Research On Composite Of Rust Resistance Suitable For The Salt Lake Area Of Inner Mongolia

With the continuous development of road construction in China,more and more roads and bridges are being built in harsh environments such as salt lakes,and the extremely high chloride content in salt lakes limits the application of reinforced concrete structures in salt lakes.Based on the background of the brine erosion environment of Jilantai Salt Lake in Inner Mongolia,this topic selected and optimized the ratio of rust inhibitors to prepare a composite rust inhibitor suitable for use in the salt lake environment,and compared the resistance with the more mature rust inhibitors currently applied.Rust effect,analysis of rust inhibition mechanism.The main research work is as follows:(1)Sampling and analyzing the salt ion content in the salt lake brine in the Jilantai Salt Lake area,and doing a brine immersion mortar test.The test confirmed that the free chloride ion content in the mortar after salt lake brine erosion reached 2%,which was enough to cause steel bar corrosion.(2)Comprehensive evaluation of the rust resistance and mortar mechanical properties of the rust inhibitor through electrode potential and mortar mechanical properties.The results show that: organic rust inhibitors triethanolamine,triisopropanolamine,inorganic rust inhibitors sodium molybdate,monofluoro Sodium phosphate can effectively inhibit the corrosion of steel bar at 1.5%,but the mechanical properties of the mortar after mixing are poor,so it is mixed with organic and inorganic rust inhibitors;the electrochemical impedance shows that the organic rust inhibitor triethanolamine: triisopropanol amine = 7:3,inorganic rust inhibitor sodium monofluorophosphate: sodium molybdate = 5:5 all have good rust inhibitory effect,and the mortar compressive strength ratio is more than 90%,can be used as rust inhibitor.(4)The organic rust inhibitor and the inorganic rust inhibitor are mixed in different proportions,and the electrochemical kinetic method is used to characterize the rust inhibition performance of the composite rust inhibitors in different proportions.The results show that: the organic rust inhibitor is in the simulated pore fluid The optimal dosage in medium is 0.6~0.8%,the optimal dosage in inorganic rust inhibitor is 0.4~1%,the adsorption of organic and inorganic rust inhibitors are all consistent with Langmuir adsorption,the best group of composite rust inhibitor is 8A6 S group,And the adsorption form of the rust inhibitor on the surface of the steel bar becomes Temkin adsorption,and the passivation film on the surface of the steel bar of the composite rust inhibitor is more complete.(5)Compare the AC impedance of five rust inhibitors after long-term immersion to characterize the rust inhibition effect of each rust inhibitor.The composite rust inhibitor has the highest impedance and the best effect.Comparing the rust inhibition mechanism of various rust inhibitors,calcium nitrite enhances the density of the passivation film to prevent rust,organic rust inhibitors form a film on the surface of the steel bar,and inorganic rust inhibitors interfere with the electrochemical reaction process of the surface of the steel bar Rust effect.The rust inhibition mechanism of the composite rust inhibitor is summarized into three processes: 1)forming a protective film on the surface of the steel bar 2)affecting the electrochemical process of the steel bar 3)inhibiting the adsorption of chloride ions on the surface of the steel bar;the composite rust inhibitor has the most protective effect on the steel bar Strong.