• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2016년도 추계 학술논문 발표대회
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• pp.100-101
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• 2016

The fineness degree of Ordinary Portland Cement (OPC henceforth) usually used in Korea's construction sites, is designated as over 2,800㎠/g. But the higher the fineness, the surface area of hydration reaction on water increases as well, resulting in large early age strength and high-intensity; so the trend is to prefer a high degree of fineness. But from a pore-space filling perspective, fine-particled cement is not always beneficial to intensity. Therefore in this study artificial modifications were given to cement fineness to analyze the effect of various fineness changes on the liquidity, air quantity and intensity of lean mixture cement mortar. As a result, the greater the degree of fineness, the better the cement was, with fine particle+OPC having the most satisfactory results due to consecutive particle distribution.

• 대한건축학회논문집:구조계
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• 제34권5호
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• pp.13-18
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• 2018

In this research, regarding the type three blast furnace slag (BS) regulated by KS F 2563 and supplied to actual ready mixed concrete plant, the fineness on specification and actually measured fineness by Blain test were compared, and by applying the hydrometer method used for early prediction of concrete strength, the feasibility of the hydrometer method for acquisition inspection of BS was analyzed. Additionally, the influence of various fineness of BS on properties of cement mortar was also assessed. According to the experimental results of this research, correlation of fineness values between specification and actually measured data were not matched. In the case of the rapid evaluation method using hydrometer, a good relation was shown between the fineness data obtained from hydrometer and Blain test. furthermore, from the cement mortar properties test, there was a good relation was obtained between fineness data from rapid evaluation method by hydrometer and cement mortar properties, while there was no clear relation between fineness data from specification and cement mortar properties. Hence, as a qulity controlling method of BS fineness, a rapid evaluation method using hydrometer is suggested as a new method.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2017년도 춘계 학술논문 발표대회
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• pp.169-170
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• 2017

Recently in the construction industry there has been an increasing use of increasing replacement of cement with blast furnace slag cement(BS), an industrial by-product, to reduce environment load and production costs, and other increasing uses of BS cement. However in the case of BS being delivered in RMC factories, only score reports submitted when the are delivered are relied upon and ways to test the quality of fineness is inadequate. Therefore this study gave many changes to various cements and BS fineness to test the variations of BS as a cement, then used the correlation between this and the density value in the Hydrometer method to test the possibility for rapid appraisal of quality fineness of BS cement. Results showed that if the one fifth graph of the density and fineness correlation were to be used, a rapid appraisal of BS cement fineness quality would be possible.

• 한국건축시공학회지
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• 제18권5호
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• pp.429-437
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• 2018

본 연구에서는 실제 레미콘 공장에 납품되는 OPC 20회분의 시료를 채취하여 성적서상 분말도와 실측 분말도 간의 상관성을 분석하고, 아울러 종전에 연구된 액체밀도계법 밀도 값과 OPC 분말도간의 상관성을 분석하므로서 시멘트 분말도 신속 추정 가능성을 평가 하고자 하였다. 또한 납품된 시멘트 시료를 이용하여 시멘트 모르타르 상태에서 유동성, 공기량, 강도 등 제반 기초적 특성과 성적서 및 실측 분말도와의 상관성을 분석하고자 하였다. 실험결과 성적서상 OPC 분말도와 실측 분말도는 매우 낮은 상관성을 나타내었다. 또한, 액체밀도계 밀도 값과 OPC 분말도간의 상관성은 성적서상 분말도는 매우 낮은 상관성을 나타낸 반면, 실측 분말도는 매우 높은 상관성을 나타내었다. 이때 액체밀도계 3분밀도 값과 OPC 분말도가 가장 높은 상관성을 나타내었는데, 그 회귀식을 활용할 경우 액체밀도계를 사용한 OPC 분말도의 신속 품질 평가가 가능할 것으로 판단되었다. 또한, OPC 분말도와 모르타르 특성치의 상관관계로서 성적서상 분말도의 경우는 상관성이 거의 없는 반면 OPC 분말도가 클수록 유동성, 공기량, 응결시간 및 강도치는 모두 높은 상관성이 나타남을 확인할 수 있었다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2023년도 봄 학술논문 발표대회
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• pp.105-106
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• 2023

Using the limestone powder as material that can alternate the clinker, it seems to get positive effect as filler and enhance workability of cement, but the amount of replacement can affect compressive strength of cement. This study was evaluated the effect of limestone mixed cement fineness and SO₃ content on cement mortar. As a result of measuring the compressive strength, it showed 93% compared to the compressive strength of Plain 28 days at fineness 4,400 and SO₃ 2.6%. It is judged that additional research is necessary to express the strength equivalent to that of Plain.

