Project Overview

The concrete piers of the Hangzhou Bay Cross-Sea Bridge are exposed to severe marine corrosion (salt spray concentration >1,500mg/m².d, tidal zone wet-dry cycles ≥2/day).

Pre-application inspections revealed critical issues:

lChloride penetration depth: 20mm

lConcrete spalling in splash zones

lSteel reinforcement corrosion rate exceeding design limits by 300%. In 2024, our C5-M marine-grade heavy-duty anti-corrosion system was deployed to achieve       30-year maintenance-free protection.

Technical Challenges

1:Complex corrosion factors: Seawater pH8.1-8.4, sulfate content exceeding Class III limits per GB/T 50476-2019.

2:Harsh construction constraints: 3-4 hour daily tidal work windows, substrate moisture content <6%.

3:Durability requirements:

lChloride diffusion coefficient <1×10⁻¹²m²/s

lFreeze-thaw resistance (300 cycles)

lImpact resistance (5kJ/m²energy absorption).

Coating System Design