• Title/Summary/Keyword: 조기 강도

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An Experimental Study for Improving the Early Strength of Ternary Blended Cement Mortar (삼성분계 혼합시멘트 모르타르의 조기강도 향상을 위한 실험적 연구)

  • Bae, Jun-Young;Jang, Young-Il
    • Composites Research
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    • v.25 no.4
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    • pp.110-116
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    • 2012
  • Recently, the development and field applications of Ternary Blended Cement(TBC), where blast furnace slag and fly ash are recycled in Ordinary Portland Cement(OPC) in order to obtain improvements in the durability and heat of hydration reduction performance in large scale civil structures, have been increasing. Also, there are continuing efforts by construction companies to reduce the construction time with the aim of reducing construction costs. Therefore, there is a need to improve the performance of TBC, which has a relatively slow early strength development. In order to improve the early strength of TBC mortar, the compressive strength, SO3 content, and SEM analysis was determined in this study on mortar with the fineness and content of blast furnace slag and anhydrite regulated. As a result, to secure the early strength of TBC mortar, using blast furnace slag with a fineness of approximately $4,200cm^2/g$, adding 3.5% anhydrite with a fineness of approximately $10,000cm^2/g$, and managing the $SO_3$ content to roughly 3.72% was found to provide the most outstanding early strength properties.

An Experimental Study on the Early Strength Development Properties of Concrete According to Curing Condition and Used Materials (사용재료 및 양생조건에 따른 콘크리트의 조기강도발현 특성에 관한 실험적 연구)

  • Lee, Sang-Soo;Song, Ha-Young;Lee, Ji-Hwan
    • Journal of the Korea Concrete Institute
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    • v.20 no.6
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    • pp.721-729
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    • 2008
  • The purpose of this study is to investigate the engineering properties of concrete for the early strength development. As a result of reviewing it by establishing each experimental factor and level, the cement had more excellent quality performance in CHC and HESPC than OPC. This study has shown that the PC series admixture was more excellent in side of elapsed time (aging) and early strength development than PNS series admixture. In addition, there was much difference according to the curing temperature, but the early strength development showed the considerable vulnerability in curing temperature below $12^{\circ}C$. To satisfy the strength requirements of 5 MPa/18 hr this study has shown that it needed the curing temperature over $17^{\circ}C$ to the minimum in OPC, over $14^{\circ}C$ in CHC, and over $11^{\circ}C$ in HESPC. On the other hand, as to the strength properties according to W/C, the less W/C was, the more strength development was excellent. If this study is to be used in construction filed on a basis of this result, this researcher is considered as possible of the economic execution of construction by advancing the early strength and by the reduction of construction cost according to shortening construction duration.

Study on the Development of Accelerator for Early Strength of Concrete using Industrial by-product (산업부산물을 활용한 조기강도 촉진제 기술 개발을 위한 연구)

  • Lee, Ji-Hwan;Lee, Jin-Woo;Lee, Jae-Sam;Lee, Kang-Jin
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.8 no.1
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    • pp.1-10
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    • 2013
  • In this study utilize industry product for OPC(ordinary portland cement) and BFS(blast furnace slag) mixing concrete early age compressive strength elevation and executed study for high strength binder. Association ratio of industry product for high strength binder manufacture is Titanogypsum (4) : Limestone (3) : Waterworks Sludge by ratio of (3) as it is proper move. high strength binder mixing rate appeared that (7~9) % are proper via preliminary test. Could confirm that display high compressive strength incidence rate in early age than plain harmony according as mix high strength binder mixing concrete compressive strength high strength binder. Also, high strength binder generality that give function than high strength binder used in existing displayed more excellent intensity, and compressive strength displayed result that multiply single breadth according as high strength binder substitute that give function increases.

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A Study on the Application of Early Estimation Method and Non-Destructive Testing for the Strength of Recycled Aggregate Concrete(I)-Part 1 : Mechanical Properties and Early Estimation of Strength- (재생골재 콘크리트의 강도 조기추정 및 비파괴실험 적용성에 관한 연구(I) -제 1 보: 역학적 성질 및 강도 조기추정-)

  • 김기철;윤기원;한천구;김무한
    • Proceedings of the Korea Concrete Institute Conference
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    • 1993.04a
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    • pp.26-29
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    • 1993
  • To analyze the using of recycled aggregate on concrete as the substitude aggregate is important problem for the reuse of waste matter and prevention of environmental pollution. Therefore, this study is designed for investigating and analyzing the mechanical properties and early estimational properties of strength on concrete using aggregate of the waste concrete. And is aimed to provide the fundamental data for recycled aggregate.

