Research On The Corrosion Resistance Of Migrating Corrosion Inhibitors For Marine Reinforced Concrete Structures

In harsh Marine environment,chloride ion erosion and carbonation greatly shorten the service life of concrete structures.Among them,the marine concrete structures mainly suffer chloride corrosion.As a corrosion protection and repair measure for Marine reinforced concrete structures,the use of migrating corrosion inhibitors is particularly attractive due to its simplicity and relatively low cost.This project mainly studies the corrosion resistance and anticorrosion mechanism of migrating corrosion inhibitor for Marine concrete structures.Therefore,the application of migrating corrosion inhibitor in practical engineering is further promoted.According to the environment characteristics of splash zone,full immersion zone and Marine atmospheric zone and the corrosion mechanism of reinforced concrete,The corrosion resistance of migrating corrosion inhibitors under dry-wet alternation and salt spray and carbonization cycle and in chloride-doped concrete was studied.And the dry and wet cycle test of concrete,concrete salt immersion test,salt spray carbonization cycle test,electrochemical test,SEM scanning electron microscope,EDS element analysis and other test methods were adopted to analyze the mechanism and performance of migrating corrosion inhibitor for steel bars in concrete under different erosion degrees in actual environment and the effect of migrating corrosion inhibitor on improving durability of concrete.And the corrosion resistance of migrating corrosion inhibitors was investigated comprehensively from the micro level by electrochemical test and EDS element analysis.Electrochemical test results show that the migrating corrosion inhibitors can significantly reduce the corrosion rate,mainly because it inhibits the promotion of chloride ion on charge transfer.And it can make the charge transfer resistance and membrane resistance increases.The corrosion current density is reduced,reducing the activity of the reinforced concrete work electrode,hindering the electrochemical process of steel corrosion,and playing a role of resistance to corrosion.For concrete structures eroded by chloride ions in marine environment,migrating corrosion inhibitors can exert their excellent corrosion resistance.Even after chloride ions reach the surface of steel bars,the passivation film formed on the surface of steel bars can maintain its passivation state,which provides favorable evidence for the application of migrating corrosion inhibitors in concrete structures mainly subject to chloride corrosion.For chloride-containing concrete structures,after applying migrating corrosion inhibitor,the corrosion resistance of the corrosion-inhibiting agent can be effectively brought into play when the chloride content of concrete is less than 1.25%.It has guiding significance for the application of migrating corrosion inhibitors in concrete mixed with sea water and sea sand.And the content of free chloride ion from concrete surface to reinforcement surface decreases significantly after the application of migrating corrosion inhibitor,and the content of free chloride ion decreases during the whole experimental period.It shows that migrating corrosion inhibitor has a strong and lasting inhibiting effect on chloride ion diffusion in concrete,and can significantly improve the durability of concrete.For concrete structures only eroded by chloride ions in marine environment,migrating corrosion inhibitors can exert excellent corrosion resistance.Even after chloride ions reach the surface of steel bars,the passivation film formed on the surface of steel bars can maintain its passivation state.It provided favorable evidence for the application of migrating corrosion inhibitors in concrete structures mainly subject to chloride attack or use concrete mixed with seawater and sea sand.In concrete specimens with concurrent carbonation and chloride ion erosion,when the degree of carbonation is low,migrating corrosion inhibitor can successfully protect concrete reinforcing bars from corrosion,continuously protect reinforcing bars,and improve the durability of concrete structure.After the degree of carbonation has a certain scale,the corrosion resistance of migrating corrosion inhibitor begins to reduce.