Fiber Rod, Grid Type Carbon Fiber).

• Architectural research
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• 제7권2호
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• pp.81-89
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• 2005

Over the years, existing bridges have had various degrees of maintenance to extend the service life. As the existing bridges continue to deteriorate, however, each Department of Transportation (DOT) of the United States of America faces increasing demands on the limited funds available for bridge maintenance. Therefore, it is very important for State Department of Transportations to establish Maintenance, Repair, and Rehabilitation (MR&R) strategies for bridge structures such that funds get allocated for appropriate maintenance over the service life. This paper identifies the state-of-art and the state-of-practice of MR&R actions and the use of MR&R strategies in concrete bridge decks. In addition, a questionnaire survey was conducted to identify the type and timing for MR&R actions as well as existing MR&R strategies taken in concrete bridge deck by each DOT. This paper also presents the results of the survey.

• 한국해양공학회지
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• 제20권5호
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• pp.63-69
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• 2006

An isolated bridge using a laminated rubber bearing provides an elastic support of continuous span and prevents the transmission of excessive seismic force from the substructure of the bridge, which uses a metal bearing, as this permits a relative displacement between the super-and substructure. Hawever, this kind of bridge is caused long periodic, as a result of enlargingtotal thickness of the rubber, since it corresponds to temperature change and increases the horizontal displacement of the superstructure. This paper uses a numerical study to describe the pounding problem between adjacent decks when subjected to a strong earthquake. Furthermore, numerical results are clarified for the buffer rubber used to mitigate the pounding force between adjacent decks.