• Title/Summary/Keyword: Low-cement

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Hydration property of Recycled Cement Using Waste Cementitious Powder (폐콘크리트 미분말을 이용하여 제조한 시멘트의 수화특성)

  • Shin, Hyeon-Uk;Song, Hun;Chu, Yong-Sik;Lee, Jong-Kyu
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2014.11a
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    • pp.47-48
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    • 2014
  • This study is to hydration property of low carbon type recycled cement from waste cementitious powder and cement raw materials. Waste cementitious powder possible to low carbon type recycled cement in small part of additive materials. Also, low carbon type recycled cement using waste cementitious powder is suitable for low heat type cement.

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Accelerated Chloride Diffusion Properties of Portland Cement Concrete (포틀랜드계 시멘트 콘크리트의 촉진 염화물 확산 특성)

  • 김진철;이찬영;이용은
    • Proceedings of the Korea Concrete Institute Conference
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    • 1999.10a
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    • pp.775-778
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    • 1999
  • Accelerated chloride diffusion tests were carried out to estimate the chloride diffusion coefficient of concrete using ordinary portland cement, low heat belite-rich portland cement, and sulphate resistant portland cement. Concrete using low heat belite-rich portland cement showed a high diffusion coefficient due to delayed hydration of low heat belite rich portland cement, while the diffusion coefficients of concrete using sulphate resistant portland cement and ordinary portland cement were low.

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Comparative Study on a Special Low-Porosity Portland Cement (저 기공성 특수 포틀랜드 시멘트에 대한 비교연구)

  • 장복기
    • Journal of the Korean Ceramic Society
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    • v.25 no.5
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    • pp.532-540
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    • 1988
  • Even the finest cement as having a specific surface area of 6.000~8.500$\textrm{cm}^2$/g (Blaine) is to convert into low-porosity hardened cement paste by the use of appropriate plasticizer. In this study, tests were carried out on such a special cement mix(fineness of 6.000$\textrm{cm}^2$/g, Ca-lignosulfonate plus k2CO3 as plasticizer and W/C=0.25) in comparison with ordinary Portland cement. Owing mainly to the high fineness of the cement powder and the low water-to-cement ratio, the hardened low-porosity cement paste showed a very tight microstructure, the pore texture of which consisted of micropores and wide pores only of small radii. The consequence of such mix was hence that the low-porosity special cement had excellent properties of early-high and very high strengths as compared to ordinary Portland cement. Its volume change when dried in the air or re-wetted, exhibited superor behaviour as well.

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The Application of Super-flowing Concrete Using Low Heat Cement (저발연 시멘트를 사용한 초유동 콘크리트의 물성)

  • 노재호;한정호;송용순;최이현;천재원
    • Proceedings of the Korea Concrete Institute Conference
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    • 1997.04a
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    • pp.649-656
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    • 1997
  • The properties of super-flowing concrete with low heat cement were experimentally investigated and compared with ordinary 25-240-15 concrete with type Vcement. The cement content of super-flowing concrete with the low heat cement was 400 kg/$\textrm{m}^3$. However the hydration heat of super-flowing concrete is relatively lower than that ordinary concrete with type V cement. Also the ability to resist chloride ion penetration of super-flowing concrete with low heat cement is 5 times better than that of the ordinary concrete.

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An Experimental Study on the Evaluation of Hydration Heat of Low Heat Concrete (in case of Belite rich Cement) (저발열 콘크리트 수화열 평가의 실험적 연구 (Belite rich 시멘트 중심))

  • 현석훈;박춘근;신영인;김용호
    • Proceedings of the Korea Concrete Institute Conference
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    • 1996.10a
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    • pp.352-357
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    • 1996
  • In hardening massive concrete, the heat of hydation gives rise to considerable thermal gradientsand thermal stresses, which might cause early age cracking. This paper deals with the results of evaluation of hydration heat of low hear concrete, using Belite rich cement (low heat cement) and compared with OPC, slag added cement and fly ash addedcement. Result of evaluation of hydration are presented in this paper. The concrete made with Belite rich cement gets low temperature of center point and low thermal gradients between surface and center points.

