PSI - Issue 62

Nico Di Stefano et al. / Procedia Structural Integrity 62 (2024) 809–814 Nico Di Stefano, Anna Bontempi, Paolo Pizzini, Fausto Minelli/ Structural Integrity Procedia 00 (2019) 000 – 000

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Figure 6: Experimental and Numerical results (Total Load VS Midspan Deflection).

4. Conclusions During the experimentation two naturally corroded 90 years old full-scale girders were tested under 4 points loading in the laboratory of the University of Brescia. After a preliminary and in-deep diagnostic, it was possible to fully understand the geometrical details and material properties of the specimens, and particularly the evaluation of corrosion for beam N2. Stirrups were the most corroded elements of the section, but that didn’t affect the behavior in terms of ultimate resistance: in fact the collapse, in both cases, led to a flexural mechanism. For beam N1, there was no significant variation of the ultimate resistance, considering the uncorroded and corroded scenario, because of the low corrosion rate of the longitudinal rebars; otherwise in beam N2 a reduction of resistance of about 19% in terms of ultimate load was seen. Moreover, the most representative scenario for the degradation condition of beam N2 was the one in which the maximum corrosion rate for the longitudinal reinforcement was considered. Numerical analyses are in good agreement with experimental results, but finer models to fully represent the real behavior of corroded girders has to be developed. The two specimens are one of the few examples of tests done on full-scale naturally corroded RC girders. 5. References Andrade, Carmen. 2020. «Initial Steps of Corrosion and Oxide Characteristics». Structural Concrete 21 (5): 1710 – 19. https://doi.org/10.1002/suco.201900318. Azad, Abul K, Shamsad Ahmad, e Syed A Azher. 2007. «Residual Strength of Corrosion-Damaged Reinforced Concrete Beams». ACI Materials Journal 104 (1): 40 – 47. Belletti, Beatrice, Jesús Rodríguez, Carmen Andrade, Lorenzo Franceschini, Javier Sánchez Montero, e Francesca Vecchi. 2020. «Experimental Tests on Shear Capacity of Naturally Corroded Prestressed Beams». Structural Concrete 21 (5): 1777 – 93. https://doi.org/10.1002/suco.202000205. Cairns, John, Giovanni A. Plizzari, Yingang Du, David W. Law, e Chiara Franzoni. 2005. «Mechanical Properties of Corrosion-Damaged Reinforcement». ACI Materials Journal 102 (4). https://doi.org/10.14359/14619. Di Prisco, Marco. 2019. «Critical Infrastructures in Italy: State of the Art, Case Studies, Rational Approaches to Select the Intervention Priorities». In Proceedings of the Fib Symposium 2019 , 49 – 58. Poland: Wit Derkowski. Rodriguez, J, Lm Ortega, e J Casal. 1997. «Load Carrying Capacity of Concrete Structures with Corroded Reinforcement». Construction and Building Materials 11 (4): 239 – 48. https://doi.org/10.1016/S0950-0618(97)00043-3. Vecchio, Frank J., e Michael P. Collins. 1986. «The Modified Compression-Field Theory for Reinforced Concrete Elements Subjected to Shear». ACI Journal Proceedings 83 (2). https://doi.org/10.14359/10416. Wong, P. S., Frank J Vecchio, e H Trommels. 2013. «VecTor2 & FormWorks user’s manual: second edition».