• Proceedings of the Computational Structural Engineering Institute Conference
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• 2010.04a
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• pp.293-296
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• 2010

일반 교량에 주로 사용되는 콘크리트 바닥판 시공을 위해서는 동바리, 거푸집 등을 설치하고 철근 배근 후 콘크리트를 타설하는 방법이 사용되어왔다. 그러나 기존 콘크리트 바닥판 시공은 계절 및 기후의 영향을 많이 받는다. 또한 시공과정에서 많은 인력이 요구되고 시공 안전성 확보를 위한 노력이 필요한 실정이다. 이러한 문제점을 극복하기 위하여 최근에 프리캐스트 바닥판을 이용한 교량 시공이 늘어나고 있는 추세이다. 프리캐스트 바닥판은 공장에서 선제작한 후 현장에서 조립하여 시공한다. 따라서 프리캐스트 바닥판 시공은 계절 및 기후의 영향을 최소화 하여 공기를 단축할 수 있고, 공장제작에 따른 양호한 품질도 보장된다. 또한 인력이 적게 요구되면서 시공 안전성도 확보할 수 있다. 그러나 이러한 기존의 프리캐스트 바닥판은 패널의 폭이 좁고 외측 캔틸레버부의 시공 시 별도의 지보공이 필요한 단점을 갖고 있었다. 이러한 단점을 보완하기 위해 장폭 외측 프리캐스트 바닥판이 제안되었다. 장폭 외측 프리캐스트 바닥판은 패널의 폭을 늘려서 장폭의 바닥판을 만들고, 가설구조물을 이용하여 지보공 없이 시공이 가능하게 고안되었다. 본 연구에서는 장폭 외측 프리캐스트 패널 캠버 조정에 사용 될 가설구조의 현장적용을 위하여, 실험 후 유한요소해석을 수행하여 비교 및 검증하였다.

• Journal of the Korean Recycled Construction Resources Institute
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• v.8 no.3
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• pp.269-275
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• 2020

In this study, flexural tests of precast concrete panels according to the thickness of cross-sectional and the with or not of reinforcement were carried out in order to develop and assess of a lightweight precast concrete panel using ultra high performance concrete. For the test, four panels were fabricated, and consisted of one normal concrete panel and three ultra high performance concrete panels. As a test result, it was found that the plain precast panel using ultra high performance concrete had a lower flexural performance than the reinforced normal concrete panel, regardless of the cross-sectional size. The flexural performance of the hollow-sectional precast panel applying ultra high performance concrete, is improved by 150% compared to that of the reinforced normal concrete panel. That is, through additional performance verification and optimization of the cross-sectional design of the panel, the ultra high performance concrete precast panel can be made lighter. Also, the practical use of lightweight precast panels with ultra high performance concrete can be available through evaluation on shear, joint connection and anchoring, etc.

• Journal of the Korea institute for structural maintenance and inspection
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• v.24 no.2
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• pp.94-102
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• 2020

Precast concrete segment arch system has an economic and construct ability that combined with advantage of precast concrete and arch behavior. A precast concrete segment arch system with outrigger is consisted of segmented precast panels, a steel outrigger rib, and V-strip to connect precast panels with a steel outrigger rib and cast-in-place anchors in precast panels to connect V-strip should have sufficient pull-out capacity to form its arch shape by site lifting for assembled precast panels and outriggers. However, it is difficult to secure its embedment depth due to the relatively shallow thickness of precast panel. It can be also occurred that flexure deformation of precast panels caused by its pull-out behaviors. In this study, pull-out capacity of cast-in-place anchor was examined for construction of precast concrete segment arch system with outriggers. Therefore, a total of 24 precast panel specimens were fabricated to examine pull-out capacities of cast-in-place anchor in precast panels, and installation depth of anchors, diameter of anchors and wire mesh effects for the precast panel were examined. From this pull-out tests, its pull-out capacities and failure modes were evaluated and the type of the cast-in-place anchor applicable to the precast concrete segment panel arch system with outriggers was determined from comparison of the design specification values.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.3
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• pp.21-31
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• 2018

This paper presents an experimental investigation on the structural performance of precast ribbed panel specimens and bridge deck specimens fabricated from the panels. The panel specimens are developed for permanent deck forms of railway bridges (PSC girder). The decks of railway bridges have short lengths compared with highway bridges. Therefore, precast panels for railway bridges are different from those of highway bridges. The precast panels have ribs designed for crack control at the bottom of the sections. Two kinds of specimens were examined: one with 400-mm width and one with 1200-mm width. Three specimens of each type were fabricated, and a total of 12 specimens were tested. In this test, the ultimate load, strain of the reinforcement and concrete, crack width, deformation, and slip were measured. The structural performance of the specimens was assessed using the Korea railway bridge design code and Eurocode. All specimens met the current design criteria for structural strength and serviceability.

