Study On Shear Behavior Of Concrete Beam After Fire

In recent years,there are more and more concrete bridge fire accidents,it may caused damage to concrete beam,which affect the bearing capacity and the service ability of the beam.The evaluation of bearing capacity of concrete beams after fire is an important basis for damage assessment and maintenance of post-disaster bridge.The shear behavior of concrete beam after fire was studied in this paper,and the main contents are as follows:(1)The damage characteristics of concrete bridge components after fire are summarized and the criteria for preliminary damage assessment and detailed assessment after bridge fire are proposed.(2)The temperature and mechanical performance test of concrete,common reinforced are carried out,the strength reduction of the above materials after cooling in different ways are obtained.(3)The temperature distribution of concrete in high temperature environment was tested.Through the data analysis,the temperature distribution law of concrete was studied.The test was simulated by ANSYS finite element software and compared with the experimental data,the test data agree well with the simulation results.(4)Based on the calculation formula of shear capacity of concrete beams in Chinese Standards and the "truss-arch" shear calculation model,the shear strength reduction method of concrete beams after fire was put forward,and compared with the results of the relevant test beam.(5)A case study of fire bridge was carried out.The decline of shear performance was obtained,and the damaged bridge was evaluated.