• 제목/요약/키워드: Alkali-activated cement

검색결과 123건 처리시간 0.026초

알칼리 활성화 슬래그 시멘트 모르타르의 내황산성 (Resistance of Alkali Activated Slag Cement Mortar to Sulfuric Acid Attack)

  • 민경산;이승헌
    • 한국세라믹학회지
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    • 제44권11호
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    • pp.633-638
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    • 2007
  • The setting time of alkali activated slag cement tends to be much faster than ordinary Portland cement, and its compressive strength had been higher from the 1 day but became lower than that of the cement on the 28 days. According to the results of the surface observation, weight loss, compressed strength, and erosion depth tests on the sulphuric acid solution. It has been drawn that alkali activated slag cement has a higher sulphate resistance than ordinary Portland cement, and in particular, the alkali activated slag cement added 5 wt% alumina cement has little deterioration on the sulphuric acid solution. The reason why the alkali activated slag cement has higher sulphate resistance than other hardened cement pastes is that it has no $Ca(OH)_2$ reactive to sulphate ion, and there is little $CaSO_4{\cdot}2H_2O$ production causing volume expansion, unlike other pastes. And it is supposed that $Al(OH)_3$ hydrates with high sulphate resistance, which is produced by adding the alumina cement increases the sulfate resistance.

레드머드 대체율에 따른 폴리머 혼입 알칼리활성화 슬래그-레드머드 시멘트모르타르의 강도 및 기공특성 (Strength and Pore Characteristics of Alkali-activated Slag-Red Mud Cement Mortar used Polymer According to Red Mud Content)

  • 권성준;강석표
    • 한국구조물진단유지관리공학회 논문집
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    • 제20권2호
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    • pp.26-33
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    • 2016
  • 알칼리활성화 슬래그-레드머드 시멘트는 알칼리활성화 시멘트 연구의 일환으로서 시멘트 조성에서 알칼리자극제, 고로슬래그와 레드머드로 구성되어져 있으며, 포틀랜트 시멘트를 사용하지 않는 클링커 프리 시멘트(Clinker Free Cement)를 의미한다. 본 논문에서는 포틀랜트 시멘트를 전혀 사용하지 않고 고분자 유기화합물인 재유화형 분말 폴리머를 혼입한 알칼리활성화 슬래그 시멘트에 레드머드의 대체율을 달리하여 강도특성, 기공특성 등을 기존 포틀랜트 시멘트와 비교 평가하였다. 그 결과 알칼리활성화 시멘트에 레드머드를 대체할 경우 C-S-H 광물상과 에트린가이트가 주요 수화생성물로 포틀랜트 시멘트와 비교하여 조직이 치밀하고 대체율 10%까지는 압축강도 및 휨강도가 증가하였다.

Hydration Mechanism of Alkali Activated Slag Cement

  • Jong Cheol Kim;Keun Ho Auh;Sung Yun Hong
    • The Korean Journal of Ceramics
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    • 제5권1호
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    • pp.35-39
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    • 1999
  • For many years, alkali activated blast furnace slag cement containing no ordinary portland cement has received much attention in the view of energy saving and its many excellent properties. We examined the structural change of slag glass which was activated by alkali metal compounds using IR spectroscopy. The properties of hydrated products and unhydrated slag grains was characterized by XRD and micro-conduction calorimeter. Ion concentration change in the liquid during the hydration of blast furnace slag was also studied to investigated the hydration mechanism.

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활성제를 사용한 슬래그 미분말 혼합 모르타르의 강도 (Strength of Alkali-Activated GGBF Slag Mortar)

  • 문한영;신화철;권태석
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2001년도 봄 학술발표회 논문집
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    • pp.481-486
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    • 2001
  • Ground granulated blast-furnace slag shows very high strength when proper alkali-activator exists. This paper deals with setting time, heat evolution rate and the strength development of alkali-activated slag cement activated by KOH, Ca(OH$)_{2}$, $Na_{2}$ $So_{4}$ , and alum(potassium aluminum sulfate). Alkali-activated slag mortar is studied by comparison with GGBF slag cement mortar. The experimental results indicate that for moisture curing at $25^{\circ}C$, the addiction of either 4% $Na_{2}$ $So_{4}$ or 4% alum increases the strength of GGBF slag cement mortar consisting of 50% GGBF slag and 50% portland cement at early age. Strength of activated GGBF slag cement mortars at 1, 3 and 7 days exceeded that of GGBF slag cement mortar. A conduction calorimeter was used to monitor early age hydration.

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알칼리 활성화 슬래그 결합재의 강도 발현 인자에 관한 연구 (A Study on the Factors Affecting the Strength of Alkali-Activated Slag Binders)

  • 황병일;강석표;김상준
    • 한국건설순환자원학회논문집
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    • 제6권2호
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    • pp.130-137
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    • 2018
  • 건설 산업분야에서는 시멘트를 전혀 사용하지 않고 플라이애쉬 또는 고로 슬래그 미분말을 이용한 알칼리 활성화 시멘트에 대한 연구가 활발히 이루어지고 있다. 본 논문에서는 보통 포틀랜드 시멘트 관리에 사용되는 화학적 정량 분석을 알칼리 활성화 슬래그 시멘트의 화학적 정량분석 결과에 적용하여 알칼리활성화 슬래그 시멘트의 역학적 성능에 미치는 영향을 최소화 하고 최적 화학 조성 허용범위를 검토하고자 하였다. 그 결과 수경율 및 석회포화도의 비율 및 계수는 모두 일정한 범위 내에 있음이 확인되었다.

