Research On Mechanical Behavior Of Steel Reinforced Concrete Filled GFRP Composite Columns

As a new type of structural column,steel reinforced concrete filled GFRP tubular composite column has been proposed in this paper,and its mechanical properties have been studied in depth.Steel reinforced concrete filled GFRP tubular composite column combines the advantages of GFRP concrete column and steel reinforced concrete column.It takes full advantage of the super tensile strength,low Poisson's ratio and high modulus of elasticity of fiberglass material.Interpolated steel can effectively improve the crack resistance of core concrete,improve the tensile and flexural properties of composite columns and consume the energy of composite columns when they are destroyed,thereby prolonging the life of composite columns.GFRP pipe has strong circumferential restraint effect on steel reinforced concrete,which makes steel reinforced concrete in triaxial compression state and greatly improves its bearing capacity;when the composite column is subjected to force,the deformation of glass fiber is small,which makes the stiffness of the composite column have a greater degree of improvement;the corrosion resistance of GFRP pipe is very strong.For the permanent protective layer of composite columns,the corrosion damage of composite columns in harsh marine environment,acid and alkali environment is avoided,and the maintenance cost of composite columns is greatly reduced;the quality of GFRP pipe is lighter than that of steel pipe,and the weight of composite columns can be reduced effectively.Reduce the cross-section area of the composite column,save more space for the building.In order to quantitatively and qualitatively understand the mechanical properties of steel reinforced concrete filled GFRP tubular composite column,81 specimens of steel reinforced concrete filled GFRP tubular composite column were designed and manufactured for experimental study.The main research contents of this paper are as follows: 1.Design of test scheme,specimen fabrication and loading scheme;2.Observation and record of loading phenomena of specimens and analysis of failure modes of specimens;3.Collection and analysis of load-displacement curve of specimens,collection and analysis of load-strain curve of specimens;4.The influence rules of three parameters(diameter-thickness ratio of GFRP pipe,strength of concrete and steel content)on the bearing capacity,stiffness,ductility and other mechanical properties of the specimens;5.The bearing capacity calculation formula of the Steel reinforced concrete filled GFRP composite column is obtained through the experimental data;6.Through the analysis,the reasonable diameter-thickness ratio,concrete strength and steel ratio of the composite columns are put forward,and reasonable design suggestions are put forward also.