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Title |
A Study on the Residual Mechanical Properties of Fiber Reinforced Concrete with High Temperature and Load
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Authors |
김영선 ; 이태규 ; 남정수 ; 박규연 ; 김규용 |
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Keywords |
잔존 역학적 특성 ; 고온 ; 초기 하중 ; 압축 거동 ; 폴리프로필렌 섬유 residual mechanical properties ; high temperature ; pre-load ; compressive behavior ; polypropylene fiber |
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Abstract |
Recently, the effects of high temperature and fiber content on the residual mechnical properties of high-strength concrete were experimentally investigated. In this paper, residual mechanical properties of concrete with water to cement (w/c) ratios of 0.55, 0.42 and 0.35 exposed to high temperature are compared with those obtained in fiber reinforced concrete with similar characteristics ranging from 0.05% to 0.20% polypropylene (PP) fiber volume percentage. Also, factors including pre-load levels of 20% and 40% of the maximum load at room temperature are considered. Outbreak time, thermal strain, length change, and mass loss were tested to determine compressive strength, modulus of elasticity, and energy absorption capacity. From the results, in order to prevent the explosive spalling of 50 MPa grade concretes exposed to high temperature, more than 0.05 vol. % of PP fibers is needed. Also, the cross-sectional area of PP fiber can influence the residual mechanical properties and spalling tendency of fiber reinforced concrete exposed to high temperature. Especially, the external loading increases not only the residual mechanical properties of concrete but also the risk of spalling and brittle failure tendency.
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