• 제목/요약/키워드: fundamental properties of aggregate

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Fundamental Properties of Porous Concrete by Aggregate Size

  • Kim, Moo-Han;Kim, Gyu-Yong;Baik, Yong-Kwan;Kim, Jae-Hwan;Cho, Bong-Suk
    • International Journal of Concrete Structures and Materials
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    • 제18권2E호
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    • pp.117-124
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    • 2006
  • Porous concrete has been used recently for the purpose of decreasing the load on the earth environment. It consists solely of cement, water and coarse aggregate of uni form size. Its fundamental properties are considerably affected by the physical properties of aggregate because the aggregate is the main material for the most part in its mix proportion. Because of this reason, this study carried out an investigation of the influence of the size and type of aggregate on the fundamental properties of porous concrete. It is shown that the fundamental properties of porous concrete was seldom affected by the size of aggregate except for the case of using $2.5{\sim}5mm$ aggregate but varied significantly by the type of aggregate. In particular, the compressive strength of porous concrete using $2.5{\sim}5mm$ aggregate was much higher than that using other aggregate, and its void ratio and coefficient of permeability was lower. Moreover, the capacity to maintain the permeability of porous concrete was found to vary by the size and type of aggregate. Of particular notice was that it decreased greatly when $2.5{\sim}5mm$ aggregate was used. Unlike ordinary concrete, porous concrete exhibited very high dynamic modulus of elasticity at early age and continued to increase but slowly afterwards.

폐전주 재생골재의 기초물성 및 대체율에 따른 고강도영역 재생골재 콘크리트의 특성에 관한 실험적 연구 (An Experimental Study on the Fundamental Properties of Electric Pole Recycled Aggregate(EPRA) and Characteristics of High Strength Concrete by Replacement Ratios of EPRA)

  • 이강우;이종호;강석표;최세진;최희용;김무한
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2001년도 봄 학술발표회 논문집
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    • pp.495-500
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    • 2001
  • In this study, it was analized and examined fundamental properties of Electric Pole Recycled Aggregate(EPRA) and hardened properties & chemical resistance with H$_2$SO$_4$by replacement ratios of EPRA, and the results are as follows 1) In the case of electric pole recycled coarse aggregate, All fundamental properties are better than that of normal recycled aggregate and both water absorption and amount of crushed loss are with level of natural aggregate 2) As the replacement ratio of electric pole recycled fine aggregate is increased strength development is decreased. but in the case of coarse aggregate, that of it is with level of natural aggregate 3) As the replacement ratio of electric pole recycled fine aggregate is increased chemical resistance is decreased. but in the case of coarse aggregate, that of it is with level of natural aggregate

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재활용플랜트에서 생산되는 재생골재의 품질현황에 관한 기초적 연구 (A Fundamental Study on the Quality of Recycled Aggregate Produced in Recycling Plant)

  • 강희관;박선규;신호철;김규용;김무한
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1997년도 가을 학술발표회 논문집
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    • pp.33-38
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    • 1997
  • The reuse of waste concrete amy settle the problems of environmental pollution and critical shortage of good natural aggregate. But recycled aggregate particles consist of substantial amount of relatively soft cement paste component. These aggregates are more porous, and les resistant to mechanical actions than natural aggregate. And the source of supply for manufacturing recycled aggregate is generally composed of different types of original aggregate and strengths of original mortar. The properties of recycled aggregate exhibit a considerable variation due to the properties of original concrete. This paper is an experimental study on the fundamental properties of recycled aggregates sampled from processing plant in the suburbs of TaeJeon.

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잔골재의 종류가 콘크리트의 기초적 특성에 미치는 영향 (Influence of Kind of Fine Aggregate on Fundamental Properties of Concrete)

  • 허영선;한창평;한민철;권오현;최영화;한천구
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2006년도 춘계 학술발표회 논문집(II)
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    • pp.153-156
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    • 2006
  • This study investigated influence of kind of fine aggregate on fundamental properties of concrete. For the properties of fluidity with various type of fine aggregate, lime stone crushed fine aggregate(Ls) exhibited favorable result, due to grain shape and particle distribution, and next was granite crushed fine aggregate(Gs), natural fine aggregate(Ns). Ns had the highest value of air content while Ls had the lowest, due to the effective filling performance by continuos particle distribution. Ls, Ns, Gs in an order had higher bleeding capacity and faster setting time. However, compressive and tensile strength value exhibited similar tendency, regardless of aggregate type.

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순환골재를 활용한 포장용 시멘트콘크리트의 최적배합 도출을 위한 기초 연구 (Fundamental Study on Optimum Mixing Proportion of Cement Concrete Pavement using Recycled Aggregate)

  • 김승원;김용재;이장용;이학용;박철우
    • 한국도로학회논문집
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    • 제18권6호
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    • pp.105-113
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    • 2016
  • OBJECTIVES : This study is to develop the optimum mixing proportions for cement concrete pavement with using recycled aggregates. METHODS : The mixture varied recycled coarse aggregates content from 50 % to 100 % to replace the natural coarse aggregates by weight. Tests for fundamental properties as a cement concrete pavement were conducted before and after hardening of the concrete. RESULTS : It was found that the variation in the amount of the recycled aggregate affected the compressive and flexural strength development, as well as the chloride ion penetration resistance. As the amount of the recycled aggregate content increased the compressive and flexural strength and the resistance to chloride ion penetration decreased. However, the resistance to freeze-thaw reaction was affected significantly. In addition, the gradation of the aggregate became worse and hence so did the coarseness factor as the recycled aggregate amount increased. CONCLUSIONS : The fundamental properties of the concrete with recycled aggregate does not seem to be appropriate when the recycled aggregate quality is not guaranteed up to a some level and its replacement ratio is over 50%. The optimized gradation of the aggregates should also be sought when the recycled aggregate is used for the cement concrete pavement materials.

