Flexural Behavior Of Preloaded Rc Beams Repaired With Prestressed Carbon Textile Reinforced Concrete Plates

The prestressed CTRC plate is a prefabricated plate composed of carbon fiber mesh textile in pre-tension state and high performance cement base.The prestressed CTRC plate has the characteristics of light weight,high strength and good corrosion resistance,which can be used to strength/repair reinforced concrete flexural members.Because inorganic matrix is use to prefabricate plate and used as the binding material,there are good compatibility and mutual permeability between the plate and the concrete substrate.In addition,the prefabrication of the prestressed CTRC plate can reduce the wet working procedure and improve the strength utilization ratio of carbon fiber mesh textile.In this paper,flexural behavior of preloaded RC beams repaired with prestressed carbon textile reinforced concrete(CTRC)plates was studied.Eight test cases are set and the flexural behavior of the unloading repaired beams and sustaining load repaired beams.Finally,the calculation method of ultimate bearing capacity of reinforced beams was obtained by theoretically deducing and the numerical simulations of all test cases were carried out.The following results can be obtained through the research in this paper:(1)The prestressed CTRC plate can significantly improve load controlled by the deflection and ultimate load of the preloaded RC beam.The ductility of all repaired beams is lower than that of reference beams.In the working process of repaired beams,the first crack in the prestressed CTRC plate is located at the beginning of the crack caused by preloading.With the increase of unloading level or suataining load level,the effect of carbon fiber textile of repaired beam in the initial period of loading increases gradually.The strain distribution along the section height for all repaired beams basically conforms to the assumption of plane section.Existence of the prestressed CTRC plate could restrain the crack width of repaired beam regardless of proloading level.And the restraining ability on crack width of the repaired beam is almost identical.(2)Based on the bending test results of repaired beams,the theoretical formula of ultimate load of repaired beams is proposed through theoretical derivation.(3)In this paper,finite element software is used to conduct numerical simulation analysis on the preloaded beam repaired with prestressed CTRC plate.By comparing and analyzing the failure mode,load-midspan deflection relation and load-strain relation of the repaired beams,the working mechanism of the repaired members is revealed.