Analysis Of Mechanical And Deformation Properties Of Reinforced Concrete Beam Column Structures Strengthened With Externally Bonded Steel

With the increasingly prominent issue of "aging" of buildings,more and more building structures cannot meet their corresponding bearing capacity requirements,so it is necessary to strengthen buildings.Existing reinforcement methods,such as external prestressed reinforcement,wrapped steel reinforcement,and increased cross-section reinforcement,have their advantages and disadvantages,and their application in different structural forms and component forms has different effects.This paper analyzes the mechanical and deformation properties of externally bonded steel reinforced concrete beam column structures,simulates the entire process of bonded steel plate reinforced beam members and wrapped steel reinforced column members using theoretical calculations and finite element software,and compares and analyzes the bearing capacity and deformation values of the members before and after reinforcement,with a view to providing some reference for practical engineering reinforcement methods and material selection.The main research work of this article is as follows:(1)Based on the actual reinforcement project,the theoretical analysis is carried out on the beam strengthened with steel plate,the column strengthened with wrapped section steel and the beam strengthened with carbon fiber cloth,and the strength,section size,pasting height,spacing and other factors of the external materials are calculated and analyzed by using the theoretical formula.The size and regularity of the above factors on the reinforcement effect of beam and column members are extracted and summarized.(2)Describe the constitutive model relationship of each material and the setting of specific material parameters.Through the finite element software,carry out the numerical simulation of the beam members strengthened with steel plates.It is found that the reinforcement effect of the beam members strengthened with steel plates at the bottom and side is significantly improved than that of the original beam and only the steel plates at the bottom.The thickness and length of the steel bottom plate play an important role in the vertical displacement of the restraint beam,while the thickness,height,width and spacing of the steel hoop plate have an obvious effect on the lateral deformation of the restraint beam.After comparison,it is recommended to paste the steel bottom plate with thickness of 3mm,length of 1650 mm and steel hoop plate with thickness of 3mm,height of 160 mm,width of 120 mm and spacing of100 mm or 120 mm to strengthen the beam.(3)Through the simulation of the externally wrapped steel reinforced column,it is concluded that the larger the section size of the angle steel,the better the improvement of the bearing characteristics of the strengthened column.The research on the influence of the thickness of the outer steel skeleton and the spacing of the steel battens on the reinforcement effect of the column under different section sizes of the angle steel shows that the thickness of the outer steel skeleton has a greater impact on the bearing characteristics of the strengthened column,and the greater the thickness of the outer steel skeleton,the better the bearing capacity of the strengthened column.The bearing capacity of the columns strengthened with steel cladding has a certain impact,but the impact is relatively small.The smaller the spacing of steel battens,the better the bearing capacity will be,and the lower the lateral displacement of the columns will be.Considering the cost performance and economy of material selection,when the section size of angle steel is L63 mm × 63 mm,when the thickness of the outer steel framework is 6mm,or when the section size of the angle steel is L70 mm ×The reinforcement effect is best when the thickness of the outer steel skeleton is70 mm and 5mm.At the same time,it is recommended to set the spacing of the steel battens between 260 mm and 300 mm.(4)This paper introduces the application of building materials such as new concrete,light steel,composite materials,grouting materials and new materials in practical reinforcement projects,and compares the economic benefits of strengthening with carbon fiber and steel plate materials through the reinforcement specifications and market prices.It is found that for most practical reinforcement projects,the material cost of pasting steel plate will be more advantageous than carbon fiber cloth.