• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2014년도 추계 학술논문 발표대회
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• pp.137-138
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• 2014

The aim of this research is suggesting the method of obtaining well-graded aggregates for concrete replacing the recycled aggregate which size range is from 5 to 13 mm to currently used gap-graded natural aggregates which size range is only 13 to 25 mm. according to the tests results, the workability of concrete was improved with replacing the aggregates of 5 to 13 mm of size range because of compensating gap-grading. Furthermore, there was an improvement in compressive strength when the aggregates of 5 to 13 mm of size range was replaced because obtained well-graded aggregates contributed on increasing adhesiveness and filling internal pore system. Comparing replacing recycled aggregate to natural aggregate, there was no significant difference on the performances.

• 한국건축시공학회지
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• 제8권4호
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• pp.105-114
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• 2008

This study investigates the saturation level of surface dryness, quantity of adhesive mortar, and the alien substance content of recycled aggregates for concrete to develop an adequate quality testing method for understanding the properties of recycled aggregates, which differ greatly from preexisting aggregates. For tests that measure the saturation level of surface dryness, where detail methods are applied differently according to the tester, various testing methods from across world were compared and analyzed. This study revealed that when measuring the saturation level of surface dryness of a certain sample, aggregates must be supplemented immediately whenever the height of the sample becomes lower than the measuring mold, and allowing the tamper to free fall on the sample will provide the most accurate results. When measuring the quantity of adhesive mortar of recycled aggregates for concrete, an acid solution was used, and since the quantity of adhesive mortar increases as the particle sizes gets smaller, the sample for testing should represent the entire granularity. Sulfuric acid solution is adequate for immersion, and the concentration should be 20% for best results. According to the alien substance content measurement, which was examined by the naked eye, the error range caused by the difference in particle size was neglectable, and therefore the sample should be $2.5{\sim}5.0mm$ in size concerning the accuracy and measuring time. Also, for coarse recycled aggregates, the sample should amount to 1kg for measuring alien substance content by the naked eye, which proves that assortment by the naked eye is the most adequate method for measuring the alien substance content of a recycled aggregate.

• 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.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 춘계 학술발표회 논문집(II)
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• pp.541-544
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• 2006

As the importance of recycled materials is being emphasized more in the Korean construction market, the production Quality has been improved to a significantly high level. Compared to the high quality, however, there are used very limitedly. Among recycled construction materials, recycled aggregates produced through the retreatment of waste concrete are drawing attention because of lack of natural aggregate and heightened consciousness of resource saving and environmental protection and, as a consequence, they are close to natural aggregates in terms of production technology and quality. Despite the high quality and productivity. however, the utilization of recycled aggregates is very low.

• 콘크리트학회논문집
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• 제24권2호
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• pp.157-164
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• 2012

이 연구에서는 순환 굵은골재를 사용한 철근콘크리트 보의 전단성능을 평가하였다. 순환 굵은골재의 치환율(0%, 50%, 100%)과 전단보강근의 유 무를 변수로 하여 총 6체의 실험체를 제작하였다. 실험체는 단순지지 형태로 4점 가력을 받도록 계획하였다. 천연 및 순환 굵은골재를 사용한 실험체의 거동을 예측하기 위하여 유한요소해석을 수행하였다. 유한요소해석은 수정 압축장 이론(MCFT)을 확장한 응력교란구역 모델(DSFM)에 바탕을 둔 2차원 비선형 유한요소해석 프로그램을 이용하여 수행하였다. 실험 결과, 순환 굵은골재 50%와 100%를 사용한 실험체와 천연골재를 사용한 실험체의 전단거동이 치환율과 전단보강근의 유무에 관계없이 서로 유사함을 알 수 있었다. 또한, 실험 결과와 해석 결과의 비교로부터 이 연구에서 제안된 수치해석 기법과 해석모델 DSFM이 순환 굵은골재를 사용한 철근콘크리트 보의 거동을 잘 예측할 수 있음을 확인할 수 있었다.

