Experimental Study On Flexural Behavior Of Reinforced Concrete Beams Reinforced With Carbon Fiber Plates

Fiber reinforced composite(FRP)mainly consists of new fiber materials which are synthesized by resin materials and processed with stronger fiber materials by means of extrusion and winding.According to enhance fiber,common types include basalt fiber(BFRP)and carbon fiber(CFRP),aramid fiber(AFRP)and glass fiber(GFRP),carbon fiber composite materials(CFRP)was there have tensile level is most prominent,at the same time is also a leading position in production technology,is particularly common among the practical application of one of the material.Comparatively speaking,the advantages of carbon fiber composite materials mainly include: high strength,light weight,good durability,easy to construct,etc.,so it is widely used in construction and reinforcement engineering.Currently,a large number of test results are all in the unloaded environment to carry out CFRP reinforcement,which basically does not include the secondary stress into the experimental parameters.In practical engineering applications,the phenomenon of no loading process is basically difficult to occur.Therefore,in fact,all the researches on reinforcement need to consider the phenomenon of secondary stress.Therefore,this paper focuses on the secondary mechanical properties of reinforced concrete beam reinforced with carbon fiber plate.Based on the experimental research,the flexural and non-linear behavior of RC beam with carbon fiber sheet are analyzed and discussed by using several theory and FEA method.First,the strengthen methods,general situation of application and Research at home and abroad and superiority of RC beam strengthened with carbon fiber sheet are summarized.Based on the tests of four full-size beams,the failure mechanics and failure modes of beams strengthened with CFRP have been Researched,the ultimate strength,deflection,crack,ductility factor,stiffness and so on are analyzed.The experimental Results showed that the cracking load of RC beam with strengthened with CFRP can not be increased obviously,but the ultimate load can be increased effectively and the propagation of cracks was reduced effectively by the Rehabilitation.Based on the strain compatibility and flexural behavior,the formulas for calculating the ultimate load capacity of beams strengthened with CFRP are proposed.The ductility ratios are calculated by using displacement method and energy method.The calculation formulas of crack distance,maximum crack width,three different stage stiffness are forwarded.The calculated Results are in good with the experimental ones.The formulas can provide Reference for theoretical research and test.The non-linear FEA program ANSYS is used to analyze the RC beams strengthened with CFRP,simulates the test Result and Reappears the test process.The Results indicated that the FEA model is valid.By parameters alteration,the effect of factors on RC beams strengthened with CFRP are analyzed.It is showed that the Reinforcement Ratio of RC beam and the CFRP area are the effect of main factors on the strengthen effectiveness.