• 한국지반신소재학회논문집
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• 제21권4호
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• pp.111-121
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• 2022

베트남에서 대량 발생하는 플라이애시는 누적 매립량이 약 1억톤에 이르고, 약 1억톤 정도이며, 고로슬래그 역시 약 585만톤 정도 발생하는 것으로 보고되고 있다. 이에 따라 최근 베트남에서도 플라이애시 및 고로슬래그를 재활용하기 위해 제도적으로 대응하고 있으나 아직 활발히 현장에 적용되지 못하고 있다. 이에 본 연구에서는 베트남 발생 플라이애시 5종에 대하여 기본 성능분석을 실시하였고, 베트남 발생 고로슬래그와 국내 발생 고로슬래그의 성능을 비교 평가하였다. 플라이애시와 고로슬래 그를 활용하여 지반안정재 압축강도시험, 지반혼합 고화토 일축압축강도 시험을 수행한 결과, 베트남 발생 플라이애시 및 고로슬래그를 지반안정재의 원료로 활용이 가능한 것을 확인하였다.

• 한국재료학회지
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• 제26권5호
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• pp.266-270
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• 2016

Glass-ceramics were developed many years ago and have been applied in many fields such as electronics, chemistry, optics, etc. Much is already known about glass-ceramic technology, but many challenges in glass-ceramic research are still unresolved. Recently, large amounts of slag have steadily increased in the steel industry as by-products. To promote recycling of industrial waste, including steel industry slags, many studies have been performed on the fabrication of basalt-based high-strength glass-ceramics. In this study, we have fabricated such ceramics using various slags to replace high performance cast-basalt, which is currently imported. Glass-ceramic material was prepared in similar chemical compositions with commercial cast-basalt through a pyro process using slags and power plant by-product (Fe-Ni slag, converter slag, dephosphorization slag, Fly ash). The properties of the glass-ceramic material were characterized using DTA, XRD, and FE-SEM; measurements of compressive strength, Vicker's hardness, and abrasion were carefully performed. It is found that the prepared glass-ceramic material showed better performance than that of commercial cast-basalt.

• 한국건설순환자원학회논문집
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• 제10권4호
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• pp.457-464
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• 2022

본 연구에서는 베트남에서 발생하는 4종의 플라이애시에 대하여, XRF, 강열감량, SEM, PSA분석을 실시하였고, 국내 발생 화력발전 플라이애시와 비교하였다. 그 결과 PC보일러 플라이애시의 경우, SiO₂, Al₂O₃, Fe₂O₃의 함량이 약 70 %를 차지하여 국내 플라이애시와 비슷한 화학조성을 갖는 것으로 나타났다. 또한, 베트남 고로슬래그와 국내 고로슬래그를 비교한 결과 유사한 품질기준과 성능을 나타내는 것으로 확인되었다. 베트남에서 수급한 4종의 플라이애시를 이용하여 지반주입재 배합시험을 실시하였으며, 양생 28일 기준 압축강도는 7.60~13.25 MPa로 나타났다. 가장 압축강도가 크게 나타난 Vinh Tan 플라이애시 원료를 선정하여 약액주입공법용 지반주입재 원료로 활용하였다. 약액주입공법의 배합은 급결재로서 규산소다 3호와 실리카졸을 사용하였다. Vinh Tan 플라이애시를 사용한 지반주입재의 겔타임과 호모겔 압축강도를 측정한 결과 국내 건설현장 적용기준을 만족하는 것으로 나타나, Vinh Tan 플라이애시의 경우 약액주입공법용 지반주입재로 활용이 가능할 것으로 사료되었다.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2006년도 제33회 KOSCO SYMPOSIUM 논문집
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• pp.156-159
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• 2006

Gasification and melting method is one of the most potential means for waste treatment process with low emission of fly ash or heavy metal, dioxin and high possibility of using slags as resources. Moisture contents influences directly a gasification characteristics of waste. So it is necessary to investigate the effect of moisture contents in gasification. But it is hard to consider the effect of moisture contents, using samples of powder form of Milligram's order in existing thermogravimetric analyser. Therefore, we made a thermogravimetric analysis device to applicate samples of Gram's order. Gasification characteristics are typically reported with result from thermogravimetric analysis date for wood and RDF samples along with changing moisture contents. It is discussed the way to apply these analysis results to gasification and melting furnace.

