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Title |
Compressive Properties of Ultra High Strength Concrete Exposed to High Temperature
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Authors |
강용학 ; 강충현 ; 최현국 ; 신현준 ; 김화중 |
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DOI |
https://doi.org/10.4334/JKCI.2014.26.3.377 |
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Keywords |
초고강도 콘크리트 ; 고온 가열 ; 반복 하중 ; 응력-변형 곡선 sultra high-strength concrete ; high temperature ; cyclic loading ; stress-strain curve |
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Abstract |
Recently, the trend toward larger architectural structures continues and accelerates demand for Ultra High Strength Concrete (UHSC) which satisfies structural performance. However, UHSC has weakness in fire and the performance tests are required. In this paper, the change of mechanical properties of 100 MPa grade UHSC exposed to high temperatures (20℃~800℃) was observed to develop high temperature material model of UHSC: residual compressive strength, modulus of elasticity, property of stress-strain on monotonous loading and property of stress-strain on cyclic loading. In addition, TG/DTA and SEM Images analyses were performed to investigate chemical and physical characteristics of UHSC, and the results of this research were compared with those of previous studies. As a result, UHSC at the heating temperature of 300℃ showed a sharp decrease of residual compressive strength and modulus of elasticity. And It was shown that UHSC had a plastic behavior at more than 400℃ on the cyclic loading and revealed a same tendency in both monotonous and cyclic loading of all heating temperatures. In addition, through TG/DTA and SEM images analyses compared with those from previous studies, it was shown that the deterioration of concrete inner tissue, water evaporation and chemical reaction caused the decrease of residual compressive strength and modulus of elasticity.
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