Experimental Research And Numerical Analysis On Shear Behavior For RC Beams With Damages Caused By Chlorine Ion At High Temperature

Building structure fire resistance research was paid more attention by people due to frequent building fires and experiments and theoretical analyses were conducted in recently years.Reinforced Concrete structure generally worked with cracks during the period of design life and the cracks had a serious influence on the coastal building's durability and resistance to fire.The studies about structure fire resistant that consider the crack's influence were very few.So it's necessary to study the influence of cracks on fire-resistance of structures.In order to study high-heat performance of RC beams which were damaged by marine environment and analyze the influence of various degree erosion damage on sectional temperature field and high-heat bearing capacity.RC beam was selected as the research object,and the electrochemical experiment which simulates marine environmental damage was conduct to get the different width of corrosive cracks that was pledged as the initial damage of the fire test and numerical analysis based on ANSYS.The main research contents are as follows:(1)The research on the concrete structures' durability and fire resistance of b uilding structure were summarized.The latest research results and existing problems about the concrete structure of the basic properties of material mechanics,component levels and structural levels were analyzed.(2)Four RC beams which are No.L1~L4 were designed.The electrochemical corrosion experiment of L1~ L3 was conducted which could cause the different width of cracks to simulate marine experiment damage.L4 specimens was designed as comparison specimens which wasn't damaged by electrochemical corrosion test,and the cracks were pledged as the initial damage of fire test.The influences of different width of crack on beam section temperature field distribution were studied.(3)The residual bearing capacity of beam after fire was tested,compared the surplus bearing capacity with theoretical values which used the equivalent cross section method.The influence of erosion damage on high-heat surplus bearing capacity of reinforced concrete beams was analyzed.(4)The fire test of RC beams after marine environment damage was simulated by ANSYS.The beam's temperature distribution nephogram,deformation diagram and the law of cracks were obtained during the high temperature.