• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2003년도 봄 학술발표회 논문집
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• pp.469-474
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• 2003

Recently, to overcome the disadvantages of RC decks, advanced countries such as Japan and USA, and Europe are using prestressing connection precast decks and loop connection precast decks. The prestressing connection precast deck, however, has a weakness against steel corrosion, because of unreliable enforced grouting. The relatively low loading and fatigue capacities of the loop connection precast deck make it difficult to be used for the bridge that requires high fatigue resistance due to the frequent over loaded vehicles. This research proposes the improved connecting method for the precast decks to minimize its shortcomings based on both numerical analyses and full scale model tests. The proposed method maximizes the advantages of precast decks and extends it's service life.

• 한국안전학회지
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• 제33권3호
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• pp.52-57
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• 2018

The pile construction method is changing from the pile driving operation to the injected precast pile method. It is to prevent environmental damage and to minimize complaints caused by noise. Therefore, economic alternatives optimized for the injected precast pile method are required. In this study, the enhanced spun reinforced concrete piles manufactured by high strength materials were proposed. Experimental tests were conducted to evaluate their structural safety and nonlinear finite element analysis was performed to improve the reliability of experimental results. The experimental results and the analytical results were in good agreement with each other and the proposed enhanced spun reinforced concrete pile has better performance than that required by the design. However, the performance of the joint using the existing method used in the PHC pile was considered to be insufficient.

• 한국공간구조학회논문집
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• 제21권4호
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• pp.65-72
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• 2021

The Precast concrete(PC) modular structures are a method of assembling pre-fabricated unit modules in the construction site. The essential aim of modular structures is to introduce a connection method that can ensure splicing performance and effectively resist shear strength. This study proposed PC module using a connecting plate that can replace splice sleeves and shear keys used in the conventional PC modular structures. To evaluate the splicing performance and shear capacity of the proposed method, the shear test was conducted by fabricating one monolithic reinforced concrete(RC) beam and two PC modular beams with a shear span-to-depth ratio as variables. The experimental results showed that the shear capacity of the PC modular beam was about 89% compared to that of the RC beam, and showed a failure of the RC beam according to the shear span-to-depth ratio. Therefore, it was considered that the connecting plate effectively transferred the stress between each PC module through the joint and ensure integrity. In addition, the applicability of shear strength equation of ACI 318-19 and Zsutty's equation to PC modular beams were evaluated. Results demonstrated that the improved shear strength equations are needed to consider reduction of shear strength in PC modules.

• Structural Engineering and Mechanics
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• 제37권2호
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• pp.177-196
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• 2011

An economic, structurally effective and practically applicable strengthening technique was developed for reinforced concrete (RC) framed buildings. The idea of the technique is to convert the existing hollow brick infill wall into a load carrying system acting as a cast-in-place RC infill wall by bonding relatively thin high strength precast concrete PC panels to the plastered hollow brick infill. For this purpose, a total of eight one-third scale, one bay, one story frames were tested under reversed-cyclic lateral loads. Test frames were designed and constructed with common deficiencies observed in practice. Four different panel types were used for strengthening. Test results showed that both strength and stiffness of the frames were significantly improved by the introduction of PC panels. Experimental results were compared with the analytical approaches suggested by the authors.

• Nuclear Engineering and Technology
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• 제56권6호
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• pp.2352-2366
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• 2024

Reinforced concrete (RC) shear walls with precast steel-concrete composite modular (PSCCM) are strongly recommended in the structural design of nuclear power plants due to the need for a large number of process pipeline crossings and industrial construction. However, the effect of the PSCCM on the mechanical behavior of the whole RC shear wall is still unknown and has received little attention. In this study, three 1:3 scaled specimens, one traditional shear wall specimen (TW) and two shear wall specimens with the PSCCM (PW1, PW2), were designed and investigated under cyclic loadings. The failure mode, hysteretic curve, energy dissipation, stiffness and strength degradations were then comparatively investigated to reveal the effect of the PSCCM. Furthermore, numerical models of the RC shear wall with different PSCCM distributions were analyzed. The results show that the shear wall with the PSCCM has comparable mechanical properties with the traditional shear wall, which can be further improved by adding reinforced concrete constraints on both sides of the shear wall. The accumulated energy dissipation of the PW2 is higher than that of the TW and PW1 by 98.7 % and 60.0 %. The failure of the shear wall with the PSCCM is mainly concentrated in the reinforced concrete wall below the PSCCM, while the PSCCM maintains an elastic working state as a whole. Shear walls with the PSCCM arranged in the high stress zone will have a higher load-bearing capacity and lateral stiffness, but will suffer a higher risk of failure. The PSCCM in the low stress zone is always in an elastic working state.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2005년도 추계 학술발표회 제17권2호
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• pp.303-306
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• 2005

For checking influence of load-position and system of stress-transmission in precast concrete bridge deck system, the test composite bridge was made a experiment by the wheel load machine. The result of experiment was the loop joint system of the precast decks has a difference which was the transmission system of longitudinal stress, comparing with general RC bridge deck system. The loop joint system has a behavior independently.

