This contribution illustrates the preliminary research findings of an ongoing structural health monitoring (SHM) campaign on prestressed concrete (PC) beams with artificially damaged prestressing strands. The specimens have been designed to be representative of a scaled bridge girder belonging to a 4-girder grillage scheme, with the transverse diaphragm here simulated by means of a transversal steel profile crossing the main girder at its mid-span. The SHM tests are aimed at analyzing both serviceability and ultimate load conditions of these PC girders under different damage scenarios by means of modal identification techniques based on operational modal analysis (OMA). Indeed, the specimens have been manufactured with small holes in their bottom face, thus enabling the execution of some cuts of prestressing strands to artificially simulate damage in the prestressing system at different locations. A network of piezoelectric and MEMS acceleometric sensors are deployed along the beam to capture the main vibration frequencies and mode shapes in the various phases of the experimental campaign. The experimental campaign includes progressively increasing load levels and different damage scenarios (in terms of locations and amounts of strands’ cuts). The experimental tests have been complemented by a finite element model (FEM) of the beams, incorporating nonlinear behavior through fiber hinges and staged construction to reproduce the various phases of the experimental campaign. This finite element modeling strategy has been preliminarily validated by comparison with previously tested PC beams with two different prestressing levels and is also corroborated by a good match with ongoing experimental results of the present experimental campaign in terms of natural frequencies and mode shapes.