• Journal of the Korea institute for structural maintenance and inspection
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• v.13 no.1 s.53
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• pp.135-144
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• 2009

The present paper represents experimental studies on the performance of concrete filled FRP columns. Eight scale-down specimens were conducted by quasi-static cyclic loading test. FRP thickness, concrete strength, horizontal rebar ratio, and diameter were selected as test parameters. The capacities of ductility for cyclic loading was evaluated and the damping ratio and failure mode from the stiffness reduction of each test specimen were compared.

• 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.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.6A
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• pp.861-872
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• 2008

Concrete-filled glass fiber reinforced polymer tubes are often used for marine structures with the benefit of good durability and high resistance against corrosion under severe chemical environment. Current research presents results of a comprehensive experimental investigation on the behavior of axially loaded circular concrete-filled glass fiber reinforced polymer tubes. This paper is intended to examine several aspects related to the usage of glass fiber fabrics and filament wound layers used for outer shell of piles subjected to axial compression. The objectives of the study are as follows: (1) to evaluate the effectiveness of filament winding angle of glass fiber layers (2) to evaluate the effect of number of GFRP layers on the ultimate load and ductility of confined concrete (3) to evaluate the effect of loading condition of specimens on the effectiveness of confinement and failure characteristics as well, and (4) to propose a analytical model which describes the stress-strain behavior of the confined concrete. Three different types of glass fiber layers were chosen; fabric layer, ${\pm}45^{\circ}$ filament winding layer, and ${\pm}85^{\circ}$ filament winding layer. They were put together or used independently in the fabrication of tubes. Specimens that have various L:D ratios and different diameters have also been tested. Totally 27 GFRP tube specimens to investigate the tension capacity, and 66 concrete-filled GFRP tube specimens for compression test were prepared and tested. The behavior of the specimens in the axial and transverse directions, failure types were investigated. Analytical model and parameters were suggested to describe the stress-strain behavior of concrete under confinement.