Under normal circumstances, the steel structure does not corrode or corrodes slowly after adding a protective layer. The life of some buildings can reach hundreds of years, but under some conditions, the steel structure has an amazing corrosion rate, which can be rusted in a few years or less. Destruction of buildings can be done within a short period of time. The corrosion process is generally as follows: micro-cracks and holes in the protective layer of the steel structure, peeling of the protective layer, intrusion of harmful media; corrosion of the steel structure; severe corrosion of the steel structure; reduction of the performance of the steel structure and damage to the structure or components. Its anti-corrosion treatment can generally be considered from two aspects:
a.Take measures according to the corrosion level
The corrosion of building steel structure can be divided into four grades: strong, medium, weak, and no. Under the condition of strong rust (a large amount of CO2, SiO2, H2S industrial environment), the corrosion rate of the material is fast, and the components and parts must be protected by surface isolation; under the condition of moderate rust, the material has a certain degree of rust, and the weight of the component can be increased. , or use simple surface protection; under weak rust conditions, the material rusts slowly, but some measures need to be taken; under no rust conditions, the material rusts very slowly or there is no obvious rust trace, and components and parts may not take protective measures.
b.Processing of key links
Base treatment: The anti-corrosion base treatment of the steel structure should be qualified and meet the specific requirements of the design drawings, such as the use of alkyd paint, epoxy zinc-rich paint, galvanized, etc.
Temperature and humidity: The ambient temperature and relative humidity during coating should meet the product requirements, the ambient temperature should be 5-38°C, the relative humidity should not be greater than 85%, and the surface should not be coated with dew. Do not rain within 4 hours after painting.
Thickness of spray coating: It should meet the design requirements, and the spray coating used on the day should be configured on the same day, and operate according to the anti-rust spray coating operation specifications. Coating performance: The influence of various harmful media on the steel structure should be considered, and the spray coating suitable for the working environment should be selected to ensure the anti-corrosion quality.