• 한국건설순환자원학회논문집
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• 제11권4호
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• pp.440-448
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• 2023

시멘트 산업의 원료대체 기술의 하나인 혼합재 활용 기술은 다른 기술에 비해 접근성이 상대적으로 좋아 쉽고 빠르게 실적용이 가능할 것으로 기대된다. 시멘트 혼합재 중 석회석 분말은 핵형성효과, 화학적효과, 충전효과를 통해 시멘트 성능을 향상시킬 수 있다고 보고하고 있어 시멘트 혼합재로써 적합성이 기대되는 재료이다. 한편, 전 세계적으로 양질의 석회석이 고갈되면서 점토질 또는 마그네시아(MgO) 함량이 높은 석회석의 사용이 점차 불가피해지는 상황이다. 따라서 본 연구에서는 국내에서 흔히 사용되는 서로 다른 품질의 석회석을 혼합한 석회석 시멘트의 기초 물성을 측정하여 혼합재로서의 적합성을 평가하고자 하였다. 결과적으로 석회석 혼합재 화학성분과 상관없이 알라이트 반응촉진 효과를 확인할 수 있었다. 하지만 화학성분보다 치환량에 따른 희석효과가 크게 나타났다. 본 연구범위 내에서 석회석의 함량이 15 % 이내의 범위에서 중품위의 석회석도 혼합재로 사용할 수 있을 것으로 판단된다. 추후 시멘트 화학성분에 따른 추가적인 실험을 통하여 석회석 혼합재의 화학성분이 미치는 영향을 평가할 예정이다,

• 콘크리트학회논문집
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• 제12권3호
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• pp.87-94
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• 2000

Disposal of casting foundry fly ash generally depends on reclamation up to the present. This is the great loss from a standpoint of saving resources and utilizing industrial wastes. Therefore, a study on the reuse of fly ash as a substitute material for construction is necessary in order to utilize industrial wastes, to reduce cost and improve quality in producing concrete products, and to protect environment from pollution. In this study, methods for the reuse of the casting foundry fly ash, industrial wastes products, as an admixture for concrete are discussed. For this purpose, fly ash was extracted from casting foundry and tests of physical and chemical properties are executed. Also, various characteristics of concrete using fly ash as an admixture are experimented. Finally, the reuse methods for casting foundry fly ash are presented.

• 대한건축학회연합논문집
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• 제21권5호
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• pp.117-124
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• 2019

When manufacturing concrete, several mineral admixture is added to improve the basic physical property and durability and to make economical concrete. Such mineral admixture includes fly ash, granulated blast furnace slag, silica fume, etc., and not only the studies about mixing these mineral admixtures but also the studies for the development of new materials have been steadily in progress. Recently, some researchers have found, as a part of the development of new materials, the rice straw ash can also be used as a pozzolanic material for concrete considering similar chemical properties of rice straw ash to that of rice husk ash. But there has been insufficient amount of study about it. So, this study was to investigate the possibility as mineral admixture of agriculture by-product, by analyzing properties of concretes using rice straw ash with replacement ratio in comparison with other mineral admixture. In order to measure amount of SiO2 of rice straw ash, XRF(X-ray fluorescence) analysis was tested. For the measure pozzolanic reaction of rice straw ash, pH change and color change was tested according to curing day. Also to evaluate properties of concrete using rice straw ash, slump test, air contents test and compressive strength was tested.

• 콘크리트학회지
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• 제9권1호
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• pp.153-163
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• 1997

본 논문은 규사 분말을 치환한 모르터의 내화학성에 관한 실험적 연구이다. 모르터 시험체에 대하여 모르터의 내화학성능 개선용 혼화재로서 규사 분말의 활용성 및 콘크리트 시험체의 내화학적 특성에 관한 예측 모델로서의 모르터 모델의사용 가능성 등을 검토하였다. 그결과 다음과 같은 결론을 얻을 수 있었다. 모르터 모델의 콘크리트 내화학성 예측 모델로서 사용 가능성 검토 결과, 혼화재의 종류 및 치환량에 따른 내화학성 실험 결과가 콘크리트의 실험 결과와 유사하게 나타나므로 콘크리트 시험체의 내화학성 예측 모델로서 활용이 가능하리라 사료된다.

