• 한국세라믹학회지
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• 제27권8호
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• pp.1034-1042
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• 1990

Investigation for the preparation of high strength hardened cement paste using ordinary portland cement, hydroxypropyl methyl cellulose(HPMC) with various admixtures was carried out. The cement paste was mixed with 0.1 of water cement ratio by twin roll mill and cured 60 days in humidity chamber. When the quartz powder or white cement was added to the paste, the flexural strength was 900∼1000kg/㎠ and the Young's modulus was 8∼9×105kg/㎠. When the silicafume was added, the flexural strength was 800kg/㎠ and the Young's modulus was 6×105kg/㎠.

• 한국방재학회:학술대회논문집
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• 한국방재학회 2009년도 정기 학술발표대회
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• pp.68.1-68.1
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• 2009

• 한국세라믹학회지
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• 제27권4호
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• pp.495-500
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• 1990

Investigation for the preparation of high strength hardened cement paste using ordinary portland cement, hydroxypropyl methyl cellulose (HPMC) with admixtures was carried out. For molding of the specimen, the paste was mixed with 0.1 of water cement ratio by twin roll mill. The maximum flexural strength of dried hardened cement paste was about 600∼700kg/㎠. When the SiC was added to the paste, the dry flexural strength was about 920kg/㎠ and the young's modulus was 5.2×105kg/㎠. When the admixtures were added to the specimens, wet strength of the harened cement paste immersed in water was showed around 50∼100kg/㎠ higher than that of plain specimen. Consequently it is recognized the water stability of hardened cement paste was remarkably improved by adequate admixture.

• 한국세라믹학회지
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• 제27권7호
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• pp.861-868
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• 1990

Investigation for the preparation of high strength hardened cement paste using ordinary portland cement, hydroxypropyl methyl cellulose(HPMC) with SiC powder was carried out. The cement paste was mixed with 0.1 of water cement ratio by twin roll mill and cured 60 days in humidity chamber. The hydration degree of cement paste cured with W/C=0.1 in 60 days was about 30% and most pores in the paste were found to be existed as gel pores of diameter less than 0.01㎛. The maximum flexural strength of hardened cement paste was about 960kg/㎠. When the SiC powder was added to the paste, the flexural strength was 1000∼1100kg/㎠ and the Young's modulus was 8∼9×105kg/㎠.

• 콘크리트학회지
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• 제6권6호
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• pp.151-158
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• 1994

본 연구에서는 수경성 시멘트 경화체의 구조적 결함인 휨강도를 향상시키시 위해 보통 포틀랜드 시멘트비를 0.1로 하여 혼합수량을 줄이고 수용성 고분자 물질인 Hydroxy Propy Methyl Cellulose(HPMC)를 첨가하여 시멘트입자의 윤활작용에 따른 균일한 분산효과와 결합효과를 얻도록 하였으며, twin roll mill로 혼련 성형하여 치밀하고 균일한 경화제 시편을 제조하였다. 이러한 고강도 시멘트 경화체의 휨강도는 약 96MPa, 탄성계수는 60GPa로 우수한 특성을 나타내었다. 고강도 시멘트의 고강도화 기구는 100${\mu}m$ 이상의 큰 기공제거 및 균열성장경로인 모세관 기공의 감소, 미수화 시멘트의 증가로 인한 탄성계수의 증가와 crack toughening(입자 가교, 고분자 섬유 가교, frictional interlocking)에 의한 파괴 인성의 향상 때문인 것으로 판단된다.

• 한국세라믹학회지
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• 제31권3호
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• pp.330-336
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• 1994

High strength cement composites (W/C=0.1) were prepared by using various blending materials such as SiC whisker and white carbon (hydrated silica: SiO2·nH2O). The effect of various blending materials on the microstructure and strength of the hardened cement paste were investigated in the view of fracture mechanics. The plain specimen showed 101 MPa of flexural strength, 81 GPa of Young's modulus and 1.32 MPam1/2 of fracture toughness. When the blending materials were added to the composites, their values were enhanced to about 110∼138 MPa, 95∼146 GPa and 1.32∼1.87MPam1/2 respectively. The improvement of the mechanical strength for the hardened cement paste may be due to the removal of macropores, the reduction of total porosity, pozzolanic reaction and the increase of various fracture toughening effect.