• 한국안전학회지
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• 제16권1호
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• pp.65-72
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• 2001

Portland cement concrete is made with coarse aggregate, fine aggregate, portland cement, water and, in some cases, selected chemical admixture such as air-entraining agents, water reducer, superplasticizer, and so on, and mineral admixture such as fly ash, silica fume, slags, etc. Typically, in the concrete, the coarse aggregate and fine aggregate will occupy approximately 80 percent of the total volume of the finished mixture. Therefore, the coarse and fine aggregates affect to the properties of the portland cement concrete. As the deposits of natural sands have slowly been depleted, it has become necessary and economical to produce crushed sand(manufactured fine aggregate). It is reported that crushed sand differs from natural sands in gradation, particle shape and texture, and that the content of micro fines in the crushed sand affect to the quality of the portland cement concrete. Therefore, the purpose of this paper is to investigate the characteristics of fresh and hardened concrete with higher micro fines. This study provides a firm data to apply crushed sand with higher micro fines.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2001년도 가을 학술발표회 논문집
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• pp.73-78
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• 2001

Portland cement concrete is made with coarse aggregate, fine aggregate, portland cement, water and, in some cases, selected chemical admixtures such as air-entraining agents, water reducer, superplasticizer, and so on, and mineral admixtures such as fly ash, silica fume, slags, etc. Typically, in the concrete, the coarse aggregate and fine aggregate will occupy approximately 80 percent of the total volume of the final mix. Therefore, the coarse and fine aggregates affect to the properties of the portland cement concrete. As the natural sands are drained, it is necessary and economical to utilize crushed sands(manufactured fine aggregate). It is reported that crushed sands differ from natural sands in gradation, particle shape and texture, and the micro fines in the crushed sands affect to the quality of the portland cement concrete. Therefore, the purpose of this paper is to investigate the characteristics of fresh and hardened concrete with high content of micro fines. This study provides firm data for the use of crushed sands with higher micro fines.

• Advances in concrete construction
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• 제4권3호
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• pp.221-230
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• 2016

This paper presents a preliminary study on the influence of laterite soil replacing conventional fine aggregates on the strength properties of GGBS-blended-concrete. For this purpose, GGBS-blended-concrete samples with 40% GGBS, 60% Portland cement (PC), and locally available laterite soil was used. Laterite soils at 0, 25, 50 and 75% by weight were used in trails to replace the conventional fine aggregates. A control mix using only PC, river sand, course aggregates and water served as bench mark in comparing the performance of the composite concrete mix. Test blocks including 60 cubes for compression test; 20 cylinders for split tensile test; and 20 beams for flexural strength test were prepared in the laboratory. Results showed decreasing trends in strength parameters with increasing laterite content in GGBS-blended-concrete. 25% and 50% laterite replacement showed convincing strength (with small decrease) after 28 day curing, which is about 87-90% and 72-85% respectively in comparison to that achieved by the control mix.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2004년도 추계 학술발표회 제16권2호
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• pp.735-738
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• 2004

In this study, it was founded to make the optimal mixture for producing concrete which is self-compacting, yet, and generates low heat of hydration by using fly ash, blast furnace slags and limestone powders as binders in addition to cement while using super-plasticizers and viscosity agents as admixture agents. The structural behaviors of the concrete produced with the selected mixture were compared with those of the concrete currently using for construction of nuclear power plants. The study shows that the blended high fluidity concrete including limestone is better in workability and durability than the concrete currently in use for nuclear power plants.

• 한국재료학회지
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• 제27권5호
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• pp.281-288
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• 2017

In this study, Fe-Ni slag, converter slag and dephosphorization slag generated from the steel industry, and fly ash or bottom ash from a power plant, were mixed at an appropriate mixing ratio and melted in a melting furnace in a mass-production process for glass ceramics. Then, glass-ceramic products, having a basalt composition with $SiO_2$, $Al_2O_3$, CaO, MgO, and $Fe_2O_3$ components, were fabricated through casting and heat treatment process. Comparison was made of the samples before and after the modification of the process conditions. Glass-ceramic samples before and after the process modification were similar in chemical composition, but $Al_2O_3$ and $Na_2O$ contents were slightly higher in the samples before the modification. Before and after the process modification, it was confirmed that the sample had a melting temperature below $1250^{\circ}C$, and that pyroxene and diopside are the primary phases of the product. The crystallization temperature in the sample after modification was found to be higher than that in the sample before modification. The activation energy for crystallization was evaluated and found to be 467 kJ/mol for the sample before the process modification, and 337 kJ/mol for the sample after the process modification. The degree of crystallinity was evaluated and found to be 82 % before the process change and 87 % after the process change. Mechanical properties such as compressive strength and bending strength were evaluated and found to be excellent for the sample after process modification. In conclusion, the samples after the process modification were evaluated and found to have superior characteristics compared to those before the modification.