PSI - Issue 84

Andrea Nino Consiglio et al. / Procedia Structural Integrity 84 (2026) 914–921

921

supported pre–tensioned concrete beam, and subjected to an additional vertical loading, was measured in the laboratory. Thus, the identified pre–tensioning forces proved the feasibility of both approaches. Yet, the “cracking” method can exclusively be applied to decommissioned PC girder-bridges requiring the knowledge of the design prestressing. In the absence of diagnostic methods and/or measurements at the time of construction, such a parameter is characterized by a poor reliability which can, in turn, reach an error of ±10%. Contrariwise, the “static deflected shape” approach requires an accurate estimate of the flexural rigidity of the PC girder-bridge. Such an evaluation is usually characterized by a poor accuracy regarding pre–tensioned concrete girder-bridges because their cross-sections often lack a good symmetry. Instead, about the elastic modulus evaluation, compression tests on a set of cores drilled along the PC girder-bridge are still highly recommended. Accordingly, in the absence of a precise measurement of flexural rigidity and vertical loading, first-order deflections represent a good approximation of the small-deflection measurements along a PC bridge. In conclusion, the feasibility of the implementation of the “static deflected shape” method for identifying residual prestressing in a multi-span “pre–tensioned” concrete bridge was verified. Acknowledgements Authors wish to acknowledge assistance work by technical staff of Akron S.r.l. and Precompressi Centro Nord for the concrete specimens. References Bažant, Z.P., Cedolin, L., 2010. Stability of Structures: Elastic, Inelastic, Fracture and Damage Theories. World Scientific, Singapore. Bonopera, M., Chang, K.C., 2021. Novel Method for Identifying Residual Prestress Force in Simply Supported Concrete Girder -Bridges. Advances in Structural Engineering 24 (14), 3238 – 3251. Bonopera, M., Chang, K.C., Chen, C.C., Sung, Y.C., Tullini, N., 2018. 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