• Title/Summary/Keyword: 철근콘크리트 바닥판

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Analysis For Effective Moment For Iinertia For Corrugated Steel-Concrete Composite Deck with I-beam Welded (교량용 I형강 접합 절곡강합성 바닥판의 휨강성 분석)

  • Son, Chang-Du;Park, Jun-Myung;Han, Kyung-Bong;Kim, Jun-Won;Lee, Jae Hwan
    • Proceedings of the Korea Concrete Institute Conference
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    • 2008.11a
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    • pp.209-212
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    • 2008
  • Corrugated steel-concrete composite deck with I-beam welded is lighter and has higher load carrying capacity than RC slabs due to an I-beam embedded in the corrugated deck. The methods suggested from ACI and design standard of roadway bridge are used to evaluate effective moment inertia of RC structures. This paper presents evaluation and application of effective moment inertia for corrugated steel-concrete composite deck with I-beam welded by using the methods suggested from design standard of roadway bridge, ACI and CEB-FIP MC-90. In order to evaluate effective moment inertia, a series of flexural experiments were carried out. Five beams were built and the parameters considered in the experiments were studs, shape of the sections and connections of the beams. By using the aforementioned methods, effective moments of inertia was calculated and they were compared with the experimental results. As a result, The method suggested from CEB-FIP MC-90 yielded more satisfactory agreement than that from ACI. It was found that the beam has studs showed high load-carrying capacity and high effective moment of inertia.

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Behavior of GFRP reinforced decks with various reinforcement ratio (GFRP 보강근으로 보강된 바닥판의 보강비에 따른 거동 실험)

  • You, Young-Jun;Park, Ji-Sun;Park, Young-Hwan;Kim, Hyeong-Yeol;Kim, Keung-Hwan
    • Proceedings of the Korea Concrete Institute Conference
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    • 2008.04a
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    • pp.49-52
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    • 2008
  • The tensile and bond performance of GFRP rebar are different from those of conventional steel reinforcement. It requires some studies on concrete members reinforced with GFRP reinforcing bars to apply it to concrete structures. GFRP has some advantages such as high specific strength, low weight, non-corrosive nature, and disadvantage of larger deflection due to the lower modulus of elasticity than that of steel. Bridge deck is a preferred structure to apply FRP rebars due to the increase of flexural capacity by arching action. This paper focuses on the behavior of concrete bridge deck reinforced with newly developed GFRP rebar. A total of three real size bridge deck specimens were made and tested. Main variable was reinforcement ratio of GFRP rebar. Static test was performed with the load of DB-24 level until failure. Test results were compared and analyzed with ultimate load, deflection behavior.

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Analytical Method for Bending Moment of Slab-on-Steel-Girder Bridge (강판형교 바닥판 모멘트의 해석기법)

  • Park, Nam Hoi;Choi, Jin Yu;Yu, Chul Soo;Kang, Young Jong
    • Journal of Korean Society of Steel Construction
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    • v.12 no.1 s.44
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    • pp.17-28
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    • 2000
  • The current specifications for bridge decks requires the same amount of upper and lower reinforcement mats. There have been many empirical activities that the partial elimination of upper reinforcing bars was not caused the structural integrity of a deck. A simplified method is derived based on thin plate theory for three and four-girder-span bridge decks. A simplified method for bridge deck considering the effect of girder deflection is proposed based on a closed-form solution that shows good agreement with the results of finite element models. In this research, a new design approach for deck slabs is proposed based on the simplified method. The negative bending moments in a deck can be evaluated with the simplified method based on the position of a wheel load, the aspect ratio and relative stiffness and the span length. This new approach can lead to a significant reduction of the quantity of the top reinforcing steel bars in a deck. Reducing the quantify of the top reinforcement not only reduces the construction costs for bridge decks, but also reduces the corrosion of reinforcement to a minimum.