• 한국건축시공학회지
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• 제11권4호
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• pp.363-370
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• 2011

본 연구에서는 화력발전소에서 발생하는 폐기물인 리젝트 애시를 자원화하기 위하여 시멘트 혼합재로 사용하는 방안을 검토하고자 하였다. 이를 위하여 포졸란 활성도 비교를 통하여 효율적인 리젝트애시의 분말도를 선정하였으며, 현재 널리 사용되고 있는 콘크리트용 혼합재인 플라이애시와 비교하였다. 고분말 리젝트애시와 플라이애시를 슬래그시멘트와 혼합하여 시멘트복합체를 제조하였으며, 제조한 시멘트복합체 및 고분말 리젝트애시의 성능 평가를 위하여 페이스트(응결, 유동성, 기기분석), 모르타르(압축강도) 실험을 실시하였다. 기기분석 결과 고분말 리젝트애시의 수화반응기구는 플라이애시와 유사하지만 미세조직이 치밀해지는 특성을 나타내었다. 물성 측정결과에서는 고분말 리젝트애시가 플라이애시와 비교하여 응결지연이 감소하고, 초기강도 및 장기강도에서 우수한 성능을 나타내었다. 따라서 리젝트애시의 분말도를 $6,000cm^2$/g 수준으로 상향시킨다면 시멘트 복합체에 활용하는 것이 가능하며, 시멘트 물성 향상에도 기여할 수 있을 것으로 예상된다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2018년도 춘계 학술논문 발표대회
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• pp.197-198
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• 2018

As part of the effort to shorten the construction period, this study examined the strength expression characteristics at the early age of concrete using high fineness cement and blast furnace slag. accordingly to provide a basic data on how to solve the problem that the initial strength is lowered.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2003년도 봄 학술발표회 논문집
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• pp.1097-1100
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• 2003

This paper describes the sulfate resistance of cement pastes and mortar with or without ground granulated blast furnace slag (GGBS). Sulfate attack was performed on the cement pastes and mortar, which had been prepared by using a water-binder ratio of 0.45. Variables were the fineness levels of GGBS and the concentrations of two sulfate solution. In this present study, compressive strength and length change were carried out to evaluate the sulfate resistance of GGBS with various fineness levels. From the test results, it can be concluded that the deterioration modes of cement matrix with GGBS were dependent on the exposure solutions. Moreover, the influence of fineness levels of GGBS on the sulfate resistance was somewhat little because of a relative short exposure period.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2010년도 춘계 학술대회 제22권1호
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• pp.359-360
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• 2010

본 연구는 슬래그시멘트의 분말도에 따른 모르타르 및 콘크리트의 물리 역학적 특성을 분석하였으며, 연구결과 분말도가 증가함에 따라 모르타르 및 콘크리트의 강도특성은 개선되는 것으로 나타났고, 초기강도 및 28일강도 개선에 효과적인 슬래그시멘트의 적정 분말도는 $5,000cm^2/g$인 것으로 나타났다.

• Journal of Ceramic Processing Research
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• 제19권5호
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• pp.428-433
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• 2018

In this study, using the pilot plant activation system, the activated cement has been manufactured and then applied to the manufacturing process of mineral hydrate insulating material. The fineness of the activated cement is controlled at $5,000cm^2/g$ and $7,500cm^2/g$ and the features of mineral hydrate insulating material, using OPC and the activated cement for each degree of fineness, has been analyzed. As the result of analyzing the crystal habit of the manufactured mineral hydrate insulting material, it is analyzed that the main crystal phase of specimen is tobermorite and some quartz peak has been detected. As the degree of fineness of the activated cement increases, the height of bubble of slurry increases as well, whereas the tendency for the density character to decrease has been detected. Along with it, as the density character decreases, the compression strength has decreases, whereas the tendency for the thermal characteristic to increases has been detected. The main features of mineral hydrate insulating material, using the activated cement with the fineness of $7,500cm^2/g$, the compression strength of 0.36 MPa, and the thermal conductivity of $0.044W/m{\cdot}K$, presents the excellent features as insulation.