Analysis Of Axial Compression Performance Of GFRP Reinforced Concrete Columns

Fiber composite materials,as a new type of material that has gradually emerged in recent years,are mainly made of various materials including resins,fibers,etc.processed by physical and chemical means.The fiber composite material has the advantages of light weight,high strength,insulation,and corrosion resistance,but the GFRP rebar material has no obvious yield step similar to the steel bar,and shows more obvious brittleness.Therefore,with regard to the performance of GFRP bars compared to ordinary steel bars in axially compressed concrete cylindrical members,the finite element software was used for numerical simulation to compare and analyze the bearing performance of GFRP steel bars and ordinary reinforced concrete columns.The size effect of unconstrained GFRP reinforced concrete column and GFRP pipe constrained concrete column is studied.On this basis,the axial compression bearing performance of GFRP reinforcement applied to the example model is analyzed by numerical simulation.The work and research results mainly include the following:(1)Using the finite element software simulation test process,the effectiveness of the numerical simulation of the axial compression performance of the GFRP reinforced concrete column is analyzed.The results show that the numerical simulation results are in good agreement with the test results,and the numerical analysis accuracy is good;The two replacement methods of GFRP bar and steel bar equal diameter replacement and equal strength replacement are discussed.The effect of reinforcement type on the bearing performance of concrete cylinder is discussed.The results show that when the method of equal diameter replacement is adopted,GFRP bar members and ordinary steel bar members are loaded.The forces are relatively close;the effect of the reinforcement ratio on the compression performance of the concrete cylinder is discussed.The results show that increasing the longitudinal GFRP reinforcement ratio can effectively improve the compression performance of the model.(2)The size effect of the axial compression performance of unconstrained GFRP reinforced concrete columns and GFRP pipe confined concrete columns is discussed.The results show that the size effect of the unconfined GFRP reinforced concrete column is not obvious;the ultimate stress of the GFRP pipe constrained concrete column under axial compression shows a nonlinear decreasing trend with the increase of the model size,and has a significant size effect.(3)Taking the bridge pier column structure in the actual project as the model background,the axial bearing capacity of the concrete pier column with GFRP reinforcement equal diameter to replace the steel material in the original design is discussed.The results show that GFRP tendons have a good application effect as longitudinal compressive tendons,and the compression performance is not inferior to ordinary reinforced members.When GFRP tendons are used in transverse stirrups,the ductility of the model is reduced to a certain extent,and improvement should be emphasized Ductility of components.