• Title/Summary/Keyword: air-blast

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An Experimental Study on the Frost Resistance of High-Flowing Concrete Using Granulated Blast-Furnace Slag (고로슬래그 미분말을 사용한 고유동콘크리트의 내동해성에 관한 실험적 연구)

  • 김무한;권영진;강석표
    • Journal of the Korea Concrete Institute
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    • v.12 no.2
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    • pp.43-51
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    • 2000
  • This study is to investigate for the frost resistance of high-flowing concrete using finely ground granulated blast-furnace slag with experimental parameters, such as type of binder, type of superplasticizer and method of curing. The resistance to freezing and thawing of high-flowing concrete by type of binder and superplasticizer is presented differently. Though the frost resistance of high-flowing concrete is satisfactory under standard condition, it is required that high-flowing concrete has entrained air like plain concrete. Because the critical spacing factor, being capacity of frost resistance, of high-flowing concrete is longer that of plain concrete, the frost resistance of high-flowing concrete, using finely ground granulated furnace blast slag, is superior to that of plain concrete.

A Study of Concrete Mix Proportioning Design using Blast-furnace Slag Cement (고로슬래그시멘트를 사용한 콘크리트 배합설계에 관한 연구)

  • 백광섭;차태환;노재호;박연동;윤재환
    • Proceedings of the Korea Concrete Institute Conference
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    • 1995.10a
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    • pp.113-118
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    • 1995
  • The purpose of this study is to suggest concrete mix proportioning design using Blast-furnace slag cement. The mix conditions are specified by concrete strength(180~400kg/$\textrm{cm}^2$), slump$(15\pm2cm)$m and air volume$(4.5\pm1%)$. From the result of concrete mix proportioning design using Blast-furnace slag cement, unit water content can be reduced by 3~8% comparing with OPC. The relationship between strength at 28days and cement water ratio is as follow. when blast-furnace slag cement is used: $\sigma_{28}$=304.OC/W-296.8. Super-plasticizer have to be used to get a slump of 15cm when water/cement ratio is less than 45%.

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Strength Characteristics of Concrete Containing Blast-Funrnace Slag as Coarse Aggregate (고로슬래그를 굵은골재로 이용한 콘크리트의 강도특성)

  • 한상호
    • Journal of the Korea Concrete Institute
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    • v.12 no.5
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    • pp.59-68
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    • 2000
  • A series of experiments were performed to investigate the strength characteristics of concrete which contain air cooled blast-furnace slag as coarse aggregate. The slag is a by product of GISC. The experimental conditions are varied with three different W/C(45%, 50%, 55%) and the weight of water and S/a are constant. The strength properties of the concrete at 7days, 28days, 90days are examined. Also the same strength properties are examined for the normal concrete which contain river gravel and crushed stone respectively as coarse aggregate. As the comparison results of the strength properties, it was found that the compressive strength development of concrete containing blast-furnace slag is better than that of concrete using river gravel at early age, however this is adversely at long-term age, and the tensile and flexural strength of the concrete were not nearly affected by water-cement ratio.

Influence of Replacement Ratio of Wasted Refractory Powder on the Properties of Mortar using Blast Furnace Slag and Recycled Aaggregate (폐내화물 미분말 치환율이 고로슬래그 미분말과 순환골재 사용 모르타르의 품질에 미치는 영향)

  • Song, Yuan-Lou;Baek, Cheol;Kim, Min-Sang;Lee, Jea-Hyeon;Han, Min-Cheol;Han, Cheon-Goo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2016.05a
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    • pp.38-39
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    • 2016
  • In this research, the possibility of wasted refractory powder pulverized from refractory block as an expansive admixture and additional alkaline stimulant for class two and three blast furnace slag cements (BSC) was assessed with its high content of free CaO or free MgO. As the replacement ratios of wasted refractory powder and blast furnace slag were increased, flow and air content were decreased, while unit volume weight was increased under same conditions. Compressive strength of mortar was increased with increased replacement ratio of wasted refractory powder, especially, in the case of class three BSC, the highest compressive strength was obtained when wasted refractory powder was replaced 10 %.

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Influence of Replacement Ratio of Wasted Refractory Aggregate on the Properties of Mortar using Blast Furnace Slag and Recycled Aggregate (폐내화물 골재 치환율이 고로슬래그 미분말과 순환골재 사용 모르타르의 품질에 미치는 영향)

  • Song, Yuan-Lou;Moon, Byeong-Yong;Kim, Min-Sang;Lee, Jea-Hyeon;Han, Min-Cheol;Han, Cheon-Goo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2016.05a
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    • pp.139-140
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    • 2016
  • In this research, the possibility of wasted refractory aggregate pulverized from refractory block as an expansive admixture and additional alkaline stimulant for class two and three blast furnace slag cements (BSC) was assessed with its high content of free CaO or free MgO. As the replacement ratios of wasted refractory powder and blast furnace slag were increased, flow and air content were decreased, while unit volume weight was increased under same conditions. Compressive strength of mortar was increased with increased replacement ratio of wasted refractory powder, especially, in the case of class three BSC, the highest compressive strength was obtained when wasted refractory aggregate was replaced 2%.

