• 한국구조물진단유지관리공학회 논문집
• /
• 제17권4호
• /
• pp.48-56
• /
• 2013

프리텐션 방식을 사용한 PSC 휨부재는 시공이 간편하고 품질관리가 용이하기 때문에 최근 토목분야에서 적용된 사례가 증가하고 있다. 특히, PSC 휨부재의 종류 중 하나인 반단면 프리캐스트 콘크리트 합성 슬래브는 롱라인 공법을 적용하여 최근에 개발되었다. 반단면 프리캐스트 콘크리트 합성 슬래브는 프리캐스트 콘크리트와 현장타설 콘크리트를 합성하여 제작한다. 이 연구에서는 롱라인 공법으로 제작한 프리캐스트 PSC를 적용한 반단면 프리캐스트 콘크리트 합성 슬래브의 프리스트레스 도입 효율과 휨강도에 대한 실험을 실시하고 그 결과를 제시하였다. 롱라인 공법은 한번의 긴장력 도입으로 여러 개의 부재를 생산할 수 있는 장점이 있다. 또한, 프리캐스트 PSC 내에 매입되어 있는 철근의 영향을 고려하여 반단면 프리캐스트 콘크리트 합성 슬래브의 휨강도를 합리적으로 평가할 수 있는 식을 제시하였다.

• 한국공간구조학회논문집
• /
• 제20권3호
• /
• pp.35-42
• /
• 2020

The purpose of this study is to develop precast concrete modules that can be used as a booth and a single-story building with a large space. This precast concrete module is originally designed to have a hexagonal facade when the upper and lower parts, which are symmetrical about horizontal connection line, are combined. A structural design was conducted to ensure structural safety of these precast concrete modules and to extend the slope of the inclined members as far as possible. Then the finite element analysis was performed to estimate the lateral and vertical deflection of complete precast concrete modular structures. And to verify the structural safety of these precast concrete modules, weight loading tests were conducted on the upper and lower modules respectively.

• 한국건축시공학회지
• /
• 제21권5호
• /
• pp.445-457
• /
• 2021

기성콘크리트 부재를 현장 생산하는 경우 공장생산보다 약 14.5-39.4%의 원가가 절감되는 것으로 이전 연구에서 확인되었다. 특히, PC공장 관계자의 인터뷰를 통해, 실제 공장주는 생산원가의 20% 이상의 이윤을 얻지 못하면 공장관리 간접비를 cover하지 못해 계약을 하지 않는 것으로 확인되었다. 그리고 동등한 조건에서 기성콘크리트 부재를 현장에서 생산한다면 공장생산 대비 동등 이상의 품질이 확보된다. 이 연구들에 따르면 원가와 품질 측면에 유리하므로 기성콘크리트 부재는 현장에서 생산하여야 한다. 그러나 주어진 공기뿐 아니라 현장생산을 위한 여러 가지 제약조건으로 모든 물량을 현장생산하기 어렵다. 그 이유는 현장생산은 프로젝트 관리 과정에서 발생할 수 있는 리스크로 인하여 기피하기 때문이다. 그러나 기성콘크리트 부재의 현장생산 수행 전 리스크 요인을 분석하고 그에 대응한다면 현장생산 기회를 높일 수 있다. 따라서 본 연구는 기성콘크리트 부재의 현장생산 리스크 평가를 위한 체크리스트를 개발한다. 체크리스트를 1개의 사례현장에 적용하여 리스크 요인을 쉽고 빠르게 평가할 수 있다는 것을 검증하였다. 그 결과 건폐율이 높은 현장의 경우 생산 및 야적을 위한 가용면적을 확보하기 어려워 리스크가 큰 현장으로 분류되는 것으로 분석되었다. 개발된 리스크 평가 체크리스트는 현장생산의 리스크요인을 효율적으로 평가하며, 프로젝트 수행 시 수시로 변경되는 리스크요인을 쉽고 빠르게 판단하여 상황에 따라 대처가 가능하다.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2013년도 춘계 학술논문 발표대회
• /
• pp.176-177
• /
• 2013

