PSI - Issue 84

Available online at www.sciencedirect.com

ScienceDirect

Procedia Structural Integrity 84 (2026) 653–660

© 2026 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the scientific committee of the Conference Abstract Reinforced and prestressed concrete bridges represent a significant portion of the existing bridge stock in Europe, serving as a critical backbone for both civil and freight transportation networks. Due to their exposure to environmental actions, the structural performance of these bridges deteriorates over time. Particularly vulnerable are prestressed concrete girder bridges with post tensioning tendons, whose internal steel tendons are susceptible to corrosion, often initiated by construction defects combined with external agents such as chlorides or carbonation. To date, numerous experimental studies in the literature have explored various models to geometrically and mechanically simulate corrosion in both mild and prestressing steel. However, enhancements are still needed in geometric modelling strategies for prestressing strands. Aiming to fill this gap, this study proposes a novel corrosion geometric model suitable for the probabilistic structural assessment of corroded bridge superstructures. The model addresses the pitting corrosion mechanism, by simulating the spatial geometry of corrosion pits assuming a parabolic shape. While existing geometric models are based on a single parameter, i.e., the maximum pit depth, and can model only discrete values of steel area loss, the parabolic shape simulates the pit area introducing a second parameter, i.e., the parabola opening, allowing a continuous variation of the area. A right-skewed Gumbel distribution is proposed for the parabola opening parameter, to render the model suitable for probabilistic analysis. The parameters of this statistical distribution are calibrated based on an available database in literature on naturally corroded prestressing strands extracted from prestressed concrete members. The model is well-suited for integration into detailed structural analyses using finite element methods. III Fabre Conference: Existing Bridges, Viaducts, and Tunnels: Research, Innovation, and Applications Enhanced geometric modelling of pitting corrosion in steel prestressing strands for bridge assessment Alessandro Nettis a,b , Andrea Nettis a *, Sergio Ruggieri a , Erasmo Caponio b , Giuseppina Uva a a DICATECH Department, Polytechnic University of Bari, Bari, Italy b DMMM Department, Polytechnic University of Bari, Bari, Italy

* Corresponding author. E-mail address: andrea.nettis@poliba.it

2452-3216 © 2026 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the scientific committee of the Conference 10.1016/j.prostr.2026.06.084