• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1992년도 봄 학술발표회 논문집
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• pp.99-104
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• 1992

There is a limit manufacturing precast products for the construction industry using conventional cement concrete and precast iron due to many reasons. Therefore, precast product technologies using polymer concrete are widely developed across the world because using polymer concrete can be over come this limitation. This study reviewed and analyzed the trends of development and practical usages of ploymer concrete precast products in foreign countries based on selected literatures. It was observed that polymer concrete precast products have been widely used as utility structures wall and slab members. decoration products, traffic products, hydraulic structures and industry equipments.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2016년도 춘계 학술논문 발표대회
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• pp.179-180
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• 2016

This study has a purpose of producing precast concrete for rapid construction of urban railway system. However, previous precast concrete has problem of its weight itself and there has been a keen interest in effect of carbon emission reduction and eco-friendly in our society. Therefore, in order to solve these two problems, we are about to produce precast concrete using lightweight aggregate and eco-lightweight concrete, with which much mineral had been replaced. As a result, we could confirm that it was possible to produce RMC B/P production satisfying the requirement performance of eco-lightweight concrete, which is replaced with a great amount of mineral for reduction of precast concrete's weight and environmental performance. Also, by confirming the possibility of producing precast concrete which lightweight concrete is used, if producing precast concrete by using eco-lightweight concrete, it would be effective to avoid destruction of environment and much useful to use multiple tower crane when constructing. Afterward, we will proceed our study by constructing precast concrete at which eco-lightweight concrete is used for continuous quality improvement.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2008년도 춘계 학술발표회 제20권1호
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• pp.661-664
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• 2008

고층 대형 건축물에 사용되는 기둥 보 등의 단면치수가 큰 Precast Concrete 부재는 제조과정에 있어서 외부에서의 가열뿐만 아니라, 시멘트수화열의 축척에 의한 내부에서의 온도 상승도 작용되기 때문에, 단면치수가 비교적 작은 벽, 밑바닥 등의 Precast Concrete 부재와는 다른 온도이력을 나타낸다고 생각할 수 있다. 이에 본 연구는 Precast Concrete적용을 위한 고강도 매스콘크리트 부재의 강도특성을 검토하기에 앞서, 온도이력특성을 밝히는 것을 목적으로 했다. 단면치수가 큰 Precast Concrete 모의부재의 단면치수, 단위시멘트량, 양생조건이 가각 다른 Precast Concrete 부재를 제조할 때의 온도이력특성을 총괄적으로 검토하여 분석하였다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 추계학술대회 논문집
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• pp.1303-1308
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• 2007

Recently, precast concrete tracks are replacing ballast track for efficient and economic maintenance of track. Precast concrete railroad tracks are manufactured in factory, and transported to railroad construction site for installation. Therefore, quality of precast concrete track itself should be sufficiently good. On the contrary to the convenient manufacturing of precast concrete track, the installation of a precast concrete track requires careful steps. Typically, a precast concrete track is placed on an approximately 15-cm thick lean concrete layer. A mortar is filled between lean concrete layer and precast concrete track to adjust the sloping angle of a precast concrete track for a safe train operation at a curvy section. Then, the use of filled mortarproduces a void underneath a precast concrete track, which is harmful to structural safety of a precast concrete track undercyclic loading. Therefore, it is essential to make sure that there is no void left beneath a precast concrete track after mortar filling. In the continuous resonance method, the amplitude of frequency response measured using an instrumented hammer and an accelerometer is plotted against a pseudo-depth, which is half of the wave velocity divided by frequency. The frequency response functions are measured at consecutive measurement locations, 6-cm interval between measurement points, and then combined together to generate a 2-D plot of frequency response. The sections with strong reflections or large amplitude of frequency response are suspicious areas with internal voids and unfilled areas. The 2-D frequency response plot was efficient in locating problematic sections just by examining the color shade of a visualized plot in 2-D format. Some of the problematic sections were drilled to make a visual inspection of mortar filling. The visual image of interface between mortar and precast concrete track was verified using the validity of the continuous resonance technique adopted in this research.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2023년도 봄 학술논문 발표대회
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• pp.253-254
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• 2023

The production plan of Precast Concrete members is closely related to the assembly plan of Precast Concrete members, and is an important management factor for the process planning of Precast Concrete construction. This may cause a delay in the construction period due to manufacturing errors occurring in the production process of members and transportation errors according to the production sequence. Therefore, it is necessary to have an efficient production plan for Precast Concrete members that can produce the necessary quantity from the point of assembly of the members and supply them in a timely manner. This study is a basic study for establishing a production plan for Precast Concrete members, and the purpose of the study is to examine the factors that affect the establishment of a production plan for Precast Concrete members. In this study, the influencing factors according to the production method and conditions when establishing a production plan for Precast Concrete members were considered. In the future, correlation analysis among influencing factors will be carried out, and it is expected that it will be used as basic data for schedule management of Precast Concrete construction and derivation of construction period calculation standards.

