FBG Sensors Application in Monitoring of Prestressed Concrete Bridges and Structures

Abstract Currently, a noticeable societal requirement to use the most accurate systems for assessing the reliability of existing structures and bridges is present. Especially, prestressed concrete bridges that were built in the 1960s today show serious failures. The connection between research and development in bridge monitoring has become very important. Experts are facing the need to use accurate measurement procedures and methods that will be functional directly in practice. Such applications include, for example, methods based on the principle of stress release from a prestressed member or detailed monitoring of the structure's response to direct and indirect loads. For such observations, it is possible to apply modern fiber‐optic FBG (Fiber Bragg Grating) sensors purposely modified to record strains. For adequate adjustment of the measurement instrument, it is important to define the specification of the required sensor so development will be focused on the accuracy of the outputs, the frequency of recordings, and the possibility of their installation. The article describes the application of these sensors on one existing post‐tensioned segmental bridge. Used sensors were developed to monitor joint openings. Finally, the advantages and disadvantages of individual applications are summarized. Such sensors can help the administrators monitor existing segmental bridges in real‐time and contribute to advanced Alert Systems for early action in the case of detected problems.