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Evaluation of Static and Fatigue Performances of Decks Reinforced with GFRP Rebar for Reinfocement Ratio (GFRP 보강근으로 보강된 바닥판의 보강비에 따른 정적 및 피로성능 평가)

  • You, Young-Jun;Park, Young-Hwan;Choi, Ji-Hun;Kim, Jang-Ho Jay
    • Journal of the Korea Concrete Institute
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    • v.26 no.4
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    • pp.491-497
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    • 2014
  • The corrosion of steel reinforcement in reinforced concrete bridge decks significantly affects the degradation of the capacity. Due to the advantageous characteristics such as high tensile strength and non-corrosive property, fiber reinforced polymer (FRP) has been gathering much interest from designers and engineers for possible usage as a alternative reinforcement for a steel reinforcing bar. However, its application has not been widespread, because there data for short- and long-term performance data of FRP reinforced concrete members are insufficient. In this paper, seven full-scale decks with dimensions of $4000{\times}3000{\times}240mm$ were prepared and tested to failure in the laboratory. The test parameter was the bottom reinforcement ratio in transverse direction. The decks were subjected to various levels of concentrated cyclic load with a contact area of $577{\times}231mm$ to simulate the vehicle loading of DB-24 truck wheel loads acting on the center span of the deck. It was observed that the glass FRP (GFRP) reinforced deck on a restraint girder is strongly effected to the level of the applied load rather than the bottom reinforcement ratio. The study results showed that the maximum load less than 58% of the maximum static load can be applied to the deck to resist a fatigue load of 2 million cycles. The fatigue life of the GFRP decks from this study showed the lower and higher fatigue performance than that of ordinary steel and CFRP rebar reinforced concrete deck. respectively.

Behavior of Reinforced Concrete Slabs Connected with Hinge Joints of Remodelling Buildings (리모델링 건물의 활절점에 의하여 연결된 철근콘크리트 바닥판의 거동 평가)

  • Sim Kyu-Kwan;Kim Sang-Sik;Lee Jung-Yoon;Choi kwang-Ho;Im Juhyeuk
    • Journal of the Korea Concrete Institute
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    • v.17 no.5 s.89
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    • pp.761-768
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    • 2005
  • Lately outmoded and functionally obsolete buildings constructed in 1960s and 1970s are often remodelled and restored. Even though there are not serious structural defects in the existing buildings, many old buildings have been reconstructed to improve residence quality or to extend residence area of the buildings. The experimental or theoretical research on plane expansion of RC apartments is quite scare. In this research, 12 specimens and 19 RC slabs connected by hinged joints were tested. The new slab was connected to the existing slab by hinge joints injecting dowel bars between two slabs. Main parameters of the slabs are types of the dowel bars (D13 and D19), spacing of the dowel bars (150mm, 300mm, and 450mm), and the locations of the steel bars in the existing slabs. The test results indicated that the shear strength of the RC test slabs having various types of dowel bars was about twice that calculated by the ACI 318-02 code. All slabs failed in concrete spatting and the dowel steel bars did not reach their yield strengths.

Analysis of Effective Flexural Rigidity of Corrugated Steel-Concrete Composite Deck with I-beam Welded (I형강으로 보강된 강합성 절곡 바닥판의 유효 휨강성 분석)

  • Son, Chang-Du;Hong, Sung-Nam;Park, Jun-Myung;Park, Sun-Kyu
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.13 no.3 s.55
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    • pp.145-154
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    • 2009
  • Steel-Concrete Composite Deck with I-beam welded is lighter and easier to construct than conventional in situ reinforced concrete slabs due to the I-beam embedded in the corrugated slab. For the calculation of effective flexural rigidity of conventional reinforced concrete structures, methods suggested in Design Standard for Roads and Bridges and ACI have been used. In this paper, the calculation methods were applied to steel-concrete composite deck with I-beam welded and then results of the steel-concrete composite deck were compared with those of reinforced concrete slabs. In addition, applicability of the methods to steel-concrete composite deck with I-beam welded was estimated. In order to compare the effective flexural rigidity, flexural experiments were conducted. Fifteen slabs were built and the variables considered in the experiments were studs, length of the slab, shape of the section and connecting methods.

