• Title/Summary/Keyword: Admixture

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A Study of Rheological Properties on Cement Paste System Mixed with Mineral Admixtures (광물혼화재가 혼합된 시멘트 페이스트 시스템의 레올로지 특성에 관한 연구)

  • 박대효;노명현;박춘근
    • Proceedings of the Korea Concrete Institute Conference
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    • 2003.11a
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    • pp.505-508
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    • 2003
  • The rheological properties of cement paste system mixed with mineral admixture for the purpose of increasing the strength and improving durability and rheology of concrete were investigated. The results were as follows: The rheological properties of one-ingredient paste system were improved with increasing the dosage of superplasticizer. For two-ingredients paste system, increasing the replacement rate of BFS(blast furnace slag) and FA(fly ash), the yield value and plastic viscosity were decreased compared with non-replacement. In the OPC(ordinary portland cement)-SF(silica fume) system, increasing the replacement rate of SF, the plastic viscosity and yield value increased linearly. In three-ingredients paste system, both OPC-BFS-SF and OPC-FA-SF system, the rheological properties were improved compared with the only replacement of SF. Both two- and three- ingredients paste system, the rheological properties using BFS were improved more than FA.

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Study of Freeze-thaw Resistance of Concrete using Fly-ash (플리이애쉬를 사용한 콘크리트의 동결융해 저항성에 관한 연구)

  • 최세규;임정호;김생빈;이석홍
    • Proceedings of the Korea Concrete Institute Conference
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    • 1998.04a
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    • pp.123-128
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    • 1998
  • Currently the study on the effective use of the fly ash is concentrated as construction materials, which is by product of electric power generating plants. Fly ash, therefore, can be used as concrete admixture for the purpose of not only increasing the concrete quality but also of utilizing materials. Within the country it is not easy to use fly ash for the construction purpose because the properties of fly ash are varied due to the use of different raw ores in the various power plants. And little previous construction experiments and the basic experiments about the formation of bubbles are performed. In this study the water-cement ratio is varied in 3 different values and compressive strength is measured and freeze-thaw experiments are preformed to establish the relationships between water-cement ratios and the durability. And also for each batch of different water-cement ratio fly ash is substituted 10%, 20% and 30% of cement and concrete mixture the admixture and the formation of bubbles and also freeze-thaw resistance.

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A Study on Physical Properties of Mortar Using Shrinkage Reducing Agent (수축저감제를 사용한 모르터의 물성에 관한 연구)

  • 이승한;이종석;이순환
    • Proceedings of the Korea Concrete Institute Conference
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    • 1995.10a
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    • pp.103-107
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    • 1995
  • The intention of this study is to reduce the drying shrinkage of the cement mortar using the shrinkage reducing agent and the inorganic admixture. In this experiment the drying shrinkage strain, rate of weight loss and strength have been measured depending on age using the motar specimen. The result show that the usage of shrinkage reducing agent up to 1.5% will give an effect of approximately 30% without loss of strength, and the efficiency will increase together with the inorganic admixture. Also, as the amount of shrinkage reducing agent increases, the rate of weight loss increases. Drying shrinkage reduces at the same rate of weight loss.

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The Performance and Application of Repair System for the Exterior Wall According to the Durability Improvement in the RC Structure(Part2:Summary of Inorganic Repair System) (내구성향상을 고려한 R.C조 외벽보수시스템의 성능과 그 활용(제2보:무기질계 보수공 법 개요))

  • Kwon, Young-Jin;Kim, Chul-Ho;Kwak, Young-Jun;Park, Deuk-Kon;Choi, Long
    • Proceedings of the Korea Concrete Institute Conference
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    • 1995.10a
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    • pp.139-144
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    • 1995
  • It is the aim of this study to introduce the performance and application of new repair system for the exterior wall by durability failure caused seasand especially. The elementary performance of this repair system is as follows (1)All the layer in the repair are cement based, same with the mother conrete (2)this repair system use SBR admixture (3)This cement and mortar powder for this repair system are premixed and ready to use just adding admixture at the job site.

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Engineering Properties of High Durable Concrete using High Durability Admixture for Mega Foundation (고내구성 혼화재 사용에 따른 Mega Foundation용 고내구성 콘크리트의 공학적 특성)

  • Kim, Jong-Baek;Bae, Jun-Yeong;Cho, Sung-Hyun;Woo, Seung-Min;Jun, Sung-Yong
    • Proceedings of the Korea Concrete Institute Conference
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    • 2010.05a
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    • pp.215-216
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    • 2010
  • This study investigated the development of high durability concrete under an oceanic region through the examination and comparison of the fundamental property and diffusion of chloride ion to apply a high durability admixture on the concrete.

