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Title |
Structural Behavior of Wall-Slab Joints with Mechanical Splice Modules under Cyclic Loading
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Authors |
김문길(Mun-Gil Kim) ; 천성철(Sung-Chul Chun) ; 김상구(Sang-Koo Kim) |
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DOI |
https://doi.org/10.4334/JKCI.2018.30.4.419 |
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Keywords |
철근이음 ; 기계적이음 ; 커플러 ; 접합부 ; 반복하중 splice of reinforcing bars ; mechanical splice ; coupler ; joint ; cyclic loading |
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Abstract |
Mechanical splice modules for re-bar connection were developed to splice reinforcing bars in delayed slab-wall joints in high-rise buildings. Each module consists of several couplers and rail that the couplers are attached to. Cyclic loading tests on slab-wall joints were conducted to verify structural behavior of the joints having the mechanical splice modules. For comparison, joints without splices were also tested. The joints with the mechanical splice modules showed typical flexural behavior in the sequence of tension re-bar yielding, crushing of compression concrete, and compression re-bar buckling, similarly to the behavior of the joints without splices. The joints with the mechanical splice modules failed with a plastic hinge at the slab. At an elastic state, cracks occurred at the interface between the wall and slab but significant slip or damage in the interface was not observed. All specimens had flexural strengths higher than nominal strengths calculated based on the actual material strengths in both positive and negative directions and had sufficient deformation capacities up to a 5 % drift ratio. At the same cumulative displacement, the joints with the mechanical splice modules dissipated more energy than the joints without splices. This implies that the splice and anchorage of the slab bars and joints of the specimens with the mechanical splice modules were sound during the tests. The stiffness degradation of the joints with the mechanical splice modules is very similar to that of the joints without splices. In addition, all requirements of ACI 374 on the strength, stiffness, and energy dissipation at a 3.5 % drift ratio are satisfied.
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