• 콘크리트학회논문집
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• 제12권5호
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• pp.3-12
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• 2000

Recently, the amount of disposed construction materials like demolished concrete is growing fast and the shortage of natural concrete aggregates is becoming serious. Therefore, recycling of aggregates extracted from the demolished concrete is getting important and use of the recycled aggregates for concrete has been seriously considered. However, the use of the recycled aggregates even for low performance concretes is very limited because there are few rational standard evaluation criteria for recycled aggregates which should be different from that for natural aggregates. In this study, rational evaluation criteria for the recycled aggregates are proposed for their use as concrete aggregates. The study also shows that the performance for both the recycled aggregates and the recycled concrete manufactured with the recycled aggregates can be evaluated effectively according to water absorption ratio of recycled aggregates.

• Structural Engineering and Mechanics
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• 제40권3호
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• pp.411-429
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• 2011

In the past decades, recycling use of demolished concrete was almost limited to the types of recycled coarse aggregate with a size of about 5-40 mm and recycled fine aggregate with a size of about 0-5 mm for concrete structures, and reuse of demolished concrete lumps (DCLs) with a size much larger than that of recycled aggregate, e.g., 50-300 mm, has been limited to roadbed, backfilling materials, or discarded to landfills. Treatment processes of DCLs are much simpler than those of recycled aggregate, leading to less cost and more energy-saving. In the future, the amount of demolished concrete is estimated to be much higher, so reuse of DCLs for concrete structures will become necessary. The objectives of this paper are to document the process of making reinforced concrete beams with DCLs, and to discuss the flexural and shear behaviors of those reinforced DCL beams through an experimental program, which includes three beams filled with DCLs and one conventional beam for investigating the flexural strengths and deformations, and 12 beams filled with DCLs and two conventional beams for investigating the shear strengths and deformations. The authors hope that the proposed concept offers another sustainable solution to the concrete industry.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 봄 학술발표회 논문집
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• pp.93-96
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• 2000

In this paper, physical properties of planting concrete using Recycled aggregates made with demolished concrete and construction wastes are investigated. According to the test results. It shows that recycled aggregates made with demolished concrete and construction wastes have low physical properties compared with crushed stone. But, recycled aggregates made with construction wastes shows better performance in absorption ratio, unit weight and thermal conductivity than crushed stone. According it is thought that they are available for being applied to planting concrete considering the sides of efficient recycling of construction wastes and saving the manufacturing cost.

• 기술사
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• 제45권1호
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• pp.42-44
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• 2012

Recently human beings are experiencing fatal matters of environmental harm from enormous demolished concrete, even though waste concrete can get much more market value if recycled. The problem is that demolished concrete can not find the place where it can be used more economically and efficiently, but eventually can be spent worthlessly for landfill or road basement. Up to now, we can barely find the right place matching for structural performance in construction site with recycled concrete, even more, can not find another place to recycle this tremendous waste concrete. in addition it needs recycling information system between demanders and suppliers managed by government and other.

• 한국방재학회 논문집
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• 제5권1호
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• pp.77-84
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• 2005

콘크리트 구조물의 성능저하, 노후화 및 용도 변경 등으로 구조물을 해체할 경우가 증가하면서 발생되는 폐콘크리트량이 급증하고 있는 추세이지만, 거의 대부분이 단순 매립용 재료로 사용되고 있다. 우리나라와 같이 부존자원이 부족한 나라에서 폐기되는 콘크리트를 포장 콘크리트용 골재로 재활용할 경우 콘크리트용 천연골재의 부족 현상 극본, 자원절약 및 환경보존 등에 크게 기여할 것으로 기대된다. 본 연구에서는 실제 구조물에 사용된 콘크리트를 해체하면서 발생한 폐콘크리트를 파쇄하여 제조한 재생골재의 혼합율을 각각 5단계로 변화시켜 제조한 재생 골재를 포장 콘크리트용 골재로 활용하기 위하여 실시한 실험결과에 대하여 고찰하였다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2002년도 봄 학술발표회 논문집
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• pp.643-648
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• 2002

