• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1999년도 학회창립 10주년 기념 1999년도 가을 학술발표회 논문집
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• pp.119-122
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• 1999

In this paper, the properties of concrete used recycled aggregate are analyzed. The specimens are manufactured for the compressive strength of 210㎏/㎠ with recycled aggaregate ratio of 0%, 20%, 40%, 60%, 80%, 100%, respectivey. At curing 28days, compressive strength, tensile strength, flexural strength, dry-shrinkage, static modulus of elasticity and poission's ratio have been tested according to replacement ratio of recycled aggregate.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2003년도 봄 학술발표회 논문집
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• pp.675-680
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• 2003

In this study, various tests are performed for the durability of the concrete using domestic recycled coarse aggregate including drying shrinkage, permeability, freezing-thawing resistance and $CO_2$ diffusivity. Tests of freezing-thawing resistance, chloride ion permeability and $CO_2$ diffusivity of recycled concrete show favorable results. But, the maximum drying shrinkage ratio to normal concrete is increased 24% with increasing substitution ratio of recycled aggregate. Therefore, for the use of recycled concrete in structures, the preventive measures of drying shrinkage is necessary in mix design and the adequate substitution ratio of recycled aggregate should be proposed.

• 한국구조물진단유지관리공학회 논문집
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• 제13권1호통권53호
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• pp.78-87
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• 2009

본 논문은 제강슬래그를 잔골재 대체재로 콘크리트에 활용할 경우 유리석회의 다량 함유로 인한 팽창성 때문에 콘크리트용 골재로서의 사용이 제한되고 있어 제강슬래그를 급냉시켜 유리석회의 함유량를 크게 낮춘 급냉제강슬래그를 잔골재로 활용한 콘크리트의 특성에 관한 연구이다. 따라서 급냉제강슬래그의 대체율 및 잔골재율을 달리하여 제작한 콘크리트 시험체의 슬럼프로스시험, XRD 및 SEM분석에 따른 수화특성, 재령에 따른 압축강도 시험, 길이변화시험 및 급속염소이온침투시험결 과를 비교 고찰하여 급냉제강슬래그의 적정 대체율 및 잔골재율을 도출하였다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2002년도 가을 학술발표회 논문집
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• pp.243-248
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• 2002

As a notion of environment protection changes throughout the world, construction engineers, as part of the effort to resolve environmental problems, have been actively doing research on environmental friendly porous concrete using large and non-uniform aggregate. Porous Concrete enables water and air to pass through a firmly hardened material and allows required nutrients to reach roots of plants. The purpose of this study is to analyze planting ability when the change of aggregate gradation and void ratio. The results of an experiment from the planting ability of the porous concrete to its influence on the compressive strength are reported in this paper. As a result of the experiment, the compressive strength is higher when the gradation of aggregate is smaller, and it also goes higher when the void ratio gets smaller The planting ability of porous concrete is decided by the germination and the grass length of Indigofera pseudo-tinctoria(IPT). The length of IPT is longer when the gradation of aggregate is greater and the void ratio gets smaller.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2001년도 가을 학술발표회 논문집
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• pp.417-422
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• 2001

The purpose of this study is to investigate experimentally the workability, compressive and flexural strength properties of rapid-set concrete with various mixture. The kinds of fine aggregate(river sand, sea sand, crushed sand), water-cement ratio(40%, 45%, 50%), sand-aggrega to ratio(33%, 36%, 39%) were chosen as the experimental parameters. Test variables are temperature of concrete, slump, air contents, compressive and flexural strength. The compressive and flexural strength for 3 hours and 6 hours were tested. As result, it was shown that temperature of concrete involved 45$^{\circ}C$, some time later decreased. The workability were decreasing in steps as the sand-aggregate ratio increased and crushed sand was the highest value. Higher compressive and flexural strength was shown following the order of river sand, sea sand, crushed sand regardless of sand-aggregate ratio. But the values of gap was just a little.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 봄 학술발표회 논문집
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• pp.53-56
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• 2000

The performance of high-strength concrete is controlled by the fact, affecting the quality management, especially by revision error in water content of the ratio of surface moisture in fine aggregate. The difference in water content results from the revision error of the ratio of surface moisture and errors in sampled aggregate in the processing ready-mixed concrete plant. This study is to investigate the properties of flowing and hardening by investionally varying the revision error of the ratio of surface moisture in fine aggregate to compare and analyze the variance in quality.

