SMA400AW is generally not the best choice for coastal structures unless supplemented with additional protection. Here's a detailed breakdown of its limitations and potential workarounds for coastal use:
Why SMA400AW is Limited in Coastal Areas
:
on SMA400AW breaks down in salt-rich environments (within 1 km of coastlines), leading to:
(localized rust penetration).
of the steel over time.
3–5× higher vs. inland environments.
JIS G3114 Restrictions:
(Class C4/C5 per ISO 9223).
When SMA400AW
:
(e.g., upper parts of bridges, not splash zones).
(>5℃) to prevent saltwater accumulation.
where salt deposits can collect.
:
zinc-rich primer + permeable topcoat (e.g., Corten-V™) on the sea-facing side only.
: Rinse with freshwater every 3–6 months to remove salt.
| SMA490AW | ||
| Stainless Steel 316L | 5–8× more expensive than SMA400AW | |
| Hot-Dip Galvanized Steel |
Cost-Benefit Analysis
| Bare SMA400AW | 10–15 years | |
| SMA400AW + Coatings | 20–30 years | Moderate (recoat every 10 yrs) |
| Stainless Steel 316L | 50+ years |
(>5 km inland):
Use SMA400AW on windward sides.
:
SMA490AW + duplex coatings.
:
(e.g., ) with enhanced chloride resistance.
