For the owners of multi-storey car parks and other major structures, this is a major dilemma, since it is assumed that both options will inevitably be costly, time-consuming and disruptive. The owners at Karihaugen BRL and Ellingsrud BRL recently faced this issue, but found a better than expected result.

On this site near Oslo, the five multi-storey car parks have been extensively used by residents for over 30 years. In addition to general disrepair, there was evidence of rebar corrosion within the floor slabs and rapid deterioration on the external facades.

To effectively assess the best solution, a number of reports were carried out on the extent of corrosion present, and the carrying capability of the structures and their future usage. These reports were carefully evaluated by consultants to forecast cost implications for repair or rebuild options, and the potential quality of each approach. Over a 70-year timespan, it was shown that the demolish/rebuild option was almost 300% higher than to carry out high quality repairs. For the owners, the decision to repair was an easy choice to make.

Following a tendering process in Scandinavia, specialists Protector AS were awarded the contract and begun work in August 2009 with OPAK AS as the Consultant. The work has included:

• thorough "dry" repair of all concrete structures
• control and establishment of electrical continuity between the existing rebars
• installation of the complete Camur ZEBRA cathodic protection system to prevent on going corrosion on inside reinforcement + protective coatings for the floor slabs, columns and soffits.
• Installing Camur : digital, remote monitoring and electronic surveillance of the CP effects and the corrosive state of the reinforcement, incl telephonelines.

Reduction in re-bar diametre

Corroding reinforcement in deck-slabs.

Having totally repaired the structural damage to the five car parks, Protector  then added new facades and installed new roofing to provide a high quality aesthetic finish to each building. The job is nearing completion, with each structure taking on average less than 2 months to finish.

With minimum disruption, and considerably lower costs, Karihaugen BRL and Ellingsrud BRL have five bright and modern-looking car parks for their residents. More importantly, they have the reassurance that the buildings are structurally safe, functional and will last for many more years to come.

ZEBRA CP system installation underway

New, bright-looking insides.

New outside appearance

New outside appearance