• Journal of the Society of Disaster Information
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• v.12 no.4
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• pp.422-431
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• 2016

This study was evaluated in the performance of the connection according to the details of the concrete casing segment in the prestressed composite girder by fabricating and testing specimens with different segments. A total of four comparative specimens were fabricated by using the variables of general composite girders, reinforcement or non-reinforcement, and details of reinforcing bars in the segments so as to evaluate the structural behavior of steel girders. In addition, the possibility of non-cracking grade design of segmented composite girders as well as the effects of stiffness and strength according to the loop connection types after cracking were analyzed, and the appropriateness of the crack width control both the embedded steel plate and the concrete surface were evaluated.

• Journal of Korean Society of Steel Construction
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• v.18 no.6
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• pp.793-804
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• 2006

Various PSC and steel-concrete composite railway bridges are being developed for short-medium spans with structural and economic efficiency. According to the design concept, the prestressed composite girder bridge has the advantages of being lightweight and having low girder depth, with the capacity for long spans. However, the dynamic behavior under a passing train is one of the critical issues concerning these railway bridges designed with more flexibility. Therefore, it is very important to evaluate the modal parameters before performing dynamic analyses. In this paper, real-scale prestressed composite girders were fabricated as a test model and modal testing was carried out to evaluate modal parameters including natural frequency and modal damping ratio. During the modal testing, a digitally controlled vibration exciter as well as an impact hammer was applied to obtain frequency-response functions, and the modal parameters were also evaluated after the fracture of test models. With application of reliable properties from modal tests, the estimation of dynamic performances of prestressed composite girder railway bridges can be obtained from various parametric studies on dynamic behavior under the passage of a moving train.

• Journal of Korean Society of Steel Construction
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• v.29 no.4
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• pp.311-321
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• 2017

This paper deals with the flexural performance of a composite girder system designed to readily form a composite section without a formwork and to easily realize multistage preflexing and prestressing. After a 3-Dimensional finite element modeling for construction stage analysis, the parametric numerical analysis was performed to analyse the stress distribution on the composite girder sections and the prestressing effects along with concrete pouring method and strand tensioning method. Based on the stress distribution analysis, a favorable construction stage model has been rationally chosen and then the ultimate flexural strengths were evaluated to conduct a comparative study, which exceed the nominal flexural strength suggested by the current design specification(ASD). It can be concluded that the proposed composite girder and fabrication procedure should have a sufficient structural performance.

• Proceedings of the KSR Conference
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• 2005.11a
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• pp.240-245
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• 2005

There has been a strong demand on more economic and lower depth girder bridges for short and medium span range, PRECOM, which is a new type steel-concrete composite girder, has been developed to realize a more economic bridge system with a lower depth girder. In the PRECOM girder bridge, a steel plate girder is simply supported and then concrete form is hung to girder. Thus, the self-weight of the concrete is loaded to the steel girder. To increase the resistance of concrete in the lower casing against tensile stress, compressive force is introduced by prestressed tendon To evaluate the manufacturability and performances of the completed bridge, four 15-m girders and a bridge specimen with two 20m girders wvere constructed. The camber during the construction and introduction of an appropriate compressive force was evaluated. Dynamic data were obtained through the modal testing of the completed girders. Static loading test was also conducted to examine cracks and evaluate the decrease in stiffness and failure behavior under extreme conditions.