P-Basement in Copenhagen
Built in the 1970s, this housing block sits on top of a heated parking garage reserved for its residents.
The Problem
This P-Basement in Copenhagen was renovated in 2022 because the reinforcing bars in thirty-six columns were corroded and caused spalling to the surrounding concrete. A common problem for parking structures in cold climates is the use of de-icing salts on public roads. When salt-covered cars park in heated garages, the ice melts off the vehicle, leaving pools of salty water inside the structure. These puddles get splashed onto the columns, and the chlorides seep into the concrete, eventually causing corrosion of the embedded steel. A silver lining for this spalling of the concrete was that the owner had an apparent visual indication that they had a corrosion problem and could take action to repair and protect it before it could become a structural problem.
Our Solution
The columns would require the unsound concrete to be removed and replaced. Because we can expect chlorides to still be present in the still-sound concrete around the repair, it was imperative to provide a cathodic protection solution to prevent damage to the surrounding steel caused by the halo effect. Each column had its unsound concrete removed; then Galvashield® Fusion® T2 units were installed, followed by the replacement of the concrete and a protective coating to reduce future ingress of chlorides.
The Result
This is the ideal application for using the Galvashield® Fusion® T2's targeted protection, as the columns are only corroding at their base. Fusion® anodes, provided for this project by our partner Max Frank, use a two-stage system where the integrated ICCP system quickly polarizes the steel stopping all corrosion in the area, then automatically switches over to the galvanic system to provide long-lasting corrosion control. 216 Galvashield® Fusion® T2 anodes in total were installed and embedded in a flowable mortar with low resistivity. This solution can be expected to provide protection for the next 30+ years without any maintenance.
Technology Used
These innovative products and technologies were used on this project.