Repair and renovation of metal structures

Repair and renovation of metal structures

To carry out repairs or renovations of metal structures, it is first and foremost necessary to know the construction material used and its characteristics :  These are, in particular, its elastic limit, its breaking load, the characteristic elongation of its ductility and its weldability. Then you have to know the history and the geometry of the work. It is also imperative to proceed with the diagnosis of defects that alter the structure. This may be cracking, corrosions, deformations or assembly defects. Finally, a possible recalculation of the structure will have to be done if need be. The actual work is done in the workshop (to prepare the elements) and on site (to connect the structure). There are various methods and techniques of steel structure repair. Those are :
Repair by welding;
Repair by bolting;
Riveting repair.
To guarantee the stability of a structure undergoing repair, the old elements of the structure must be reinforced so that they can support the new structure. It is then necessary to know the resistance capacity of a bar before undertaking any repair or renovation so that the other elements do not deform or become damaged by false installations.

Corrosion prevention techniques

Construction materials, especially steel, suffer significant damage because of corrosion caused by soil, air, but also the sea. More information on corrosion under pipe support. To avoid this deterioration, several techniques can be used. We have the cathodic protection, the protection by laying of paint (or other special surface coatings) and the dimensioning of the steel. One or more of these precautions can be chosen, but the choice depends, among other things, on the aggressiveness of the environment, the duration of the protection sought, without forgetting the feasibility of the project with regard to the available financial means and the maintenance work to consider. Corrosion refers to the formation of rust on steel. It results from the interaction of the metal with its environment. It has the effect of modifying the properties of the metal, most often it degrades it.
Painting or anti-corrosion coating is a fairly common precaution when it comes to protecting metal structures against corrosion. It is a practical and economical preventive compared to other methods.
Steel can also be corroded by opting for cathodic protection. This is to defend the submerged structures by avoiding the anodic reaction of iron corrosion.
Finally, by opting for the dimensioning of steel, it is added thickness taking into account the decrease in consistency due to the effects of corrosion.

Reconstruction of damaged parts

To rebuild a metal structure, it can be partially dismantled and then replaced damaged elements. Here, it is better to put in place a transient mechanism to ensure that the new element does not imbalance the entire structure. A lash bar can be used to support a tense bar. For high strength bars, it is best to avoid shocks, pressure and welds. If the reconstruction concerns a compressed bar, the temporary device used must be similar with buttresses and cylinders. We can not always know in advance the particular characteristics of a metal structure. So, in order to ensure that the reconstruction is adequate and the temporary mechanisms are adapted, some important checks must be made. There is, for example, the establishment of the temporary device, then the positioning of the bar and its gusset attachment, the removal of fastening rivets not to interfere with the movements and adjustment of the device. It also happens that the element to be rebuilt is a gusset of bar fasteners, which is a little delicate, because this element most often connects 3 bars. So, the temporary device must take into account these 3 elements.

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