Laboratory and field performance of FOS sensors in static and dynamic strain monitoring in concrete bridge decks

There is a growing need for designing and constructing innovative concrete bridges using FRP reinforcing bars as internal reinforcement to avoid the corrosion problems and high costs of maintenance and repair. For efficient use and to increase the lifetime of these bridges, it is important to develop efficient monitoring systems for such innovative structures. Fabry-Perot and Bragg fibre optic sensors (FOS) that can measure the strains and temperature are promising candidates for life-long health monitoring of these structures. This article reports laboratory and field performance of Fabry-Perot and Bragg FOS sensors as well as electrical strain gauges in static and dynamic strain monitoring in concrete bridge decks. The laboratory tests include tensile testing of glass FRP bars and testing of full-scale concrete bridge deck slabs reinforced with glass and carbon FRP bars under static and cyclic concentrated loads. The field tests include static and dynamic testing of two bridges reinforced with steel and glass FRP bars. The obtained strain results showed satisfactory agreement between the different gauges.