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Title |
Variation of Pore Structure of High Strength Concrete Including Silica Fume Exposed to High Temperature
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Keywords |
화재; 고온; 공극률; 강도 콘크리트; 실리카퓸; fire; high temperature; porosity; high strength concrete; silica fume |
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Abstract |
This work involves quantitatively investigating the correlation between reductions in strength and variations in pore structure under high temperature that can be utilized as estimation for predicting the inner temperature of member damaged by fire. The experimental results were remarkedly affected by micro-filling effect of silica fume and the different water-binder ratios. The increase of the exposure temperature caused the increase of porosity, which resulted from the reason that evaporable water in gel pore or capillary pores as well as chemically bound water was eliminated from hardened cement paste due to the dehydration of C-S-H and Ca(OH)₂. Thermal shrinkage of hardened cement paste gives rise to micro-crack, which cause the increase of porosity. Based on the experimental result that the increase of porosity is in charge of exposure temperature, how porosity is distributed can predict temperature-time history and assess the performance of concrete damaged by fire.
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