prestressed concrete girders as shown in Figure 4.14. Two different types of CFRP reinforcements were used in the bridge. Two girders were pretensioned with 15.2mm diameter CFCC, produced by Tokyo Rope of Japan; at the other end of the bridge two further girders were pretensioned with 10mm diameter (indented) Leadline bars produced by Mitsubishi Chemical Corporation of Japan. Both types of CFRP were also used to provide shear reinforcement in two of the CFRP prestressed girders. Figure 4.14: Precast Taylor Bridge I-beam girder, (below) schematic of the girder and its reinforcement design. 
56Taylor Bridge is the first “smart bridge” and it was opened on 28 October 1997. It can be monitored remotely by engineers at a central monitoring station, which used phone lines to communicate with the onsite demodulation system and computer that interrogates the imposing array of 66-fiber optic Bragg grating sensors integrated into the bridge as shown in Figure 4.15. The bridge was instrumented with an array of fiber optic Bragg grating strain sensor and a number of conventional strain gauges. The 66 FBG sensors were distributed throughout the bridge to measure the strain in the: steel and CFRP prestressing tendons, steel and CFRP stirrups, concrete deck, and concrete barrier wall. Strain-temperature discrimination was done by installing a total 17 thermocouples were also installed for the strain sensing system. The installation of the sensors was undertaken by a team from ISIS-Canada and ElectroPhotonics Corporation (EPC). The scale of the girder can be gauged from Figure 4.16, which shows some of fiber optic sensors being installed within one of the girders. Figure 4.17 shows a fiber optic sensor being installed within part of the bridge barrier wall that is reinforced with glass FRP. Figure 4.15: Schematic of the fiber optic sensing system incorporated into the Taylor Bridge. 
57Figure 4.16: Installation of FBG sensors into the CFRP shear reinforcement frame for one of the precast concrete girders for Taylor Bridge.  Figure 4.17: Installation of FBG sensors into Taylor Bridge barrier wall reinforcement frames. 
58The fiber optic sensing system was developed specially for this bridge to operate over the wide range of weather conditions expected at the bridge site (-40ºC in the winter to +40ºC in the summer). Demodulation of the FBG sensor array was undertaken by means of a ruggedized EPC-FLS3500R, equipped with a 32-channel multiplexing unit for mapping the strain from both ends of the bridge and tracking it over the life of the bridge. In addition, a fast-response EPC-FLS3100 single-channel demodulation unit was provided for monitoring the dynamic response of the bridge to traffic loads. An overview of the fiber optic sensing system is schematically illustrated in Figure 4.18, with the inset showing the actual cables and demodulation system at the bridge site.