A research for recycling the demolished-concrete as concrete aggregate has been concerned in all over the world. There, however, are some problems that qualities of recycled aggregates are not only largely different, but also mechanical properties of recycled aggregate concrete decrease a little in comparison with that of natural aggregate concrete. In this study, the resistance of freezing and thawing of concrete using source-concrete recycled aggregate(SRN) and demolished-concrete recycled aggregate(DRA) was investigated. Futhermore a research for improvement of freeze and thaw durability of recycled aggregate concrete was performed. Relative dynamic modulus of elasticity of SRN and DRA recycled aggregate concrete was dropped 60% before 150 of freezing and thawing cycle, and was much lower than that of control concrete. Relative dynamic modulus of elasticity of recycled aggregate concrete was increased to decrease water-cement ratio, but the freeze and thaw durability of recycled aggregate concrete was not enough improved. Futhermore, when metakaolin and silica fume were repalced, the freeze and thaw durability of recycled aggregate concrete containg metakaolin was more improved than that of silica fume.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2001년도 가을 학술발표회 논문집
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• pp.217-220
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• 2001

Due to the tendency of increase in demolished-concrete produced by alteration and deterioration of concrete structures, recycling of those demolished-concrete is necessary to solve the exhaustion of natural aggregate, in order to save resources and protect environment, especially being want of resources in Korea. For this purpose, concrete made with the pozzolanic cement and recycled aggregate was tested for compressive and tensile strength. The pozzolanic cement was a mixture of OPC(Ordinary Portland Cement) and pozzolans such as fly ash, other siliceous materials and early rapid hardening cement(ERC). It was found that the compressive strength of the pozzolanic cement was enhanced when 0.75% of ERC was dozed, as compared with OPC mortar. It was also shown that compressive and tensile strength of concrete with recycled aggregate and pozzolanic cement were higher than those of concrete with crushed stones and OPC. It was concluded that the pozzolanic cement influenced on the increase of concrete strengths with recycled aggregate.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1995년도 가을 학술발표회 논문집
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• pp.256-261
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• 1995

Large-scaling recycling of demolished concrete will concrete will contribute not only to the solution of a growing waste disposal problem, it will also help to consweve natural resoures of sand and gravel and to secure future supply of reasonly priced aggregates for building and other construction purposes within large urban areas. Because recycled aggregate particles consits of substantial amount of relatively soft cement paste component, it is less resistant to mechanical actions. With this view in mind, to obtain a reference data for the development of recycling system and to a basic data the guiedline of recycled aggregate concrete construction and engineering properties of recycled aggregate concrete according to the factors, such as blending ratio of recyced aggregete with the natural aggregate, addition to the factors, such as blending ratio of recycled aggregete with the natural aggregate, addition of flyash, water coment ratio.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2004년도 춘계 학술발표회 제16권1호
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• pp.580-583
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• 2004

Due to the tendency of increase in demolished-concrete produced by alteration and deterioration of concrete structures, recycling of those demolished-concrete is necessary to solve the exhaustion of natural aggregate, in order to save resources and protect environment. In this an experimental study herein, the Chlorine-ion and Carbonation resistance of the recycled aggregate concrete was investigated. Coarse aggregate was replaced with $100\%$ of the recycled aggregate and cement and fine recycled aggregate was replaced with various amount. It was shown that the concrete can obtain resistance of chlorine-ion, when fly ash replaced with up to $30\%$ of cement.

• 콘크리트학회논문집
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• 제14권1호
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• pp.16-23
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• 2002

우리나라의 건설공사 현장에서는 해마다 수백만톤의 콘크리트 폐기물이 배출되고 있다. 이를 효율적으로 재활용할 경우는 환경파괴를 방지할 뿐만 아니라 경제적으로도 큰 효과를 기대할 수 있다. 하지만 기존의 콘크리트 폐기물에 관한 재활용 방법으로는 성토, 잡석다짐, 매립 등의 일부용도에만 사용될 뿐 폭넓게 활용하기에는 한계가 있었다. 따라서 본 연구에서는 골재로 재활용할 수 있는 다양한 종류의 건축폐기물을 환경친화적인 식재용 콘크리트에 이용하여 강도, 내구성 등의 물리적 특성을 검토하였다. 연구결과, 재생골재를 이용한 식재용 콘크리트의 물성은 부순돌에 비하여 압축강도, 동결융해 저항성면에서는 다소 불량하게 나타났지만, 흡수율과 열전도율면에서는 우수한 효과도 입증되었고, 특히 콘크리트 폐기물의 효율적인 재활용 측면을 고려한다면 식재용 콘크리트로의 활용가치는 충분이 있는 것으로 사료된다.