Mechanical Behavior Of Reinforced Concrete-filled BFRP Tubes Columns Under Eccentric Load

The new material-Basalt Fiber Reinforced Plastics(BFRP)is a continuous basalt fiber made of natural basalt rock after high temperature drawing.This material not only has high tensile strength,but also has strong corrosion resistance.Therefore,BFRP materials will be widely used in engineering fields with severe corrosion such as ports,docks,bridges,etc.However,there are few studies on the combination structure of basalt fiber tubes at home and abroad.To this end,through experimental research and theoretical analysis,this paper studies the BFRP pipe reinforced concrete column bias pressure performance.The completed work is as follows:(1)In this paper,through the eccentric compression test of 10 BFRP pipe reinforced concrete columns and 1 reinforced concrete column,the effects of eccentricity,length-to-diameter ratio and pipe wall thickness on the mechanical properties of BFRP reinforced concrete composite columns are studied.(2)When the BFRP pipe reinforced concrete column is eccentrically compressed,its failure stage is mainly divided into three stages: elastic deformation stage,elastoplastic development change stage and stress strengthening stage.As the eccentricity increases,the combined column changes from small eccentric compression to large eccentric compression,and the failure form also changes from compression failure to tensile failure.(3)Under the condition that the thickness of the pipe wall is 8 mm and the aspect ratio is 5,as the eccentricity increases,the bearing capacity will be greatly reduced.Under the condition of eccentricity of 80 mm and length-todiameter ratio of 5,as the thickness of the BFRP pipe wall increases,the bias bearing capacity of the specimen increases,and the ductility of the composite column is improved.Under the condition of eccentricity of 80 mm and pipe wall thickness of 8mm,as the aspect ratio increases,the lateral deflection of the reinforced concrete composite column of BFRP pipe increases,and the eccentric compression bearing capacity decreases.(4)Based on the analysis of the eccentric compression model of the BFRP pipe reinforced concrete column and the eccentric compression test of the BFRP pipe reinforced concrete column completed in this paper,a formula for calculating the eccentric compression bearing capacity of the BFRP pipe reinforced concrete column are proposed.Through the comparison of experimental data and theoretical analysis,the validity of the theoretical formula calculation results is verified...