Semi-Empirical Prediction of Crack Width of the Strengthened Bridge Deck with External Bonding Plastic (외부부착 보강된 교량 바닥판 균열폭의 반경험적인 예측)

  • 심종성;오홍섭
    • Journal of the Korea Concrete Institute
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    • v.14 no.2
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    • pp.231-238
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    • 2002
  • Dry shrinkage md temperature change cause to develope concrete bridge decks on main girders have initial unidirectional cracks in longitudinal or transverse direction. As they receive traffic loads, the crack gradually propagate in different directions depending on the concrete dimension and reinforcement ratio. Since existing equations that predict crack width are mostly based on the one directional bond-slip theory, it is difficult to determine the actual crack width of a bridge deck with varying the spacing of rebar or strengthening material and to estimate the improvement rate in serviceability of the strengthened bridge deck. In this study, crack propagation mechanism is identified based on the test results and a new crack prediction equation is proposed for evaluation of serviceability. Although more accurate results are derived using the proposed equation, the extent of error is increased as the strain of the rebar or the strengthening material increases after the yielding of rebar Therefore, further research is required to better predict the crack width after the rebar yields under fatigue loading condition.

Flexural Behavior of RC Arch Deck Subjected to Static Loading (철근콘크리트 아치 데크의 정적 휨 거동)

  • Eom, Gi-Ha;Yang, Dal-Hun;Kim, Sung-Jae;Kim, Jang-Ho Jay
    • Journal of the Korea Concrete Institute
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    • v.29 no.4
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    • pp.371-378
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    • 2017
  • In this study, the flexural behavior of the RC Arch Deck under static loading was evaluated. Flexural test was carried out using an actual size RC Arch Deck with a length of 2.5 m, a center thickness of 100 mm and an end thickness of 160 mm. The test results showed that it's ultimate load was 1.74 times higher than the ultimate design load. On the other hand, it showed that the flexural behavior has different behaviors (i.e. different stiffness). This type of structural behavior indicates that it has inter-dependency between the deck and the supporting girder. Therefore, it is necessary to confirm the precise behavior by the static loading test of the RC Arch Deck, excluding the girder effect in the future study. The overall results showed that RC Arch Deck has excellent structural performance due to the structural advantages of the arch shape. In the future, the RC Arch Deck can be applied as a long span slab.

Strength of PSC Bridge Decks using Half-Depth Precast Panel with Loop Joint (루프이음 반단면 프리캐스트 패널을 이용한 PSC 바닥판의 강도평가)

  • Chung, Chul Hun;Kim, Yu Seok;Hyun, Byung Hak;Kim, In Gyu
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.29 no.5A
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    • pp.433-445
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    • 2009
  • The panels are used as a composite part of the completed deck. They replace the main bottom transverse deck reinforcement and also serve as a form surface for the cast-in-place concrete upper layer that contains the top of deck reinforcement. Research has also demonstrated that mechanical shear ties on the top of the panels are required. In a composite deck with precast panels, it is required to notice behavior of transverse joints between panels. In this paper, static tests of composite deck with shear ties and loop joints were conducted. From the results, the validity of loop joints for continuity of deck was observed. Also, a composite behavior was abserved between precast panel and slab concrete. Tested composite decks with shear ties have 140~164% ultimate strength than have no shear ties due to the increase of composite action. Therefore, the shear ties between the slabs were sufficient to enforce composite flexural behavior to failure.

Penetration of De-icing Salt in Bare Concrete Bridge Decks in Highways (고속도로 콘크리트 노출 바닥판에서의 제설 염화물의 침투 특성)

  • Suh, Jin Won;Ku, Bon Sung;Rhee, Ji Young
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.11 no.2
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    • pp.85-92
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    • 2007
  • In 1980s, a number of bridges with bare concrete deck were constructed on the Korea highway. After 20 years service, many bare concrete decks are still in good condition without special maintenance activity. Therefore, the application of the bare concrete deck is being reestimated from the view of construction and maintenance. As a part of the program, the characteristic of penetration(surface chloride and apparent diffusion coefficient) of de-icing salt into bare concrete bridge deck was analyzed in order to predict the service life of bridge on Korea highway.