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Study on Low Heat Cements (저발열형 시멘트 개발에 관한 연구)

  • Choi, Jae-Woong;Ha, Jae-Dam;Kim, Dong-Seuk;Kim, Ki-Soo;Choi, Long
    • Proceedings of the Korea Concrete Institute Conference
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    • 1999.04a
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    • pp.46-51
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    • 1999
  • Mass concrete structures have many critical points in service. The cracks caused by the heat of hydration is the most serious problem, so that many method ot control cracks(precooling, postcooling, etc) have been applied to construction. But cooling methods take high cost and many installation and limits of field. Therefore it is useful to use the low heat hydration cements for low cost. This paper describes the characteristics of a low heat cement mixing the ternary components of cement(portland cement, blast furnace slag, fly ash) recently developed for mass concrete, belite cement, low heat slag cement(belite base) and fly ash cement (belite base). The objective of this paper is to study on low heat cement about initial compressive strength and hydration heat.

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Hydration Properties of Low Carbon type Low Heat Blended Cement (무기질 자극제를 사용한 탄소배출 저감형 저발열형 혼합시멘트의 수화특성에 관한 연구)

  • Choi, Sung-Woo;Ryu, Deuk-Hyun;Kim, Hun-Sang;Kim, Gyu-Yong
    • Journal of the Korea Institute of Building Construction
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    • v.13 no.3
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    • pp.218-226
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    • 2013
  • Of construction materials, cement and steel are the representative material that carbon dioxide. to reduce carbon emissions in the use of these materials The purpose of this study is low heat type blended cement, which is manufactured using a amount of cement than ordinary low heat blended cement. Low heat blended cement, mixing ratio of 10%, was investigated hydration properties and adiabatic temperature of concrete. The study in order to activate the reaction mineral admixture, a separate source of CaO and $SO_3$ areneeded. gypsum and lime, it expected amount of cement, low-carbon low-heat blended cement could reduce the hydration heat concrete than currentlyused low heat blended cement.

A Study on the Properties of Low-Heat Cement Concrete (저발열시멘트 콘크리트의 기초적 성질에 대한 연구)

  • 문한영;김성수;신화철;강석화
    • Proceedings of the Korea Concrete Institute Conference
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    • 1997.10a
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    • pp.57-60
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    • 1997
  • The properties of Low-heat cement are especially in lower heat of hydration than that of other types of cement. In other respect, Low-heat concrete is more advantageous than OPC concrete in chemical resistance, long term age compressive strength, slump loss and resistance to seawater. This paper deals with 28 days age compressive strength and slump loss by elapsed time of mortar and concrete that made with Low-heat cement and 3 types of other cement.

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Properties of Low-heat Cement and Concrete (저발열 시멘트 및 콘크리트의 특성)

  • Noh, Jae-Ho;Park, Yon-Dong;Song, Yong-Soon;Kim, Hoon;Kang, Suck-Hwa
    • Proceedings of the Korea Concrete Institute Conference
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    • 1996.10a
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    • pp.345-351
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    • 1996
  • The study on the properties of low-heat cement that hear of hydration is relatively lower than that of ordinary portland cement and concrete made of this low-hear cement has been performed to test the hear of hydration and compressive strength, chemical resistance of concrete using low-hear cement to compare with concrete using other several typers of cements.

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PROPERTIES OF LOW-PH CEMENT GROUT AS A SEALING MATERIAL FOR THE GEOLOGICAL DISPOSAL OF RADIOACTIVE WASTE

  • Kim, Jin-Seop;Kwon, S.;Choi, Jong-Won;Cho, Gye-Chun
    • Nuclear Engineering and Technology
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    • v.43 no.5
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    • pp.459-468
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    • 2011
  • The current solution to the problem of using cementitious material for sealing purposes in a final radioactive waste repository is to develop a low-pH cement grout. In this study, the material properties of a low-pH cement grout based on a recipe used at ONKALO are investigated by considering such factors as pH variation, compressive strength, dynamic modulus, and hydraulic conductivity by using silica fume and micro-cement. From the pH measurements of the hardened cement grout, the required pH (< pH 11) is obtained after 130 days of curing. Although the engineering properties of the low-pH cement grout used in this study are inferior to those of conventional high-pH cement grout, the utilization of silica fume and micro-cement effectively meets the long-term environmental and durability requirements for cement grout in a radioactive waste repository.