Research On Curve Tensioning Technology And Application Of Prestressed Carbon Fiber Sheet

The use of prestressed carbon fiber sheets to reinforce equal-section bridges has been used extensively,while the use of reinforced cross-section beam bridges is relatively rare.For the reinforcement of variable cross-section bridges,this paper takes the prestressed carbon fiber board with tensioned tension as the research object,and attempts to explore the prestress loss and tensioning process of the prestressed carbon fiber board in the cross section bridge reinforcement.Through the study of this paper,the following main conclusions are obtained:1,first through experiments to explore the friction between the prestressed carbon fiber sheet and the steering block in the tension state under tensile state,use the waveform anchoring tension system to control the tension angle of the carbon fiber sheet,by changing the different friction media and The number of different steering blocks was used to explore the loss of prestress caused by the contact between different friction media between the prestressed carbon fiber board and the steering block,in order to develop a tensile carbon fiber sheet tensile test.In the experiment,the physical properties of various media materials were analyzed and compared.Four groups of different friction media were compared and related calculations were performed.2.In the position of the steering block,since the normal pressure distribution between the contact between the carbon fiber board and the steering block caused by the curvature change of the carbon fiber board and the contact block is actually non-uniform,the author proposes three on the basis of the elastic contact analysis.This simplified distribution hypothesis derives the contact pressure expression and pre-stress friction loss equation between the contact of the carbon fiber board and the steering block in the bending state,and the comparative analysis shows that the friction loss calculated by the uniform distribution is larger,and the tension is increased.When the value is small,the friction loss is calculated on the basis of a uniform distribution,so the friction formula calculated by uniform distribution can be applied to the actual project.3.Taking the reinforcement of the variable cross-section continuous girder bridge of the Sancha River Bridge in Nanjing as an example,the curve tensioning construction technology was introduced in detail,and the prestress loss during the construction of the carbon fiber board during actual construction was tested,and the paper used this paper.The results of the study were compared and analyzed to further verify the accuracy ofthe prestress friction formula.The successful implementation of the reinforcement of the Sancha River Bridge in Nanjing proved that the prestressed carbon fiber sheet reinforcement technology is a more applicable and effective reinforcement method for the variable section beam bridge.