The anti-rust base treatment of steel structure should be qualified and meet the specific requirements of design drawings, such as alkyd enamel, epoxy zinc-rich paint, chlorosulfonated polyethylene, galvanizing, etc.
Generally speaking, the steel structure with protective layer is corroded or corroded slowly. Some buildings can live for hundreds of years, but under some conditions, the steel structure has an alarming corrosion rate, which can cause damage to the building in a few years or less. Corrosion process is generally as follows: steel structure protective layer produces micro-cracks and holes, protective layer exfoliates, harmful media intrusion; steel structure corrosion; steel structure serious corrosion; steel structure performance degradation, structure or component damage. Its anticorrosion treatment can generally be considered from two aspects:
1. Measures to be taken according to corrosion grade
The corrosion of building steel structure can be divided into four grades: strong, medium, weak and non-corrosive. Under the condition of strong corrosion (large amount of CO2, SiO 2, H2S industrial environment), the material corrosion speed is faster, and the structure and fittings must be protected by surface isolation; under the condition of medium corrosion, the material has certain corrosion, which can be used to increase the weight of the component itself or to adopt simple surface protection; under the condition of weak corrosion, the material corrosion is slower. However, some measures need to be taken; under the condition of no rust, the material rusts very slowly or without obvious rust marks, and the components can not take protective measures.
2. Treatment of Key Links
Base treatment: The anti-rust base treatment of steel structure should be qualified and meet the specific requirements of design drawings, such as alkyd enamel, epoxy zinc-rich paint, chlorosulfonated polyethylene, galvanizing, etc.
Temperature and humidity: The ambient temperature and relative humidity during painting should meet the requirements of the product. The ambient temperature should be 5-38 C, the relative humidity should not be more than 85%, and the surface should not be coated when dewing. No rain within 4 hours after painting.
Spraying coating thickness: It should meet the design requirements. The spraying coating used on that day should be disposed on the same day, and the diluent should not be added at will. Coating performance: Considering the influence of various harmful media on the structure of steel, spraying coating suitable for working environment should be selected to ensure the quality of corrosion protection.