Glass fiber-reinforced plastic composites are particularly attractive as bridge deck systems due to their high strength, low density, and excellent corrosion resistance, which are of importance to the bridge industry. According to ACI 440.3R-04, the tests consisting of 100 glass fiber-reinforced plastic bridge deck samples were conducted to evaluate the mechanical behaviors of glass fiber-reinforced plastic bridge decks (including tensile property and flexural property) in terms of temperature of the alkaline solution and time period. The parameters of temperature included 40 C and 60 C, and the investigated corrosion time included 3.65 days, 18 days, 36.5 days and 92 days, respectively. The micro-formation of the glass fiber-reinforced plastic bridge deck samples surface were surveyed under scanning electron microscopy, which indicated that corrosion pits on the surface of glass fiber-reinforced plastic bridge decks became obvious and the interface between fibers and resins was severely damaged with the aging time and temperature increased. After being exposed to alkaline solution for 92 days at 40 C and 60 C, the tensile strength of glass fiber-reinforced plastic bridge decks decreased by 35.43% and 40.58%, respectively, while the flexural strength decreased by 21.36% and 42.10%, respectively. In addition, the degradation model of tensile strength and flexural strength of glass fiber-reinforced plastic bridge deck under alkaline solution were proposed based on Arrhenius equation.

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Five steel-concrete composite beams are tested under low reversed cyclic loading. The failure patterns, hysteretic characteristics, hysteretic model, deformation restoring capacity, ductility, energy dissipation capacity, stiffness degradation and slips of the prestressed composite beams are discussed. Attention is paid to the effects of partial prestress ratio and degree of shear connection on the seismic performance of these beams. Studies show that the prestressed composite beams behave in a relatively ductile manner. Ductility of the composite beams decreases as the partial prestress ratio and the degree of shear connection increase. It was also observed that the applied prestressing is favourable for energy dissipation during downwards loading. Slips between concrete slabs and steel beams have adverse effects on energy dissipation in positive moment regions of composite beams. Tests also show that the effects of partial prestress ratio and the degree of shear connection are negligible to degradation of stiffness in composite beams.

Bond strength of glass fibre-reinforced polymer (GFRP) bars with helically wound ribs was experimentally investigated in this study and compared to that of smooth glass fibre-reinforced polymer bars and steel bars. A total of 63 pullout specimens are tested. Variables of the tests involved four types of bars, namely, glass fibre-reinforced polymer bar with helically wound ribs, smooth glass fibre-reinforced polymer bar, ribbed steel bar and smooth steel bar, as well as different bonding agents, including normal concrete, high-performance concrete, grout and epoxy resin. Test results showed that bond failure of glass fibre-reinforced polymer bars with helically wound ribs is because of the shearing off of the ribs with small slips, and the ribs helically wound can improve the bond strength of glass fibre-reinforced polymer bars by 3∼14 times, which is around 13, 9·31 and 15·7 MPa in concrete, grout and epoxy resin, respectively. In addition, polypropylene fibres in high-performance concrete can improve the bond behaviour of anchors.

Prestressed concrete(PC) channel bridge, consisting of a PC deck slab, two PC girders and two end crossbeams, is a new type of bridge structures. The PC channel bridges have been widely used in the structures such as highway, railway as well as urban rail transport. This paper presents a finite element method (FEM) analysis of mechanical behaviours of channel bridges with three girders in the construction, service and ultimate limit stage. The primary results include:(1) the channel bridges act elastically in the construction stage. (2) under the service loads, the deflections in the mid-span and the stresses on the whole concrete cross section could meet the requirements of the current codes. (3) the FEA results of flexural capacity of the channel bridges agree well with the results calculated according to the current codes, and the average loads of flexural capacity are about 3.26 times the design loads.