| The frequent occurrence of building fire in recent years teaches us a painful lesson which brings widespread attention at home and abroad of further research on fire resista nce of engineering structure.Concrete structure usually works with cracks in normal services.For reinforced concrete structures serving in the marine environment,chloride ion erosion is the main factor of leading to the corrosion of the steel,but at present few scholars involved in the research of fire resistance of corroded reinforced concrete structures in marine environment.In order to study the fire resistance performance for RC columns with damages caused by marine environment under axial compression,a electrochemical accelerated corrosion test was carried out,producing the crack caused by corrosion along the stirrup of samples with different width,as the initial damage index.Finally,all of the specimens carry on the test under axial constraint in fire.Analyzing how the damage index affects the temperature field distribution of the column section and the degeneration law of bearing capacity.The main research works are as follows:(1)The present situation of the research on the fire resistance of reinforced concrete structures and the durability of the marine environment are summarized,and the mechanical properties and high temperature properties of corroded steel bars are summed up;(2)This paper designed 4 RC columns samples to stimulated marine environment damage through electrochemical corrosion experiments,which obtain different width crack(0.1mm,0.2mm,0.3mm)as the initial condition;(3)To study temperature field distribution of the column section and the degradation law of bearing capacity by observing and recording the experimental phenomena,deflection,distribution of section temperature field through fire test for RC columns with chloride ion damage;(4)The bearing capacity of RC columns at elevated temperature is calculated and summarized by according to the temperature field of each section. |
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