• 한국건축시공학회지
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• 제14권2호
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• pp.170-176
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• 2014

본 연구에서는 알칼리활성 황토콘크리트의 응력-변형률 관계에 대한 화학적 침식의 영향을 평가하였다. 배합의 주요변수는 물-결합재비와 공기량이다. 알칼리활성 황토콘크리트의 응력-변형률 관계는 재령 28일 이후 침지일이 0, 7, 28, 56 및 91일일 때 측정하였다. 실험결과를 기반하여, 화학적 침식하에서 감소된 알칼리활성 황토콘크리트의 압축강도 모델이 제시되었다. 또한, 화학적 침식하에서 알칼리활성 황토콘크리트의 응력-변형률 관계는 공기량과 화학용액에 침지된 일수에 현저한 영향을 받았는데, 침지일수에서 탄성계수의 저하는 동일한 압축강도 저하비율에 비해 더 컸다. 결과적으로 CEB-FIP 기준의 예측모델은 화학적 침식하에서 측정된 응력-변형률 관계와 잘 일치하지 않았다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2010년도 춘계 학술대회 제22권1호
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• pp.389-390
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• 2010

본 연구는 콘크리트 결합재로 사용되는 시멘트의 대체재 개발을 위해 천연황토에 수산화나트륨(NaOH) 수용액과 액상 규산나트륨($Na_2SiO_3$)을 혼합한 후 $60^{\circ}C$에서 알칼리 활성화하여 경화시켜 강도 발현 양상을 분석한 천연황토 콘트리트 결합재 개발을 위한 기초연구이다.

• Architectural research
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• 제11권1호
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• pp.25-33
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• 2009

This study presents the testing of 15 hwangtoh-based cementless concrete mixes to explore the significance and limitations of the development of eco-friendly concrete without carbon dioxide emissions while maintaining various beneficial effects. Hwangtoh, which is a kind of kaolin, was incorporated with inorganic materials, such as calcium hydroxide, to produce a cement-less binder. The main variables investigated were the water-to-binder ratio and fine aggregate-to-total aggregate ratio to ascertain the reliable mixing design of hwangtoh-based cementless concrete. The variation of slump with elapsed time was recorded in fresh concrete specimens. Mechanical properties of hardened concrete were also measured: including compressive strength gain, splitting tensile strength, moduli of rupture and elasticity, stress-strain relationship, and bond resistance. In addition, mechanical properties of hwangtoh-based cement-less concrete were compared with those of ordinary portland cement (OPC) concrete and predictions obtained from the design equations specified in ACI 318-05 and CEB-FIP for OPC concrete, wherever possible. Test results show that the mechanical properties of hwangtoh-based concrete were significantly influenced by the water-to-binder ratio and to less extend by fine aggregate-to-total aggregate ratio. The moduli of rupture and elasticity of hwangtoh-based concrete were generally lower than those of OPC concrete. In addition, the stress-strain and bond stress-slip relationships measured from hwangtoh-based concrete showed little agreement with the design model specified in CEB-FIP. However, the measured moduli of rupture and elasticity, and bond strength were higher than those given in ACI 318-05 and CEB-FIP. Overall, the test results suggest that the hwangtoh-based concrete shows highly effective performance and great potential as an environmental-friendly building material.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2011년도 추계 학술논문 발표대회
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• pp.25-26
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• 2011

The objective of this study is to develop the prototype system for microwave heating in a manufacture process of alkali activated Hwangtoh binder as replacement materials for the cement in concrete. In order to achieve this, four research phases are carried out as follows: 1) establishment of a system concept 2) deduction of a system element 3) design of the entire system 4) making of the prototype system for microwave heating.