Study On Migration And Corrosion Resistance Of Alcohol Amine Migration Corrosion Inhibitor In Fly Ash Concrete

Migration corrosion inhibitor is favored by civil engineering industry because of its advantages of environmental protection,economy and simple operation.Many studies and practices have shown that it is an effective way to inhibit the corrosion of steel bars to apply the migrating corrosion inhibitor on the surface of concrete.In recent years,alcohol amine migration corrosion inhibitor has developed rapidly,and has shown excellent performance in experiments and some engineering applications.However,whether its migration performance and long-term working performance in concrete structure can meet the expected requirements needs further study.Especially in some special concrete(such as fly ash concrete),the working performance is rarely studied.Therefore,supported by the National Natural Science Foundation of China(51778272),this paper studies the migration and corrosion resistance of alcohol amine migration type corrosion inhibitor in fly ash concrete.1.Study on migration performance of alcohol amine migration corrosion inhibitor in fly ash concrete.The migration performance of alcohol amine corrosion inhibitor in fly ash concrete was studied by Nessler’s reagent spectrophotometry.The influence of different fly ash content on the migration performance was analyzed.The feasibility and specific effect of MCI natural migration and electric field accelerated migration were discussed.The results show that: 1)the migration corrosion inhibitor has the ability of continuous migration in conventional concrete.With the increase of time,it can migrate to 40-45 mm away from the surface under natural migration.2)Under natural migration,with the increase of fly ash content,the migration performance in concrete is affected to a certain extent,and the influence is slightly greater when the fly ash content is 30%.3)Electric field can effectively accelerate the migration of corrosion inhibitor.The composition of corrosion inhibitor can reach 50 mm after 24 hours under the action of external electric field,and the distribution is uniform at each depth.4)The effect of external electric field can reduce the effect of fly ash on the migration of corrosion inhibitor in concrete,which is not obvious within 12 hours,but after 24 hours,the migration effect of corrosion inhibitor in fly ash concrete is basically the same as that in conventional concrete.2.Study on corrosion resistance of alcohol amine migration corrosion inhibitor in fly ash concrete.Through the immersion drying cycle test,the concrete members are corroded rapidly,and then through the weight loss test,the mass loss of reinforcement before and after erosion is calculated and analyzed.The results show that: 1)the fly ash concrete itself has a certain anti-corrosion function,in which the dosage of 30% is the best.After four soaking and drying cycles,the anti-corrosion efficiency of z0fa30 group is 64.84%,after eight cycles,the anti-corrosion efficiency is 60.78%,and when the number of cycles reaches 12,the anti-corrosion effect is better 64%.The results show that the addition of fly ash can effectively inhibit the corrosion of steel bars.2)Alcohol amine migration corrosion inhibitor has a good effect in fly ash concrete,and the best amount of fly ash is still 30% of cementitious materials.With the increase of the number of cycles,the efficiency of corrosion resistance is improved.After 12 soaking and drying cycles,the corrosion resistance efficiency of fa30 group reached 81.11%,and that of the other groups reached more than 70%.3)From the data measured by half cell potential method,it can be seen that alcohol amine migration corrosion inhibitor can play a role in fly ash concrete and effectively improve the corrosion potential of reinforcement in fly ash concrete.With the increase of soaking and drying cycles,the potential value of the steel bar in FA0 group was significantly lower than that of the other three groups,which indicated that the effect of migration corrosion inhibitor alone was not very ideal in the long-term harsh corrosive environment.3.The electrochemical data of the working electrode after the immersion drying cycle were tested,including EIS AC impedance spectrum and LPR linear polarization test.The influence of the optimal amount of fly ash and the different amount of fly ash on the resistance arc radius,corrosion current density and polarization resistance of the steel bars in the specimen are analyzed.The main conclusions are as follows: 1)the application of alcohol amine migration corrosion inhibitor on the concrete surface can effectively adsorb the film on the surface of the reinforcement,and play a good role in protecting the reinforcement.The use of corrosion inhibitor increases the radius of the resistance arc,the film resistance and the charge transfer resistance,and effectively suppresses the electron charge transfer rate and the electrochemical reaction of the negative and anode on the surface of the steel bar.After 12 times of immersion and drying cycles,the corrosion resistance efficiency of the steel bars in each group of specimens coated with the migration corrosion inhibitor was more than 50%.2)Under the action of corrosion inhibitor,the corrosion current density of steel bars in each group of specimens was lower than that of the steel bars without migration corrosion inhibitor.The corrosion current density of the surface after 12 cycles was 0.521μA·cm-2,and the corrosion of the steel bars was not accelerated.In this study,the comprehensive performance of alcohol amine migration corrosion inhibitor in fly ash concrete under simulated marine environment was tested and evaluated,which laid the foundation for its application and research in actual marine engineering.