Discussing the hot-dip galvanizing protection for bridges
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The guardrails, escalators of steel bridges, as well as prefabricated small steel bridges are protected against corrosion through hot-dip zinc plating. The thickness of this zinc coating generally does not exceed 80μm, and it provides effective protection for around 10 years in a typical industrial atmospheric environment. The hot-dip zinc coating process requires immersing the workpiece in a bath of molten metallic zinc; due to the limitations of the bath’s capacity, it is not possible to apply this anti-corrosion treatment to steel bridge components of larger sizes. Secondly, hot-dip zinc coating for corrosion protection cannot be applied on-site; it can only be done in specialized factories, which inevitably results in high costs associated with back-and-forth transportation. Furthermore, once the hot-dip zinc coating is damaged, it cannot be repaired on its own. Therefore, using the hot-dip galvanizing method for comprehensive anti-corrosion of steel bridges has significant limitations
Hot-dip galvanizing is a common method for protecting steel bridges, and it is often used for small components such as guardrails and escalators. Its principle is to immerse the workpiece in molten zinc, thereby forming a protective layer whose thickness generally does not exceed 80 micrometers; this layer can remain effective for about 10 years in normal industrial conditions. However, this method also has many limitations. First, the size of the galvanizing tank is limited, so larger steel bridge components cannot be placed inside it. Secondly, construction can only be carried out in a factory; it is not possible to perform the work on-site, which increases transportation costs. Furthermore, if the galvanized coating is damaged, it cannot be repaired on its own; the entire surface has to be redone. Therefore, although hot-dip galvanizing is quite useful for small steel components, it is not very suitable for large steel bridges. .