• Title/Summary/Keyword: Concrete admixture

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An Experimental Study on the Freezing Temperature of Admixture Agent for Concrete (콘크리트용 혼화제의 동결온도에 관한 실험적 연구)

  • 한경익;이건철;이진규;윤기원;한천구
    • Proceedings of the Korea Concrete Institute Conference
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    • 1996.04a
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    • pp.48-51
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    • 1996
  • Recently, frost damage of storage tank for admixture agent caused by low temperature in winter and quality deterioration of admixture agent ofen happened. But, many problems are caused because of no applicable regulations of admixture agent facility and so on. Therefore, this study presents the reference data about using and quality control of admixture agent in practice and the judgement data about working out a counter plan of suitable heat insulation of injecion equipment of admixture agent exposed at outside in winter by measuring the freezing point of admixture agent for concrete.

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The High-Strengthing of Concrete with Admixture -On the Crushed Stone Concrete (혼화재에 의한 콘크리트의 고강도화에 관한 실험 연구(I) -쇄석 콘크리트를 대상으로-)

  • 김화중;김태섭;이용철;한종훈
    • Proceedings of the Korea Concrete Institute Conference
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    • 1993.10a
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    • pp.113-117
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    • 1993
  • The purpose of this study is to raise the strength of concrete with admixture. The natural zeolites and mud stone, abundant in this country, were used as admixture for high-strengthening of concrete. Proper workability was gained by using the superplasticizer. The optimum replacement ratio of zeolite mud stone was 10% on unit -cement amount. At these optimum replacement ratio, the strength development over the plain concrete was 34% for zeolite and 16% for mud stone. Through this study, we concluded the natural zeolite and mud stone were adequate admixture for the high-strengthening of concrete.

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The Effects of Coloring Admixture on the Material Properties of Color Concrete (착색재가 칼라콘크리트의 물성에 미치는 영향)

  • 이성로;김종식
    • Proceedings of the Korea Concrete Institute Conference
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    • 2000.10a
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    • pp.150-154
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    • 2000
  • Coloring admixture is used for take color inside and outside of mortar and concrete, differently form pigment and spray paint take color limited surface. In our country, Using the coloring admixture is very slight and regulation is not yet about it. But that is expected the increase with raising the standard of living. Especially it is used to civil structure like dam and seawall for the environment harmony. Then we observe, in this experiment, the effect of coloring admixture on the material properties of color concrete and propose the suitable mix-proportion of color concrete.

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Manufacture and Application Properties of High Strength Admixture for Improving Compressive Strength of Cement and Mortar (시멘트.몰탈의 압축강도 개선을 위한 고강도 혼화재의 제조 및 적용특성)

  • 노재성;김도수;임채영
    • Proceedings of the Korea Concrete Institute Conference
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    • 1998.04a
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    • pp.83-88
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    • 1998
  • II-anhydrite, slag, and fly ash produced as industrial by-product were reutilized for the manufacture of high strength admixtures for cement and concrete. The effects of these admixtures on the compressive strength of cement mortar and concrete were examined with those of domestic admixture. At the condition mortar and concrete. Especially, adding of II-anhydrite was very effective for the increasing of compressive strength. Therefore it is possible that these admixture as a high strength admixture apply to cement and concrete.

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An ExperimentalStudy on the Freeze-Thaw Resistance Properties of High Strength Concrete (고강도 콘크리트의 동결융해 저항 특성에 관한 실험적 연구)

  • 송태경;이남주;김제원;설광욱;정환욱;부척량
    • Proceedings of the Korea Concrete Institute Conference
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    • 1997.10a
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    • pp.456-461
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    • 1997
  • The purpose of this experimental study are to produce a durable concrete and to investigate the various factors that can deteriorate the concrete when freezing and thawing activity. Among the various factors that can influence the frost resistance of concrete, this study examined mainly the relationship of the frost resistance with the water-cement ratio, admixture and admixture replacement ratio and propose the available water-cement ratio, admixture and admixture replacement ratio.

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Study on the Development of High Strength Admixture using Paper Sludge Ash (제지 애쉬를 사용한 고강도 혼화재 개발에 관한 연구)

  • 이재환;서형남;김창률;민경소
    • Proceedings of the Korea Concrete Institute Conference
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    • 1998.10c
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    • pp.87-92
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    • 1998
  • The purpose of this study is to use paper sludge ash as a material in manufacturing high strength admixture. The reactivity of paper sludge ash as iteself is low for the crystallized non-reactive $SiO_2$, but when the $SiO_2$ was removed, the phase component is mainly composed of glass phase which could react with cement hydrates. In this study, we manufactured high strength admixture using separated paper sludge ash, and examined the strength of mortar, spun concrete with and without this high strength admixture in steam curing. The strength of spun concrete with high strength admixture including paper sludge ash was more higher than that of spun concrete without admixture. As a result, it was found that paper sludge ash could be used to a pozzolanic material in manufacturing high strength admixture.

