Experimental Study On Flexural Behavior Of Self-Compacting Concrete Thin-Walled Box Girder Prestressed With External Carbon Fiber Reinforced Polymer Sheets

Self-compacting concrete thin-walled box girder prestressed with external carbon fiber reinforced polymer sheets not only combines the advantages of carbon fiber reinforced polymer sheets high strength, light weight, corrosion resistance, good fatigue resistance and self-compacting concrete high strength, durable, vibration-free, environmental protection, energy saving and so on, but also can be applied externally prestressing easily. The self-compacting concrete thin-walled box girder prestressed with carbon fiber reinforced polymer sheets would become more popular both in new construction and in strengthening of existing structures. The flexural behavior of the self-compacting concrete thin-walled box girder prestressed with carbon fiber reinforced polymer sheets was studied experimentally and theoretically, and the following works have been done:1,The experimental study on flexural behavior of the self-compacting concrete thin-walled box girder prestressed with carbon fiber reinforced polymer sheets showed that: Strain distribution along height at rib is agreed with the basic assume, i.e. Plane section before deforming remain plane. Strain of concrete section, longitudinal compression and tension ordinary steel strain and prestressed CFRP strain, box girder cracking load, yield load, ultimate load and the development and distribution of crack were discussed by the elasticity test before concrete cracking and whole process of destructive testing.2,The experimental study and analysis of the self-compacting concrete thin-walled box girder prestressed with carbon fiber reinforced polymer sheets showed that: The CFRP external prestress increment mainly lies on the whole deformation of the members and the section eccentricity of the external prestressed carbon fiber reinforced polymer sheets, also the calculated formulae before or behind cracks has been deduced,and the calculated results agree with test ones.3,According to the experimental and theoretical analysis of the self-compacting concrete thin-walled box girder prestressed with carbon fiber reinforced polymer sheets, the fully process analysis of the equivalent I-shaped section girder has been conducted. Meantime, combined the flexural carrying capacity ultimate state characteristic of concrete thin-walled box girder, when the strain of longitudinal steel at tensile region firstly arrives at 0.01, the ultimate flexural capacity calculated formula and designed formula of concrete thin-walled box girder have been obtained. The calculated value is safer than experimental vaule, which satisfies the engineering design request.