Q:Is hot-dip galvanizing or electro-galvanizing recommended for ordinary building structures?
A:Hot-dip galvanizing is preferred for ordinary building structures because of its thick coating, stable corrosion resistance and high economy.
Electrogalvanizing (cold galvanizing) is not recommended because of its thin coating (5–30μm) and easy failure due to long-term exposure.
Q:What impact does environmental adaptation have on lifespan?
A:1. Ordinary atmospheric environment (urban, rural):
The zinc layer thickness can meet the requirements according to the above standards, and the service life can reach 20-30 years (no serious pollution or mechanical damage).
If the building is located in an industrial area or a lightly polluted area, it is recommended to increase the zinc layer thickness appropriately (such as increasing by 10-20μm).
2. High humidity or rainy areas: The zinc layer thickness must be ≥70μm (regardless of the steel thickness), and the integrity of the coating must be checked regularly.
Q:What precautions should be taken when using galvanized steel in the construction industry?
A:1. Post-processing:
If the galvanized profile is cut, welded or drilled, the exposed substrate edge needs to be zinc-filled (such as coated with zinc-based paint) to avoid local rust.
2. Contact with concrete: The galvanized layer may react in an alkaline concrete environment (pH>12). It is recommended to add an isolation layer (such as epoxy coating) on the contact surface.
3. Economic balance: There is no need to excessively pursue high zinc layer thickness. Ordinary buildings can be implemented according to the standard. Ultra-thick coatings will significantly increase costs.
Q:What is the required thickness of the galvanized layer for ordinary building structures?
A:Light components (≤3mm steel): 55–70μm.
Heavy components (>6mm steel): ≥85μm.
Standard basis: Directly refer to GB/T 13912 or ISO 1461, and match the coating according to the thickness of the steel.
Q:What are the factors affecting the selection of zinc layer thickness in the construction industry?
A:The specific zinc layer thickness selection also needs to comprehensively consider factors such as the building's environment and design service life. If the building is located in a corrosive environment such as an industrial pollution area or a coastal area, the zinc layer thickness should be appropriately increased; for buildings with a longer design service life, a thicker zinc layer is also required to ensure long-term corrosion resistance. At the same time, relevant national standards and industry specifications should also be referred to to ensure that the zinc layer thickness meets the quality and performance requirements.