Description
Given the present landscape of existing bridges in Italy, a significant portion of which dates back to the mid-20th century, the need to conduct detailed investigations on the current deterioration state and on the safety of these infrastructures becomes indispensable. This work, focusing on a case study involving reinforced concrete tie rods removed from a 70-year-old arch bridge and preserved for mini-invasive diagnostics, addresses the critical need of estimating the current condition of these elements while verifying whether the common non-destructive techniques can be used to monitor the progress of deterioration. Both electrochemical measurements (e.g. corrosion potential and electrical resistivity) were used to detect the current corrosion conditions of steel bars; small core samples were also extracted to assess the presence of carbonation. In addition, this study allowed to investigate the effectiveness of the past restoration interventions, determining whether they achieved the designed outcomes. This research questions the effectiveness of these diagnostic measures to propose their repetition in situ for reliable, non-continuous monitoring of the structural health of these elements over time. The next steps involve visual inspection and mechanical characterization of the reinforcement to demonstrate the effectiveness of the diagnostics presented.
