• 한국안전학회지
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• 제30권6호
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• pp.70-77
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• 2015

In this study, the governing design factors of GFRP-reinforced concrete bridge deck are analyzed for typical bridges in Korea. The adopted bridge deck is a cast-in-situ concrete bridge deck for the prestressed concrete girder bridge with dimensions of 240 mm thickness and 2.75 m span length from center-to-center of supporting girders. The selected design variables are the diameters of GFRP rebar, spacings of GFRP rebars and concrete cover thicknesses, Considering the absence of the specification relating GFRP rebar in Korea, AASHTO specification is used to design the GFRP-reinforced concrete bridge deck. The GFRP-reinforced concrete bridge deck is proved to be governed by the criteria about serviceability, especially maximum crack width, while steel reinforced concrete bridge deck is governed by the criteria on ultimate limit state. In addition, GFRP rebars with diameter of 16 mm ~ 19 mm should be used for the main transverse direction of decks to assure appropriate rebar spacings.

• 한국구조물진단유지관리공학회 논문집
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• 제15권3호
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• pp.163-170
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• 2011

본 연구에서 교량바닥판용으로 조립식(Modular) 유리섬유 보강(GFRP) 바닥판의 개념을 제안하였다. 본 조립식 GFRP 바닥판시스템은 GFRP 주 단위모률(unite module)과 연결 단위모듈로 구성되어 있다. 본 GFRP 바닥판의 구조성능을 평가하기 위해 정적하중실험을 실시하였다. 그리고 구조성능 결과에 대해서 범용 유한요소 프로그램인 LUSAS을 이용한 수치해석 결과와 비교 분석하였다. 본 연구에서 제안한 조립식 GFRP 바닥판은 교량적용에 매우 유용할 수 있음을 확인할 수 있었다. 제안된 GFRP 바닥판의 파괴모드가 개발된 다른 상용화된 GFRP 바닥판의 파괴모드와 매우 유사한 파괴모들 나타내었다.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2003년도 춘계학술발표대회 논문집
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• pp.152-156
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• 2003

In this paper, we present the results of an experimental research on the load-deflection characteristics of full-scale concrete bridge decks reinforced with GFRP re-bars. Similar researches have been conducted in many countries to extend the service life of concrete bridge decks, which are under harsh environmental condition. Concrete bridge decks are one of the major concerns for the maintenance of bridges. GFRP re-bar available in the domestic construction market was investigated and the concrete deck reinforced with GFRP re-bars was tested under flexure to investigate the applicability of GFRP re-bar on the bridge deck construction.

• 대한토목학회논문집
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• 제28권5A호
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• pp.719-727
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• 2008

GFRP 보강근의 인장강도 및 부착성능 등은 철근과 다르기 때문에 GFRP 보강근을 콘크리트 구조물에 적용하기 위해서는 GFRP 보강근으로 보강된 콘크리트 부재의 거동에 관한 연구가 선행되어야 한다. GFRP는 높은 비강도, 경량성, 비부식성 등의 장점을 가지고 있으나 탄성계수가 철근보다 작아 상대적으로 큰 처짐이 발생하는 단점이 있다. 교량 바닥판은 아칭효과 등에 의해 휨성능이 증가하므로 FRP 보강근을 우선 적용할 수 있는 대상 중 하나이다. 본 논문은 국내에서 개발된 철근 대체재용 GFRP 보강근의 콘크리트 구조물로의 적용 가능성을 관찰하기 위한 실험연구에 관한 것이다. 대상 실험체는 폭과 길이가 3,000 mm, 4,000 mm이고 두께가 240 mm인 실제 크기의 콘크리트 바닥판이다. 실험변수는 보강근 종류(철근, GFRP 보강근)와 보강비로 총 3개의 바닥판을 제작하였다. 정적실험을 수행하였으며 DB-24 하중등급의 축하중을 모사한 재하면적을 가진 직사각형 강재로 바닥판이 파괴될 때까지 집중하중을 가하였다. 철근 보강 바닥판과 GFRP 보강 바닥판의 거동차이를 최대성능, 처짐 및 균열 거동 등에 대해 비교 검토하였다.

