• Title/Summary/Keyword: blast furnace slag blaine

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A Study on the Improvement of an Early-age Quality of Blast-Furnace Slag Concrete (고로슬래그 콘크리트의 초기 품질 하락 극복을 위한 연구)

  • 반성수;최봉주;유득현;전영환;조현태
    • Proceedings of the Korea Concrete Institute Conference
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    • 2000.10b
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    • pp.1215-1220
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    • 2000
  • Blast-Furnace Slag, a by-product of the iron or steel industry, has potential sa a cementitious material. The addition of a Blast-Furnace Slag generally reduces the heat of hydration and can confer significant improvements in resistance to sulfate attack and alkali-aggregate reaction, as well as increases in ultimate strength. But it also reduces early-age strength. In this study, for the purpose of improvement of early-age quality of Blast-Furnace Slag concrete, we choose blaine fineness of $6, 000~8, 000cm^2/g$ of Blast-Furnace Slag, and investigate the various properties of concrete. As a result, workability and early-age strength of Blast-Furnace Slag concrete were improved according to the increase of blaine fineness of Blast-Furnace Slag.

Basic Properties of Concrete with Ultrafine-Blaine Air Cooling Slag as Admixture (초미분말 서냉 슬래그를 혼화재로 사용한 콘크리트의 기초적 특성)

  • Heo, Jae-Hyuk;Jeong, Sung-Wook;Her, Jae-Won;Lim, Nam-Gi
    • Journal of the Korea Institute of Building Construction
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    • v.9 no.2
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    • pp.77-83
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    • 2009
  • In this study, a test has been carried out to solve the problem with ground granulated blast-furnace slag, low early strength & lack of supply and to find out a way to use as concrete admixture of the ultrafine blaine air cooling slag which is all disposed as the by product of air cooling slag and its test was conducted to the replacement rate of ultrafine blaine air cooling slag & mixing condition of every concrete admixtures by type for the purpose of obtaining later a basic data for practical use of the cement that used ultrafine blaine air cooling slag by conducting comparative analysis. If ultrafine-blaine air cooling slag is used to the concrete following the results, a high efficiency water reducing agent won't be needed much for flow acquisition due to a high increase in flow, and the stripping time of concrete form will be shortened thanks to the acquisition of early strength, And though, it has the problems with long term strength which is similar or a little lower than the 3 types of ground granulated blast-furnace slag, it's still applicable as the substitute materials for 3 types of ground granulated blast-furnace slag at 10, 15% replacement rate of ultrafine-blaine air cooling slag, at which it shows higher activation index than 3 types of ground granulated blast-furnace slag.

Evaluation of the Fundamental Properties of Zero-Cement Mortar Using Blast Furnace Slag From Different Areas (산지 별 고로슬래그 미분말 변화에 따른 무시멘트 순환잔골재 모르타르의 기초적 특성 평가)

  • Zhao, Yang;Lee, Hong-Kyu;Kang, Byoung-Hoi;Jo, Man-Ki;Han, Min-Cheol;Han, Cheon-Goo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2014.05a
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    • pp.210-211
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    • 2014
  • Nowadays, as to reduce the emission volume of CO2, blast furnace slag has been widely used to replacement of cement. Techniques about using industrial by-products has been extensively studied. For the previous study, blast furnace slag has been used with recycled fine aggregates. In thess study, considering about the different properties of blast furnace slag, as the change of blaine and chemical performances of blast furnace slag, the results of flowability and compressive strength has been analysed.

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Improvement of Early Strength of Blast-Furnace Slag Blended Cement at Low Temperature (고로 슬래그 시멘트의 저온 조기 강도 증진)

  • 장복기;임용무;김윤주
    • Journal of the Korean Ceramic Society
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    • v.36 no.2
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    • pp.130-135
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    • 1999
  • The enhanced slag fineness and the batch water of low water-to-cement ratio(W/C) were employed in order to improve the early strength of blast-furnace slag blended cement at low temperature. A grinding aid was used to grind the blast-furnace slag into the fineness of 6,280$\textrm{cm}^2$/g (Blaine), and this fine slag was then homogeneously mixed with the ordinary Portland cement to produce the blast-furnace slag blended cement containing 40% slag by weight composition. On the other hand, the batch water could be reduced from W/C=0.50 (KS L 5105) to W/C=0.33 through a commercial, naphthalene type superplasticizer. Through the method mentioned above, the early strength of the blast-furnace slag blended cement at low temperature could be enhanced even somewhat higher than the Portland cement strength. And the microsturcture of the cement was studied by both the pore structure analysis and the A.C. impedance measurement.

