Title |
Evaluation of Punching Shear Strength of Two-Way Slab-Column Connections Strengthened with Ultra-High Performance Fiber Reinforced Concrete
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Authors |
염현수(Hyun-Soo Youm) ; 홍성걸(Sung-Gul Hong) ; 임우영(Woo-Young Lim) |
DOI |
https://doi.org/10.4334/JKCI.2019.31.1.029 |
Keywords |
계면 전단 균열 ; 뚫림 전단 ; 단면증대 ; 이방향 슬래브-기둥 접합부 ; UHPFRC near interface cracking ; punching shear ; section enlargement ; two-way slab-column connection ; UHPFRC |
Abstract |
This paper presents the test results on 5 UHPFRC-RC two-way slab-column connections to investigate retrofitting effect of section enlargement using ultra-high performance fiber reinforced concrete (UHPFRC) on punching shear capacity. The test parameters were the section enlargement thickness and the amount of steel re-bar in it. Sand blasting method was conducted to roughen the interface. The test results showed that by adding a thin layer of UHPFRC, considerable increases in global punching shear resistance and structural rigidity were achieved. Furthermore, although it is noticeable that two governing cracking patterns (diagonal tensile cracking in RC section, near interface cracking) were observed, all the composite slabs appeared to experience punching shear mode due to propagation of diagonal tensile cracking. The test results were compared with predicted strength by refined code provisions using equivalent design parameters. The comparison results showed that the refined code provisions addressed comparatively good prediction of the test results with reasonable safety margin.
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