DFOS sensors were glued to the upper surface of the girder using two-component epoxy to monitor strains within the anchorage zone (along longitudinal and transverse sections at the same time). With high-spatial-resolution strain measurements, the transmission length of the tendon – related to the quality of cement injection – was analyzed in exceptional detail. Measurements were conducted in both static and dynamic (high-frequency) modes as one of the tendons was cut. Additionally, this approach enabled the detection of existing microcracks and estimation of their widths. The tests demonstrated the significant potential of DFOS technology for assessing existing prestressed concrete structures.