The process of assembling metal structures consists of several stages. The first is the preparation of the structural elements for assembly, which is usually carried out in a warehouse.
The parts are checked for defects that need to be eliminated on site. If necessary, they are assembled in large quantities. In other words, what is difficult to do at height needs to be done on the ground.
In particular, the algorithm of actions during the assembly of metal structures includes the correction of bent elements using special tools (wedge, lever, jack, sledgehammer, etc.).
The detected defects are usually corrected by cold straightening. If we are talking about profiles with a symmetrical cross-section, the radius of curvature should be at least 50 times the sheet thickness, the height of the I-beam, the width of the I-beam flanges, etc. For elements with an asymmetrical cross-section (angle, channel), this figure should be at least 90.
In cases where the radius of curvature is smaller, straightening is carried out using a hot method with heating the metal from +900 °C to +1,100 °C using a forge or gas burner. Straightening of the structural elements should be completed at a temperature of at least +700 °C.
If it is impossible to eliminate defects by cold or hot straightening, the damaged elements should be reinforced in a manner agreed upon with the developers of the design documentation.