Mechanic Analysis Of Bridge Reinforcement With Mesh And Steel Fiber Reinforced Concrete And Construction Technology

The cast-in-plates between T-beams appeared transverse and longitudinal cracks, leakages and perforations easily. Some bridges were designed by Britian standard without pavement layer. Because of poor constuction, there are above diseases in these bridges. It's difficult to settle, even if repaired, new diseases will occur again shortly.The bridge deck localized cracks, leakages or even perforations on the operation of Dongguan Northern Bridge. The causes are mainly that the bridge was designed originally on the base of British specification BS5400, so there's not concrete bridge deck pavement. Moreover, because the concrete shrinkage and creep and construction quality, the wetland joint between the flanges of the prefabricated T.beam has lower quality. On the operation, the cracks propagate continuously, and there are a lot of fracture widths heavy over standard. The rainwater leaks though the crack, result to localized corrosion of steel bars and strength decreases. On the loaded car impact effect, localized cast.in.place plates perforate and even slump. The above are endangering safety of bridge service.The concrete reinforced both by steel bars and SFRC are called additional paving mesh and steel fiber reinforced concrete reinforced layer. Practice proves that the method is effective and easy. It's applicable to Dongguan Northern Bridge.This paper investigates parameter of the method. Using FEA soft analyzes global and local mechanical.In global mechanical analysis, Original bridge and the three reinforce of different deck thickNess are eablished, and the stress states of all load combinations are analyzed. Then, strength and crack width are checked with the transverse framework of models calculating. The optimal thickNess of mesh and SFRC bridge deck will be given.In local mechanical analysis of bridge deck, the top and bottom joins are assumed to be articulated and propagated throughout the body. The reinforcement ratio of reinforced layer is give. Then the checking meets safety requirement. It's proved that the heavily damaged cast.in.place plate should be removed. It can settle the above diseases. Especially, the top and bottom joins that assumed to be articulated and propagated throughout the body can save lots of capital, and short construction period.In order to improve the combination of reinforced overlay and the original bridge deck, the anchored steel bars are placed between the two layers. Considering shrinkage tensile stress and shear resistance mechanism between old and new concrete, the optimal anchor bar's distance has been discussed.Finally, the paper discusses construction technology of the method. The method has been applied to Dongguan Northern Bridge reinforcing construction successfully.