• Structural Engineering and Mechanics
• /
• 제42권1호
• /
• pp.55-72
• /
• 2012

Precast-cast insitu concrete bridge construction is widely practiced for small to medium span structures. These bridges consist of precast pre-stressed concrete beams of various cross-sections with a cast in-situ reinforced concrete slab. The connection between the beams and the slab is via shear links often included during the manufacturing process of the beams. This form of construction is attractive as it provides for standardisation, reduced formwork and construction time. The assessment of the integrity of shear connectors in existing bridges is a major challenge. A procedure for assessment of shear connectors based on vibration testing and finite element model updating is proposed. The technique is applied successfully to a scaled model bridge model and an existing bridge structure.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
• /
• pp.1659-1663
• /
• 2011

Precast concrete slab track is a track structure to be installed by transporting and assembling precast concrete slabs manufactured at the factory. This method can improve concrete quality, provide easy maintenance and reduce construction time, compared with in-situ concrete track. However, the concrete slabs being continuously connected in longitudinal direction, due to the temperature change between summer and winter, the openings at slab joints have occurred. Thus, in this study, to identify the cause of this opening of slab joint, the joint opening caused by temperature drop in the longitudinally continuous precast concrete slab track has been predicted using three-dimensional finite element analysis, and compared with field measurements. Based on the proven model, the slab joint opening, and the stress pattern of concrete slab and steel reinforcement according to concrete slab-base friction properties, concrete-reinforcement bond properties, and prestressing were analyzed.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2001년도 가을 학술발표회 논문집
• /
• pp.173-178
• /
• 2001

The cost on transmission and election of precast concrete members largely depends on the weight of them. In this study, the weight of prestressed precast beam could be reduced by control the section and prestressing force to meet the required strength on the basis of the optimum process. The top and bottom concrete stress of the section considered is required to check according to each construction step for this process. The original rectangular beam weight could be reduced up to 50~39% due to the development of a U-beams from the optimum process.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2010년도 춘계 학술대회 제22권1호
• /
• pp.447-448
• /
• 2010

본 연구는 조립식 포장 공법에서 사용할 고성능 프리캐스트 콘크리트 슬래브의 제작 가능성을 분석하기 위해 수행되었다. 세부요소기술을 포함하여 슬래브를 설계하였으며 이를 토대로 매우 우수한 프리캐스트 슬래브의 제작이 가능하였다.

• 한국구조물진단유지관리공학회 논문집
• /
• 제25권2호
• /
• pp.43-48
• /
• 2021

프리캐스트 콘크리트는 일반적으로 건설 기간을 줄이고 시공 능력을 향상시키는 데 주로 사용되고 있다. 그러나 분할 과정에서 원래 구조 시스템과 다른 경계 조건과 구조적 거동을 적용하여 구조적 문제가 발생할 수도 있다. 이 연구에서는 시공 후 휨모멘트 및 크리프 증가로 인해 처짐과 균열이 발생한 프리캐스트 콘크리트 슬래브를 대상으로 검토하였으며, 이는 프리캐스트 콘크리트 슬래브의 지지 조건 및 구조거동에 대한 잘못된 적용에서 비롯된 것임을 알 수 있었다. 프리캐스트 콘크리트 슬래브 하부에 2 개의 지지대를 삽입하여 휨모멘트를 줄이고 보강 작업시 구조적 안전성을 확보하기 위해 잭킹력에 따른 캠버를 추정해야 한다. 따라서 기존 구조물의 처짐 및 균열을 확인하기 위해 역 해석을 통해 프리캐스트 콘크리트 슬래브의 다양한 지지 조건과 휨강성을 고려하였으며, 프리캐스트 콘크리트 슬래브의 잭킹력에 따라 캠버를 추정하고 안전한 구조물을 만드는 보강방법을 제안하였다.