재생골재 콘크리트의 강도 조기추정 및 비파괴실험 적용성에 관한 연구(I) -제 1 보: 역학적 성질 및 강도 조기추정- (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-)

  • 김기철;윤기원;한천구;김무한
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1993년도 봄 학술발표회 논문집
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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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전기슬래그 굵은골재 사용 콘크리트의 제물성 (A Fundamental Study on the Properties of Concrete Using Electric Arc Furnace Slag)

  • 문한영;유정훈;문재흠;천승환
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1998년도 가을 학술발표회 논문집(I)
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    • pp.72-75
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    • 1998
  • In this study, we investigate the difference of concrete between natural aggregate and electric are furnace(EAF) slag one in oder to use EAF slag aggregate as coarse aggregate in concrete. We find the physical and chemical properties of EAF slag aggregate for the aging process. We consider the properties od the concrete made with EAF slag aggregate which are compressive strength, splitting tensile strength and modulus of elasticity.

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골재 크기에 따른 포러스콘크리트의 기초물성에 관한 실험적 연구 (Fundamental Properties of Porous Concrete According to the Sizes of Aggregate)

  • 김무한;백용관;강석표;김용로;김재환
    • 콘크리트학회논문집
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    • 제13권5호
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    • pp.438-446
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    • 2001
  • 최근 지구환경부하 저감을 목적으로 포러스콘크리트의 수요가 점점 증대되고 있지만 낮은 강도수준으로 인해 사용용도에 제약을 받고 있으며, 또한 대부분 그 기능성을 무시한 채 강도 및 색채에 의해서만 관리되고 있어 그 기능성(특히 투수성능)에 많은 문제를 유발시키고 있다. 이에 본 연구에서는 포러스콘크리트의 배합상 대부분을 차지하는 골재가 포러스콘크리트의 기초물성에 미치는 영향을 파악하여 강도 및 투수성능 향상을 위한 기초적 자료를 제시하고자 하였다. 그 결과 포러스콘크리트의 강도, 공극율 및 투수계수는 동일 단위시멘트량에서 골재 크기에 관계없이 유사하게 나타났으나 2.5~5mm 골재를 사용한 경우에는 다른 골재에 비하여 크게 다른 값을 보이고 있으며, 동일 조건에서도 골재 종류에 따라 다르게 나타났다. 또한 혼탁액 투과에 의한 투수계수 감소율은 골재 크기가 작을수록 크게 되며, 특히 2.5~5mm 골재의 경우에는 급격히 저하하였다. 또한 골재 종류에 따라서도 그 값은 다르게 나타나 포러스콘크리트의 장기 투수성능 확보를 위해서는 재료선정시 골재 크기 및 입형을 충분히 고려해야 할 것으로 판단된다. 포러스콘크리트의 압축강도와 초음파속도 및 동탄성계수 사이에는 높은 상관성을 보이고 있으며 또한 단위용적중량에 의한 포러스콘크리트의 공극율 추정이 가능한 것으로 나타났다. 또한 포러스콘크리트의 동탄성계수는 일반콘크리트에 비하여 초기재령부터 매우 높게 발현되고 있으며, 재령 7일 이후 동탄성계수의 상승구배는 매우 완만하게 나타났다.

재생미분말의 가열온도에 따른 기초물성 및 시멘트혼화재 적용성에 관한 연구 (A Study on the Fundamental Properties and Application as Cementious Admixture by Heating Temperature of Recycled Powder)

  • 장종호;김용로;최세진;최희용;김문한;김무한
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2001년도 봄 학술발표회 논문집
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    • pp.635-640
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    • 2001
  • Recently, it has been processed to study about recycled aggregate but a study about using of recycled powder is producted when manufacturing recycled aggregate has not been acted. So in this study on the fundamental properties and application as cementious admixture by heating temperature for mortar properties of recycled powder and sand is obtained like following results. It is judged that application of recycled powder of heat treatment on $600^{\circ}C$ and cement replacement ratio below 10% is available.

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순환잔골재 치환율 변화에 따른 고로슬래그 미분말 모르터의 기초적 특성 (Fundamental Properties of Blast Furnace Slag-Based Mortar Made with Recycled Fine Aggregate)

  • 김영희;한상윤;손호정;이향재;한민철;한천구
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2011년도 추계 학술논문 발표대회
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    • pp.213-214
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    • 2011
  • This study investigates the fundamental properties of bast furnace-based mortar made with recycled fine aggregate. Results showed that increasing recycled fine aggregate accelerated setting time, proportionally increased the compressive and flexural strength of mortar specimens. However, it is concluded that for quality and cost effectiveness, the optimum content of this recycled fine aggregate in mortar was found to be 80%.

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