Behavior Of Recycled Concrete-filled Circular Steel Tube Column Subjected To Eccentric Compression Under The Environment Of Acid Rain

Along with the steady development of urban economy,the speed of buildings update is quicker,and the discharge of waste concrete is increasing,at the same time,the demand for concrete is getting higher and higher.At this time,we break down waste concrete and make it into recycled concrete in order to use natural aggregate lessly.Now,the environment is getting worse and worse,the life of building is greatly reduced under the environment of acid rain,so the behavior of recycled concrete-filled circular steel tube column subjected to eccentric compression under the environment of acid rain has important practical significance.A comparative research was conducted to investigate the mechanical properties of recycled concrete-filled circular steel tube column subjected to eccentric compression by the experimental method and the finite element method.Finally,using the simplified calculation formulas of CFST to calculate the bearing capacity of all specimens.The main achievement were presented as follows:(1)Concrete-filled circular steel tube column with different corrosion degrees? types of concrete and eccentricity ratio were tested under the environment of acid rain,in order to analyze the mechanical properties under the environment of acid rain.(2)When the corrosion test is over,all test specimen were tested subjected to eccentric compression,in order to study the mechanical properties.During this process,we should observe the phenomenon of destruction.To analyzing the test data in detail,the load versus longitudinal strain curves and the load versus relative compression rate of concrete-filled circular steel tube column with different corrosion degrees?types of concrete and eccentricity ratio were compared.(3)Load-deformation relationship curves of concrete-filled circular steel tube column were analyzed by finite element software ABAQUS,the numerical results are compared with the experimental results.And the work mechanism was analyzed at three aspects: load distribution by steel tubes and concrete,interaction between steel tubes and concrete and stress distribution.We considered the influence of acid rain corrosion environment from two aspects: reducing the thickness of the steel tube or reducing the thickness of the steel tube and the property of the steel which corroded by acid rain with finite element modelling.(4)We calculate the bearing capacity by using the simplified calculation formula for the bearing capacity of concrete-filled circular steel tube column subjected to eccentric compression.As a result,the calculation results obtained by simplifying the calculation formula for the bearing capacity of recycled(normal)concrete-filled circular steel tube column are more secure than the experimental values.