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Title |
Comparison of Flexural Tensile Strength according to the Presence of Notch and Fiber Content in Ultra High Performance Cementitious Composites
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DOI |
https://doi.org/10.4334/JKCI.2012.24.5.525 |
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Keywords |
섬유보강 ; 초기균열강도 ; 휨인장강도 ; 섬유혼입률 ; 노치 fiber reinforcement ; first cracking strength ; flexural tensile strength ; fiber content ; notch |
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Abstract |
In this study, bending tests were performed on beam specimens made of UHPCC with the fiber content range of 0~5 vol% to investigate the contribution of fiber content to first cracking strength and flexural tensile strength. Also, four-point bending tests for unnotched beam as well as three-point bending test for notched beam were performed to estimate the effect of the presence of notch on the strengths. The experiment result showed that the increase in fiber content made linear improvement in the flexural tensile strength; whereas first cracking strength was enhanced only when at least 1 vol% of fibers was incorporated. Comparison of the bending test results with and without notch showed that the notch effect varied with the fiber content. The increase in fiber content diminished the effect of stress concentration on the notch tip, reducing the difference in the strengths. With much higher fiber content, the effect of stress concentration almost disappeared and the defection on cracking plane or the size effect dominated the strengths, consequently resulting in higher strengths in the notched beams than the unnotched ones.
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