Stay cable bridge systems have been used for centuries and as engineering knowledge and new materials has developed, these bridges have become larger, more elegant, and overall greater engineering feats. As these bridges become more popular, it is not only important to carefully design these bridges, but also to routinely inspect the health of the in-service bridges. Detrimental conditions such as corrosion, section loss, strand breakage, segregated grout, voided grout, water infiltration, and general tendon deterioration in the anchorage system are documented issues that can occur within stay cable bridges and can have extremely harmful effects. In order to monitor the health of these bridges, non-destructive evaluation (NDE) can be a very useful tool in order to inspect these bridges without having to repair the system after inspection. In this research, ground penetrating radar, magnetic flux leakage, infrared thermography, ultrasonic tomography, sounding, and borescope inspections are all performed on a series of mock-up stay cable specimens fabricated with certain detrimental conditions located within. The applicability, capabilities, and limitations of each NDE method are evaluated based on empirical data from physical testing. Furthermore, each method is ranked in categories of precision, accuracy, ease of use, inspection requirements, and cost. This research concludes that only magnetic flux leakage has the ability to determine any sort of steel strand defects, including corrosion, section loss, and strand breakage; and it was very effective in doing so, as testing data closely matched fabricated defects. Ground penetrating radar, infrared thermography, ultrasonic tomography, and sounding were all able to accurately identify grout voids within the tendon but could not differentiate between a voided region and a region infiltrated with water or poor grout conditions. In future research, additional testing to differentiate testing results between these three conditions should be explored, as each one can require completely different solutions to remedy the problem. In addition, none of the methods explored in this research were able to detect any defects within the concrete masses representative of the anchorage regions, although infrared thermography and sounding were effective at determining voided areas within the grout caps. Lastly, borescope inspection was a very useful tool to qualitatively evaluate conditions that have already been identified by one of the other methods.
