• Title/Summary/Keyword: 저분말도

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Durability Characteristics in Concrete with Ternary Blended Concrete and Low Fineness GGBFS (삼성분계 콘크리트와 저분말도 슬래그를 혼입한 콘크리트의 내구 특성)

  • Kim, Tae-Hoon;Jang, Seung-Yup;Kwon, Seung-Jun
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.7 no.4
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    • pp.287-294
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    • 2019
  • GGBFS(Ground Granulated Blast Furnace Slag) has been widely used in concrete for its excellent resistance chloride and chemical attack, however cracks due to hydration heat and dry shrinkage are reported. In many International Standards, GGBFS with low fineness of 3,000 grade is classified for wide commercialization and crack control. In this paper, the mechanical and durability performance of concrete were investigated through two mix proportions; One (BS) has 50% of w/b(water to binder) ratio and 60% replacement ratio with low-fineness GGBFS, and the other (TS) has 50% of w/b and 60% replacement ratio with 4000 grade and FA (Fly Ash). The strength difference between TS and BS concrete was not great from 3 day to 91 day of age, and BS showed excellent performance for chloride diffusion and carbonation resistance. Two mixtures also indicate a high durability index (more than 90.0) for freezing-thawing since they contain sufficient air content. Through improvement of strength in low fineness GGBFS concrete at early age, mass concrete with low hydration heat and high durability can be manufactured.

Properties of Fresh State and Characteristics of Shrinkage in Concrete Containing Low Fineness GGBFS (저분말도 고로슬래그 미분말을 혼입한 콘크리트의 굳지 않은 상태의 특성 및 수축 특성)

  • Kim, Tae-Hoon;Yoon, Yong-Sik;Kwon, Seung-Jun
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.8 no.1
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    • pp.1-7
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    • 2020
  • GGBFS(Ground Granulated Blast Furnace Slag) is one of the most actively used mineral admixtures with excellent long-aged strength and chloride diffusion resistance. Unlike Standard covering GGBFS in Japan and the U.K., the domestic standard for GGBFS does not contain low fineness of GGBFS under 4000 grade. In this paper, several basic tests are carried out for the concrete with 3,000 grade GGBFS concrete and ternary blended concrete for reducing hydration heat by mixing 4,000 grade GGBFS and fly ash, such as fresh concrete properties, compressive strength, and shrinkage properties. The air content and slump between the ternary blended concrete and the concrete with low-fineness GGBFS showed the similar level, and the results of difference in setting time from them were less than 20 minutes, showing no significant difference. In the evaluation of compressive strength and shrinkage characteristics, the ternary blended concrete showed lower long-aged strength and higher shrinkage than the low-fineness GGBFS concrete.

The research about properties of modified low heat slag cement (개질 처리된 저발열 슬래그시멘트 특성에 관한 연구)

  • Kim, Hong-Joo;Kim, Won-Ki;Kim, Hoon-Sang;Lee, Won-Jun;Shin, Jin-Ho
    • Proceedings of the Korea Concrete Institute Conference
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    • 2008.04a
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    • pp.677-680
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    • 2008
  • The surface of particles was energetically modified by inter-grinding OPC and BFS in vibration mill for improvement of the early strength and low-heat evolution of concretes. BFS was pre-grinding in ball-mill to 2535(BS2) and 3245 $cm^2/g$(BS3), in blaine surface area. The inter-grinding time in vibration mill was changed from 10 minutes to 30 minutes. And Mixing ration of BFS to OPC was changed in 60, 70, 80%. After inter-grinding, the change of specific surface area, particle size distribution, hydration heat of cement and compressive strength of mortar were measured. As the result of comparison test with LHC, it was found that the mixture and inter-grinding time satisfying the value of over 100% of compressive strength for 7 days and under 170J/g of heat of hydration for 72 hours. and it was confirmed that the possibility of low heat slag cement utilizing blast furnace slag(BS2, BS3) with the low fineness in high volumes.

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Influence of Houttuynia cordata Thnub Powder Mixtures on Plasma Lipid Composition in Pigs (어성초 분말 혼합 식이가 돼지의 혈장 지질성분에 미치는 영향)

  • Kang Min-Jung;Shin Jung-Hye;Seo Jong-Kwon;Choi Sun-Young;Lee Soo-Jung;Sung Nak-Ju
    • The Korean Journal of Food And Nutrition
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    • v.19 no.1
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    • pp.103-109
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    • 2006
  • This study was designed to investigate the influence of Eosungcho (Houttuynia cordata Thunb) mixture on the plasma lipids of pigs. Experimental groups were divided into 3 groups: control group(0%), 5% and 10% Eosungcho feeding groups. Plasma concentration of total cholesterol, atherosclerotic index, free cholesterol and cholesteryl ester were significantly lower in the Eosungcho powder 5% and 10% feeding groups than control group. Plasma contents of HDL-cholesterol, cholesteryl ester ratio, triglyceride and phospholipid were significantly different between 10% Eosungcho feeding group and control group. Plasma concentration of LDL-cholesterol was significantly love in 10% Eosungcho feeding group($76.5{\pm}5.4mg/dL$) than in control group($86.5{\pm}5.6mg/dL$). Plasma concentration of VLDL and chylomicron were showed similar tendency to LDL-cholesterol. Also, blood sugar, GOT and GPT concentration were significantly lower in 10% Eosungcho feeding group than in control group. In control group, the ratio of saturated fatty acid to unsaturated fatty acid was 58.1 : 51.9, but in 5% and 10% Eosungcho feeding groups, those were 42.1 : 57.9 and 41.0 : 59.0, respectively. The component of main fatty acid was different between control group and Eosungcho feeding groups. In Eosungcho feeding groups, main unsaturated fatty acids were oleic acid(18:1) and linoleic acid(18:2). From the results, addition of Eosungcho powder might be effective in improving the plasma lipid components in pigs.