Study On The Performance Degradation Of Concrete And Concrete Components Under The Action Of Sulfur Dioxide

Industrial production emits a large amount of SO2 gas,which causes the concrete structure to be corroded by SO2 gas for a long time,causing the concrete protective layer to expand and loose,or even flake.The vulcanization reaction of concrete is a process from the surface to the inside.The outermost layer of the concrete deteriorates to a certain extent and cannot continue to protect the internal concrete,resulting in a reduction in the strength of the concrete and a reduction in the ability of the protective layer to constrain the reinforcement.Reinforcement,the steel bars are more prone to corrosion;in turn,it affects the performance of reinforced concrete members and even affects the safety of the structure.Therefore,it is of great significance to study the performance degradation law,constitutive relationship and concrete component performance degradation law of vulcanized concrete for the durability and life prediction of concrete structures under industrial environment.In this paper,a combination of test analysis and numerical simulation is used to study the performance degradation of vulcanized concrete and its components.The main work is as follows:(1)The environmental simulation box was used to simulate the industrial environment,and the physical and mechanical properties of SO2 corroded concrete were tested.The water-cement ratio and corrosion time were comprehensively analyzed for the concrete’s apparent morphology,mass loss rate,compressive strength,and relative dynamic elastic modulus.Quantity and damage layer thickness degradation.The results show that: from the appearance damage,the smaller the water-cement ratio,the more serious the corrosion of the concrete surface;as the corrosion time increases,the concrete quality gradually increases,the compressive strength increases first and then decreases,and the relative dynamic elastic modulus Increase first and then decrease;the thickness of the concrete damage layer gradually increases with the age of corrosion,and the greater the water-cement ratio,the greater the thickness of the damage layer.(2)The experimental study on the constitutive relationship of SO2 corroded concrete under uniaxial compression was carried out.The effects of water-cement ratio and corrosion age on the uniaxial compression performance and stress-strain curve of vulcanized concrete were analyzed.Different water ash was established The time-varying model of peak stress,peak strain and elastic modulus of concrete;the full-curve stressstrain curve equation of concrete and damaged layer concrete under the action of SO2 is established.The results show that,compared with ordinary concrete,the cracking time of concrete after curing is advanced,and the vulcanization products are precipitated at the corners,causing the specimens to become loose at the corners and shatter at the touch.As the corrosion time increases,the peak point of the stress-strain curve first rises to the left and then decreases to the right.(3)Using ABAQUS finite element analysis software,the concrete section of the reinforced concrete beam is divided into a damaged layer and an undamaged layer.The flexural bearing capacity of the reinforced concrete beam under the action of SO2 is numerically analyzed.The effect of degradation on the bending capacity of the beam.Combined with the simulation results,the degradation law of load-deflection curve of reinforced concrete beams with corrosion time was analyzed.