• 한국건축시공학회지
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• 제8권4호
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• pp.87-93
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• 2008

With an increased use of alternative aggregate due to exhaustion of quality aggregate resources, the amount of used crushed aggregates have been increased and as a result, development of admixture materials has also been improved and its amount of use is increasing from day to day in order to secure quality in concrete. Accordingly, the purpose of this study is to make concrete of good quality by using chemical admixture developed in this study by replacement rate of fine aggregate. At first, susceptibility, compressive strength ratio and length change ratio in both fresh and hardened concrete were evaluated according to corresponding regulation. As for high performance related regulation, APC NO.3 and PC series were going to rule, and as for AE agent regulation, replacement ratio of fine aggregate of high performance chemical admixture was 10:0 and other chemical admixture met quality regulation for AE agent.

• 한국농공학회지
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• 제37권5호
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• pp.90-100
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• 1995

This study was performed to develop the lightweight concrete using synthetic lightweight aggregate and natural coarse aggregate. Mixing ratios were three types, the first type was mixed cement and synthetic lightweight fine aggregate (Type CP), the second type was mixed cement, synthetic lightweight fine aggregate and synthetic lightweight coarse aggregate (Type CPE), the third type was mixed cement, synthetic lightweight fine aggregate and natural coarse aggregate (Type CPN). The results of this study are summarized as follows ; 1. The W/C of each mixing ratio was increased with increase of the amount of cement used, and it was shown higher in order of Type CP, CPN, CPE. 2. The unit weight of Type CP, CPE and CPN was 1.473~1.647g/cm$^3$, 1.467~1.622g/cm$^3$ and 1.658~1 .838g/cm$^3$, respectively. And the absorption ratio was approximately 20%, which was higher than that of the normal cement concrete. 3. The compressive strength of Type CP was shown 178 ~249kg/cm2, Type CPE was shown 149~241kg/cm$^2$ and Type CPN was shown 196~297kg/cm$^2$, respectively. Each strength ratio was smaller than that of the normal cement concrete. 4. The pulse velocity of Type CP, CPE and CPN was 2, 688~3, 240m/sec, 2, 981~3, 324m/sec and 2, 989 ~ 3, 545m/sec, respectively. And it was increased with increase of strength and unit weight. 5. The length change ratio at 28 days was in the range of 0.057~0.077%, and earlier length change ratio was higher than that of the later.

• 콘크리트학회논문집
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• 제14권4호
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• pp.623-629
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• 2002

최근 환경보존에 대한 인식전환이 범세계적으로 확산되고 있는 가운데 건설기술자들은 환경문제를 해결하기 위한 일환으로 콘크리트에 잔골재를 사용하지 않고 불연속 입도의 굵은 골재를 사용한 환경친화적 건설재료인 다공질콘크리트에 주목하려 다양한 방면에서 연구가 활발히 진행되고 있다. 따라서 본 연구는 환경친화적인 식생용 포러스콘크리트를 제조하기 위한 기초적 연구로서, 골재입도와 페이스트골재비 및 산업부산물의 혼입에 따른 식생용 포러스콘크리트의 물리ㆍ역학적 특성과 식생능력을 평가하였다. 시험결과 골재입도가 감소함에 따라, 페이스트골재비가 증가함에 따라 압축강도는 증가하였으며, 공극률은 점차 감소하였다. 식생능력 평가 결과 씨앗 파종후 30일까지는 골재입도 및 페이스트골재비에 관계없이 동일한 생육양상을 보였으나, 30일 이후에서는 골재입도가 줄어듬에 따라, 페이스트골재비가 증가함에 따라 초장이 감소하였으며, 특히 5~10mm골재를 사용한 경우에는 10~20 mm 20~30mm 입도의 골재를 사용한 경우보다 현저히 초장이 줄어드는 경향이 나타났다.

• 한국건설순환자원학회논문집
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• 제7권1호
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• pp.50-56
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• 2019

본 연구에서는 자원 재활용 가능성을 위해 재활용 제품으로 레드머드와 순환 굵은골재를 사용한 무시멘트 인조석재의 제조와 특성에 대한 분석을 실시하였다. 레드머드의 치환율이 증가함에 따라 무시멘트 경화체의 유동성, 공기량, 흡수율은 감소하는 것으로 나타났으며 밀도와 강도는 증가하는 것으로 보인다. 순환 굵은골재를 사용한 인조석재의 경우, 순환 굵은골재의 치환율이 증가할수록 유동성과 흡수율은 감소하며 공기량과 밀도는 증가하는 것으로 나타났다. 순환 굵은골재의 치환율 60%까지 강도는 증가하지만 이후 치환율이 증가하면서 강도는 저하되는 것으로 보인다. 무시멘트 인조석재의 출석률은 순환 굵은골재 치환율과 비례하여 증가하는 것으로 나타났다.