Long-Term Monitoring of FRP-Concrete Composite Bridge Deck for Cable-Stayed Bridges Using Optical Fiber Sensors

The Korea Institute of Construction Technology has developed a precast FRP-concrete composite deck to be applied to cable-stayed bridges. This deck is a precast structural system in which concrete is disposed at the upper part and a hollow FRP tube is disposed at the bottom to play the role of tensile reinforcement and form. This paper presents the prototype of the so-developed FRP-concrete composite deck fabricated for trial construction. Electrical resistance sensors and optical fiber sensors were installed on the prototype to evaluate its structural stability and serviceability during the 17 months of operation through a series of field loading tests. From the field loading test results, the FRP-concrete composite deck was verified to secure sufficient structural stability and serviceability along the 17 months of operation even after the repeated passage of the heavy construction trucks. Besides, it appeared also that, for long-term monitoring, the optical fiber sensor provided more reliable measurement than the electrical resistance sensor glued to the structure.