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Title |
Influence of transverse reinforcement elements for flexural strength of lap spliced ultra- high-strength reinforced concrete beams
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Authors |
배백일(Baek-Il Bae) ; 최현기(Hyun-Ki) |
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DOI |
https://doi.org/10.11112/jksmi.2022.26.5.135 |
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Keywords |
초고강도콘크리트; 강섬유보강콘크리트; 이음; 횡방향철근 ultra-high strength concrete; steel fiber reinforced concrete; lap-splice; transverse reinforcement |
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Abstract |
In this study, lap spliced ultra-high strength reinforced concrete beams were tested and the code criteria for calculating the lap splice length which was affected by the transverse reinforcement and concrete covering performance were reviewed. The main variables for test were set as fiber volume fraction and transverse reinforcing bar arrangement to improve the confining performance of the concrete cover. The change of the confining performance of concrete cover according to the increase in the fiber mixing amount at 1% and 2% volume ratio was examined, and D10 stirrups with a spacing of 100 mm were placed in the lap spliced region. As a result of the test, the specimens confined by the stirrups showed a sudden drop of load bearing capacity with horizontal cracking at the position of tensile longitudinal reinforcement. However, horizontal cracks were not appeared at the location of longitudinal reinforcement for the specimens with steel fiber. And these specimens showed gradual decrease of load bearing capacity after experiencing peak load. In particular, it was found that the strain at the position of the tensile longitudinal reinforcements of the specimens to which the mixing ratio of 2% was applied exceeds the yield strain. As a result of measuring the strain on the concrete surface, it was found that the fiber was more effective in preventing damage to the concrete surface than the stirrups for short lap spliced region.
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