PSI - Issue 62

Gianluca Bottin et al. / Procedia Structural Integrity 62 (2024) 177–184 G. Bottin et al./ Structural Integrity Procedia 00 (2019) 000–000

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From these results, it can be estimated that the probability of a maximum load larger than 1000 kN (sum of the maximum load of the two MTS servo-hydraulic actuators hypothesized for the experimental design) is of about 4%, which is considered fairly low, permitting to confirm the use of the selected facilities. On the contrary, the initially hypothesized stroke of the actuators is insufficient to reach the failure condition of the girder as clearly demonstrated by the analyses carried out using the mean values of material parameters. The designed ad-hoc solution providing special shimming system for the reaction frames, to be removed when the actuator stroke is reached, allows reaching a maximum mid-span deflection of 900 mm. The probability of reaching this maximum deflection is estimated from the analyses to be about 12.4%, which is considered fairly low and acceptable within the scope of this research. 4. Conclusion The paper presents the first phases of a comprehensive experimental-numerical research on a 80-years RC bridge scheduled for demolition. The research aims to test the entire process of acquiring knowledge and to provide new insight in the assessing of the structural performance of naturally degraded RC elements. After a brief overview of the on-site tests and investigation to characterize the geometry, the constructive details, the materials and the conservation state of the existing artefact, in this work focus is given on the design of the experimental test with the support of an extensive predictive numerical campaign. With the data obtained from on-site test campaigns, full-scale laboratory tests and FE analyses, it will be therefore possible to provide some preliminary indications on the reliability of the type of tests that can be carried out on site both for mechanical characterization and, above all, to estimate the extent of the degradation. Acknowledgements The studies were carried out as part of two research projects: the first is envisaged by the Agreement between the High Council of Public Works (CSLLPP) and the ReLUIS Consortium implementing Ministerial Decree 578/2020 and Ministerial Decree 240/2022 (the contents of this paper represent the authors’ ideas and do not necessarily correspond to the official opinion and policies of CSLLPP). The second activity is within the RETURN Extended Partnership and received funding from the European Union Next-GenerationEU (National Recovery and Resilience Plan – NRRP, Mission 4, Component 2, Investment 1.3 – D.D. 1243 2/8/2022, PE0000005). The kind support of the Padova Province is also acknowledged. 5. References Ministry of Infrastructures and Transports, 2020. Ministerial Decree 578 on 17.12.2020. Guidelines for risk classification, safety assessment and structural health monitoring of existing bridges, Italy (in Italian). McKenna, F.; Scott, M.H.; Fenves, G.L., 2010. Nonlinear Finite-Element Analysis Software Architecture Using Object Composition. J. Comput. Civ. Eng. 24, 95–107. Petracca, M.; Candeloro, F.; Camata, 2017. G. STKO user manual, ASDEA Software Technology. Cheilakou, E.; Theodorakeas, P.; Koui M.; Moustakidis, S.; Zeris, (2013) K. Application of Ground Penetrating Radar (GPR) As a Diagnostic Technique in Concrete Bridges Inspection. NDE for Safety / Defektoskopie 2012, 42nd International Conference, Oct 30 - Nov 1, 2012, Se č , Czech Republic. https://www.ndt.net/?id=14413. Cosenza, E, Losanno, (2021) D. Assessment of existing reinforced-concrete bridges under road-traffic loads according to the new Italian guidelines. Structural Concrete 22: 2868–2881. Savino, P.; Tondolo, F.; Sabia, D.; Quattrone, A.; Biondini, F.; Rosati, G.; Anghileri, M.; Chiaia, B. (2023) Large-Scale Experimental Static Testing on 50-Year-Old Prestressed Concrete Bridge Girders. Appl. Sci. 13, 834. https://doi.org/10.3390/app13020834. Jiang, H.; Mo, F.; Chen, Z.; Wu, J.; Fang, H.; Fang, Z.; Zhang, S.; Xu, Z. (2023) Full-Scale Experimental Study of Shear and Flexural Behavior of 16-m Retired Reinforced Concrete T-Beams. Buildings 13, 2075. https://doi.org/10.3390/buildings13082075. Pape, T.M.; Melchers R.E.. (2013) Performance of 45-year-old corroded prestressed concrete beams Proceedings of the Institution of Civil Engineers. Structures and Buildings, 166:10, 547-559. Tonelli, D.; Rossi, F.; Brighenti, F.; Verzobio, A.; Bonelli, A.; Zonta, D. (2023) Prestressed concrete bridge tested to failure: the Alveo Vecchio viaduct case study. J Civil Struct Health Monit 13, 873–899 (2023). https://doi.org/10.1007/s13349-022-00633-w.