• Structural Engineering and Mechanics
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• v.69 no.4
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• pp.371-381
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• 2019

A hybrid prestressed segmental concrete (HPSC) girder utilizing low carbon materials was developed in this paper. This paper introduces the hybrid prestressing concept of pre-tensioning the center segment and assembling all segments by post-tensioning, as well as the development process of the low carbon HPSC girder. First, an optimized mix proportion of 60 MPa high strength concrete containing high volume blast furnace slag was developed, then its mechanical properties and durability characteristics were evaluated. Second, the mechanical properties of 2,400 MPa high strength prestressing strands and the transfer length characteristics in pre-tensioned prestressed concrete beams were evaluated. Third, using those low carbon materials and the hybrid prestressing concept, the HPSC girders were manufactured, and their structural performance was evaluated. A 30-m long HPSC girder for highway bridges and a 35-m long HPSC girder for railway bridges were designed, manufactured, and structurally confirmed as having sufficient strength and safety. Finally, five 35-m long HPSC girders were successfully applied to an actual railway bridge for the first time.

• Proceedings of the KSR Conference
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• 1999.05a
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• pp.434-441
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• 1999

The newly proposed Precast Segmental Mettled (PSM), which makes use of precast elements for election, is relatively new, efficient and fast mettled for the construction of prestressed box girder bridges. A precast segment of 25m long pretensioned in the fabrication yard is transported by a special trailer and a launching truss to its final position. The segments are then connected in the site by post-tensioning to make a continuous prestressed concrete box girder bridges. The purpose of this parer is to analyze and evaluate the design of precast prestressed concrete box girder bridges. The detailed analyses including time-dependent behavior of PSM bridges are conducted. The major results and findings, which have been obtained from finite element analysis of PSM bridge, are discussed in this paper and these results will be a good base for the design and analysis of a new precast bridges.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.05a
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• pp.415-418
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• 2005

Prestressed composite girder bridges with PS tendon at positive flexural moment region offer elastic behavior to higher loads, increased ultimate capacity and reduced structural steel weight. Two beams were tested to examine ultimate behaviors of prestressed composite girder bridges subjected to positive flexural moment. The experimental observations of the Prestressed composite girder bridges subjected to positive flexural moment are investigated and compared to the numerical results obtained by sectional analysis method, and 1-D. and 3-D. finite element analysis methods.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.05a
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• pp.419-422
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• 2005

Prestressed composite girder bridges with concrete infilled steel tube at negative flexural moment region takes the advantages provided due to the interactive reaction in the steel tube and concrete interface layer, enhancing local buckling resistance and the concrete strength provided by the lateral confining effect of concrete. Two beams were tested to examine ultimate behaviors of prestressed composite girder bridges subjected to negative flexural moment. The experimental observations of the Prestressed composite girder bridges subjected to positive flexural moment are investigated and compared to the numerical results obtained by sectional analysis method, and 1-D. and 3-D. finite element analysis methods.

• KCI Concrete Journal
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• v.12 no.1
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• pp.17-22
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• 2000

This Paper deals with the analysis of both unstrengthened and strengthened prestressed concrete girder bridges. Finite element method is utilized to perform the analysis of superstructures. Based on the grillage method of analysis. emphasis is Placed on the modeling techniques for structures. The conventional grillage method of analysis is modif'=ed so that the interaction between the slab and gilder behaviors can be taken into account in the analysis A Prototype of simply supported prestressed I-type girder bridge is selected for the analysis. The results of numerical analyses are compared with those of load test. The results of analysis indicate that the proposed method of analysis gives more realistic response of bridges than the conventional grillage method.

• Magazine of the Korea Concrete Institute
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• v.5 no.4
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• pp.135-144
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• 1993

A fatigue analysis procedure for prestressed concrete composite girder bridges is established, which includes the time-dependent effects of component materials. The procedure can take into account the movement of neutral axis depth as crack develops and give quite good agreement with experimental results available. It is also assured that Korean Standard prestressed concrete composite girder has enough fatigue resistance. The procedure in this paper gives a way to express the fatigue capacity of prestressed concrete beams in the form of S-N curve, which can be utilized under variable amplitude fatigue load.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.357-360
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• 2008

This study was performed to estimate the workability and the static behavior for Bi Prestressed Concrete Girder(Bicon girder) which could introduce effectively prestressed forces into concrete girders. A bicon girder is manufactured by means of introducing pure bending moment that prestress simultaneously the compressive member(steel bar) and the tensile member(steel tendon). Static test was executed for 20m railway bridge girder specimen and evaluated whether pure bending moment was introduced or not, and the behaviors after cracking, and at the ultimate load. Test results showed that a bicon girder had the enough safety in the introduction of pure moment, the serviceability, and the ultimate behavior.

• Magazine of the Korea Concrete Institute
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• v.6 no.2
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• pp.148-158
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• 1994

The goal of this study is to develop an equivalent fatigue load model for prestressed concrete composite girder bridges in Korea. To meet this goal, the probabilistic characteristics of traffics which cause fatigue damage in bridges are properly modeled. An equivalent fatigue load inodel for prestressed concrete composite girder bridges with constant. amplitude and frequency is established. The model proposed in this paper is very simple to use and gives fairly good results.

• Journal of the Korean Society for Railway
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• v.9 no.4 s.35
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• pp.467-472
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• 2006

This paper deals with the applicability of long-gauge deformation fiber optic sensors (FOS) to prestressed concrete structures. A main motivation is the desire to monitor the deflection of the railway bridges without intervenes of the signal intensity fluctuations. A 25 m long, 1.8 m deep PSC girder was fabricated compositely with 22 cm thick reinforced concrete deck. Two pairs of 3 m long-gauge sensors are attached to the prestressed concrete girder with parallel topology. Using the relationship between curvature and vortical deflection and the quadratic regression of curvatures at the discrete point, it is possible to extrapolate the deflection curve of the girder. The estimated deflection based on the developed method is compared with the results using conventional strain gauges and LVDTS. It has been demonstrated that the proposed instrumentation technique is capable of estimating the vertical deflection and neutral axis position of the prestressed concrete girder up to weak nonlinear region.

• KCI Concrete Journal
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• v.11 no.3
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• pp.141-151
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• 1999

In the replacement of bearing system of bridges, the jacking work to secure work spaces may cause damage of the superstructure, hence the behavior of superstructure by the jacking force must be considered. Especially, in prestressed concrete I-type girder bridges, considering the stress concentration at the girder and the load redistribution of superstructure, the allowable jacking force and jacking sequence have to be determined. In this study, an analytical method is proposed to calculate the jacking force and overall jacking sequence for the replacement of bearing system without any damage to the superstructure. The stress concentration at the girder and load redistribution of the deck due to jacking force are considered to compute the allowable jacking force for each girder and overall jacking sequence for girders in the deck. Using the solution algorithm developed in this study, the optimum jacking sequence and required jacking force for the prestressed concrete I-type gilder bridge having the standard sections are calculated.