The Tensile Force Test Model of Vertical Prestressing Finishing Rolling Rebar in Box Girder

Vertical prestressing tendons finishing twisted steel is widely used in the concrete box girder, but ,it is hard to effectively control the loss of anchor stress. Based on the dynamic, the three-parameter model was built which include the frequency of the exposed segmentthe segment length of the exposed steel reinforcements and effective tensile force. The vertical tensioning force of the box girder webs model was designed at laboratory .The natural frequency was obtained through test. Relying on experimental test data ,the model of the nonlinear relationship between fine bundle the rebar tensile force and the exposed segment frequency was established. Here in NDT methods to be able to quickly and effectively measured vertical prestressing tension.