• Steel and Composite Structures
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• 제19권5호
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• pp.1221-1236
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• 2015

Since the coefficients of thermal expansion (CTE) between concrete and GFRP, steel and GFRP are quite different, GFRP laminates with different laminas stacking-sequence present different thermal behavior and currently there is no specification on mechanical properties of GFRP laminates, it is necessary to investigate the thermal influence on composite girder with stay-in-place (SIP) bridge deck at different levels and on different scales. This paper experimentally and theoretically investigated the CTE of GFRP at lamina's and laminate's level on micro-mechanics scales. The theoretical CTE values of laminas and laminates agreed well with test results, indicating that designers could obtain thermal properties of GFRP laminates with different lamina stacking-sequence through micro-mechanics methods. On the basis of the CTE tests and theoretical analysis, the thermal behaviors of composite girder with hybrid GFRP-concrete deck were studied numerically and theoretically on macro-mechanics scales. The theoretical results of concrete and steel components of composite girder agreed well with FE results, but the theoretical results of GFRP profiles were slightly larger than FE and tended to be conservative at a safety level.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2007년도 정기 학술대회 논문집
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• pp.393-398
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• 2007

Fatigue Behavior of a GFRP bridge deck consisting of rectangular unit modules is studied by an experimental method. The experiment focuses on how the damage in the transverse direction influence the overall behavior of the deck It is proposed filling the space in each module with a soft foam. Using the recent experimental data, the fatigue behavior is discussed. If the space of the deck is filled with the foam, the fatigue life of the deck was increased about 1,000 times for the same level of the stress variation as the reference deck not filled.

• 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.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2006년도 정기 학술대회 논문집
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• pp.906-913
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• 2006

The failure mechanism of a hollow bridge deck which is made of glass fiber reinforced polymer(GFRP) is investigated using both experiments and analysis. While the load-displacement behavior of the deck in the transverse direction shows a strong nonlinearity even in its initial response with relatively small magnitude of loads. In order to imporve the structural behavior of the deck in the transverse direction, we suggested that the empty space of the bridge deck is filled with a foam and investigated experimentally the static behavior of the orthotropic bridge deck which is made from GFRP and polyurethane foam. It is found that although the elastic modulus of the foam compared to that of the GFRP is about the order of $10^{-3}$, the structural behaviors in the weak axis such as nominal strength, stiffness, etc. are greatly improved. Owing to the low mass density of the foam used in this study, the bridge deck is still light enough with the improved structural properties.

• Structural Engineering and Mechanics
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• 제5권4호
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• pp.399-414
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• 1997

This paper presents an investigation into the seismic response characteristics of a proposed ligh-weight pedestrian cable-stayed bridge made entirely from Glass Fiber Reinforced Plastics(GFRP). The study employs three dimensional finite element models to study and compare the dynamic characteristics and the seismic response of the GFRP bridge to a conventional Steel-Concrete (SC) cable-stayed bridge alternative. The two bridges were subjected to three synthetic earthquakes that differ in the frequency content characteristics. The performance of the GFRP bridge was compared to that of the SC bridge by normalizing the live load and the seismic internal forces with respect to the dead load internal forces. The normalized seismically induced internal forces were compared to the normalized live load internal forces for each design alternative. The study shows that the design alternatives have different dynamic characteristics. The light GFRP alternative has more flexible deck motion in the lateral direction than the heavier SC alternative. While the SC alternative has more vertical deck modes than the GFRP alternative, it has less lateral deck modes than the GFRP alternative in the studied frequency range. The GFRP towers are more flexible in the lateral direction than the SC towers. The GFRP bridge tower attracted less normalized base shear force than the SC bridge towers. However, earthquakes, with peak acceleration of only 0.1 g, and with a variety of frequency content could induce high enough seismic internal forces at the tower bases of the GFRP cable-stayed bridge to govern the structural design of such bridge. Careful seismic analysis, design, and detailing of the tower connections are required to achieve satisfactory seismic performance of GFRP long span bridges.

• 복합신소재구조학회 논문집
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• 제2권3호
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• pp.12-17
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• 2011

본 논문은 노후교량바닥판 대체용으로서 하이브리드 GFRP-강재 바닥판의 휨거동을 구조적 거동특성을 기술하고 있다. 하이브리드 GFRP-강재 바닥판의 구조적 특성을 조사하기 위해 정적하중의 실험적 연구를 수행하였다. 하이브리드 바닥판의 파괴모드는 초기항복을 지나서 연성거동을 나타내었다. 결과는 유한요소프로그램 ANSYS의 값과 비교하였다. 제안된 하이브리드 바닥판이 교량적용에 유용함을 확인하였다. 하이브리드 바닥판의 두께는 유사한 휨 강성을 갖는 완전복합신소재 바닥판께와 비교하였을 때 감소될 수 있었다.