Study On The Bending Capacity Of Damaged Concrete Beam Reinforced By Prestressed Carbon Fiber Plate

With the gradual formation of the national road network,the focus of the transport infrastructure construction industry is gradually shifting from the new construction to the equal emphasis on building and maintaining.The reinforcement of bridge becomes to the hot topic emerging under the background of this era.Carbon fiber plate has been promoted and used in the reinforcement and improvement of bridge structures by the virtue of its excellent material properties and convenient practical performance.The prestressed carbon fiber plate reinforcement technology draws on the design concept of prestressed reinforce concrete,combines with the lightweight,high-strength feature of pasting carbon fiber reinforcement technology,which is a more efficient active reinforcement technology,and has a wide range of application prospect and value.In this paper,four rectangular concrete beams were designed,through the combination of model experiment and theoretical analysis to make a study on the bending capacity of the concrete beam reinforced by carbon fiber plate,The main research contents and conclusions are as follows:1.Maked the static loading tests on concrete beams that are not reinforced,reinforced by bonding carbon fiber plate,reinforced by prestressed carbon fiber plate,then compared and analyzed from load bearing capacity,deflection,ductility,cracks propagation,cooperate to bear the load,strain distribution of carbon fiber plate,and The Flat Section Assumption and equal angles for the test results.The results show that bonded and prestressed carbon fiber plate reinforcement technology significantly improves the cracking load,the yield load of steel bars,and the ultimate load of concrete beam over non-prestressed bonded carbon fiber plate,and in reducing the deformation deflection of concrete beams.It is also more significant in reducing the deformation deflection and suppressing and delaying the development of cracks of concrete beams.2.In view of the fact that most of the researchers had previously conducted studies on non-destructive concrete beams reinforced by carbon fiber plate,this is inconsistent with the fact that the reinforcement objects in actual reinforcement projects are mostly damaged concrete beams.In this paper,make a static loading test on destructive concrete beam reinforced by carbon fiber plate,and make a study on the bending capacity of the damaged concrete beam after reinforcement,and compare with the non-destructive concrete beam reinforced by carbon fiber plate.The results show that: The mechanical performance of the damaged beam and the intact beam strengthened by the prestressed carbon fiber plate remains the same,the prestressed carbon fiber plate reinforcement technology can restore some of the damaged components well and make a significant effect in closing the existed cracks,thus improve the overall stiffness and the flexural load-bearing capacity of damaging beam.3.Based on the constitutive relation of material,the assumption of the plane section and the balance relationship of forces,some of the theoretical calculation formulas are deduced.which include the prestressed level limit of concrete beam reinforced by prestressed carbon fiber plate,the reversed arch value of tensioned carbon fiber plate,the cracking load,the yield load,the ultimate load and the yield deflection,and the results agree well with the experimental values,indicating that the theoretical calculation formulas deduced in this paper are reasonable.