플라이애시와 슬래그 혼합 알칼리 활성 시멘트의 미세구조 특성 (Microstructural Characteristics of Alkali-Activated Cements Incorporating Fly Ash and Slag)

  • 장정국
    • 도시과학
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    • 제7권1호
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    • pp.39-43
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    • 2018
  • This study investigates microstructural characteristics of alkali-activated cements incorporating slag and fly ash. Samples were prepared with four fly ash:slag ratios, i.e., 100:0, 90:10, 70:30 and 50:50, and they were synthesized by using an alkali activator. Microstructural characteristics of the alkali-activated cements were determined by XRD, TGA, SEM, N2 gas adsorption/desorption methods, and compressive strength test. The results showed that properties of alkali-activated fly ash/slag were significantly affected by slag contents. Alkali-activated fly ash/slag with slag content of 30-50% showed higher compressive strength than ordinary Portland cement paste. An increase in slag content resulted in a denser microstructure, which composed of amorphous gel, therefore contributed to strength development of the material.

알칼리활성화 슬래그-레드머드 시멘트 모르타르의 흡수계수가 백화발생에 미치는 영향 (Effects of Moisture Absorption Coefficient of Alkali-Activated Slag-Red Mud Cement on Efflorescence)

  • 강혜주;김병기;김재환;강석표
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2016년도 춘계 학술논문 발표대회
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    • pp.130-131
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    • 2016
  • In this study, moisture absorption coefficient and efflorescence properties of Ordinary Portland cement and alkali-activated slag cement mortar were assessed according to their red mud substitution ratio. Tests were conducted to determine the cause of efflorescence, which is a significant obstacle to the recycling of red mud as a sodium activator in alkali-activated slag cement, and to find a method to control efflorescence.

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액상 레드머드 첨가방식에 따른 ASRC 콘크리트의 특성 (Characteristic of Alkali-Activated Slag Red Mud Cement Concrete according to Liquefaction Red mud Input Method)

  • 황병일;강혜주;박경수;강석표
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2018년도 춘계 학술논문 발표대회
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    • pp.134-135
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    • 2018
  • In this paper, we investigate the characteristic of ASRC concrete with the addition of liquefaction red mud using red ud which can be used as an alkali activator of alkali-activated slag cement. as a result, the compressive strength and the efflorescence area increased, and as the amount of liquid red mud increased, the compressive strength decreased and the efflorescence area increased.

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플라이 애쉬를 활용한 알칼리 활성시멘트 콘크리트의 압축강도와 최적혼합비 (Compressive Strength and Optimal Mixing Ratio of Alkali Activated Cement Concrete Containing Fly Ash)

  • 한상호;박상숙;강화영
    • 한국구조물진단유지관리공학회 논문집
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    • 제11권4호
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    • pp.152-158
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    • 2007
  • 본 연구는 알칼리 활성시멘트(Alkali Activated Cement)를 콘크리트에 활용하기 위한 기초적인 연구로서 잔골재 및 굵은골재의 혼합비는 일정하게 하고, 활성화제/플라이 애쉬의 혼합비, 그리고 활성화제 중 물유리, 수산화나트륨, 물의 혼합비를 변화시킨 AAC 콘크리트에 대한 압축강도를 측정하였다. 또한 각 변수에 따른 압축강도의 특성을 분석하고, AAC 콘크리트의 최적 혼합비를 구하였다. 그 결과 최대 압축강도 발현을 위한 활성화제 중 물유리, 수산화나트륨, 물의 최적 혼합비는 4.0:1.0:2.5 이었으며, 활성화제/플라이 애쉬의 최적 혼합비는 0.7 이었다.

알칼리 활성반응에 의한 Briquette ash의 강도 발현 특성 (The Compressive Strength Development of Briquette Ash by Alkali Activated Reaction)

  • 서명덕;이수정;박현혜;김윤종;이수옥;김택남;조성백
    • 한국재료학회지
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    • 제18권9호
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    • pp.463-469
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    • 2008
  • Non-sintering cement was manufactured with briquette ash. Alkali activator for compression bodies used a NaOH solution. In order to apply alkali-activated briquette ash and the non-sintering cement to concrete, several experimental studies were performed. It was necessary to study the binder obtained by means of a substitute for the cement. This study concentrated on strength development according to the concentration of NaOH solution, the curing temperature, and the curing time. The highest compressive strength of compression bodies appeared as $353kgf/cm^2$ cured at $80^{\circ}C$ for 28 days. This result indicates that a higher curing temperature is needed to get a higher strength body. Also, geopolymerization was examined by SEM and XRD analysis after the curing of compression bodies. According to SEM and XRD, the main reaction product in the alkali activated briquette ash is aluminosilicate crystal.