Research On Prestress Loss And Reinforcement Of Prestressed Concrete Simply Supported Beam In Seasonal Frost Region

In the research field of prestressed concrete bridge,the study of prestressing loss has been a topic of great concern and attention.The prestressing loss can not only reduce the crack resistance of bridge structure,but also reduce the stiffness of the structure,and then affect the ultimate bearing capacity of the structure.Because the bridge is often in the outer environment,the prestressing loss is greatly affected by the objective environment.In addition,some of the existing bridges are in the stage of serious damage.Compared with the demolition and reconstruction,it is a good choice to strengthen the bridge,which can prolong the service life and reduce the economic burden of the country.In this context,the Jilin Provincial Department of science and technology specially establish the research subject,the study is based on the project of the Jilin provincial science and technology department development plan —Research on safety identification and reinforcement of Prestressed concrete simply supported beam in Seasonal Frost Region.The main contents of this paper be summarized as follows:1.Design,manufacture,maintenance,prestressing tension,natural freezing thawing treatment,natural high temperature treatment and loading of prestressed concrete test beam.2.Fatigue,natural freeze-thaw and natural high temperature impact on the test beam deflection,concrete fatigue strain,steel fatigue strain and fatigue strain of steel strands and other changes of the law and comparative analysis of three.3.Study on fatigue prestress loss of prestressed concrete test beam under 3.factors of fatigue,natural freezing thawing and natural high temperature three factors.4.The prestressed concrete test beams strengthened with carbon fiber sheet(CFPR)are reinforced and subjected to static loading.The deflection of the test beams,the strain of concrete,the strain of steel bars and the development of cracks are compared before and after the reinforcement,and the reinforcement effect is studied.5.On the basis of the experiment,the finite element simulation is carried out by using ABAQUS software to verify the correctness of the test results,and the accuracy of the finite element model is verified reversely.