PSI - Issue 62

A. Lupoi et al. / Procedia Structural Integrity 62 (2024) 963–971 A. Lupoi, F. Romano / Structural Integrity Procedia 00 (2024) 000–000

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the experimental results. Instead, the collapse load that activate a shear failure is F SHEAR = 1540 kN, located approximately 3 m from the mid-span section, since the shear force increases because of the girder self-weight, the stirrups spacing is double with respect to the girder ends, and the positive contribute of the curved tendons to the shear force is absent. Therefore, the expected collapse mode is due to a fragile flexural failure, consistently with the experimental results, and such expected collapse load is about 4.5% higher than the one measured by the experimental test ( F EXP = 718.4 kN). It can be concluded that the original girder capacity is still preserved after reparation and about 50 years of service life. A complete numerical simulation of the test is under development for future publication. The paper reports the results of an experimental cyclic three-point test performed on an existing prestressed concrete bridge girder, removed from a bridge of the Italian highway network. Before the test, an existing full-depth horizontal crack located close to the mid-span zone have been repaired by high-pressure injection of specific high-resistance mortar. The experimental test results show a flexural failure of the girder, attained in a fragile manner, namely without the spread of significant crack patterns throughout the cycles. The collapse occurred far away from the intervention area and from the mid-span section, and the concentrated load value at collapse is close to the expected analytical load that cause the mid-span flexural failure. Such observations demonstrate the high performance of the materials adopted and the effectiveness of the injection technique used to restore the pre-cracking condition of the damaged area. 4. Conclusions

Acknowledgements

The authors would like to thank Autostrade per l’Italia SpA , in particular the Direzione di Tronco 3 , for funding the experimental test.

References

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