Project Overview
The restoration project focused on concrete structures supporting the Sanyo Shinkansen Bullet Train system. Severe quality control concerns emerged due to chloride-contaminated concrete, resulting in widespread spalling and corrosion. The affected areas required repair and long-term protection to prevent further deterioration.
Problem
Concrete used in the construction of bullet train bridges contained seashore sand with a chloride concentration of 2–3 kg/m³ (10.12–19 lbs/ft³). This contamination caused crater ratios exceeding 70%, resulting in poor concrete quality.
The structures also showed:
• Multiple spalled areas exposing corroded reinforcement
• Additional deterioration that required both repair and corrosion prevention
A comprehensive repair solution was necessary to restore structural integrity and protect the reinforcement from continued chloride attack.
Application
The following MCI® products were selected for the restoration work:
• MCI®-2023: 32.02 kg (72.5 lbs)
• MCI®-2020: 31.02 kg (68.4 lbs)
• MCI®-2005: 3.69 kg (8.1 lbs)
MCI®-2023 was mixed with Tough Eco Emulsion produced by LION Co. These products were applied to protect corroded reinforcement and enhance the durability of repaired concrete areas.
Conclusion
More than sixty treatment products from fifteen manufacturers were evaluated for the project. Among all tested systems, Cortec® MCI® products demonstrated the highest performance and were selected for corrosion control of the Bullet Train structures.