Test And Analysis Of Flexural Bearing Capacity Of Normal Section Of Steel Reactive Powder Concrete Beam

As the building structure gradually develops in the direction of super-high and super-span,and is more and more used in freezing and thawing areas and erosive environments,this puts forward higher requirements on the bearing capacity,stiffness and durability of components.In order to solve the aforementioned problems,this paper proposes to apply Reactive Powder Concrte(RPC)to the steel reinforced concrete structure and construct a new type of composite component,namely the steel reinforced powder concrete component.This combined component has the advantages of high bearing capacity,high rigidity and good seismic performance.It can also solve the problems of built-in steel and steel bar corrosion in harsh environments,and has a broad application prospect.This paper mainly carried out the experiment,numerical analysis and theoretical research on the bending capacity of the cross section of the steel reactive powder concrete beam.First,the flexural performance test of eight steel-reactive powder concrete beams under four-point symmetric loading was carried out.The experiment mainly investigated the effects of longitudinal reinforcement ratio,profile flange width and thickness,profile location,profile yield strength and other parameters on vertical load.The crack distribution,failure form,load-deflection curve and strain of the test beam were systematically studied Variations were obtained for the test beam cracking,yielding and ultimate load.On the basis of the experiment,the general finite element software ABAQUS was used to perform finite element simulation on the steel-reinforced powder concrete beam,and compared with the measured results.Then,the failure process of the test beam was analyzed in detail.Finally,based on the test results,a calculation model for the bending capacity of the steel section of the active powder concrete beam is established,and the corresponding calculation formula for the bending capacity of the section is proposed.Research indicates:(1)Both of the steel-reinforced powder-concrete beams have the lower longitudinal steel bars or the lower flanges of the steel beams first subjected to tensile yielding,and then the concrete at the top of the beam is crushed by suitable bars;after the concrete is crushed,the displacement increases with vertical loading Large,steel-reinforced powder concrete beams still have high bearing capacity and ductility,and exhibit good bearing performance.(2)The vertical bearing capacity of the steel-reinforced powder concrete beam increases with the increase of the reinforcement ratio,flange thickness,flange width,and the yield strength of the steel section.At the same time,the downward eccentricity of the built-in steel section can also greatly increase its Vertical bearing capacity;during the whole loading process,the test beam basically conforms to the assumption of flat section.(3)The load-deflection curve,load-strain curve,failure mode,etc.calculated by ABAQUS are in good agreement with the test results,and the validity of the numerical model established in this paper is verified;through parameter analysis,it is found that the vertical bearing capacity of the test beam The increase of the thickness of the steel web,the thickness of the flange,and the area of the longitudinal reinforcement obviously increased,but the increase in the strength of the concrete did not significantly affect the vertical bearing capacity of the test beam.(4)The formula for calculating the bending capacity of the cross section of the steel-reinforced powder-reinforced concrete beams fully considers the influence of the tensile strength of the active powder,and the calculation results are in good agreement with the test,which provides Theoretical basis for a calculation method of the bending capacity of the steel-reinforced powder-reinforced concrete beams.