• 한국지진공학회논문집
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• 제14권2호
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• pp.15-26
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• 2010

PC(Precast Concrete) 구조시스템은 건식화 조립식 공법으로 구조물 건설에 있어 공기, 노동력 절감 등의 여러 장점을 가지고 있다. 하지만 구조벽체의 경우 이를 PC화하여 사용할 경우 접합부의 내진성능이 떨어지므로 PC 구조벽체를 사용하는 경우는 드물다고 할 수 있다. 본 연구에서는 이러한 점을 감안하여 접합부 성능을 개선하여 횡력저항요소로 사용가능한 2종류의 PC 구조벽체를 제안하였다. 제안된 PC 구조벽체는 RC 벽체 및 PC 벽체가 혼합된 복합 PC 벽체와 벽체하부 연결철근의 일부를 단면감소시키고 비부착상세를 적용한 PC 벽체로서 지진발생 시 충분한 강도와 변형능력을 확보할 수 있도록 하였다. 제안된 PC 구조벽체의 내진성능평가를 위하여 RC 벽체를 포함한 3가지 벽체에 대한 실험체를 제작하여 주기 횡하중 실험을 수행하였다. 실험결과, 제안된 PC 구조벽체는 강도, 강성, 변형능력 및 에너지 소산능력이 기존 PC 구조벽체보다 월등히 향상되어 우수한 내진성능을 확보할 수 있는 것으로 나타났다.

• 한국공간구조학회논문집
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• 제20권3호
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• pp.35-42
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• 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.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2009년도 춘계 학술논문 발표대회 학계
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• pp.119-122
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• 2009

As architectures have recently become high-risers and mega-structured, stable high strength products have been ensured. Accordingly, use of precast concrete accouplement has been increased in order to facilitate air compression and rationalize construction. Since not only external heating but a1so internal temperature rise caused by the accumulation of cement hydration heat in manufacturing process, precast concrete members with large cross-section used for high-rise mega-structure's columns and beams may exhibit different temperature history compared to the precast concrete members for wall and sub-floor with relatively small cross-sections. Therefore, this study aims to elucidate the characteristics of temperature history of mass concrete members cast with high-strength concrete fur precast concrete application. In this study, large cross-sectional precast concrete mock-up, unit cement quantity, and temperature histories in manufacturing precast concrete member under different curing condition were inclusively investigated.

• Advances in concrete construction
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• 제10권1호
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• pp.21-34
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• 2020

Precast deck joints have larger crack width than cast-in-place concrete decks. The initial crack typically occurs at the maximum moment but cracks on precast joints are significant and lead to failure of the deck. The present crack equation is applied to cast-in-place decks, and requires correction to calculate the crack width of precast deck joints. This research aims to study the crack width correction equation of precast decks by performing static tests using high strength and normal strength concrete. Based on experimental results, the bending strength of the structural connections of the current precast deck is satisfied. However it is not suitable to calculate and control the crack width of precast loop connections using the current design equation. A crack width calculation equation is proposed for crack control of precast deck loop joints. Also included in this paper are recommendations to improve the crack control of loop connections.

• 대한토목학회논문집
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• 제30권5A호
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• pp.463-473
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• 2010

이 연구의 목적은 프리캐스트 세그먼트 PSC 교각의 조립식 코핑부의 성능을 파악하는데 있다. 제안된 프리캐스트 시스템은 현장에서의 작업을 줄이고 공사기간의 단축을 가져올 수 있다. 조립식 코핑부는 프리캐스트 세그먼트 PSC 교각의 현장타설 코핑부를 대체할 목적을 갖고 있다. 조립식 코핑부 실험체는 단조증가 하중 하에서 파괴 실험을 수행하였다. 그 결과 제안된 조립식 코핑 시스템은 기존의 현장타설 시스템과 동등한 소요성능을 보임을 확인하였다. 연계논문에서는 프리캐스트 세그먼트 PSC 교각의 조립식 코핑부의 성능평가를 위해 실험 및 해석적 연구를 수행하였다.