In the painting manual of the bridge, the suggestions for the matching painting of pedestrian guardrails and lamp posts are listed in Table 1.

The hot-dip galvanizing process is not only a high-energy consumption process, but also causes serious environmental pollution due to the "three wastes", making it difficult to maintain the galvanized layer. Therefore, we recommend the high-performance cold galvanizing material - Strong Zinc - to the bridge command center and relevant steel structure factories as a matching primer for pedestrian guardrails and lamp posts.

1、 Painting matching

2、 Planning criteria

3.1 Process flow

Steel pipe cutting - arranged into pieces - sandblasting rust removal - spraying strong zinc - spraying epoxy sealing paint - spraying epoxy cloud iron paint - spraying * * fluorocarbon process - shipping to the bridge construction site - welding assembly - weld polishing treatment - applying strong zinc or intermediate coating - spraying second fluorocarbon coating - checking coating quality - repairing - submitting documents

3.2. Surface treatment before painting

Choose sandblasting treatment. It is a high-efficiency surface treatment method that uses compressed air as a power source to spray sand particles (abrasives) at a certain speed onto the surface of the steel pipe being treated. The impact and grinding effect of abrasives on the surface of the steel remove the oxide scale, rust, and other dirt on the surface of the steel.

Attention:

(1) After a period of use, if the nozzle wears out, the aperture becomes larger, the jet flow disperses, and the cutting ability of sand particles is reduced, it should be replaced in a timely manner;

(2) The effective pressure of compressed air;

(3) Compressed air needs to be processed through an oil-water separator;

(4) Operation. After spraying the single side of the arranged steel pipes, rotate the pipes 180 degrees and rearrange them neatly before spraying the other side and paying attention to safety. It is necessary for operators to have a high sense of responsibility. Craft sandblasting covers the entire surface to be cleaned in sequence, with the nozzle angled at 70-80 degrees to the surface.

Appearance quality requirements:

Cleanliness meets Sa2.5 level according to GB 8923 (or ISO 8501-1) specifications

The planned roughness value is Rz=40-60um