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The Characteristics of Blastfurnace Slag Blended Cement with Low Blaine Slag Powder (저 분말도 슬래그를 사용한 슬래그 시멘트의 특성)

  • 변승호;최현국;김재영;송종택
    • Proceedings of the Korea Concrete Institute Conference
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    • 1998.10c
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    • pp.19-24
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    • 1998
  • In this study, blended cement with low blaine(2000, 3000$\textrm{cm}^2$/g) blast-furnace slag power by 10-70wt.% was investigated through the measurement hydration heat, physical properties. The experiment results indicated compressive strength was decreased as low blaine slag blended, but hydration heat was reduced significantly and flow of the cement paste was increased.

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Properties of Fresh Concrete admixed with Blast-Furnace Slag Powder with variations of Blaine and Content (분말도 및 치환율 변화에 따른 고로슬래그 미분말 혼입 콘크리트의 초기물성)

  • 최진만;김형래;임정수;김상규;이도현;변승호;윤철현;최현국
    • Proceedings of the Korea Concrete Institute Conference
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    • 1999.10a
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    • pp.297-300
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    • 1999
  • This study was carried out to present the properties of fresh concrete made with ground granulated blast-furnace slag (BFS) powder with variations of blaine and content, and to estimate the utilization of the BFS concrete as admixtural materials for concrete structures of the building. According to the results, the fluidity of concrete which BFS dosage rate was 45% had the considerable difference from that of concrete which BFS dosage rate was not bigger than 35%. Also, the diminution of bleeding was appeared with the increase of blaine and content of BFS. It is concluded that BFS concrete of low blaine can be used effectively in concrete structures of the building.

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A Study on the Determinational Method of Slag Admixture Replacement Ratio in Fresh Concrete with Blast-Furnace Slag Powder (고로슬래그미분말을 첨가한 콘크리트의 슬래그 정량분석에 대한 연구)

  • 박유신;김승진;홍종성;김대영;김장수
    • Proceedings of the Korea Concrete Institute Conference
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    • 2000.10b
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    • pp.951-956
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    • 2000
  • Blast furnace slag powder(BFS) is potential hydration material, and that usage is increased the construction. But, the amount of BFS is important factor with the properties of concrete. The determinational method of slag powder experiments by salicylic acid-methyl alcohol solution method. From these results we can determine the amount of slag powder with blaine 4, 000 and 6, 000 in fresh concrete.

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Effect of blast-furnace slag particle fineness changes on the engineering characteristics of mortar (고로슬래그 미분말의 분말도 변화가 모르타르의 공학적 특성에 미치는 영향)

  • Lee, Jae-Jin;Moon, Byeong-Ryong;Park, Yong-Jun;Joo, Eun-Hui;Han, Min-Cheol;Han, Cheon-Goo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2016.10a
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    • pp.102-103
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    • 2016
  • Recently on construction sites, there is increased use of concrete with large quantities of blast-furnace slag(BS) admixture replacements, for purposes of reducing CO2 created from cement, one of the ingredients of concrete. But such high-BS fineness changes can have a huge effect on the quality of mortar and concrete. Therefore in this study an experiment was conducted in which liquidity and intensity of mortar depending on an artificially-applied change in fineness degree at degree 7. The results, though subtle, were that the larger the fineness degree, liquidity increased and air quantity decreased, and compression and flexural strength increased.

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Analysis of a possible rapid assessment of blast-furnace slag fine particles with a liquid densimeter (액체밀도계에 의한 고로슬래그 미분말의 분말도 신속평가 가능성 분석)

  • Lee, Jae-Jin;Kim, Min-Sang;Baek, Cheol;Joo, Eun-Hui;Han, Min-Cheol;Han, Cheon-Goo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2016.10a
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    • pp.54-55
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    • 2016
  • Recently in the construction industry, industrial by-product admixtures like blast-furnace slag fine particles (BS henceforth) are being used as binding material, reducing the use of cement, and measures to reduce CO2 emissions are being examined on various levels. However, the BS being used domestically varies depending on the origin of resources, and by circulating BS that is inappropriate to the KS standard, problems are occurring in terms of changes and declines in the quality of concrete which uses it. Therefore in this study the liquid densimeter principle was used to assess various BS fineness qualities; with 100 g/L fixed, a 1,000cc mass cylinder was most appropriate for assessing the quality of cement fineness.

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Effect of Blast-Furnace Slag Powder on the Mechanical Properties of Hardened Concrete (고로슬래그 미분말을 사용한 콘크리트의 역학적 특성에 관한 연구)

  • 김형래;최진만;임정수;김상규;변승호;윤철현;최현국
    • Proceedings of the Korea Concrete Institute Conference
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    • 1999.10a
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    • pp.207-210
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    • 1999
  • This experimental study was carried out to estimate the effects of mixing dosage rate and blaine on the mechanical properties of concrete admixed with ground granulated blast-furnace slag (BFS) powder. According to the test results, compressive strength of concrete admixed with slag not more than 35% was at least 80% of compressive strength of OPC concrete at 3 days age, and much bigger than that of OPC concrete at 28 days age. Consequently, in order to apply the BFS to the concrete is demanded, and rigorous construction management should be followed.

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