• Journal of the Korean Ceramic Society
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• v.38 no.8
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• pp.716-723
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• 2001

시멘트 모르터의 소성수축에 의한 균열을 방지하기 위해 소성수축 특성에 관한 연구를 수행하였다. 우리나라 봄철의 대표적인 기후인 온도 20$\pm$3$^{\circ}C$, 상대습도 55%, 풍속 3.5m/s의 기후조건으로 하였으며, 모르터의 물 시멘트 비, 시멘트 골재 비, 팽창재 사용, 플라이 애쉬 치환, 수분증발을 억제하기 위한 중점제 등을 사용하여 소성수축의 특성을 검토하였다. 연구 결과 소성수축 변형은 응결시간과 밀접한 관계가 있으며 응결시간이 빠를수록 변형은 크게 나타났다. 또한 물시멘트 비에 의해서도 소성수축 변형은 큰 것으로 나타났다. 모르터에서의 골재 비율이 작거나, 플라이 애쉬의 치환율이 클수록 소성수축 변형은 매우 크게 나타났다. 중점제의 사용은 소성수축 변형을 줄이는데 효과가 있었으며, 건조수축 보상용 팽창재의 사용은 소성수축 변형율을 크게 하는데 이는 ettringite 생성에 의한 물 시멘트 비의 감소효과를 가져오기 때문이다.

• Cement
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• s.48
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• pp.62-65
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• 1972

• Journal of the Korean Recycled Construction Resources Institute
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• v.10 no.3
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• pp.211-218
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• 2022

Coal ash is being considered as a source of silica and alumina for cement clinker. The purpose of this study was to investigate the effect on cement clinker sintering by confirming the high-temperature microstructural change according to the firing temperature in the cement clinker sintering process of coal ash. In the coal ash used as a raw material for cement clinker, the shape change of the particle surface was confirmed from the sintering tem perature of 950 ℃. The shape of the coal ash disappeared from the sintering temperature higher than 1250 ℃. It was confirmed that the Al and Fe components of the coal ash were converted to the cement interstitial phase at a temperature higher than 1350 ℃. In addition, the clinker using a large amount of coal ash as a raw material showed a low content of Lime and a high content of Belite in the sintering tem perature range of 1150~1200 ℃. From this, it was confirmed that the formation of calcium silicate mineral proceeds more easily at the initial sintering temperature by the application of coal ash.

• Journal of the Korean Recycled Construction Resources Institute
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• v.8 no.4
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• pp.514-519
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• 2020

In this study, cement clinkers were sintered at each temperature by replacing some of the clay components of cement clinkers with coal materials. The mineral phase change of sintered cement clinker was quantitatively analyzed by XRD-Rietveld method. As the sintering temperature of cement clinker increased, the amount of belite decreased, the amount of alite increased, and the amount of free-CaO decreased. The form of alite and belite could be distinguished at sintering temperature of 1450℃ or higher. The crystal size was greatly increased at 1500℃ sintering. It was confirmed that the excessive sintering was progressed. Free-CaO decreased with the increase of sintering temperature. At 1450 ℃ or higher, it was less than 0.5%. In 1450℃ or greater, it is determined that enough sintering is included. Therefore, the application of fly ash as a raw material of cement clinker was judged to be usable as a source of chemical components of alumina and iron raw materials.

• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.1
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• pp.20-25
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• 2021

The cement clinker, the main raw material of cement, is manufactured using limestone as the main material. Depending on the quality of limestone, the use of subsidiary materials changes, and has a great influence on the production of cement clinkers. In this study, the effect of CaO content of limestone, a cement clinker material, on Raw Mill grinding and sintering of cement clinker was investigated. The grinding time of the union materials changed in the content of limestone CaO was measured to identify the grinding properties. The raw material combination was cleaned within a range of 1,350-1,500℃. The sintering performance of cement clinker by Burnability index calculation was identified. The lower the grade of limestone, the lower the grinding quality of the raw material combination. The lower the CaO content of limestone, the greater the variation in F-CaO for sintering temperature. The lower the class of limestone, the higher B. I. value was calculated, indicating the lower cement clinker sintering. In addition, the mineral analysis results of cement clinker showed that if the F-CaO value was low due to the increase in sintering temperature, the Belite content decreased and the Alite content increased. In the case of Alite, the ratio of R-type decreased and that of M-type increased as the content of limestone CaO increased.

• Cement
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• s.90
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• pp.42-45
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• 1983

• Cement
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• s.45
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• pp.32-41
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• 1971

• Cement
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• s.118
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• pp.54-60
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• 1990

• Cement
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• s.47
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• pp.23-30
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• 1972

• Cement
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• s.113
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• pp.23-28
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• 1988