Review and analysis of RC bridge half-joints strengthening techniques

• Published in: Procedia Structural Integrity 2024, Vol.62, p.1020-1027
• Main Authors: Picciano, Valentina, Santarsiero, Giuseppe, Masi, Angelo, Ventura, Giuseppe
• Format: Article
• Language: English
• Subjects: Bridge; Degradation; Finite Element Analysis; Half-Joint; Rehabilitation; Repair
• ISSN: 2452-3216; 2452-3216
• DOI: 10.1016/j.prostr.2024.09.136

In the past, the extensive use of the Gerber scheme in the construction of existing bridges has been justified by the advantages in terms of reduced stresses of the statically determined scheme and rapid execution. On the other hand, the presence of junction elements at the ends of the beams has over time led to a series of issues, especially related to their durability. In fact, the half-joints’ geometric configuration leads to the accumulation of degradation due to platform water seepage, resulting in the initiation of reinforcement corrosion, especially in the presence of chlorides derived from de-icing salts used in the winter season. Furthermore, these elements have been designed for lower loads than those specified in current regulations, and therefore, they may be in critical conditions where the strength reduction, due to existing degradation, can lead to failure. For these reasons, local repairs and/or strengthening interventions are necessary to ensure adequate levels of safety. Within this study, the topic of reinforcing half-joints is addressed, first by describing the currently available intervention techniques in the literature, and then by deepening an intervention technique based on the use of external post-tensioned bars, applied to a case study bridge through nonlinear numerical simulations. These analyses allow quantifying the performance improvements of this technique under both service conditions and ultimate loads, considering various parameters, including the pre-stress value applied to the external tendons and different scenarios of chloride-induced corrosion.