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Title |
Performance of Fresh and Hardened Ultra High Performance Concrete without Heat Treatment
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DOI |
https://doi.org/10.4334/JKCI.2014.26.1.023 |
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Keywords |
초고성능 콘크리트 ; 충전밀도 ; 상대밀도 ; 경화 전 성능 ; 경화 후 성능 ultra high performance concrete(UHPC) ; packing density ; relative density ; fresh performance ; hardened performance |
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Abstract |
This study investigates the relationship between the performance of fresh and hardened Ultra-High Performance Concrete (UHPC) without heat treatment. The performance of fresh UHPC is determined by the slump flow test related to the fluidity of concrete mixtures, and the air content test. The variables of these tests are the water to binder ratio, superplasticizer dosages and volume fractions of steel fiber. Generally, insufficient fluidity and excessive air contents in concrete mixtures lead to the insufficient packing density related to the performance of harden concrete. The performance of hardened UHPC is determined by the compressive and flexural tensile tests. The results of the fresh UHPC tests show that there is the linear correlation between each variable and the slump flow diameter, and that the slump flow diameter is linearly decreased as the air content ratio increase. Using these results, the formula is developed to predict the fresh performance before mixing UHPC. The results of the hardened UHPC tests show that the hardened performance is not influenced by the air content ratio in the range of 3.2 to 4.2 per cent. However, the flexural tensile strength dominantly influenced by the volume fractions of steel fiber.
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