• 한국건축시공학회지
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• 제5권1호
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• pp.123-129
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• 2005

This study is as a part of the new disposal and recycling plans of heat-resource waste of Daegu dyeing industrial center we tried to examine applicable possibility of crushed thing(waste aggregate) as aggregates for mortar and concrete. To examine applicable possibility of waste aggregate as a lightweight-aggregate for concrete and mortar, we carried this study by mainly property examination of concrete according to replacement ratio of waste aggregate. We carried slump, unit weight, compressive strength and bending strength test according to replacement ratio of waste aggregate. As the result of that, if we use waste aggregate, lightweight of concrete and mortar will be possible. Specially it shows a strength improvement effect of cement hardening according to using this so it is judged that applicable possibility as aggregate for concrete and mortar is very excellent.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2005년도 춘계 학술기술논문발표대회 논문집
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• pp.99-104
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• 2005

This study is as a part of the new disposal and recycling plans of heat-resource waste of Daegu dyeing, industrial center we tried to examine applicable possibility of crushed thing(waste aggregate) as aggregates for mortar and concrete. To examine applicable possibility of waste aggregate as a lightweight-aggregate for concrete and mortar, we carried this study by mainly property examination of concrete according to replacement ratio of waste aggregate. We carried slump, unit weight, compressive strength and bending strength test according to replacement ratio of waste aggregate. As the result of that, if we use waste aggregate, lightweight of concrete and mortar will be possible. Specially it shows a strength improvement effect of cement hardening according to using this so it is judged that applicable possibility as aggregate for concrete and mortar is very excellent.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1995년도 봄 학술발표회 논문집
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• pp.195-200
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• 1995

This paper presents the practical use of high strength concrete on 28-story Samsung Shin-dacbang Housing-Commercial Combined Building with 8-story basements located in Seoul. 700 Kg/$\textrm{cm}^2$ compressive Strength concrete was placed for basement core-walls and 500 kg/$\textrm{cm}^2$ concrete was used for structural frames up to 10th floor. The thermal sensors were installed prior to concrete casting into the core walls to measure the heat of hydration during hardening process. The correlation of core strength to the standard cylinder test strength was also discussed. The successful utilization of 500 and 700 kg/$\textrm{cm}^2$ concrete shows that the practical application of high strength concrete has a great potential to the high-rise R.C building construction.

• 한국레이저가공학회:학술대회논문집
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• 한국레이저가공학회 1999년도 춘계학술발표대회 논문개요집
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• pp.29-32
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• 1999

The material properties of laser welding zone such as strength coefficient, work-hardening exponent, and plastic anisotropic ratio are analytically obtained from those of base metals based on the tensile tests. . The finite element formulation is developed for predicting strain distributions and weld line movements in the forming processes of laser welded blank. The welding zone(WZ) is modelled with the several, narrow finite elements whose material characteristics are based on the experimental results and the analytical equations. In order to show an application of the developed weld element the stamping process of auto-body door inner panel is simulated. FEM predictions are compared and showed good agreements with experimental observations.

• Structural Engineering and Mechanics
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• 제6권8호
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• pp.857-870
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• 1998

This paper deals with a special class of inverse problems in discrete structural plasticity involving the identification of elastic limits and hardening moduli on the basis of information on displacements. The governing equations lead naturally to a special and challenging optimization problem known as a Mathematical Program with Equilibrium Constraints (MPEC), a key feature of which is the orthogonality of two sign-constrained vectors or so-called "complementarity" condition. We investigate numerically the application of two simple algorithms, both based on the use of the general purpose nonlinear programming code CONOPT accessed via the GAMS modeling language, for solving the suitably reformulated problem. Application is illustrated by means of two numerical examples.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2006년도 추계 학술논문 발표대회 논문집
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• pp.61-65
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• 2006

Urethane, epoxy, acrylic have common property to adhere on the concrete dried surface in the waterproofing materials at present. In the wet condition, however, the materials such as urethane, epoxy, acrylic need a long hardening time and it become a reason of water leakage as the materials breaking down. it is one of the problem to adhere to the substrate. Therefore, in this thesis, I focused to assure the structural safety and durability and quality for waterproofing and safe of construction cost by cut down the cost of labor and reduce the term of works as searching the application of field condition for hish adhesive spray type of degenerated and rubberized asphalt membrane material.

