• 제목/요약/키워드: hardened properties

검색결과 558건 처리시간 0.026초

고온에 노출 된 시멘트 매트릭스의 미세구조 특성 (Microstructure Properties of Cement Matrix Exposed to High Temperature)

  • 이건영;이건철;최중구;高山;허영선
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2015년도 추계 학술논문 발표대회
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    • pp.24-25
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    • 2015
  • To secure fundamental materials for the performance change in concrete structure damaged by fire, this study analyzed SEM and XRD of hardened cement depending on high temperature conditions. As a result, at more than 200℃, SEM and XRD were not observed because of dehydration of Ettringite; at more than 500℃, calcium hydroxide was rapidly decomposed; at more than 700℃, calcium oxide was found; at 1000℃, the highest peak point appeared.

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고로슬래그미분말의 입도와 양생방법에 따른 모르터 물성에 관한 연구 (A Study on the Properties of Mortar With Particle Size of Blast Furnace Slag Powder and Curing Methods)

  • 김승진;박유진;조재우;김영근;김대영
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1999년도 학회창립 10주년 기념 1999년도 가을 학술발표회 논문집
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    • pp.191-194
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    • 1999
  • Recently in Korea, may workers have reported the effects of the granulated blast furnace slag[BFS] of high fineness on the strength development of slag cement. We have studied the effect of slag fineness on the strength development of mortar with curing conditions, in order to get the basic data of high strength concrete using BFS. In this paper, we discussed the effects of slag fineness and porosity of mortar and the reaction of slag in hardened slag cement.

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고로슬래그미분말을 혼입한 수중불분리콘크리트의 특성에 관한 연구 (A Study on the Characteristics of Antiwashout Underwater Concrete Using Finely Ground Granulated Furnace Blast Slag)

  • 이상명;최홍윤;이환우;김명식
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1999년도 학회창립 10주년 기념 1999년도 가을 학술발표회 논문집
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    • pp.95-98
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    • 1999
  • Recently, the use of the underwater concrete constructions with the antiwashout underwater concrete is increasing. In this study, we investigate the properties of pH, suspended solids, slump flow, box test, air contents of fresh antiwashout underwater concrete and the Unit weight, compressive strength of hardened antiwashout underwater concrete which Ground Granulated Blast Furnace Slag contents 0%, 10%, 20%, 30%, 50%, 60% at 7days and 28days age which is produced and cured in the water and sea water. As a result, Ground Granulated Blast Furnace Slag contents 30% was excellent.

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석회석 미분말의 종류 및 함유율 변화에 따른 고유동 콘크리트의 특성 (The Properties of High Flowing Concrete with the Kind and Content of Limestone Powder)

  • 조중동;홍상희;조병영;장기영;한천구
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1999년도 학회창립 10주년 기념 1999년도 가을 학술발표회 논문집
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    • pp.267-270
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    • 1999
  • In this paper, the application of limestone powder, which produced by being gathered electrically in the process of manufacturing of cement, to high fluidity concrete are investigated. According to the experimental results, especially, high viscosity and the loss of air content are accomplished by applying limestone powder as the partial substitution of fine aggregates. In case of hardened concrete, high compressive strength can be achieved by using limestone powder.

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콘크리트 장기특성 실험연구 (A Study on the Long-term Behavior of Concrete)

  • 박홍석;이장화;김긍환;송영철
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1994년도 봄 학술발표회 논문집
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    • pp.187-190
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    • 1994
  • During the initial design phases for prestressed concrete structures, the mecessary information concerning the physical properties of the hardened concrete such as creep, drying shrinkage, modulus of elasticity, and Poisson's ratio are obtained from design assumptions or accepted standards. But these assumptions may not totally reflect the actual long-term behavior of the concrete. So they may be of limited use in predicting the actual behavior. The purpose of this paper is to describe the test procedures and methods of evaluation which were used during the long-term study.

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EP-DUST를 사용한 시멘트 모르터의 특성에 관한 기초적 연구 (A Fundamantal Study on the Properties of Cement Mortar Using E.P-dust)

  • 조중동;한민철;조병영;장기영;한천구
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1998년도 가을 학술발표회 논문집(I)
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    • pp.117-120
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    • 1998
  • The objective of this study is to investigate the possibility for application of E.P-dust as both admixture and fillers for aggregates under various mixproportion, replacing method and the ratios of replacement. According to the experimental results, improvement of viscosity and reducing of segregation at fresh state and gain in strength at hardened state can be achieved by applying E.P-dust. It can be considered from the results that application of E.P-dust will be more efficient as fillers for aggregates than as binder

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고강도 콘크리트용 고성능감수제 성능평가 (Tests on Superplasticizers for High Strength Concrete)

  • 노재호;김기철;조일호;한정호;박연동
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1994년도 가을 학술발표회 논문집
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    • pp.151-156
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    • 1994
  • This study is to investigate the quality of superplasticizers in domestic market. Therefore, the physico-chemical characteristics, the fluidity characteristics of fresh cement paste and mortar were tested. Also fresh and hardened properties of mortars and concretes using these superplasticizers were tested. From these results, differences of quality among superplasticizers are checked clearly in low water/cement ratio. And it is concluded that several superplasticizers have better dispersion ability than others in every tests. It has known that all samples are naphtalene sulfornate formaldehede types by the UV(ultra-violet) test.

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석회석 미분말의 함유율 변화에 따른 고유동 모르터의 특성 (The Properties of High Flowing Cement Mortar with the Content of Limestone Grain)

  • 조중동;전충근;조병영;장기영;한천구
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1999년도 봄 학술발표회 논문집(I)
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    • pp.605-608
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    • 1999
  • In this paper, the application of limestone grain, which produced by being gathered electrically in the process of manufacturing of cement, to high fluidity concrete are investigated. High fluidity mortar is used for this experiment. According to the experimental results, especially, high viscosity and the loss of air content are accomplished by applying limestone grain as the partial substitution of fine aggregates. In case of hardened mortar, high strength development at early age can be achieved by using limestone grain. But excessive dosage of limestone grain can cause high drying shrinkage.

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자기충전용 ECC를 개발하기 위한 레올로지 특성에 관한 실험 (Rheological control to develop a self-consolidating ECC)

  • 김정수;이정한;김윤용;김진근
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2009년도 춘계 학술대회 제21권1호
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    • pp.539-540
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    • 2009
  • 이 연구에서는 레올로지 제어를 이용하여 자기충전용 ECC(Engineered Cementitious Composite)를 개발하는데 그 목적을 두었으며, 레올로지 제어를 위하여 시멘트 페이스트에 대한 시멘트와 혼화제(감수제, 증점제)의 흡착정도를 평가하였고, 모르타르에 대하여 자기충전성과 유동특성을 평가하였다.

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강섬유보강 폴리머침투콘크리트의 기계적 성질에 관한 연구 (Mechanical Behavior of Steel Fiber Reinforced Polymer-impregnated Concrete)

  • 변근주;송영철;정해성;정기영
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1993년도 가을 학술발표회 논문집
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    • pp.156-161
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    • 1993
  • This paper is to develop steel fiber reinforced polymer-impregnated concrete(SFPIC) by impregnation polymer impregnate into hardened steel fiber reinforced concrete(SFRC). Steel fiber induces ductile behavior and polymer impregnant increase compressive strength. Steel fiber reinforced polymer-impregnated concrete specimens are prepared with fiber contents of 0.0, 1.5, 2.0, 2.5% and tested to obtain uni-axial and bi-axial compression strengths, tensile strength and flexural strength. The strength and mechanical properties of normal concrete, SFRC, SFPIC are compared.

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