Port of Tokyo Industrial Pier
The Port of Tokyo port is one of the largest seaports in the Pacific Ocean with an annual capacity of about 100 million tons of cargo and 4.5 million containers.
The Problem
One of the largest industrial piers in the Port, measuring 150m long by 20m wide, required an intervention to extend its service life. Being a seawater port, the concrete pier was exposed to aggressive chlorides, eventually penetrating the concrete cover and causing reinforcing steel corrosion. Expansive corrosion by-products cause concrete cracking, spalling and delaminations. Previously executed concrete repairs did not fix the problem, as evidenced by continued corrosion.
Our Solution
Our local representative, Credence Corporation, based in Tokyo, worked with the owner and contractor to determine that ongoing patch-accelerated and macrocell corrosion needed to be mitigated to rehabilitate the pier. The pier repair project was divided into three sections to accommodate the arrival of large ships during the construction period. Since the underside of the pier is constantly exposed to high humidity and prone to rebar corrosion, the recommended solution included removing the chloride-contaminated concrete for the entire slab and bottom of beams and installing Galvashield® DAS distributed anode system. Galvashield DAS is a sacrificial anode system that provides a high level of galvanic cathodic protection over a wide area. Approximately 6500 linear meters of Galvashield DAS Type F89 were installed to mitigate active and future corrosion.
The Result
The concrete repair and protection system were completed in 2019 as designed. After one year of limited monitoring, the effectiveness of the cathodic protection system was confirmed, and a visual inspection indicates no visible change in the external appearance. The Galvashield DAS system has proven to be a very effective corrosion mitigation option for this critical pier.
Technology Used
These innovative products and technologies were used on this project.