Security Identification And Strengthening Design Studies On A Concrete Frame Structure After Fire

In addition to fire was released by the United Nations in the 20 th century war one of the world’s ten most dangerous disasters. Since entering the 21 st century, building fire presents multiple trends. When buildings in the event of a fire, it not only bring huge economic loss but also threaten people’s lives. At present, the domestic and foreign about concrete structure after the fire performance of materials, structural testing, structure strengthening and repair has a lot of fruitful research, but still has not formed a complete theoretical system and the application of mature technologies. There are still many problems to be solved in actual engineering. This paper set an example of concrete frame structures detection, identification and reinforcement design after fire in Changde city, argue that concrete structure detection, identification and strengthening design, etc after fire, then discount the mechanical properties of reinforced concrete materials after fire, also propose damaged components remaining bearing capacity calculation method which is adaptable to this project. The author hope to provide some reference to similar project detection, identification and reinforcement afterward.First, inspect the degree of damage fire range, residues and component damage degree in scene of fire,recognize component surface temperature reached within the scope of fire through a variety of methods, then do preliminary evaluation of the damaged components based on the existing testing specification and field investigation results of the fire.Secondly, do detection analysis of section size, deformation and strength of materials, steel bar configuration, concrete protective layer thickness, neutralization, etc of the component, summarize previous research on the mechanical properties of reinforced concrete after high temperature, confirm reduction factor of steel and concrete strengthof materials of this project after fire combined with the material sampling test results.Again, on the basis of the proposed in this paper the residual bearing capacity calculation method of severely damaged concrete members bearing capacity calculation, which severely damaged concrete members are detailed appraisal rating and security rating, through multi-level comprehensive appraisal ratings determine safety level of concrete frame structure after the fire.Finally, Select rational and economical reinforcement scheme based on damage of this project, choose severely damaged component as a typical component then do the reinforcement calculation,formulate layout of reinforcement of this type of component and draw the schematic diagram of it.