• Journal of the Korea Concrete Institute
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• v.13 no.1
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• pp.1-8
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• 2001

Recently, prestressed concrete(PSC) bridge structures with many repetitive spans have been widely constructed using the segmental construction method in many countries. In these segmentally constructed PSC bridges, there exist many construction joints which is required coupling of tendons or overlapping of tendons to introduce continuous prestress through several spans of bridges. The purpose of this paper is to investigate in detail the complicated stress distributions around the tendon coupled joints in prestressed concrete girders. To this end, a comprehensive experimental program has been set up and a series of specimens have been tested to identify the effects of tendon coupling. The present study indicates that the longitudinal and transverse stress distributions of PSC girders with tendon couplers are quite different from those of PSC girders without tendon couplers. It is seen that the longitudinal compressive stresses introduced by prestressing are greatly reduced around coupled joints according to tendon coupling ratios. The large reduction of compressive stresses around the coupled joints may cause deleterious cracking problems in PSC girder bridges due to tensile stresses arising from live loads, shrinkage and temperature effects. The analysis results by finite element method correlate very well with test results observed complex strain distributions of tendon coupled members. It is expected that the results of this paper will provide a good basis for realistic design guideline around tendon coupled joints in PSC girder bridges.

• Journal of the Korean Society of Hazard Mitigation
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• v.2 no.3 s.6
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• pp.101-108
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• 2002

There exist many construction joints in segmentally constructed bridge girders. It is required coupling of tendons or overlapping of tendons to introduce continuous prestress through several spans of bridges. Even though tendon coupling method is easier to use in practice, some cracking problems around construction joints have been reported and complicated stress states around construction joints in PSC girders is not clearly investigated. The purpose of this paper is to investigate in detail the complicated longitudinal stress distributions around the construction joints in prestressed concrete girders with tendon couplers. To this end, a comprehensive experimental program has been set up and a series of specimens have been tested to identify the effects of tendon coupling and segmental construction of bridge sections. The present study indicates that the longitudinal stress distributions of PSC girders with tendon couplers are quite different from those of PSC girders without tendon couplers. The longitudinal compressive stresses introduced by prestressing are greatly reduced around coupled joints according to tendon coupling ratios.