Standing 87.5 metres tall and with its view over the Meir, Antwerp's KBC Tower was the first skyscraper in Europe and an icon of the art deco style. Construction of the Tower, also known as the Boerentoren, was completed in 1931. It was later topped off with the panorama room and KBC's logo, bringing it to a height of 95.75 metres.
Its architects applied a construction technique frequently to be found in many American skyscrapers like the Empire State Building. It's a technique that makes use of steel structures around which the building is then erected. Due to a gradual incursion of damp through the outer walls over more than 80 years, the steel structure is now being affected by corrosion.
Active cathodic protection, a frequently used method for restoring steel structures.
Naturally, it's not possible to replace the steel structure itself. For that reason, the restorers will apply impressed current (ICCP) through the outer walls. This is done in practice by inserting ceramic titanium anodes into a number of joints, thus placing the steel structure under a constant, very low electrical current. The process offers an environmentally friendly, permanent solution to both the consequences of existing rust and against future rust formation, and stabilises the central steel structure.
Around the world, ICCP is a tried and tested technique for restoring steel-structured buildings, maintaining pipelines and in shipyards. This is the first time the technology will be used in Belgium in the large-scale restoration of a steel-skeleton structure with stonework cladding. A total of around
7 000 cathodes will be fitted, which altogether will consume no more electricity than a regular computer.
At the same time, KBC is taking the opportunity to do some light, general cleaning to the outside of the Tower, to even up its overall appearance. Some of the stone cladding has been affected by the underlying
corrosion and will be either replaced or repaired as necessary. The cleaning works also include moss-repellent treatment, repairs to the concrete, new putty round the windows where needed, checks of the flashings, the replacement of PVC drainpipes with zinc ones, cleaning and inspection of the roofs and terraces, and anti-rust treatment and painting of two of the iron stairways.
Works will be phased up to the end of 2014
The works will be carried out in four phases, one for each side of the building. They will start on 10 March 2014 and take until at least December of this year. The phasing of the works is intended to keep the nuisance to those living in the vicinity, pedestrians and staff working at the KBC Tower and in neighbouring premises to an absolute minimum.
KBC's chosen contractor is Verstraete & Vanhecke NV.They will be working together with the Dutch firm Vogel KB for the cathodic protection procedures. The scaffolding will be in the hands of Kaefer. The Antwerp firm of Steenmeijer Architecten BVBA has been engaged in conjunction with Triconsult NV from Lummen to design the project.
Note for editors:
- Verstraete-Vanhecke NV of Wilrijk are specialists in renovation and restoration works. Prestigious projects on which they've been engaged include the central concourse of Antwerp Railway Station, the Brussels Stock Exchange and Ghent Town Hall.
- Vogel Kathodische Bescherming BV of Zwijndrecht are specialists in impressed current cathodic protection and concrete repair works.
- Steenmeijer Architecten BVBA of Antwerp have specialised for over 30 years in conserving, restoring and converting listed and heritage properties. Their foremost projects include restoration of the Cathedral of Our Lady in Antwerp. KBC already engaged them a number of years ago to convert and refurbish its exhibition salons in the Grand Place in Brussels.
- Triconsult NV of Lummen is a spin-off of Leuven University (KUL) and specialises in stability surveying, reinforcement and consolidation of buildings and structures and the study, research and development of materials and components.
- Kaefer België NV of Sint-Niklaas is a subsidiary of Kaefer Isoliertechnik GmbH & Co. KG., Bremen, Germany.
- For further information on Start It @KBC, go to www.kbc.com.