Bending Test And Analysis Of GFRP Self Compacting RPC Composite Members

Glass fiber reinforced polymer(GFRP)is a heterogeneous and anisotropic material that does not exhibit plastic deformation.The material has high strength,good designability,strong corrosion resistance and low specific gravity.Combining GFRP materials with different construction methods and concrete with specific functions to meet the functional requirements of GFRP composite structures has been widely used in the field of civil engineering.Reactive Powder Concrete(RPC)has the characteristics of high fluidity and high strength.In this paper,according to the mechanical properties of GFRP and RPC materials,a GFRP-self-compacting PRC composite structure was designed and fabricated,and the mechanical properties and design methods of the composite structure were studied.In the production process of the composite structure,the GFRP board replaces the formwork in the concrete pouring,and the use of self-compacting RPC does not require manual vibration,which simplifies the construction process and reduces the construction difficulty.This paper studies and analyzes the performance of GFRP-self-compacting RPC composite flexural members,reveals the force mechanism of the composite structure,and proposes a calculation method for the flexural bearing capacity of GFRP-self-compacting RPC composite members.This research provides an experimental and theoretical basis for the application of the combined mechanism.The main research contents of this paper are as follows:(1)Taking the section height and stirrups of the GFRP-self-compacting RPC composite structure as design parameters,six design schemes were proposed.The test results show that when the composite structures under the six design schemes fail,there is no obvious yield step in the mid-span load-displacement curve,and the structures all have RPC shear cracking failure in the bending shear zone.The maximum utilization rate of GFRP plate material is the material strength.about 48% of that of the composite specimens;the flexural stiffness of the composite specimens with the same section height is basically the same;the configuration of stirrups significantly improves the bearing capacity of the inclined section of the composite member specimen,and the bearing capacity of the inclined section increases regularly with the spacing of the stirrups.At the same time,the damage pattern has been improved.The research results provide the experimental basis for the finite element numerical simulation calculation and the derivation of the ultimate bearing capacity calculation formula of the composite structure.(2)The finite element analysis software ABAQUS is used to carry out numerical simulation calculation and analysis of GFPR-self-compacting RPC composite members.According to the characteristics of GFRP-self-compacting RPC composite components,a refined model modeling method for GFRP-self-compacting RPC composite components is proposed,and the feasibility of the method is verified by comparing with the experimental results.The reason for the debonding failure of the composite member in the shear-bending section due to the lack of interfacial connection force is revealed,which provides a basis for the establishment of the theoretical calculation model.The parametric analysis results of GFRP-self-compacting RPC composite members show that the higher the GFRP area ratio in the section,the higher the stiffness and ultimate load of the composite structure,but it has little effect on the deformation capacity of the structure;The stiffness has little effect.This study provides recommendations for the design of GFRP-self-compacting RPC composite components.(3)A theoretical calculation method for flexural bearing capacity design of GFRP-selfcompacting RPC composite members is proposed.Based on the section analysis method,a calculation model of the normal section of the composite member is established,and the theoretical calculation results of the GFRP bottom plate strain and the mid-span deflection of the composite structure are compared with the test to verify the accuracy of the method.Through the calculation and analysis of the normal section,the minimum GFRP area ratio of the GFRP plate is obtained when the composite structure meets the ultimate bearing capacity of the normal section.By comparing the existing calculation methods of inclined section,a calculation method of the inclined section bearing capacity of GFRP-self-compacting RPC composite member is proposed.This study provides a theoretical basis for the design of GFRP-self-compacting RPC composite components.