• Journal of the Korean Society of Hazard Mitigation
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• v.10 no.1
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• pp.29-34
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• 2010

The main objective of this research is to present the behaviors of precast concrete slab under moving wheel loads. The simulated moving wheel tester and precast concrete slab were designed for this research. In particular, a comparative analysis between the structural analysis and the moving wheel load test was evaluated in connection parts, deformation, bedding layer of concrete slab panels. In the comparisons of the test results from static and moving wheel loads, the maximum deformations were similar. It should be noted that the deformation of panel 2 from the static loading test was larger than that of other panels, while the deformations of panels 1 and 3 were more noticeable than that of panel 2.

• 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.

• Journal of the Korea Concrete Institute
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• v.28 no.5
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• pp.545-553
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• 2016

This paper presents experimental static test results of the precast concrete panels developed for short-span concrete bridge deck form. Different from LB-DECK, concrete rib attached to the bottom surface of concrete panel, and Top-bar is not used at the top surface of concrete panel. Number of concrete ribs and cross-section details of concrete rib are determined from the analytical results of parametric study considering the span length and the thickness of concrete bridge decks. Shear rebars are installed at the top surface of concrete panel for composite action between precast concrete panel and cast-in-place concrete. In order to evaluate the safety and the serviceability of the developed short-span concrete panel subjected to design load, static load test is conducted. Three test panels with span length of 1.6m are fabricated, and during the load test displacements, strains and cracks of test panels are measured and final failure modes are investigated. Serviceability of the test panels is evaluated based on the results of displacements, cracking load, and crack width at the design load level. Safety is also evaluated based on the comparison of the ultimate strength and the factored design load of test panels. Based on the test results, it is confirmed the short-span precast concrete panel satisfies the serviceability and safety regulated in design codes. In addition, the range of span length of concrete bridge decks for the short-span concrete panel is discussed.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.1A
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• pp.35-43
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• 2010

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. However, in order to apply the precast panels to bridges properly, it is necessary to fully understand the structural characteristics of joint in precast panels. Particularly, since the bridge deck is under repeated loads such as traffic loads, fatigue behavior and characteristics of joint should be investigated. In this paper, fatigue tests of composite deck with shear ties and loop joints were conducted. The fatigue tests were conducted with an application of repeated loading and wheel loading. Test results were analyzed to examine the current design code for fatigue of reinforcement bar and serviceability under repeated loading.

• Journal of the Korea Concrete Institute
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• v.14 no.4
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• pp.483-491
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• 2002

This paper summarizes the results of experimental studies concerning the flexural strengthening of reinforced concrete beams by the external bonding of the new reinforcement material, which is composite panel with an advanced fiber sheet bonded on light concrete precast panel. The structural behaviors of strengthened beams are compared with codes in terms of yield load and ultimate load, deflection, flexural stiffness, ductility. Thirty nine large-scale beams were tested experimentally to evaluate the strength enhancement provided by the composite panel. According to the results, it is shown that beams strengthened with composite panel are structurally efficient and that the strength of the strengthened beams are improved comparing with beams strengthened with fiber sheet.

• Journal of the Korea institute for structural maintenance and inspection
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• v.17 no.3
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• pp.10-19
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• 2013

Recently, researches related to precast modular construction have been actively conducted for nuclear power plant, LNG gas tank, and small-medium PCCV as well as bridges and buildings. In this study, the precast panel cast with steel mesh reinforced mortar (SRM) which is similar reinforced ferrocement was developed for efficient precast construction, construction time reduction, and easy transportation. Mortar mixture with high strength and flowability was obtained from various case studies using silica fume and GGBS. Also, $1,200{\times}600{\times}150mm$ SRM and reinforced concrete (RC) panels were manufactured with reinforcing ratio of 2% and 4%. To verify structural performance of the SRM specimen, the basic material tests, free shrinkage test, and 3-point flexural test with a line loading were carried out. From the test results, it was determined that SRM specimens showed outstanding flexural capacity and ductility. However, the 4% reinforced SRM specimens must consider shear reinforcing to be used as a precast modular member.