Okinawa Prefecture Marine Expo Park Promenade Coastal 3 Years and 9 Months Follow-up Survey Report

It is said that there are no materials that can completely prevent 100% re-corrosion after repair painting work, and a follow-up survey of the Earthcoat anti-corrosion painting system in Okinawa Prefecture.

Environmental conditions in Okinawa Prefecture: - In addition to the conditions of heavily salt-damaged areas in Honshu, it is under a high-temperature and high-humidity environment for almost the entire year. - The distance from the coastline is short, resulting in significant influence from high-concentration salt carried by the sea. - Being close to the equator and having high levels of ultraviolet radiation creates a harsh environment where steel materials are prone to corrosion. - Research shows that the average corrosion rate is 2 to 10 times higher. Main causes of re-corrosion: 1. When newly constructed bridges are exposed outdoors, the coating on the steel deteriorates over time. 2. Water and air infiltrate through fine scratches and cracks that develop in the coating. 3. Corrosive factors come into contact with the steel surface, leading to corrosion. - In cases where the corrosion area is treated with sanding and repainting specifications, 4. Even if the steel surface is exposed through sanding, there may be residual rust that cannot be visually confirmed. 5. It is difficult to completely remove chloride ions that are attached to the rust inside. The durability of areas that have experienced corrosion is significantly inferior compared to when they were newly constructed, leading to relatively early re-corrosion of the coating. Why can long-term rust prevention effects be expected with Earth Coat? - Long-term corrosion prevention is achieved through a special function that incorporates a patented rust-inhibiting additive (Patent No. 3796580). - It can suppress corrosion acceleration caused by deliquescence due to salt damage.

Bridge Construction