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A Study on Concrete using by Fiber to Enhance Dispersion Effect (분산효과를 향상시킨 섬유를 이용한 콘크리트에 관한 연구)

  • Lee, Yong-Soo;Jeon, Joong-Kyu;Ryou, Jae-Suk
    • Proceedings of the Korea Concrete Institute Conference
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    • 2010.05a
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    • pp.431-432
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    • 2010
  • In this study, The Mineral Admixture(Fly-ash, GGBFS) using Nylon Fiber to improve the dispersibility, in order to improve the performance of concrete, were applied to Self-Consolidating Concrete(SCC) needed high strength and fluidity. Especially, the GGBFS reachs the higher satisfaction than other admixture.

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Properties of LightWeight Foamed Concrete According to Mixing Ratio of Admixtures. (혼화재 혼입에 따른 경량기포콘크리트의 특성)

  • Kim, Jae-Kyung;Ahn, Jung-Hyun;Lee, Sang-An;Kim, Wha-Jung
    • Proceedings of the Korea Concrete Institute Conference
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    • 2010.05a
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    • pp.297-298
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    • 2010
  • This study was investigates to the lightweight foamed concrete are uses by foamed agent to hydrogen peroxide($H_2O_2$). and then, lightweight foamed to improve the physical characteristics were mixed. mixes to type of admixture/level by changes/character to investigates, It is a purpose to look up admixture and mix proportion to be suitable in order to improve lightweight foamed concrete.

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Development and Applications of the Intrinsic Model for Formwork Pressure of Self-Consolidating Concrete

  • Kwon, Seung-Hee;Kim, Jae-Hong;Shah, Surendra P.
    • International Journal of Concrete Structures and Materials
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    • v.6 no.1
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    • pp.31-40
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    • 2012
  • Self-consolidating concrete (SCC) is a recently developed innovative construction material. SCC fills in a formwork without any vibrating consolidation, which allows us to eventually achieve robust casting. However, high formwork lateral pressure exerted by SCC is a critical issue regarding its application as cast-in-place concrete. In order to control the risk caused by high formwork pressure, a comprehensive prediction model for the pressure was previously proposed, investigated, and validated with various SCC mixtures. The model was originally designed to simulate the intrinsic pressure response of SCC mixtures while excluding other extrinsic influencing factors such as friction and flexibility of the formwork. The model was then extended to consider extrinsic factors such as friction between SCC mixtures and formwork. In addition, other interesting topics for peak formwork pressure and mineral admixture effects were summarized in the paper.

The Study on Improvement in Subcooling of TMA Clathrate for PCM in Ice Storage System (빙축열시스템 PCM용 TMA-포접화합물의 과냉도 개선에 대한 연구)

  • Kim, J.H.;Chung, N.K.;Kim, C.O.
    • Proceedings of the KSME Conference
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    • 2003.04a
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    • pp.1663-1666
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    • 2003
  • TMA clathrate that is used by PCM of ice storage system in this research creates hydrate crystallization at higher temperature than pure water, and application is expected as PCM because having comparative big dormant temperature without phase separation phenomenon. In case this research uses TMA clathrate by PCM, choose admixture by purpose to control or remove subcooling of TMA clathrate and evaluated experimentally. Subcooling is improved and can expect contraction of freezing machine running time and increase of coefficient of performance as that add admixture to TMA clathrate conclusively. Also, may supply thermal storage system that apply low temperature potential heat thermal storage material that subcooling is improved more extensively laying stress on medium size building and small size building, can expect allowance through localization of ice storage system.

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The New Repair System of R.C Structure caused by carbonation and salt damage (중성화 및 염해를 입은 콘크리트구조물의 보수시공기술)

  • Kwon, Young-Jin;Kim, Chul-Ho;Jang, Tea-Min;Park, Deuk-Kon;Choi, Long
    • Proceedings of the Korea Concrete Institute Conference
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    • 1996.04a
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    • pp.414-417
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    • 1996
  • It is the aim of this study to introduce the performance and application of new repair system for the exterior wall by durability failure caused carbonation and salt damage. The elementary performance of this repair system is as follows. (1) Al the layer in the repair are cement based, same with the mother concrete (2) this repair system use SBR admixture (3) This cement and mortar powder for this repair system are premixed and ready to use just adding admixture at the job site.

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