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The influence of load pulse shape on pressure-impulse diagrams of one-way RC slabs

  • Wang, Wei;Zhang, Duo;Lu, Fangyun
    • Structural Engineering and Mechanics
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    • v.42 no.3
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    • pp.363-381
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    • 2012
  • This study is aimed at providing an efficient analytical model to obtain pressure- impulse diagram of one-way reinforced concrete slabs subjected to different shapes of air blast loading using single degree of freedom method (SDOF). A tri-linear elastic perfectly plastic SDOF model has been used to obtain the pressure-impulse diagram to correlate the blast pressure and the corresponding concrete flexural damage. In order to capture the response history for the slab, a new approximately SDOF method based on the conventional SDOF method is proposed and validated using published test data. The influences of pulse loading shape on the pressure-impulse diagram are studied. Based on the results, a pressure-impulse diagram generation method using SDOF and an analytical equation for the pressure-impulse diagram is proposed to different damage levels and different blast loading shapes.

Improvement of Early age Concrete Strength Using Blast Furnace Slag Powder (콘크리트의 초기강도 향상을 위한 고로슬래그 미분말의 사용에 관한 실험적 연구)

  • Yoo, Jang-Won;Lee, Ju-Sun;Park, Byung-Kwan;Pei, Chang-Chun;Han, Min-Cheol;Han, Cheon-Goo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2009.05b
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    • pp.77-80
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    • 2009
  • The purpose of the study was to examine engineering characteristics due to fine particle cement and gypsum contents to improve early strength of concrete substituted blast furnace slag powder. The results were as follows. Above all, For fluidity, generally all mixtures had lower fluidity than Plain mixture and was not satisfied target scope, but for mixture substituted the gypsum showed a little increasing trend. For air content, generally all mixtures compared to Plain mixture had decreasing tendency. However, all mixtures were satisfied target scope. For compressive strength, long-term strength was better than early strength according to ternary blast furnace slag contents was increased. For complex mixture was better than individual use of gypsum and fine particle cement.

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Fundamental Properties of High Strength Concrete Containing Blast Furnace Slag Using CBS-Dust as Admixture (CBS-Dust를 혼화재로 사용한 고로슬래그 미분말 함유 고강도 콘크리트의 기초적 특성)

  • Sin, Se-Jun;Han, Soo-Hwan;Lee, Dong-Joo;Kim, Jong;Han, Min-Cheol;Han, Cheon-Goo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2020.06a
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    • pp.62-63
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    • 2020
  • In this study, fundamental properties of high strength concrete containing blast furnace slag are investigated analyzed according to CBS-Dust replacement rate. As the CBS-Dust replacement rate increased, air content, fluidity and strength decreased, but concrete with 5~10 % of CBS-Dust showed excellent compressive strength in its early age. Therefore, 5~10 % substitution of CBS-Dust on high strength concrete containing blast furnace slag will have a positive effect on reducing waste disposal cost and improving the strength.

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Properties of Fine Dust Adsorption Matrix According to the Powdered Activated Carbon Mixing Method based on Blast Furnace Slag (고로슬래그 기반 분말활성탄 혼입방법에 따른 미세먼지 흡착형 경화체의 특성)

  • Kim, Yeon-Ho;Jo, Eun-Seok;Lee, Sang-Soo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2020.06a
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    • pp.68-69
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    • 2020
  • Recently, the problem of air pollution is drawing attention as a social problem worldwide. Particularly, fine dust is the biggest issue among air pollutants, and it is analyzed that fine dust is generated from air pollutants such as burning fossil fuels such as petroleum or coal, or exhaust gases from automobiles. In addition, yellow dust originating from China adjacent to Korea flows into the Korean Peninsula in a western wind, causing the concentration of fine dust to deteriorate. Fine dust is a harmful substance to the human body such as asthma or respiratory disease, and awareness of the risk is also increasing to a degree designated as a primary carcinogen. In this study, as a method for improving the indoor air quality, the Properties of the matrix according to the mixing ratio of powdered activated carbon based on blast furnace slag are reviewed. The flexural strength and compressive strength were measured, and a fine dust concentration measurement experiment will be conducted later.

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