• 한국안전학회지
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• 제34권4호
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• pp.76-84
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• 2019

The precast pannels are used as formwork in Half-depth precast deck systems. Therefore, it has many advantages, including safe and convenient construction and reduced construction period compared to cast-in-place construction method. In half-depth precast deck systems, the bonding of precast pannels to cast-in place concrete is very important. To enhance the performance of half-depth precast deck system, it is necessary to improve the composite efficiency of the interface or increase the stiffness of the precast pannel to reduce deformation or stress on the interface. In this study, a flexural test of half-depth precast deck system was performed, in which the shear connecting reinforcement was applied to increase the bonding performance at the interface, and the rib shape precast panels were applied to improve stiffness. In addition, the safety and serviceability of these systems were evaluated. Test results show that all of specimens have the required flexural strength under the ultimate strength limit design. It was also evaluated to have sufficient safety for the serviceability of deflection and crack under the serviceability limit design.

• 한국구조물진단유지관리공학회 논문집
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• 제23권6호
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• pp.105-112
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• 2019

본 논문은 비내진 상세를 갖는 철근콘크리트 골조 및 필로티 건물의 보강방법으로 높은 연성을 갖는 ECC를 적용한 PC 벽판을 내진 보강요소로 사용하고자 하였다. PC 벽판의 형상비 및 설치 위치를 변수로 RC 골조에 대한 반복가력실험을 실시하여 내진성능을 평가하였다. 실험결과 PC 벽판을 보강함에 따라 기존 RC 골조의 내력 증진, 강도저하 방지, 강성증진 및 에너지 소산능력 향상에 효과적인 것으로 나타났다. 실험결과를 근거로 비내진 상세를 갖는 골조의 강도 증진을 위하여 ECC PC 벽판을 골조의 중앙에 설치하고 연성증진을 위하여 세장한 벽판을 골조의 양측면에서 설치할 것을 제안한다.

• 한국구조물진단유지관리공학회 논문집
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• 제19권5호
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• pp.56-66
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• 2015

이 연구의 목표는 학교 건물과 같은 저층 보-기둥 철근콘크리트 구조 건물에서 프리캐스트 벽패널을 사용한 새로운 내진보강 방법을 개발하는 것이다. 1개의 무 보강 보-기둥 실험체와 U형 PC 벽패널로 보강한 2개의 보강 보-기둥 실험체에 대한 정적 이력 하중실험을 진행하였다. 앵커접합 PR1-UA 실험체와 철판접합 PR1-UP 실험체는 무 보강 실험체보다 평균 2.8배(평균 591.8 kN)의 강도 증가를 보여 주었다. 최대 변위비도 1.4%에서 2.7%사이 값을 보여주었다. RC 골조 우측 상단에서 좌측방향으로 가력 할 때 우측에 있는 RC 기둥과 보강 PC 패널의 수직 요소는 완전 합성상태로 가정하였고, 좌측에 있는 RC 기둥과 PC 패널은 완전 비 합성 거동하는 것으로 가정하여 해석한 결과 전체적인 휨 거동은 실험 결과와 대체적으로 부합하는 것으로 판단되었다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 춘계학술발표회 논문집(I)
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• pp.146-149
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• 2006

In many previous studies, a prestressed concrete column has a larger flexural strength, shear strength and restoring force than a RC column. Recently, a precast prestressed concrete column is rising up a very rational column structure in that a economic aspect. In a precast prestressed concrete column, it makes in a factory. So, it needs a small construction site and acquires a higher durability than a cast in place concrete column. Seven precast concrete columns were tested under a constant axial load and a cyclically reversed horizontal load to investigate the performance. It is designed with a hollow section and consisted of 4 segments. The main variables of the test were a amount of prestressed, a type of joints and a boding type of strands. The test results show that the performance of a precast prestressed concrete column; failure mode, maximum load, energy dissipation and stiffness degradation.