For the eye and the wallet
Aluminum bridges with special look and vandalism protection
Glück GmbH from Engen is a pioneer in aluminum bridge construction. The high demand for a durable and economical solution plays a role in the coating process: The bridges are delivered with a sophisticated antigraffiti protective finish using a wet paint process.
"Aluminum is a material I can only rave about," says Werner Glück. The 73-year-old founded Glück GmbH in Engen in 2002 and put this enthusiasm into practice in bridge construction: 880 Glück bridges made of aluminum, a more than unusual material for this application until then, have been manufactured and installed by the company to date. As pedestrian and cycle bridges, they span valleys and rivers throughout Europe. One of these is the new pedestrian and cycle bridge over the Lämmergrund in the Saxon resort of Paulsdorf. The truss trough bridge has a total span of more than 69 meters and weighs 25 tons. It is made up of three spans, the largest of which is the central section measuring 36 meters in length. Like all bridges made by the Engen-based manufacturer, its construction is based on an aluminum profile technology developed by the company itself. There is only one thing that amazes when looking at the bridge: It doesn't look like aluminum at all. The surfaces of the bridge components present themselves in a heavyweight micaceous iron look
Beautiful things well protected - even by vandalism
"With aluminum, corrosion protection is not an issue. Nevertheless, we coat our bridges in a two-layer wet paint process - for one visual and one functional reason," clarifies Werner Glück. With the painting process - in contrast to the much more costly anodizing process - an enormously wide range of colors is feasible. For such large structures, which also have to blend ideally into their surroundings in terms of color, this argument counts. The functional aspect is aimed at the maintenance of the bridges. Glück GmbH uses a product with antigraffiti protection in the final coating. This enables municipalities to prevent the most common damage caused by vandalism: With this coating finish, the unloved decorations do not have to be expensively repainted, nor do bridge components have to be costly dismantled, but they can simply be wiped off at virtually zero cost.
Wet painting in one piece
Each of the three bridge segments for Paulsdorf was finished and coated manually in the company's own 56-meter-long paint shop in Engen using the air-assisted process - another advantage over anodizing, where each component would have to be treated individually. "Only our hall length thus limits the maximum length dimension of a bridge element," Werner Glück elaborates. Each Glück bridge is always an individually dimensioned one-off, which would make the use of a powder coating system of little use. In Engen, the wet paint is applied in a two-coat system - primer and top coat - and each pass requires one day for application and drying. For the high coating quality required for bridge structures, Werner Glück has experimented with different wet paint systems. His conclusion: "Not every manufacturer is familiar with coating aluminum. In my experience, three factors are crucial. They are called substrate preparation, substrate preparation, substrate preparation," he emphasizes. "This is where individual consultation and technical tests are needed. This is exactly the service we received from Brillux Industrielack, which is why we switched to a wet paint system from this manufacturer in 2016."
Using original aluminum profiles from Glück, Brillux Industrielack determined the ideal procedure for sanding, cleaning and degreasing the components as part of a technical consultation. A coating proposal was then prepared and the surfaces were subjected to the salt spray test according to DIN EN ISO 9227 and the condensation water constant climate test according to DIN EN ISO 6270 for 720 hours. "The test results were flawless," summarizes Holger Schroth. The technical consultant from Brillux Industrielack is regularly present in Engen and can be contacted personally for any questions.
Antigraffiti protection saves money
Today, Glück GmbH exclusively uses the high-solids Brillux industrial paint primer 2K-EP-Haftgrund 5706 for wet painting. This epoxy resin primer was developed in the system as an ideal adhesion promoter for the also extremely hard-wearing top coat with 2K-PUR-Antigraffiti Paint 5749. The 2K-PUR-Antigraffiti-Lack is available in an almost unlimited variety of colors in the gloss levels high gloss and silk gloss. The anti-graffiti protective finish is based on a special coating system with an anti-adhesive effect: solvent-based paint - whether applied with permanent markers or sprayed - does not penetrate the coating, but remains on the surface. "In fact, graffiti can be wiped off without leaving any residue using a rag and cleaning agent - I've tried it myself," confirms Werner Glück. His customers are thus spared the high costs of repairing defaced bridges. Especially for public clients whose buildings, street furniture or vehicles are the first address for graffiti artists, 2K-PUR anti-graffiti paint opens up a wide field with a lot of savings potential. "From switch cabinets to silos, from doors to garage doors, from vending machines to commercial vehicles, endangered public areas benefit from an antigraffiti protective coating," says Holger Schroth. Brillux Industrielack also offers antigraffiti paints as powder coatings. Even with combined powder and wet coatings, there are no color deviations, because the manufacturer supplies in the system.
The installation of the pedestrian and cycle path bridge in Paulsdorf was just as routine as the well-rehearsed coating process. Glück GmbH erected the structure withiin one day. Thanks to the weight being halved compared to steel bridges, aluminum bridges can be used with lighter cranes and much faster. The Pirna District Office will benefit in the long term from the bridge's durability of 80 to 100 years, its ease of maintenance and its low maintenance costs. Even if it should ever need to be replaced, it will remain sustainable: its aluminum is completely recyclable. You begin to understand why Werner Glück is so enthusiastic.