Experimental Research On The Flexural Fatigue Behavior Of Concrete Beams Reinforced With Bonded Prestressed CFRP Plate

In recent years,because of its light weight,high strength,good durability,corrosion resistance and other excellent mechanical properties,Carbon Fiber Reinforced Polymer has been widely used in the concrete structure reinforcement engineering.The reinforcement technology of prestressed CFRP materials can improve the strength of CFRP materials,improve the mechanical properties of the structure,and delay the peeling failure,effectively.Therefore,it has broad prospects for development in the reinforcement engineering.At present,a lot of experiments and theoretical analysis on the concrete structure reinforced with prestress CFRP plate have done by domestic and foreign scholars,and fatigue damage is one of the main failure types of bridge,crane beam and so on,so it is necessary to carry out fatigue tests and theoretical analysis on the fatigue test of the concrete beams reinforced with prestressed CFRP plate.Two groups of three reinforced specimens were tested under fatigue loading and static loading to investigate the effect of anchoring style and prestress level on the fatigue properties of concrete beams reinforced with bonded prestressed CFRP plate.Failure modes,verification of plane hypothesis,material strain and deflection were analyzed.The results show that the fatigue performance of concrete beams strengthened with bonded prestressed CFRP plate can meet the requirements of normal use.Increasing the level of prestress can improve the crack resistance of the component,limit the development of cracks effectively,reduce the fatigue stiffness degradation of components and improve the ability to resist deformation.With the increase of the level of prestress,the ductility of the strengthened members will be decreased,which we should pay special attention to when designing reinforced component;Under the premise of good working performance of the anchorage,the anchorage mode has a little influence on the fatigue properties of the reinforced members.Based on the experimental research of reinforced concrete,the fatigue properties of steel,concrete,and CFRP plate are introduced in detail,the fatigue design method of normal section for reinforced members is proposed,and the test data is used to verify the reliability of the existing deflection calculation formula of fatigue.