• 한국구조물진단유지관리공학회 논문집
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• 제18권1호
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• pp.75-83
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• 2014

콘크리트의 취성파괴를 방지하기 위해 강섬유 보강재는 효과적인 복합재료이다. 그러나 시멘트 사용량이 많아지면 건조수축이 증가하고 이로 인해, 강섬유 보강재의 연성증가 효과가 제한될 수 있다. 팽창재를 사용한 콘크리트 내부의 강섬유 보강재는 화학적 프리스트레싱 효과가 발생하여 강섬유 보강효과를 증가시킬 수 있다. 본 연구에서는 CSA 팽창재와 강섬유 보강재를 혼입하여 콘크리트의 역학적인 특성을 분석하였다. 체적비 1~2%의 강섬유 보강재와 시멘트 중량의 10%의 CSA 팽창재를 혼입하였으며, 다양한 역학적 특성과 휨거동을 분석하였다. 강섬유 보강재를 혼입한 CSA 콘크리트는 인장강도와 초기균열강도의 증가를 나타냈으며, 균열후의 파괴에너지 증가와 같은 연성거동을 뚜렷하게 나타내었다. 적절한 팽창재 사용과 최적의 강섬유 보강재의 혼입률이 도출된다면 이들의 상호작용은 콘크리트의 취성을 더욱 효과적으로 제어할 수 있다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2009년도 춘계 학술대회 제21권1호
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• pp.415-416
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• 2009

Concrete with Self-healing Admixture provides waterproof protection by using a organic-inorganic chemical compound throughout the concrete. Using cement chemicals eliminate the need to use additional waterproofing, If crack is occurred, this system enhance self-healing ability to increase the structural safety. In this study, we investigate material properties to conclude mixture rate of concrete to apply a construction site.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2004년도 추계 학술발표회 제16권2호
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• pp.505-508
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• 2004

This paper investigated the setting and compressive strength of concrete with the combination of mineral and chemical admixture. According to test results, plain concrete with high early strength development type AE water reducing agent(HEAEWRA) and $10\%$ of CKD respectively had earlier setting time than concrete with AE water reducing agent by $0.5\~1.5$ hours. Setting time of concrete with retarding type AE water reducing agent(RAEWRA) and FA $30\%$, BS $60\%$ respectively retarded by as much as $4\~7.5$ hours compared with plain concrete. Plain concrete with HEA WRA, $10\%$ of CKD and RAEWRA had higher strength than that of AE water reducing agent by as much as 5MPa at 28days. From the result of the paper, it is found that the combination of mineral admixture and setting accelerating or retarding agent can reduce the hydration heat cracks by setting time difference and hydration heat reduction effects.

• 콘크리트학회논문집
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• 제12권3호
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• pp.11-19
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• 2000

It has been reported that few manufacturers of cement mortar for precast products use chemical and mineral admixture due to the absense of restrictions related to the application of admixture and the poor manufacturing facilities. Therefore, this paper is intended to contribute to the improvement of quality by investigating the properties of cement mortar for precast products using fly ash, blast furnace slag and AE water reducing agent. According to the test results. it was found that the cement mortar products using fly ash and AE water-reducing agent had better qualities than those of ordinary portland cement.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2017년도 춘계 학술논문 발표대회
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• pp.222-223
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• 2017

In the automotive industry, such as scrap metal and plastic scrap process is being recycled. Although the glass beads are used as road paving or other additives and processing crushing, recycling is known that there are limits. The utilization of waste glass was evaluated as a concrete admixture by using powder characteristics and chemical composition of the glass. As a result of using waste-glass powder as an admixture, it is difficult to expect the pozzolanic effect, but it is found that it can increase the fluidity of concrete and ensure the durability performance in the appropriate amount range.

• 한국건축시공학회지
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• 제3권3호
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• pp.73-81
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• 2003

In this paper, salt damage resistance of high durable concrete was tested. High durable concrete was made by using low water cement ratio, chemical admixture called super-durable admixture and mineral admixtures such as fly-ash, ground granulated blast-furnace slag, silica fume. Two kinds of salt damage resistance test were carried out. One method is chloride ion penetration test(ASTM C1202), and the other one is depth of chloride penetration test in saline solution. Test results were as followers: 1) The depth of chloride ion penetration increased exponentially as water cement ratio was increased and time passed. 2) Super-durable admixture had little effect on the improvement of salt damage resistance of concrete. 3) Silica fume and ground granulated blast-furnace slag were effective on salt damage resistance because of pozzolanic reaction, but fly-ash had a little effect.