Most medium-span bridges are constructed with prestressed reinforced concrete. As these structures age, reliable monitoring systems are essential for detecting potential damage. Nonetheless, the ability to identify specific damage types and severities, specifically those related to prestress effects, and the conditions under which they can be detected remain open questions. To address these challenges, this study involved the construction of a full-scale prestressed bridge deck system, made of three prestressed girders that sustain a reinforced concrete slab. The prototype deck was subjected to progressively increasing loads and various damage scenarios to evaluate the effectiveness of a monitoring system in detecting structural damage. The monitoring system deployed in this study includes a comprehensive sensor network consisting of accelerometers, strain gauges, Linear Variable Differential Transducers LVDTs, temperature sensors, and inclinometers. These sensors capture critical structural responses, including natural frequencies, mode shapes, rotations, and strains, under ambient vibration testing (AVT) conditions prior to and after the application of each induced damage scenario. Specifically, damage scenarios includes the progressive reduction of prestress forces and localized stiffness loss, while also accounting for the environmental factors. The experimental findings were then compared with numerical results obtained through finite element analysis using SAP2000, providing an in-depth evaluation of the bridge system’s response to damage. This work contributes to the development of more effective structural health monitoring and maintenance strategies for prestressed concrete bridge systems, enhancing the understanding of their behavior under a wide range of damage conditions.

Keywords: Ambient Vibration Testing, Structural Health Monitoring, Finite Element Analysis, Prestressed concrete beams, Prestress loss, Damage assessment.