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Evaluation on Early-Age Strength of Very-Early-Strength Dry-Mix Shotcrete (초속경 건식 숏크리트의 조기강도 평가)

  • Choi, Sung-Yong;Seo, Jae-Yeop;Jung, Beom-Seok;Yun, Kyong-Ku;Kim, Ki-Heon;Kim, Yong-Gon
    • Proceedings of the Korea Concrete Institute Conference
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    • 2009.05a
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    • pp.519-520
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    • 2009
  • The purpose of this research was to develop a very-early-strength dry-mix shotcrete without accelerator using a rapid-setting cement, to analyze the correlationship of test results among cube test, core test, pullout test and maturity

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A Study on the Application of Early Estimation Method and Non-Destructive Testing for the Strength of Recycled Aggregate Concrete(II) (재생골재 콘크리트의 강도 조기추정 및 비파괴실험 적용성에 관한 연구(II)-제 1보 : 역학적 성질 및 강도 조기추정)

  • 최청각;윤기원;한천구;김무한
    • Proceedings of the Korea Concrete Institute Conference
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    • 1993.10a
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    • pp.57-60
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    • 1993
  • To analyze the using of recycled aggregate on concrete as the substitude aggregate is important problem for the reuse of waste matter and prevention of environmental pollution. Therefore, this study is designed for investigation and analyzing the mechanical properties and early estimational factors of strength on concrete sing aggregate of the waste concrete. And is aimed to provide the fundamental data for recycled aggregate.

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Suggestion for Non-Destructive Testing Equation to Estimate Compressive Strength of Early Strength Concrete (조기강도 콘크리트의 압축강도 추정을 위한 비파괴검사 실험식의 제안)

  • Lee, Tae-Gyu;Kang, Yeon-Woo;Choi, Hyeong-Gil;Choe, Gyeong-Choel;Kim, Gyu-Yong
    • Journal of the Korea Institute of Building Construction
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    • v.16 no.3
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    • pp.229-235
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    • 2016
  • In construction field, it used various technique for concrete formwork. Part of them, non-destructive test has been conducted to estimate a compressive strength of concrete easily such as rebound method and ultrasonic pulse velocity method etc. Former research has recommend proposed equation based on experimental data to investigate strength of concrete but it was sometimes deferent actual value of that from in field because of the few of data in case of early strength concrete. In this study, an experiment was conducted to analyze strength properties for early strength concrete using cylinder mold and $1,000mm{\times}1,000mm{\times}200mm$ rectangular specimen. And compressive strength of concrete was tested by non-destructive test, and calculated by the equation proposed former research. As a result, the non-destructive test results showed approximately 70 percent of the failure test value for all conditions, and worse reliability was obtained for high strength concrete samples when the ultrasonic pulse velocity method was used. Based on the scope of this study, the experimental equation for estimating compressive strength of early strength concrete from 24MPa to 60MPa was proposed.

A Study on the Optimum Mix Proportion for Early Strength of Concrete in the Upper Layers of High Rise Building (Part I - 40MPa) (초고층 빌딩용 상층부 콘크리트의 조기강도 확보를 위한 최적배합 도출에 관한 연구 (Part I - 40MPa를 중심으로))

  • Jeon, In-Ki;Park, Yong-Kyu;Lee, Joo-Hun;Choi, Myung-Hwa;Yoon, Gi-Won
    • Proceedings of the Korea Concrete Institute Conference
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    • 2008.11a
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    • pp.321-324
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    • 2008
  • Recently increasing interest in high-rise building around the world for more than 100 floor, the trend is the increasing use of high-strength and high-flowable concrete so as of productivity improvements and cost savings to improve the performance of the early strength development. This study is to reach the optimal combination by reviewing the performance of high-rise building which is required. The results show that $30.0{\sim}32.5%$ of W/B, $155㎏/m^3$ of unit water and FA10+SP10 is best properties for early strength of concrete.

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