• International Journal of Internet, Broadcasting and Communication
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• 제14권2호
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• pp.70-78
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• 2022

The trenchless entire repair technology (TERT) have many different names depending on the companies, and they have the same or similar methods as well as materials. In addition, there was quiet difficulty in application of field working and even confuse to classify for new TERT, while application criteria of TERT is not listed systematically. This study proposed standardization and method for TERT affecting by pipe condition, working materials, working method, specification/quantity per unit according to field condition, strange affairs and others. Determination criteria of defective sewer pipe has proposed to effective method which modify a criteria between Ministry of Environment and Seoul Metropolitan City. A Cured-in-place pipe (CIPP) is suitable for TERT, and the design criteria for the entire broken pipe are proposed when the pipe itself deforms more than 10%. A check lists are specimen preparing, hardening site made by clamped mold, numbers, flexural and tensile property, water leak and desquamation test, and have to use material property of minimum CIPP value depend on ISO 11296-4, ISO 11297-4, KS M3550-7 and KS M3550-9.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2013년도 춘계 학술논문 발표대회
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• pp.85-86
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• 2013

Weakness of fine powder of blast furnace slags includes the decrease of initial intensity and delay of setting time. To solve this problem, there has been research on the alkali activation to induce hardening using alkaline chemical. However, the use of chemicals is dangerous and not cost effective, which can be solved by using recycled aggregates, one of construction wastes. The role of alkali activator can be substituted by alkali of non-hydrated cement included in recycled aggregates. In this study, the alkaline value of recycled aggregates will be evaluated through the comparison of molarity of sodium hydroxide (NaOH).

• 콘크리트학회논문집
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• 제27권1호
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• pp.37-44
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• 2015

본 연구는 변형경화형 시멘트 복합체(strain hardening cement composite, SHCC)가 고강도 철근이 배근된 보의 휨 거동에 미치는 영향을 알아보기 위하여 실시되었다. 또한, 본 연구에서는 SHCC가 철근콘크리트 휨 부재의 균열완화성능 및 연성에 미치는 영향을 분석하였으며, 실험결과를 토대로 하여 이론적인 휨 강도 예측 방법을 제안하였다. 실험을 위하여 시멘트 복합체의 종류 및 강도, 철근의 항복강도를 변수로하여 총 6개의 실험체를 제작하였다. 가력을 위해 단순 보 실험체를 500 kN용량의 유압 엑추에이터를 사용하여 변위제어 방식으로 4점 가력 하였다. 실험결과 SHCC를 사용한 경우 일반 고강도 철근콘크리트 보에 비하여 균열완화성능 및 연성이 증가하는 양상을 나타내었다. 특히 고강도 철근을 배근한 경우 휨 내력에 큰 차이를 나타내었으며, 이는 SHCC 대체가 800 MPa급 이상의 고강도 철근을 휨 철근으로 적용할 수 있는 가능성을 보여주는 것으로 판단된다. 예측된 휨 거동 산정 기법을 제한된 실험의 휨 내력을 잘 예측하는 것으로 나타났으며, 향후 SHCC의 인장강도 모델분석을 통해 보다 명확한 제안을 할 수 있을 것으로 판단된다.

• 한국작물학회지
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• 제14권
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• pp.97-109
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• 1973

1. 생장온도가 낮을 때에 내한성이 중정도에 속하는 품종들은 내한성의 향상을 보였으나 내한성이 극히 강하거나 극히 약한 품종들은 생장온도의 영향을 크게 받지 않는 경향을 보였다. 2. 냉각온도가 높고 또 냉각기간이 비교적 짧았을 때에는 $2^{\circ}C$에서 보다 $5^{\circ}C$에서 경화가 잘 되었다. 3. 일장은 경화전이나 경화중 별로 영향하지 않았다. 4. 토양습도가 높을수록 내한성은 저하되었다. 5. 질소시용은 내한성을 증가시켰으며 식물체의 건물중을 증가시켰다. 건물중과 내한성간에는 고도의 상관관계가 인정되었다. 6. 경화기간은 길수록 유리하지만 시험편의상 4일정도가 적당하다고 판단되었다. 고온하에서의 연화는 불과 1일-4일이내에 끝남을 알 수 있었다. 7. 내한성검정에 적합한 냉각조건은 $-8^{\circ}C$에서 24시간정도이었다. 8. 품종에 따라서는 냉각처리 직후 그 피해가 나타나기도 하지만 회복력을 가지는 품종도 있으므로 처리후 일주일간 정상온도에 두었다가 동피해정도를 조사함이 타당한 것으로 추정되었다. 9. 전체적으로 보아 CD 80과 83의 내한성이 가장 높았고 다음은 Cappelle과 Mris Otter의 순서이었다. 4개의 추파연맥과 Jufy I은 중정도로 구분되었으나 3개의 춘파연맥은 극히 약하였다. Peniarth는 Maris Otter와 대등하였고 S 147은 추파연맥중 가장 약한 경향을 나타내었다. 10. 수용성탄수화물함량이 내한성에 어느 정도 관여하고 있음은 사실이나 이 자체가 내한성을 조절하는 관건은 아님을 알 수 있었다.