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:

✔ Chloride penetration depth: 20mm

✔ Concrete spalling in splash zones

✔ Steel 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:

    ✔ Chloride diffusion coefficient <1×10⁻¹²m²/s

    ✔ Freeze-thaw resistance (300 cycles)

    ✔ Impact resistance (5kJ/m²energy absorption).

Coating System Design