• Title/Summary/Keyword: low-heat concrete

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The Effect on the Properties of High Flowing Concrete Using Low Heat Portland Cement by Material and Mixing Variations (저열 포틀랜드 시멘트를 사용한 고유동콘크리트의 사용재료 및 배합 변동에 따른 특성 평가)

  • 하재담;김태홍;유재상;이종열;권영호
    • Proceedings of the Korea Concrete Institute Conference
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    • 2001.11a
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    • pp.303-308
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    • 2001
  • Recently, concrete structures have become larger and higher and are demanding high performance concrete with lower heat to prevent thermal cracking, far greater workability, high strength and durability, Application of low heat portland(Type IV) cement for the high performance concrete is the best solution to satisfied those requirements. Here are explained the effect on the properties of high flowing concrete using low heat portland cement by material and mixing variations. Variables for sensitivity test were selected items like finess modulus of aggregates, particle size of limestone powder, unit water, superplasticizer, viscosity agent and concrete temperature. The results of this study were be applied to slurry wall of #215 and #216 of underground LNG tank in Inchon.

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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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Study on Hydration Heat Analysis of Pier Foundation-Column Using Low Heat Concrete (저발열 콘크리트를 사용한 교각 기초-기둥의 수화열 해석에 관한 연구)

  • Jeon, Joong-Kyu;Kim, Sun-Gil;Jeon, Chan-Ki;Kim, Ki-Hyung
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.2 no.3
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    • pp.217-224
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    • 2014
  • This study carried out to evaluate the hydration heat analysis and fundamental characteristics such as air content, slump and compressive strength for field application of low heat concrete with premixed cement. The results of experiment show that low heat concrete with premixed cement have sufficient performances on the workability and compressive strength. In addition, hydration heat analysis shows that low heat concrete with premixed cement make sure of target thermal cracking index. Therefore, it is desirable to apply the low heat concrete with premixed cement on pier foundation-column.

Hydration Heat Analysis of Mass Concrete considering Heat Transfer Coefficient and Hydration Heat Difference (수화발열량차 및 열전달계수 변화를 고려한 매스콘크리트의 수화열 해석)

  • Han, Seung-Baek;Lee, Seong-Su;Shin, Hyo-Bum;Kim, Ho-Soo
    • Proceedings of the Korea Concrete Institute Conference
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    • 2008.11a
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    • pp.249-252
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    • 2008
  • In recent large-scale structures, as mass concrete type structure is frequently applied to the building, temperature crack due to hydration heat needs to be considered. Since a volume change is internally or externally restricted in a mold after placing concrete, temperature crack of mass concrete takes place. By this reason, the reduction method to control this crack is required. In this study, low heat mixture and hydration heat difference is used to execute the analysis of hydration heat, considering the changes of heat transfer coefficient according to curing conditions and block placement of mass concrete. For the analytical modelling, original portland cement and concrete of low heat mixture are placed in the upper and lower payer, respectively. A convection boundary condition is fixed because mass concrete of block placement is characterized by the difference of mold form and curing condition. Through the analysis results considering the changes of low heat mixture, block placement, and heat transfer coefficient, we check out the temperature and stress distribution and analyze the temperature crack reduction effect.

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Consideration on the Application of Low-Heat Concrete with Ferronickel Slag Aggregate to LNG Storage Tank (페로니켈슬래그 골재를 활용한 저발열 콘크리트의 LNG 저장탱크 적용성 검토)

  • Sang Hyeon Cheong;Sukhoon Pyo;Hyeong-Ki Kim
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.12 no.1
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    • pp.17-24
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    • 2024
  • The characteristics of low-heat concrete, mixed with ground blast furnace slag and ferronickel slag aggregate, were analyzed. Moreover, the applicability of this concrete for mass concrete in LNG storage tanks was examined. Initially, the study investigated the characteristics of fresh and hardened concrete. Subsequently, the temperature rising curve was obtained. Utilizing the obtained parameters from the curves, a series of thermal stress analyses for the LNG storage tank were conducted to assess the risk of cracking. The results confirmed that concrete mixtures incorporating ground blast furnace slag and ferronickel slag aggregate not only exhibited sufficient workability but also achieved a compressive strength of approximately 40 MPa within 28 days. Furthermore, the concrete demonstrated a lower terminal heat rise and a faster heat generation rate compared to low-heat Portland cement concrete. An analysis of thermal stress in various sections of the LNG tank validated a low risk of cracking.

