Study On Assessment Techniques Of Fire-damaged Concrete Structures For Mall

The modern mall is the shopping and leisure center of a city.With complex functions,comprehensiveness and large crowds,heavy casualties and serious economic losses once fire or other incidents occurred.The losses caused by fire in mall at home and abroad maintain on high leval all the time.After fire,the damaged building should be evaluated as soon as possible to determine whether it can be reused after repairment or reinforcement.The damage assessment of building structure after fire depends on the research results of fire science,nondestructive testing technology,material damage and structural analysis.The assessment results are the scientific basis for building repairment,reinforcement or demolition after fire.Therefore,it is very important to study the damage assessment techniques of mall after fire.Reinforced concrete frame structure is the main structure of mall.Taking the reinforced frame concrete structure as an example,based on the research results of the damage assessment after fire of building structure at home and abroad,combining with the relevant specifications and engineering examples,this paper studied the damage assessment techniques of mall after fire.The main contents are as follows:(1)To analysis the contents of fire field examination.From the fire loading investigation,fire burning time analysis and fire temperature estimation,etc.this paper studied the contents and technical methods of field fire effect analysis.Theoretical calculation method,apparent detection method,carbonation experimental method and numerical simulation method are carried out,and summarized the application of each technique.(2)Simulating a fire inside buildings by FDS software,the distribution of temperature field and the influencing factors are analyzed.(3)The damage of concrete structure after high temperature are researched.Through analyzing the relevant experiments results,behavior of steel and concrete materials after high temperature as well as the change of adhesion with temperature between them are explored,which provide reference bases for structural damage detection.(4)The contents and methods of damage detection for concrete structures are analyzed.Based on the relevant rating standards,taking the fire-damage assessment of one mall as a case,the damage degree of steel and concrete components is diagnosed,and corresponding repair advices are provided.Besides,this paper used computer software to simulate and analyze the fire temperature field of the mall which is compared with the presumed temperature field by fire scene examination and analysis of residue.