• 한국기계가공학회지
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• 제19권3호
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• pp.57-62
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• 2020

Concrete pump cars are a type of construction equipment that continuously supplies concrete using hydraulic pressure. When manually casting concrete, there may be a problem in the final quality of the concrete due to differences in the degree of cure between the pre-poured and subsequent concretes. Concrete pump cars are the most efficient machines to supply concrete in the shortest time; however, it is difficult to calculate their margin of safety during operation. In this paper, we verified the structural safety of the concrete pump car using a static/dynamic analysis at various position angles. Next, these results were compared with experimental results; strains using strain gages were compared with the strains measured using FEM software to verify the static analysis. In addition, the maximum displacement during the pumping was measured and it was used for fatigue analysis to evaluate the dynamic structural safety.

• 한국건설안전학회 논문집
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• 제6권1호
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• pp.7-11
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• 2024

펌프카는 콘크리트를 타설하는 장소에 필요한 만큼 운반하는 장비로, 짧은 시간에 많은 양의 콘크리트 타설하기 위해서는 펌프카를 사용하는 것이 경제성 및 품질관리 측면에 가장 효율적이다. 그러나 최근에는 콘크리트 타설중에 붐 파손으로 인한 인명피해가 많이 발생하고 있으므로 본 연구에서는 장비 제작단계, 노후장비에 대한 검사기준, 장비대여제도 등의 개선이 필요함을 제언한다. 그 이유는 펌프카의 유한요소해석 결과, 붐 2단에서 작용하는 상당응력과 붐상단에서 최대응력이 895.39MPa로 나타났고, M.S. 0.04로 가장 낮게 평가되었으므로 보강의 필요성을 인식했다. 그리고 2단계 붐은 1~5단계 붐대 중 가장 스트레스가 많고, 취약한 부분임을 확인했다. 따라서 설계 및 제작 단계에서 부재의 두께와 강성을 높이고, 현재 사용되는 장비의 강판에 대한 보강이 필요하다. 또한, 일반 건설기계 전체에 대한 비파괴 검사를 의무적으로 반영하고, 비파괴검사 및 정기검사시 붐대 결함 누락에 대한 책임을 검사기관에 부담시키는 제도 구축이 시급하다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2010년도 춘계학술대회 논문집
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• pp.671-679
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• 2010

The construction of concrete track for the first time in Korea gives lots of meanings to civil engineering in various aspects. Settlement level needs to be kept minimal for the safety of the track. Concrete track has different structural characteristics comparing to conventional ballast track, so load distribution in concrete track is also different. Since it is the first time to build concrete track, there are very few experience and data available on the subject. Therefore it is important to evaluate how much load is transferred to the ground due to the running vehicle in concrete track and to determine the optimal thickness of layers. In this research, 9 individual earth pressure cells were installed at OOOk930 site in 2nd stage of Kyungbu high speed railway during under construction. The in-situ pressure data were measured at each layers during pump-car and locomotive were moving on the high speed railway surface.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1997년도 봄 학술발표회 논문집
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• pp.521-526
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• 1997

The Spin Tester(High Speed Balancing and Overspeed Test Facility), which is designed for the quality control of turbine, generator, and rotors was supposed to be constructed with the use of Steel Fiber Reinforced Concrete(SERC) for reducing the risk of accident while operation. However, it was very existence of fiber concrete due to there are two major concern in the SFRC work: one is existence of fiber ball due to inhomogeneous mixing, the other is the segregation of the concrete materials. To avoid these possible problems, the S/a was controlled about 55% to reduce the segregation and the high range AE water reducing agent was used to maintain the slump over the value of 18cm. With these careful consideratons, the SFRC work was done successfully by only using regular equipments like pump car and vibrator.

• KIEAE Journal
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• 제9권1호
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• pp.91-97
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• 2009

In this thesis presents the application to the field of Hwangto-used concrete highlighted as an eco-friendly material and performs an experiment in the aspect of construction and quality on the construction for all parts of buildings, rather than for some parts of buildings as shown from existing application and got the conclusion as followings. 1) It was turned out that Hwangto concrete showed lower hydrated heat and arid contraction comparing to those of cement concrete. And this phenomenon is judged to appear high when applied to mass building and huge span structures. 2) The construction of Hwangto concrete is judged to be possible in applying to constructions since the mechanical construction seems to be possible by using pump car and ready-mixed concrete which are used at the practical sites at the moment. 3) The pockmarks appearing on the exposure surface were about 2% of total area. This has great cohesion by Hwangto concrete but is judged that it will be improved through enough vibration stamping. Through the experiments of quality and construction of Hwangto concrete as environment-friendly construction materials, it is possible to judge modernized application of Hwangto concrete. It is in need of more studies about economical efficiency, structural stability, design application, etc. afterwards.

• 한국기계가공학회지
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• 제17권6호
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• pp.105-110
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• 2018

A concrete docking hose of pump car's boom pipe line have been used in many construction sites. They are long structures with continuous cornering, similar to a trunk of the elephant, characterized by a very high pressure resistance of 20MPa. They need flexible materials and structure in order to move the hose smoothy. But commercial concrete hose is hard to handle and heavy owing to adaption of steel reinforcement. In this study, it is tried an experimental approach to the characteristic of inner rubber layer and abrasion resistance. Also, we are investigated the bursting pressure according to the reinforcement of the hose and propose the usefulness of the hose reinforced with high strengthened aramid fiber.

• 대한토목학회논문집
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• 제39권4호
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• pp.477-483
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• 2019

최근 원자력발전소 및 LNG 저장탱크 등 특수구조물의 공사 기간과 비용 절감을 목적으로 PSC 구조물 대신 프리캐스트 형식의 SCP 모듈의 사용이 증가하고 있다. SCP 모듈 내부는 강재와 콘크리트의 일체 거동을 위해 스터드로 연결되어 있어 고유동 콘크리트의 사용이 요구된다. 고유동 콘크리트는 일반적으로 많은 단위결합재량를 가지기 때문에 수화열 및 수축의 증대, 비경제적인 강도 발현 문제 등이 발생한다. 따라서 본 연구에서는 저분체 기반 고유동 콘크리트 최적 배합을 선정하기 위해 재료적 특성에 따른 고유동 콘크리트의 유동성 및 철근의 간극 통과성능을 검토하고, 펌프카를 활용하여 펌핑 전후에 따른 콘크리트의 물성을 검토하며, 최종적으로 강재와 강재 사이를 콘크리트로 채우는 SCP Mock-up 부재에 대하여 고유동 콘크리트의 충전 성능을 평가하였다.