Study On Temperature Field And Mechanical Properties Of Fiber Reinforced Concrete Structures Under High Temperature

Building structures in their life cycle,may face the threat of fire,the fire caused huge economic losses and casualties.Ordinary reinforced concrete structure has great burst risk at high temperature.The fiber concrete structure studied in this paper possesses superior ductility and anti-blast performance under fire,which can provide the foundation for fire-resisting design of building structure and post-fire structure repair.Because of the long period of fire test,high cost and difficulty in operation,the numerical simulation software is used to analyze the high temperature of the reinforced concrete structure and the structural components of the structure.Finally,Performance becomes more important.In this paper,the finite element analysis software ABAQUS is used as the platform to study the temperature field and mechanical properties of the reinforced concrete column and the frame structure under fire,based on the previous theoretical and experimental research.The research results mainly include:(1)Reinforced concrete column is an important load-bearing component of structure.Based on the thermo-mechanical properties and high-temperature stress-strain constitutive relationship of reinforced concrete and fiber concrete,ABAQUS is used to analyze the distribution characteristics of the temperature field of reinforced concrete column under fire.The effects of parameters such as section size,reinforcement ratio,axial compression ratio,slenderness ratio and load eccentricity on the high-temperature mechanical properties of reinforced concrete columns are studied.The results show that the above parameters have the effects on the deformation and ultimate load-Significantly affected.(2)A single-layer and double-span reinforced concrete frame model was established and analyzed by ABAQUS.The distribution of temperature field,deformation characteristics of beam,column and the whole structure under different fire conditions were studied.Internal force variation law.The results show that the temperature field of the double-span fire-girder and the side-column is the same as that of the single-span fire when the single-span fire and double-span fire are two different fire conditions,while the center column and the core And the temperature distribution of core frame is obviously lower than that of surrounding beam and column section.The axial compression ratio of fire-bearing method and frame column has a significant effect on the high temperature mechanical reaction of frame structure.(3)Many experimental studies have shown that ordinary reinforced concrete structures in the building after the fire,most of them can be repaired,and repair costs generally do not exceed 40%of the reconstruction removed,this chapter ABAQUS,The load-deflection curve under the action of one-third of the concentrated force is calculated.The load-deflection curve under the action of one-third of the concentrated force is calculated by simulating the process of using the carbon fiber sheet to reinforce and then carry on the static load test.