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Title |
Durability and Crack Control of Concrete Using Fluosilicates Based Composite
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Authors |
윤현도 ; 양일승 ; 김도수 ; 길배수 ; 한승구 |
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Keywords |
규불화염계 복합 조성물 ; 균열제어 ; 건조수축 ; 수밀성 ; 내구성 |
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Abstract |
The crack presented in concrete structures causes a structural defect, the durability decrease, and external damages etc. Therefore, it is necessary to improve durability through the effort to control the crack. Fluosilicic acid(H₂SiF6) is recovered as aqueous solution which absorbs SiF4 produced from the manufacturing of industrial-graded H³PO₄or HF. Generally, fluosilicates prepared by the reaction between H₂SiF6 and meta! salts. Addition of fluosilicates to cement endows odd properties through unique chemical reaction with the fresh and hardened cement. Mix proportions for experiment were modulated at 0.45 of water to cement ratio and 0.0~2.0 % of adding ratio of fluosilicate salt based inorganic compound. To evaluate correlation of concrete strength and adding ratio of fluosilicate salt based inorganic compound, the tests were performed about design strength(21, 24, 27MPa) veith 0.5 % of adding ratio of fluosilicate salt based inorganic compound. Applications of fluosilicate salt based inorganic compound to reduce cracks resulted from plastic and drying shrinkage, to improve durability are presented in this paper. Durability was evaluated as neutralization, chloride ion penetration depth, freezing thawing resistant tests and weight loss according reinforcement corrosion. It is ascertained that the concrete added fluosilicate salt based inorganic compound showed an ability to reduce the lota! area and maximum crack width significantly as compared non-added concrete. In addition, the durability of concrete improved because of resistance to crack and watertightness by packing role of fluosilicate salt based inorganic compound obtained and pozzolanic reaction of soluble SiO₂ than non-added concrete.
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