Experimental Research On Concrete Beams Strengthened With Carbon Fiber Sheet Integrated

Through the experiments of eight pieces of reinforced concrete simple T-beam, the cracking resistance, deformation capacity, ductility and the ultimate bearing capacity of reinforced concrete beams strengthened respectively by carbon fiber sheet,angle steel,external prestressing tendons and compositely by them.will be analyzed.The mechanical behavior of the combined reinforced beams strengthened by carbon fiber sheet,angle steel and external prestressing will be researched to find the effects and advantages of combined reinforcement.By study on the test failure phenomenon of eight pieces of beam,through carbon fiber sheet in combination respectively with angle steel and external prestressing tendons,the reinforced concrete beams can effectively improve the anchorage of the carbon fiber sheet,guatanteed carbon fiber sheet strength into full play,the reinforcement beams have excellent performance.By the rebound resilience of angle steel bending deformation,the CFRP-angle steel beam can ensure the anchorage of carbon fiber sheet.Through the good synergy effcet of carbon fiber sheet and angle steel,the beam can effectively limit the development of cracks,lead the stiffness degradation to be not obvious,and have a high carrying capacity.Prestressing equivalent load can ensure the reliable anchorage of carbon fiber sheet. Through the good synergy effcet of carbon fiber sheet and prestressing tendons,CFRP-prestressing tendons beam has a high cracking load,good stifness and high bearing capacity.Test data analysis of beam strengthened by carbon fiber sheet,angle steel and prestressing tendons has shown that the beam can give full play to advantage of composite strengthened beam,greatly improve the mechanical behavior,the improved value is higher than all of which strengtheded respectively by carbon fiber sheet,angle steel and prestressing tendons.Compared with beam strengthened by one kind of material,composite strengthened beam lead to complementary advantages and combined effect.By using finite element analysis program ABAQUS.a three-dimensional nonlinear finite element model of composite reinforcement testing beams is set up to do simulation analysis and to compare with experimental results,which indicates a good agreement. Based on the model of ABAQUS, the parameters of composite reinforcement are analyzed to improve the model test and to make up the deficiency. Through analysis of the parameters and sensitivity analysis of stochastic finite elements,the paper explores a reasonable range of values of reinforcement materials.And the analysis shows that on the strength of concrete,the area of externally prestressing tendons,effective prestress degree and the area of angle steel is sensitive to the reinforcement effect by bonding carbon fiber sheet with angle steel and external prestressing.Based on the test results,this paper propose formulas of the ultimate bearing capacity and stiffness on composite reinforcement beams.The theoretical calculation results indicate a good agreement on experimental results after compared.By using the test results.The corresponding ductility factor of eight pieces of reinforced concrete simple T-beam,can be calculated based on defletion metohd and energy metood to study the ductility of eight pieces of test beams.The beam strengthened by angle steel can improve the ductility.The paper apply fuzzy comprehensive evaluation model to consider different reinforcement requirements involved the technical index and economic index,elect optimized reinforcement program,select the optimization scheme and provide a reference value for reinforcement engineering.