Fundamental properties and mechanical characteristics of high performance cement composite with steel fibres under high temperature

초록

High-performance fibre-reinforced cementitious composite (HPFRCC) is characterized by multiple functioning composite materials comprising fibre and cement matrix. HPFRCC is able to withstand tensile stress forming distributed micro-cracks since embedded fibres in concrete are to improve energy-absorption capacity and apparent ductility. This characteristic can be applied to protect structures under an extreme state of loading, such as blast or impact. In order to determine a mix proportion, this study considered various variables in the mix. Following experimental results, this study suggests an optimum mix proportion of HPFRCC and investigated fundamental properties of the considered mixes. Flexural performance is one of the representing characteristics of the high-fracture energy-absorbing materials. This study investigated the flexural performance of HPFRCC, which used high-strength steel fibres with volume fraction 8%. Under ASTM 1609, load-deflection curves were obtained. The major test variables include silica fume replacement ratio 0 and 15% and exposure temperature, ambient and 400 degrees C. The flexural strength was similar to the compressive strength and the absorbed fracture energy was relatively greater than other typical HPFRCC. This may be a composite reaction of the strong bonding between fibre and matrix and high-compressive strength of the matrix itself.

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