(1) Reduction of corrosion current
The main function of steel bar rust inhibitor is to prevent or slow down concrete The corrosion rate of the internal steel bars, and the size of the corrosion current is the most important parameter that formally describes the corrosion rate. Steel bars in an ideal non-corrosive state have a thin oxide layer on their surface. This oxide layer can protect the steel bars from corrosion in an alkaline environment. The potential of the steel being protected in this case is not the same as the potential of the steel where the rust occurs. Electricity measurement methods can provide information on how the corrosion risk of steel bars changes in different parts of the structure.
(2) Performance of filtering out chloride ions
The impact of Cl- content in concrete on steel bars The impact of corrosion is great. When concrete contains Cl-, even if the alkalinity of the concrete is still high and the concrete around the steel bars has not yet been carbonized, the steel bars will rust. This is because Cl- has a small radius, high activity, and a strong ability to penetrate the passivation film, causing local destruction of the passivation film on the surface of the steel bar, resulting in the so-called pit corrosion phenomenon of the steel bar. Chloride ions continuously combine with Fe2+ to form ferric chloride, react with OH- and then release again, continuing to combine with new Fe2+. This reaction process is vicious, and the chloride ions in the concrete and on the surface of the steel bars will not die. As long as chloride ions are present, this reaction will continue until the steel bar is completely rusted. Some data show that when the chloride content in concrete reaches 0.6~1.2kg/m3, the corrosion process of steel bars can occur. Due to the harm of chloride ions to reinforced concrete, the chloride content in concrete should be strictly controlled.
Therefore, whether a rust inhibitor can effectively reduce the chloride ion content in concrete and on the surface of steel bars has become the most important factor in evaluating its rust inhibitor performance. . The national standard "Code for Design of Reinforcement of Concrete Structures" clearly stipulates that the reduction rate of chloride ion content of spray-type rust inhibitors must be greater than 90%.
(3) Working performance in high temperature and high humidity environment
High temperature and high humidity Conditions are important external environments that accelerate the deterioration of reinforced concrete structures. Rust inhibitors that are effective at room temperature may not continue to maintain their effectiveness under high temperature and high humidity conditions. Serious corrosion often occurs in harsh environments such as high temperature and high humidity. Therefore, the working performance of rust inhibitors in high temperature and high humidity environments has become very important.
(4) Environmental performance
The main features of spray-type rust inhibitors The ingredients are organic chemicals and environmental pollution should be avoided during their storage, transportation and use. Non-toxic, harmless and environmentally friendly rust inhibitors should be selected. </p
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