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Title |
Cyclic Loading Test for Shear Strength of Low-rise RC Walls with Grade 550 MPa Bars
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DOI |
https://doi.org/10.4334/JKCI.2013.25.6.601 |
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Keywords |
550 MPa 급 철근 ; 원전구조물 ; 낮은 전단벽체 ; 전단강도 ; ACI 349 규정 grade 550MPa bars ; nuclear power plants ; low-rise shearwall ; shear strength ; ACI 349 provision |
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Abstract |
In the construction of nuclear power plants using massive walls, the use of high-strength re-bars for shear design is necessary to enhance the constructability and economy. In this study, low-rise walls (aspect ratio of 1.0) with grade 550 MPa bars were tested under cyclic loading to investigate the shear capacity and deformation capacity. The test parameters were the grade of horizontal re-bars (550 MPa, 420 MPa), strength of concrete compressive strength (46 MPa, 70 MPa), horizontal/vertical reinforcement ratio, use of lateral confinement hoops, shape of cross section, and failure modes (shear failure before or after flexural yielding). The test results were compared with those of walls with grade 420 MPa bars and predicted strength by current design codes. The results showed that the shear strength of the walls with 550 MPa bars was comparable to that of the walls with 420 MPa bars though the safe margin slightly decreased. ACI 349 provides underestimated shear strength for the walls with 550 MPa bars. In case of the wall with flexural yielding, a large deformation capacity was achieved. This result indicates that the ACI 349 provisions can be safely applied to seismic design of the low-rise walls (aspect ratio of 1.0) with grade 550 MPa bars.
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