Experimental investigations on novel double-sleeve tubebolt moment connection to concrete filled tubular column / Mahdi Zeinizadeh Jeddi
Concrete-filled tubular (CFT) columns have been commonly used as part of special moment-resisting frames in high-rise buildings for decades. Blind-bolts mechanical systems are widely adopted for on-site bolting of open beam to tubular column connections. The common types of blind bolts are Hollo-...
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| Format: | Thesis |
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2017
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| Online Access: | http://studentsrepo.um.edu.my/8276/ http://studentsrepo.um.edu.my/8276/2/All.pdf http://studentsrepo.um.edu.my/8276/1/Thesis%2DMahdi.pdf |
| Summary: | Concrete-filled tubular (CFT) columns have been commonly used as part of special
moment-resisting frames in high-rise buildings for decades. Blind-bolts mechanical
systems are widely adopted for on-site bolting of open beam to tubular column
connections. The common types of blind bolts are Hollo-Bolt (HB) and its modified
version, Extended Hollo Bolt (EHB). However, EHB bolts could not provide sufficient
moment-resistance capacity and exhibited several shortcomings such as bolt slippage,
low load transfer mechanism, bolt elongation and column face bending. A new blind bolt
called Double sleeve-TubeBolt was proposed in this research to solve the above
mentioned problems. The first part of this research was experimental pull-out tests of
individual bolt under monotonic loading to obtain the performance of the TubeBolt and
EHB bolt. The force-displacement, anchorage and elongation behavior of the bolts were
determined. The test specimens were varied according to type of bolts, bolt diameter,
concrete confinement and column wall thickness. For the second part of this study, six
half scale cruciform specimens, connecting an open beam to CFT column with the novel
blind bolt connection were tested under cyclic loading to investigate the seismic
performance of the connections. The effects of different parameters on the behavior of
the connection, such as bolt type, bolt grade and stiffeners at the top and bottom of the
endplate were investigated. The failure modes, hysteretic performance, rotation capacity,
strength and stiffness degradation, ductility and energy dissipation of the connections
were analyzed. The pull-out test results indicate that the tensile capacity of the TubeBolt
is 2.5 times higher than the existing EHB bolt. In addition, the Tubebolt has better anchorage and the elongation has reduced to 68% compared to the existing EHB bolt.
The cyclic test results of the cruciform specimens demonstrate that the new blind bolted
connections exhibit a large hysteretic enclosed area, good ductility, and excellent energy
dissipation compared to the EHB connection. The TubeBolt has achieved better
performance compared to the EHB bolt, with 36% and 24% increase in the maximum
strength and initial stiffness, respectively. No column face deformation and concrete
damage is observed in the test. The results prove that the proposed TubeBolt connection
satisfies the seismic provisions and ductility design requirements to be utilized in
moment-resisting frames in seismic zones. |
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