• 한국지반환경공학회 논문집
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• 제11권6호
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• pp.47-55
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• 2010

화강풍화토와 상용화된 순환잔골재를 활용하여 정해진 혼합비율별로 제작한 혼합토에 대하여 물성 특성, 다짐특성 및 전단특성을 위한 시험을 행하였으며, 시험결과를 분석하여 다음과 같은 결론을 얻었다. A다짐시험 결과 화강풍화토에 비해 순환잔골재는 다짐효과가 낮은 것으로 나타났으나 화강풍화토와 순환잔골재를 혼합한 혼합토의 경우에는 화강풍화토보다도 다짐효과가 높게 나타났으며, 화강풍화토와 순환잔골재의 혼합비율을 중량비 70:30으로 한 경우 최대의 다짐효과를 얻을 수 있었다. 직접전단강도시험 결과 점착력은 모든 함수비에서 화강풍화토의 혼합비율이 커질수록 증가하는 경향이 나타났다. 화강풍화토는 최적함수비 근처에서 최대점착력을 보인 반면 혼합토는 전반적으로 최적함수비의 습윤측에서 상대적으로 점착력이 크게 나타났는데, 이러한 경향은 순환잔골재에 잔류하고 있는 시멘트 성분의 영향으로 판단된다. 내부마찰각은 화강풍화토에서 최적함수비 근처에서 최대로 나타난 반면, 순환잔골재 및 혼합토에서는 건조측에서 오히려 크게 나타나는 경향을 보이고 있다. 또한, 순환잔골재의 혼합비율이 높아질수록 내부마찰각은 증가하는 것으로 나타났다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1998년도 가을 학술발표논문집(II)
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• pp.392-397
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• 1998

In this paper, the properties of cement mortar used recycled aggregate are analyzed and compared with river and crushed sand mortar. Recycled aggregates are made by crushing wasted concrete had various compressive strength, and test items are the properties of fresh mortar, hardened mortar and durability. According to the experimental results, flow, unitweight, strength and durability of cement mortar used recycled aggregates decrease compared with those of river and crushed sand mortar.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2001년도 봄 학술발표회 논문집
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• pp.221-224
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• 2001

In this paper, the properties of concrete using recycled fine aggregate are anlyzed. Five different contents. 0%, 40%, 60%, 80% and 100% of recycled concrete were used for this study. At curing 280days, compressive strength, dry-shrinkage, static modulus of elasticity and poission's ratio have been tested according to replacement ratio of recycled fine aggregates.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2002년도 봄 학술발표회 논문집
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• pp.625-630
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• 2002

The availability of natural aggregates has decreased in recent years due to depleting reserves. From the viewpoint of energy and resources saving, it may be advantageous to use the waste concrete as construction aggregates. The purpose of this study is to analyze petrographic and chemical properties of recycled aggregate, and to investigate the resistance of concrete to rapid freezing and thawing by using replacement ratios (0, 10, 20, 30, 40, 50, 60, 70, 100% ) of recycled aggregate.

• 한국농공학회논문집
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• 제56권4호
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• pp.21-28
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• 2014

In this study, evaluated ware the strength and durability of the vegetated water purification channel concrete to which recycled aggregates, hawang-toh and jute were applied. Box-Behnken method of response surface analysis in statistics was applied to the experimental design. Experimental variables are as follows, recycled coarse aggregates, hawang-toh, blast-furnace slag and jute fiber. In the experiment, conducted were the tests of compressive strength, chloride ion penetration, abrasion resistance and impact resistance the replacement rate effects of the recycled aggregates, blast-furnace slag and hwang-toh on the performance of vegetated water purification channel concrete were analyzed by using the response surface analysis method on the basis of the experimental results. In addition, an optimum mixing ratio of vegetated water purification channel concrete was determined by using the experimental results. The optimum mixing ratio was determined to be in 10.0% recycled coarse aggregates, 60.0% blast-furnace slag, 10.1% hwang-toh and 0.16% jute fiber. The compressive strength, chloride ion penetration, abrasion rate, and impact number of fracture test results of the optimum mixing ratio were 24.1 MPa, 999 coulombs, 10.30 g/mm3, and 20 number, respectively.