• International Journal of Concrete Structures and Materials
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• 제10권3호
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• pp.373-381
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• 2016

As part of this study, has been developed a numerical method which allows to establish abacuses connecting the normal force with bending moment for a circular section and therefore to predict the rupture of this type of section. This may be for reinforced concrete (traditional steel) or concrete reinforced with steel fibers. The numerical simulation was performed in nonlinear elasticity up to exhaustion of the bearing capacity of the section. The rupture modes considered occur by plasticization of the steel or rupture of the concrete (under compressive stresses or tensile stresses). Regarding the fiber-reinforced concrete, the rupture occurs, usually, by tearing of the fibers. The behavior laws of the different materials (concrete and steel) correspond to the real behavior. The influence of several parameters was investigated, namely; diameter of the section, concrete strength, type of steel, percentage of reinforcement and contribution of concrete in tension between two successive cracks of bending. A comparison was made with the behavior of a section considering the conventional diagrams of materials; provided by the BAEL rules. A second comparative study was performed for fibers reinforced section.

• 콘크리트학회지
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• 제7권5호
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• pp.23-32
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• 1995

• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집
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• pp.565-573
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• 2009

Even in case of new materials, materials that are not only harmless for the current global environment but also have high-performance and high-function are sought-after in consideration of the global environmental problems. Moreover, in construction areas where a large amount of cement and concrete are used, the establishment of the recycling technology or transformation into resources and energy materials are being put in place. And also, in a situation where the slow and relaxed city and rural life have a high priority, the need for cement and concrete as environmentally friendly new materials that best suit the emotions in human beings is on the rise and a new way to make good use of cement and concrete as new materials in construction technology should be sought. The recently introduced functional and environmentally friendly concrete is aimed at enhancing health through the adjustments of the body biorhythm using far-infrared. Minerals that contain a great amount of the elements with the frequent occurrence of the infrared among earth minerals and concrete are mixed to use structures or finishing materials, which will tackle the issues of smells, mold and corrosion.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 춘계 학술발표회 논문집(II)
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• pp.317-320
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• 2006

In this paper, in order to inspect effect of marketed repair materials, it inspected first the repair material through laboratory work by repair method. After we carry out laboratory work and choice the construction with ongoing deterioration to inspect performance of repair materials, we apply the repair materials there. This results will be make use of reference whenever selection of repair materials and repair method. Also which will be used basic data for repair construction code.

• 대한수학교육학회지:학교수학
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• 제18권1호
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• pp.159-173
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• 2016

실제 교육 현장에서는 구체적 맥락에서 추상화하는 과정과 반대로 추상화된 개념을 먼저 가르치고 구체적인 문제 상황을 도입하는 경우도 있다. 즉, 추상적 지식을 구체화 해야 하는 경우가 있는 것이다. Freudenthal은 이런 상황을 반교수학적인 전도라고 표현하며 부정적인 견해를 나타낸 바 있지만 모든 수업상황이 구체적 상황이나 구체물에서 출발하는 추상화로 진행될 수 있는지는 의문의 여지가 있다. 본 연구에서는 구체물을 추상화하여 추상적 개념을 형성하는 과정과 추상적 개념을 구체적인 상황으로 구체화하는 과정에서 나타나는 수학적 사고의 차이점을 비교 분석하여 그 교육적 시사점을 살펴보고자 한다. 이를위해 AiC의 분석틀을 활용하여 구체물의 추상화 과정에서의 수학적 사고를 분석하였고, AiC의 분석틀을 토대로 연구자가 구안한 방식으로 추상적 개념의 구체화 과정에서의 수학적 사고를 분석하였다. 두 과정을 비교 분석한 결과 구체물의 추상화 과정만큼이나 추상적 개념의 구체화 과정에서도 유의미한 수학적 사고를 유도할 수 있음을 확인할 수 있었다.

• Computers and Concrete
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• 제19권5호
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• pp.515-526
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• 2017

Recent trend is to use the lightweight concrete in the construction industry because it has several advantages over normal weight concrete. The Lightweight concrete can be produced from the industrial waste materials. In South East Asian region, researchers are very keen to use the waste materials such as oil palm shell (OPS) and palm oil clinker (POC) from the palm oil producing industries. Extensive research has been done on lightweight concrete using OPS or POC over the last three decades. In this paper the aggregate properties of OPS and POC are plotted in conjunction with mechanical and structural behavior of OPS concrete (OPSC) and POC concrete (POCC). Recent investigation on the use of crushed OPS shows that OPSC can be produced to medium and high strength concrete. The density of OPSC and POCC is around 20-25% lower than normal weight concrete. Generally, mechanical properties of OPSC and POCC are comparable with other types of lightweight aggregate concrete. It can be concluded from the previous study that OPSC and POCC have the noteworthy potential as a structural lightweight concrete.

• 콘크리트학회논문집
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• 제24권4호
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• pp.361-368
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• 2012

보수 보강재는 강도, 안정성, 내구성, 모재와의 부착력 등 많은 특성이 필요하며, 최근 변형경화형 시멘트 복합체(strain-hardening cement-based composite, SHCC)가 기존의 재료를 대체할 수 있는 성능으로 많은 연구가 이루어지고 있다. 팽창형 SHCC는 팽창재를 이용하여 수축이 발생하는 SHCC의 단점을 보완하여 성능을 개선시킨 복합체로 이를 이용해 보강재의 성능을 만족시키면서 동시에 강도 증진 효과를 가져올 수 있을 것으로 예상된다. 따라서 이 연구에서는 SHCC 보강재의 강도, 팽창재 대체 여부 및 보강 두께를 변수로 하여 휨 성능을 평가하였으며, 실제 보강에 적용 시 기초 자료로 활용하고자 한다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1995년도 봄 학술발표회 논문집
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• pp.212-218
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• 1995

This study experimentally evaluated the performance of damaged section which was repaired using polymer materials in reinforced flexural flexural members Six different materials, two types of polymer, two types of polymer-cement and two types of cement, were used by means of injection method on prepacked concrete and spray mortar patching method. As results, the repair works could be done easily and surfaces of the repaired section were smooth.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2003년도 가을 학술발표회 논문집
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• pp.523-526
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• 2003

Functions of the building structures are recently expended, because the structures are getting larger and people's indoor staying times are getting longer. Therefore, various functional materials such as yellow mud, carbon soot, and jade are widely used. But functions of those materials have not permanent and continued an effect. Specially, the development of construction materials containing anti-insect is highly important to delight the environment of residence. This research try to examine to develop the mortar and concrete which contain microcapsules with long-term effect of anti-insect.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1995년도 가을 학술발표회 논문집
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• pp.350-354
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• 1995

Deteriorated concrete components are repaired using various repair materials for preventing functional deficiencies. However, the durability performance of these materials is not very well investigate. This study aims to examine the dynamic behavior of R/C beams repaired by Polymer, Polymer-Cement and Cemtitious material through dynamic test. Totally 18repaired R/C beams were tested, and the results from dynamic test of beams repaired with various materials were compared.