The composite PC rahmen structure, called Green Frame, allows the main structural members such as PC column and beam to be produced on the site, resulting in a reduction of PC member transportation cost and the margin of PC plant (operation cost and profit), making it more economic than the bearing wall structure. To apply the Green Frame to practice, not only installation but also insitu-production process should be considered. Therefore, this study analyse the influence factors on insitu-production and installation schedule of composite precast concrete members. The results shall be used as basic criteria on the planning of insitu-production and installation of Green Frame.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2009년도 춘계 학술논문 발표대회 학계
• /
• pp.65-68
• /
• 2009

Recently, as architectural concrete structures become high-rise and megastructured, concrete become high-strengthened and, by ensuring products of more stability, and rationalization of construction are required.large cross-sectional precast concrete members such as columns show large temperature increase in manufacturing process not only by external heating but also by concrete itself's hydration heating. Therefore, it is expected that specimen for management to predict strength and compression strength of precast concrete member shows different strength characteristics. Concerning this, in order to suggest strength characteristics of high strength mass concrete suitable for precast concrete application, this study comprises the inclusive investigations on the relations between core strength and the strength characteristics per member cross-section dimensional value and per water-bonding material ratio value.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2006년도 춘계학술발표회 논문집(I)
• /
• pp.522-525
• /
• 2006

This study is intended to discuss the application of blast slag for concrete to improve the durability of precast concrete box culvert. The precast concrete box culverts with blast slag are tested to verify the effect of early strength. The results show that the initial cracking load and yielding load of the blast slag concrete members are increased when they are compared with those of the normal concrete. In the prototype precast concrete box culvert experiment, initial crack control effect and ductility index are increased. It can be concluded that the use of blast slag was improved the durability in precast concrete box culvert.

• Advances in concrete construction
• /
• 제6권5호
• /
• pp.527-543
• /
• 2018

Crack control of precast members is crucial for durability. However, there is no clear provision to check the crack width of precast joints. This study presents an experimental investigation of loop joint details for use in a precast bridge deck system. High strength concrete of 130 MPa was chosen for durability and closer joint spacing. Static tests were conducted to investigate the cracking and ultimate behavior of test specimens. The experimental results indicate that current design codes provide reasonable estimation of the flexural strength and cracking load of precast elements with loop joint of high strength concrete. However, the crack width control of the loop joints with high strength concrete by the current design practices was not appropriate. Some recommendations to improve crack control of the loop joint were derived.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2007년도 추계 학술논문 발표대회
• /
• pp.49-52
• /
• 2007

Recently, as architectural concrete structures become high-rise and megastructured, concrete become high-strengthened and, by ensuring products of more stability, air compression and rationalization of construction are required. In general, product management test of precast concrete member, specimen for management cured in the same condition with precast concrete member is substitutively used for strength test. However, large cross-sectional precast concrete members such as columns show large temperature increase in manufacturing process not only by external heating but also by concrete itself's hydration heating. Therefore, it is expected that specimen for management to predict strength and compression strength of precast concrete member shows different temperature history and strength characteristics. Concerning this, in order to suggest temperature history and strength characteristics of high strength mass concrete suitable for precast concrete application, this study comprises the inclusive investigations on the relations between management specimen with similar temperature history and core strength, and the strength characteristics per member cross-section dimensional value and per water-bonding material ratio value.

• 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.

• Architectural research
• /
• 제2권1호
• /
• pp.55-60
• /
• 2000

Recently, there is a great demand for precast reinforced concrete (RC) construction methods on the purpose of simplicity in construction. Nishimatsu Construction Company has developed a construction method with precast reinforced concrete members in medium-rise building. In this construction method, how to joint precast members, especially the anchorage of the main bar of beam, is important problem. In this study, the structural performance of exterior joints with precast members was investigated. The parameters of the test specimens are anchorage type of the main bar of beam (U-shape anchorage or anchorage plate) and the ratio of the column axial force to the column strength. Specimens J-3 and J-4 used U-shape anchorage and the ratio of the column axial force of specimen J-4 was higher. On the other hand, specimens J-5 and J-6 used anchorage plate, and the anchorage lengths are 15d and 18d, respectively. Experimental results are summarized as follows; 1) For the joints with beam flexural failure mode, it was found that the maximum strength of specimen with anchorage plate is equal to or larger than that of specimen with conventional U-shaped anchorage if the anchorage length of more than 15d would be ensured, 2) Each specimen shows stable hysteretic curves and there were no notable effects on the hysteretic characteristics and the maximum strength caused by the anchorage method of beam main bar and the difference of column axial stress level.