• 한국안전학회지
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• 제11권3호
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• pp.160-167
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• 1996

The construction waste concrete produce from the demolished concrete structures. These waste concrete materials are useful and valuable for fill and subgrade and are considered to use as the subgrade material of the road. To use the subgrade of the road with the waste concrete, the several experiments involved with compaction test and laboratory C. B. R. etc. are performed. These experiments are compared with criteria of the road construction manual. It is shown that the quality of the construction waste concrete satisfies that of the subgrade mentioned in the road construction manual.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2000년도 봄 학술발표회 논문집
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• pp.536-541
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• 2000

In recent years there has been a steady increase in geoenvironmental engineering research where geotechnical engineering has been combined with environmental concerns in the field of construction and industrial waste reusing in civil works. Many of these projects involve some investigation on the characteristics of geotechnical and environmental properties. In this study, investigation and test on the characteristics of demolished waste concrete was carried out to detect the physical, mechanical, and environmental properties for reusing as embankment and backfill materials in civil works.

• 한국도로학회논문집
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• 제7권2호
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• pp.13-22
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• 2005

건설폐기물로부터 선별된 재생골재의 사용은 천연자원이 부족한 현실에 있어 많은 기회를 제공한다. 전 세계적으로 한정된 천연자원은 고갈되어가고 있으며 골재의 장거리 수송은 낮은 가격의 재생골재를 사용하는 것보다 더 비경제적 일 수 있다. 연간 한국에서 대략 7백만톤의 폐콘크리트가 발생하지만 이중 대략 2-3백만 정도만 재활용되고 있는 실정이다. 본 연구는 폐콘크리트로부터 얻어진 재생골재를 이용하는 방법에 대해서 제시하고자 한다. 재생콘크리트는 압축강도, 휨강도, 피로시험을 위해 w/c 40, 50, 60%에 대하여 제작했으며, 혼화재로는 플라이애쉬 (15%)를 사용하였다. 천연골재에 대한 재생골재의 대체율은 0, 25, 50%로 하였다. 이 연구의 목적은 재생골재 콘크리트의 피로수면과 천연골재 콘크리트의 피로수명을 비교하는데 있다. 본 연구를 통해 재생골재 콘크리트의 피로수명은 천연골재에 대한 재생골재의 대체율과 w/c에 상관성이 있음을 알 수 있었다.

• Structural Engineering and Mechanics
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• 제69권1호
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• pp.77-93
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• 2019

Although much research has been carried out using recycled aggregates sourced from normal strength concrete, most of the buildings to be demolished are constructed with low strength concrete. Therefore, the properties of the concrete incorporating recycled aggregates, sourced from the waste of structural elements cast with low strength concrete, were investigated in this study. Four different concrete mixtures were designed incorporating natural and recycled aggregates with and without fly ash. The results of the mechanical and durability tests of the concrete mixtures are presented. Additionally, full-scale one-way reinforced concrete slabs were cast, using these concrete mixtures, and subjected to bending test. The feasibility of using conventional reinforced concrete theory for the slabs made with structural concrete incorporating recycled aggregates was investigated.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1993년도 봄 학술발표회 논문집
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• pp.12-15
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• 1993

Critical shortage of natural aggregate for production of concrete is developing in many urban area. At the same time increasing quantities of demolished concrete form deteriorated and obsolete structures are generated as a waste material in the same areas. The reuse of a waste concrete may settle the problems of environmental pollution and shortage of adquate aggregate, Therefore, this study is to reuse a waste concrete as aggregate for concrete, It is the purpose of this present study to investigate and analyze how the addition rates of superplasticizer and curing condition affect the properties of fresh and hardened recycled aggregate concrete comparing with those of ordinary concrete and crushed stone concrete.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1998년도 가을 학술발표논문집(II)
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• pp.489-494
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• 1998

This paper describes the possibility to reuse concrete waste produced by demolition of reinforced concrete structures as aggregate for concrete from the viewpoint of strength. Concrete rubble obtained from the demolished buildings at Taejon were crushing machine to reuse as coarse aggregate. The strength properties, such as compressive strength, splitting tensile strength, bending strength and shear strength, of recycled and normal concrete were examined and compared experimentally when water cement ratio was varied. From the results of this study, it was thought that in case of non-washed aggregate concrete, strength properties of recycled coarse aggregate is similar to that of normal concrete, In W/C 55%~45%, stress-strain curve of recycled concrete shows more stable than that of normal concrete, while in W/C 35%, it shows brittle behavior.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2001년도 가을 학술발표회 논문집
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• pp.85-88
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• 2001

Utilization of demolished-concrete as recycled aggregate has been researched for the purpose of substituing for insufficient natural aggregate, saving resources and protecting environment. There, however, are some problems that qualities of recycled aggregates are not only largely diverse, but also mechanical properties of recycled aggregate concrete decrease a little in comparison with those of natural aggregate concrete. In this study, the resistance to freezing and thawing of recycled aggregate concrete was highly different due to adhered mortar on recycled aggregate, and durability factor of concrete with NA SRA and DRA was decreased more than that of control concrete. However, durability factor of concrete with AA SRA was larger than that of control concrete.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2012년도 춘계 학술논문 발표대회
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• pp.95-97
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• 2012

Recycled aggregate (RA) produced from demolished concrete waste can bring about several problems on concrete performance, when it is used as aggregate for new concrete. Because RA generally has lower quality than natural aggregate due to the residual cement paste attached on RA and various impurities. It is also very difficult to ensure that the quality of RA remains consistent, because generally RA is produced variously. Thus, in concrete recycling, it is extremely important to estimate the risk of the impurities which could affect performances of recycled aggregate concrete (RAC) focusing on the material flow of concrete waste and its recycling. This study suggests an evaluation result to expect the possibility of impurity mixing in RA production procedure. and suggests a risk evaluation model to expect the changes of RAC performances based on conventional data in Japan.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2009년도 추계 학술논문 발표대회
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• pp.87-91
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• 2009

Recycling demolished concrete as an alternative source of coarse aggregates for the production of new concrete can help solve the growing waste disposal crisis and the problem of depleted natural aggregates. The purpose of this study is to investigate chloride migration of recycled aggregate concrete containing pozzolanic materials by chloride migration coefficient. The specimens were made with recycled coarse aggregate as various replacement ratio(10, 30, 50%) and metakaolin, blast furnace slag, fly ash is replaced for recycled concrete with mixing ratio 20%. The major results are as follows. 1) Compressive strength of recycled aggregate concrete containing pozzolanic materials increase as curing age and chloride migration decrease. 2) When the replacement ratio of recycled coarse aggregate is 30%, the chloride migration coefficient of recycled concrete containing blast furnace slag, metakaolin shows the similar or lower value than plain concrete at all ages.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1998년도 가을 학술발표회 논문집(I)
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• pp.1-6
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• 1998

Recently, as to destruction and renovation of aged building, waste concretes have been reclaimed near foreshore and filled up underground. Recycling demolished concrete as aggregate helps to settle economic and environmental problems of obtaining superior aggregates from natural sources and to dispose waste concretes. An experimental study was carried out to investigate the strength characteristics of no-fine concrete containing recycled aggregates. The cement-aggregate weight ratios of 1: 5, 1: 6, 1: 7 and water-cement ratios of 30, 35, 40, 45% were chosen for the mix design of no-fine concretes. The compressive and splitting tensile strength at 7 and 28 days were measured for 12 different mixes. On the basis of test results, the optimum mix proportion of no-fine concrete containing recycled aggregates was determined and applied to the production of retaining wall block.