A Study on the Quality Properties of Low Heat Concrete according to Kinds of Cement (시멘트 종류에 따른 저발열 콘크리트의 품질특성에 관한 연구)

  • Kim, Sung;Choi, Sung-Woo;Jo, Hyun-Tae;Jun, Joun-Young;Ryu, Deuk-Hyun
    • Proceedings of the Korea Concrete Institute Conference
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    • 2006.11a
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    • pp.777-780
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    • 2006
  • Recently, owing to the development of industry and the improvement of building techniques, the concrete structure is becoming larger and higher. In hardening these large concrete, the heat of hydration gives rise to considerable thermal stress depending on the size and environmental condition of concrete, which might cause thermal cracking. Especially, the crack may cause severe damage to the safety and the durability of concrete structure. This study is investigated the thermal properties of concrete according to several binder conditions, such as OPC, Belite Rich Cement(BRC), Low-Heat-Mixed Cement(LHC), Fly ash added cement. As a result of this study, the Flowability of concrete was beetter with BRC and LHC than FA(25) and OPC. On the other hand, LHC gets superior effect in the control of heat hydration, it's caused by the volume of OPC.

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An Experimental Study on the Resistance of Low-Heat Cement Mortar in Chemical Attack (저발열시멘트 모르터의 호학저항성에 대한 실험적 연구)

  • 문한영;신화철;김성수;강석화
    • Proceedings of the Korea Concrete Institute Conference
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    • 1998.04a
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    • pp.183-186
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    • 1998
  • This paper deals with 28, 56, 91 days age compressive strength and ratio of weight when OPC and Low-Heat cement mortar immersed in chemical solution. As a result of experiment, the resistance of Low-Heat Cement motar in chemical attack is more effective than that of OPC, because of lower $C_3$A content and Pozzolanic reactions. Especially in long term age compressive strength, Low-Heat cement mortar shows higher strength in all kind of chemical solution compared with compressive strength of OPC motar.

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Thermal Crack Control of SRC Pier Using Low-Heat Portland Cement (저열 포틀랜드 시멘트 적용을 통한 SRC 교각 온도균열 제어)

  • 김태홍;하재담;유재상;이종열
    • Proceedings of the Korea Concrete Institute Conference
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    • 2001.11a
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    • pp.297-302
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    • 2001
  • SRC pier at KTE 6-1 construction area is a very important structure. Precise control of quality is needed. This pier has 3.50m$\times$3.73m section and 38.20m length. So this structure must be treated as mass concrete and thermal crack caused by hydration heat should be controled. In this project belite cement concrete is used to control the thermal crack. As a result of adapting belite cement concrete perfect control is achieved. Finally, hydration heat FEM analysis of horizontal element is executed for Ordinary Portland Cement concrete and belite cement concrete. In comparison of two results, it is confirmed that using low heat portland cement concrete is necessary.

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Properties of Low Heat Portland Cement Concrete by Changing Temperature of Aggregate (골재의 온도 변화에 따른 저발열 포틀랜드 시멘트 콘크리트의 특성)

  • Cho, Yong-Chin;Park, Kwang-Su;Shin, Su-Gyun;Won, Jong-Pil
    • Journal of The Korean Society of Agricultural Engineers
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    • v.46 no.4
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    • pp.49-55
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    • 2004
  • Properties of concrete using low heat portland cement is different from using ordinary portland cement and temperature of aggregate can be expected to have an important influence on its properties. In this study, experiment by setting up 5 levels (40, 30, 20, 4, $-2^{\circ}C$) by temperature of aggregate for evaluation properties of concrete using low heat portland cement was conducted. The experiments include slump test, air content test, change of slump, change of air content and compressive strength of concrete test. As the result of experiments, slump and air content was decreased by increasing temperature of aggregate. But it was not exceeding it's limit. Change of slump and air content was rapidly decrease by decreasing temperature of aggregate. At early age, compressive strength was influenced by the temperature of aggregate.

Strength Development of Low Heat Portland Cement Concrete according of Substitution of Fly-ash in High Strength Range (플라이 애쉬 치환율에 따른 저열 포틀랜드 시멘트 콘크리트의 고강도 영역에서의 강도발현 특성)

  • Kim, Tae-Hong;Ha, Jae-Dam;Um, Tai-Sun;Lee, Jong-Ryul;Kwon, Young-Ho
    • Proceedings of the Korea Concrete Institute Conference
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    • 2005.11a
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    • pp.603-606
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    • 2005
  • Strength development of low heat portland cement(Type IV) concrete according of addition of fly-ash in high strength range is tested. In this study strength development according to water-binder ratio, strength development according to age, effect of fly ash are tested. This study tests effect of low heat portland cement in high strength range concrete and provide guide line concrete mix design for later study and construction.

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