• 대한건축학회논문집:구조계
• /
• 제35권9호
• /
• pp.151-158
• /
• 2019

A concrete core is used widely as lateral stability systems in high-rise modular buildings. As an alternative to traditional cast in-situ core, the precast concrete(PC) method can accelerate the construction of reinforced concrete cores. A core composed of precast elements differs from a in-situ core in having connections between the precast elements. The typical vertical connection between PC panels is consisted of shear keys, loop bars, lacer bars and grout. In this study, the effect of vertical connection components on shear strength is investigated experimentally. The test results show that the contribution to the shear strength is greater in order of grout strength, shear keys, lacer bars and loop bars. In addition, the numerical models to estimate the shear strength according to two crack patterns in the vertical joint of the PC panels are derived. The feasibility of the numerical models is evaluated by comparing the estimated shear strength and the test results.

• 한국구조물진단유지관리공학회 논문집
• /
• 제24권2호
• /
• pp.94-102
• /
• 2020

프리캐스트 콘크리트의 장점과 및 석조 아치의 거동을 접목한 콘크리트 패널 분절 아치 시스템은 가설재가 불필요한 시공성을 확보할 수 있는 경제적 시공법이다. 분절된 프리캐스트 콘크리트 패널의 연속 배치로 구성된 아치는 인양 및 시공을 위한 V형-스트립 연결부의 선설치 앵커 설치가 필수적이다. 그러나 좁은 폭과 얇은 두께의 콘크리트 패널은 선설치 앵커의 충분한 묻힘 깊이 확보를 보장할 수 없고 앵커 인발 거동 시 패널의 휨변형을 동반하는 등 앵커 저항성능 확보를 위한 콘크리트 패널의 기하학적 영향이 고려되어야 한다. 따라서 본 연구에서는 프리캐스트 패널과 강재 아웃리거로 구성된 아치구조의 제작시 설치되는 선설치 앵커의 인발 강도 평가를 위한 실험 연구를 수행하였다. 이를 위해 실제 아치 시스템과 동일한 크기의 프리캐스트 콘크리트 패널을 제작하였으며, 선설 앵커의 직경, 앵커 묻힘 깊이, 와이어 매쉬 사용 등의 영향에 따라 총 24개 실험체의 선설치 앵커 인발 강도를 측정하였다. 또한 측정 변수에 따른 설계기준강도 확보 및 파괴 모드 평가를 통해 프리캐스트 콘크리트 패널 분절 아치 구조에 적용 가능한 선설치 앵커의 형태를 결정하였다.

• 대한건축학회논문집:구조계
• /
• 제35권10호
• /
• pp.155-162
• /
• 2019

Hybrid precast concrete panel is a wall element that is able to quickly construct the core wall structure for moderate-rise modular buildings. Hybrid precast concrete panel has unique characteristics which is a pair of C-shaped steel beams combined at the top and bottom of a concrete wall, In this study, an improved anchorage detail for vertical rebar is proposed to ensure the lateral force resistance performance of hybrid precast concrete panel emulating monolithic concrete wall. Also, the structural performance of horizontal connection is investigated experimentally with the bolt spacing parameter. And the behavior of hybrid precast concrete panel with the improved detail is compared with the monolithic concrete wall tested in a previous study. Finally, the required thickness of C-shaped steel beam to eliminate or minimize the deformation in horizontal connection is calculated by prying action equation.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2009년도 추계 학술논문 발표대회
• /
• pp.97-100
• /
• 2009

Fire resistance properties and mechanical properties of high strength concrete mock-up column using organic fiber by KS F 2257 Methods of fire resistance test for elements of building construction and compression test was investigated for application of precast concrete column method of high rise building in this study. As a test result, it was appeared that ECC permanent form is available as fire resistance method of high strength concrete and new precast concrete construction method for facilitating construction of high rise building.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 1992년도 봄 학술발표회 논문집
• /
• pp.86-89
• /
• 1992

In the precast segmental method of construction, segments of a structure are precast, assembled, and tied together by post-tensioning to form the structure. Shear strength and behavior of points in precast concrete structures are important problems in the design of these structures. An experimental program was set up study the shear behavior of precast concrete shear keys. experimental models of keyed joints include a single key, representing one of a series include the shear key shape, d/h ratio(1/4, 1/5, 1/7), and inclined angle (45。 60。 75。). Two different types of joints, i.e., epoxied joint and dry joints were studied. From the present tests, it is found that epoxied joints have higher shear strength than those of dry joints, and that high d/h ratio keys have higher shear strength than those of low d/h ratio keys. The keys with 60。-inclined angle shows the highest shear strength among various angles.