Efficient Prestressed High Strength Concrete Deck Hollow Plate Pilot Study

At present, the main difference between China civil engineering industry and that of developed countries is that the strength of the concrete applied in China is lower and not economic. The using of high strength concrete on bridge structure, can effectively lower the structural weight and depth, increase structural rigidity and bridge span, and furthermore, improve the structural durability. Aimed at middle and small span bridge, optimum design and prototype experiment of high strength prestressed concrete hollow beam is done. The main works are as follows:1. Based on the requirement of highway engineering, the optimum design of hollow beam section and reinforcement that using high strength concrete are done. The section and reinforcement design method of prestressed high strength concrete hollow beam is suggested, and comparison is made with normal prestressed concrete hollow beam.2. To improve the structural mechanism of prestressed concrete hollow beam that using C80 high strength concrete and high uniform elongation & low relaxation class 270 high strength strand , the experiment of a prototype 16m hollow beam is made.3. Based on the experiment result, the structural mechanism of secant section and obagonal section of experiment beam is proved. And furthermore , it is proved that the brittleness of the high strength concrete can be improved by adjusting the reinforcement in the compression zone. By using high uniform elongation & low relaxation class 270 high strength strand, the elongation of the beam can be increased significantly ,and fulfill or higher than the Code requirement.The optimum design method give in this paper is of practical meaning, and give scientific research basis for the application of high strength prestressed concrete hollow beam in the bridge engineering, and give valuable experience for the further research.