1. A Study on the Structural Test and Mechanical Behavior of the GFRP I Beam Superstructure Yeou-Fong Li 1 and Yen-Chun Chen 2 Keywords ： Fiber Reinforced Plastic, temporary bridge Abstract :This study presents Fiber Reinforced Plastic (FRP) composite components used in temporary bridge for emergency relief. There are some advantages of FRP, including light weight, high strength, weather resistance and easy storage, making FRP suitable for temporary bridge. There are two types of FRP temporary bridge in this study. First type is pedestrian bridge. Second type is vehicular bridge. The pedestrian bridge is suspension bridge made by the cable, FRP deck, FRP bar and FRP frame. Use SAP2000 to establish the numerical model. Load several different types of loads to simulate the real load and check the safety factor. Finally, make the FRP suspension bridge. The vehicular bridge use FRP beam-deck system as superstructure. Use SAP2000 to establish the numerical model. Establish the numerical model of different spans. The type of the load is according to the design of bridge code. Then check the safety factor. Finally, make the best type of FRP vehicular bridge. 1 Professor of the Department of Civil Engineering, NTUT, Taipei, Taiwan. 2 Master of the Department of Civil Engineering, NTUT, Taipei, Taiwan. Non Transverse Beam Transverse Beam Non DeckN.A. W4X2-T4 Deck W4X2-PC W4X2-PA N.A. Double Plate (Supporting pad) W4X2-P2W4X2-TP2 Screw Deck Transverse Beam Bolt Supporting Pad Screw Main Beam The Small-Scale Model GFRP bridge superstructure (I girder-deck) system. T4 is 3 Main Beam with 4 pair Transverse Beam fabricate by Bolt PC is 3 Main Beam with Deck fabricate by Epoxy PA is 3 Main Beam with Deck fabricate by Epoxy and Screws P2 is 3 Main Beam with Deck and Supporting pad fabricate by Epoxy and Screws TP2 is 3 Main Beam with 4 pair Transverse Beam fabricate by Bolt and with Deck fabricate by Epoxy and Screws also L1 is 1 Main Beam in prototype L1 C is 1 Main Beam in prototype connected at Midpoint P2C1 is 3 Main Beam of P2 system connected at Midpoint P2C1 is 3 Main Beam of P2 system connected at One-third point interlaced SpecimensP max (kN)K (kN/cm) Failure mode W4X2-L120.5921.22 T、CT、C W4X2-T4111.1855.75 V、FV、F W4X2-PC91.1767.30 S、IS、I W4X2-PA101.4574.18S W4X2-TP2118.0679.57F W4X2-P2141.9471.9 C、FC、F W4X2-L1C19.0319.89T W4X2-P2C1107.6267.35B W4X2-P2C2105.7461.21 B、WB、W T: Lateral Torsional Buckling C: Local crushing at loading area V: Shear failure at loading area I: Interface of the beam and deck fail. S: Shear failure at the bearing F: Weds cracking along fiber direction B: Bolts-hole tear W: Webs cracked in connection area Conclusions Test Result MidpointOne-third point ConnectionW4X2-P2C1W4X2-P2C2 The GFRP bridge superstructure (I girder-deck) system can be to avoid the prototype beam lateral torsional buckling. Install deck, transverse beam and supporting pad appropriately, can avoid local crushing and shear failure, increase strength and stiffness. When the strength is increased, the strength gradually passed to the webs of main beam, lead the failure mode changes to weds cracking along the fiber direction. This shows the interface strength of resin and fiber is not enough, the bolt hole will lead to a destruction occurred early. The connection bolts at the midpoint will slip relatively suddenly than one- third point interlaced In accordance with the span of the choice of Euler and Timoshenko beam theory formula can accurately predict the stiffness of the GFRP beam members. Local crushing at loading area Shear failure at loading area Interface of the beam and deck fail Shear failure at the bearingWeds cracking along the fiber direction Bolts-hole tear Webs cracked in connection area