• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.2
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• pp.355-365
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• 2014

Concrete-filled tubes (CFTs) have been used in civil engineering practices as a column of buildings and a bridge pier. CFTs have several advantages over the conventional reinforced concrete columns, such as rapid construction, enhanced buckling resistance, and inherited confinement effect. However, CFT component have not been widely used in civil engineering practice, since the design provisions among codes significantly vary each other. It leads to conservative design of CFT component. In this study, the design provisions of AISC and EC4 for CFT component were examined, based on the extensive test results conducted by previous researchers and finite element analysis results obtained in this study. Especially, the focus was made on the validation of P-M interaction curves proposed by AISC and EC4. From the results, it was found that the current design codes considerably underestimated the strength of CFT component under general combined axial load and bending. Finally, the modified P-M interaction curve was proposed and successfully verified.

• Composites Research
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• v.21 no.3
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• pp.24-30
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• 2008

Durability problems may arise in the concrete, which is one of the major construction materials, used in the construction field. Bridge piers and foundation piles are usually made with concrete and they are exposed to the moisture and hence the durability of the concrete reduced significantly due to oxidization of re-bar and icing of concrete. To mitigate such problems, FRP tube has been developed and the concrete filled FRP tube (CFFT) has been investigated to find the confinement effect which is provided additionally. It was reported that if the concrete is wrapped with FRP, strength and chemical resistance are improved significantly. In order to apply such a member in the construction field, structural behavior and applicable design guideline or design criteria must be thoroughly investigated. In the experimental investigation, the results are compared with the previous research results and the relationship which can predict the ultimate strength and strain is suggested. In addition, some comments found at the compression tests are given briefly.

• Journal of the Earthquake Engineering Society of Korea
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• v.11 no.3 s.55
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• pp.87-96
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• 2007

A new Energy-Dissipating Sacrificial Device (EDSD) is developed for steel plate girders, which can effectively dissipate the energy stored in the structures during seismic actions. To verify the performance of the EDSD, various seismic responses of a sample bridge with the EDSD are analyzed in terms of energy, member forces and deformation. The full scale model tests are conducted to certify the performance of the EDSD when it is applied on existing bridges. Using the improved hysteretic model of the sacrificial member, the seismic analysis for an example bridge is performed. The results show that the proposed EDSD under seismic excitations can significantly decrease the energy stored in the bridge structures and reduce the relative displacements of each superstructure to the ground. The EDSD is also found to function as a structural fuse under strong ground motions, sacrificing itself to absorb the excessive energy. Consequently, economical enhancement of the seismic performance of bridges can be achieved by employing the newly developed energy-dissipating sacrificial device.