Bridge Steel Structure Anti-Corrosion Solution

Application Scenarios

Highway bridges, railway bridges, urban elevated roads, pedestrian overpasses, and other steel structure anti-corrosion coating applications.

Selection Logic

Bridge steel normally requires a multi-coat system because the structure is exposed to UV, rain, temperature cycling, vibration, and difficult maintenance access. The final coating system should be confirmed by exposure class, design life, surface preparation grade, and whether the bridge includes splash-zone or high-humidity sections.

Recommended Coating Systems

Option 1 (Standard)

Coat	Product	Coats	DFT (μm)
Primer	Epoxy Zinc-Rich Primer (30%)	2	100
Intermediate	Epoxy MIO Intermediate Coat H1100C	1	80
Topcoat	Acrylic Anti-Corrosion Topcoat	2	70
Total		5	250

Option 2 (Premium)

Coat	Product	Coats	DFT (μm)
Primer	Epoxy Zinc-Rich Primer (60-80%)	2	100
Intermediate	High-Build Epoxy MIO Intermediate Coat	1	120
Topcoat	Fluorocarbon Topcoat	2	80
Total		5	300

Option 3 (Bridge Bottom / Immersed Areas)

Coat	Product	Coats	DFT (μm)
Primer	Epoxy Zinc-Rich Primer	2	100
Intermediate	High-Build Epoxy MIO Intermediate Coat	1	120
Topcoat	Epoxy Coal Tar Anti-Corrosion Paint	2	120
Total		5	340

Surface Preparation

• Blast cleaning Sa2½
• Surface roughness Rz 50-85 μm
• Cleanliness: Free of oil and dust

Design Life Reference

• Standard option: 15-20 years
• Premium option: 20-25 years
• Immersed area option: 25-30 years

Related ISO 12944 Classes

• C3-C4: urban bridges, inland industrial bridges, and moderate exposure.
• C5: coastal bridges, high-humidity bridge sections, and aggressive industrial exposure.
• CX: only after project-specific review for severe marine or offshore-like exposure.