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Void ratio and Strength Properties of Porous Concrete Utilizing Rice Husk Ash and Recycled Aggregate for Planting (식생 적용을 위한 왕겨재와 순환골재를 활용한 포러스 콘크리트의 공극률 및 강도 특성)

  • Kim, Young-Ik;Sung, Chan-Yong
    • Korean Journal of Agricultural Science
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    • v.33 no.2
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    • pp.167-177
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    • 2006
  • This study was performed to evaluate void ratio, compressive and flexural strength, and pH properties according to the admixture ratio of rice husk ash, aggregate size, and neutral treatment time of porous concrete with an admixture of rice husk ash produced as an agricultural by-product. The SEM results for cement mortar with a 5% rice husk ash admixture for the weight of cement formed more C-S-H hydrates due to the $SiO_2$ present in the applied rice husk ash. According to the results of the SEM test, the $SiO_2$ that was a major chemical element of rice husk ash generated a large amount of calcium hydroxide in the early stage of the hydration process of cement leading to the formation of ettringite. The void ratio of porous concrete with an admixture of rice husk ash decreased with increasing admixture ratio of rice husk ash. In addition, the void ratio of porous concrete with an admixture of rice husk ash decreased compared to porous concrete with no admixture of rice husk ash. The compressive and flexural strength of porous concrete with a 5% and 10% admixture ratio of rice husk ash slightly increased compared to concrete with no admixture of rice husk ash. The pH value of porous concrete rapidly decreased immediately after neutral treatment. Then, it gradually increased and decreased again after 14 days. Also, for neutral treatment, the pH value of porous concrete showed appropriate pH levels(less than 9.5) in all mixtures for planting at 28 curing days.

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Development of Self Waterproofing Admixture for Concrete Using Inorganic Admixture (무기질 혼화재를 이용한 콘크리트용 구체방수재의 개발)

  • 한천구;박상준
    • Journal of the Korea Concrete Institute
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    • v.13 no.6
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    • pp.527-535
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    • 2001
  • The watertight property of concrete was examined, that is affected by the sort of self waterproofing admixture and the change of the addition ratio of admixture. Various self waterproofing admixtures were made by changing the mixing ratio of silica fume, zinc stearate and silica sand. The result showed as follows. As the adding ratio of self waterproofing admixture increases, the fluidity is increased and the setting time is delayed. While compressive strength of concrete with self waterproofing admixture A which is currently using is increased until the adding ratio of self waterproofing admixture reached 18kg/㎥ and decreased over 24 kg/㎥, that with self waterproofing admixture B, C and D which are developed are higher than that of A. Absorption is decreased as the adding ratio of self waterproofing admixture and the increasing of age in concrete. Especially, when self waterproofing admixture has a lot of zinc stearate, absorption is decreased manifestly. The property of permeability is similar to that of absorption; permeability is decreased as the adding ratio of self waterproofing admixture and the increasing of age in concrete. Consequently, when the ratio of silica fume, zinc stearate and silica sand in self waterproofing admixture is 1 : 2 : 1 and addition ratio of self waterproofing admixture is 6kg/㎥, the high quality concrete is obtained comparing to the concrete with existent self waterproofing admixture.

A Study on Basic Properties of Natural Minerals with Silica-Component as Admixture for Concrete (천연 실리카질 혼화재를 사용한 콘크리트의 기초적 특성 연구)

  • 최광일;김진춘;강민호
    • Proceedings of the Korea Concrete Institute Conference
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    • 1996.04a
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    • pp.52-56
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    • 1996
  • In this study, when natural mineral with Silica components(Zeolite & Mudstone) abundant in Korea used as an admixture for concrete, it is investigated that the properties of strength increase and economic effect compared with Silica Fume, the general admixture of high strength concrete.

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An Experimental Study on Application of Waterproofing admixture of power (구체혼화용 분말방수재의 적용성에 관한 실험적 연구)

  • 곽규성;김원화;오상근
    • Proceedings of the Korea Concrete Institute Conference
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    • 1999.04a
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    • pp.83-88
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    • 1999
  • The purpose of this study is to offer the basic information of waterproofing admixture of powder for field application. Through before study and fly ash in mortar, Various properties as fly ash ratio in concrete were checked. According to the experimental result, it was shown that proper Waterproofing admixture of powder increased by cement weight in concrete was generally positive effect to flowing, compressive strength, suction ratio of water, length change ratio. So if Waterproofing admixture of powder is well done quality considered as good on application of concrete.

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