A Shark Has Bitten a Building in Barcelona!
The coast of Barcelona (Spain) is a great place to stroll and admire the scenery. Amongst the marvels around, the sinuous, modern architecture of the new headquarters of Gas Natural Group is a striking one, especially its glass façade in the shape of a bite-mark, caused by an imaginary shark that could have risen from the adjacent Mediterranean Sea.
The dramatic architectural effect is created by 100 trapezoidal glass panels. Some of these panels measure up to five by two metres in size. They use a combination of strong and rigid plastics structural interlayers and an original fixation system to provide overhead glazing. This allows a high safety factor and excellent post breakage properties. The entire glass façade of this new Gas Natural buildings was designed, produced and installed by Permasteelisa España SA.
The new Gas Natural headquarters stands at the very place where the first gasworks were built in Spain 160 years ago. It was designed by local architects Enric Miralles and Benedetta Tagliabue, whose agency MBT won the call for ideas with a proposal characterised by a spectacular 20-storey glass tower that has already become a landmark on the skyline of the Catalan capital. Three further architectural structures make up the entire Gas Natural complex, each lending the building a strong personality and enabling the skyscraper to integrate into the surrounding city: one is a four-storey annexe in the shape of waterfall cascading to the sea; another is a cantilevered building projecting from the centre of the tower; and the last is the ‘capitel’, with its distinctive bite-mark, which overhangs the main entrance to the building.
It is the under-side of this curved section, representing the indentations left in the building by the shark’s teeth, that uses plastics interlayers over an area of approximately 220 square metres. A total of 100 trapezoidal laminated glass panels of different sizes are used, each comprising 8 mm tempered interior glass +1.52 mm plastics interlayer + 8 mm tempered exterior glass and produced by Spanish manufacturer Glass XXI. “With the biggest panels measuring 5131 x 1820 millimetres, and despite their complex shape, we were able to demonstrate how the plastics interlayers become an engineered component within the glass, holding more weight, so the glass can serve as a more active structural element in the building envelope with a high degree of safety,” explains Luis Villanueva, general manager of the glass manufacturer.
Glass Sticks and Structure Resists
Post-breakage stability of the laminated glass was further enhanced by the adoption of the Puntpart Overhead Glazing™1 fixation system from Bellapart Engineering. The system is especially impressive, due to the unique ability of the interlayer to flow around the metal fixings and adhere to them, as well as to the glass, providing outstanding stiffness and strength. This allows use of a thinner overall glass construction which, at the same time, makes the overall glass laminate construction substantially more stable, even in hot summer temperatures of over 45°C.
Among Interlayers, the Champion is DuPont
Plastics interlayers are the heroes of the laminated glass all over the world. In the DeLuxe category, high strength rigid DuPont™’s SentryGlas® is undoubtedly an asset. Thanks to its high-strength performance, the glass panels can be made both thin and light enough to facilitate the use of particularly small point-supported fixtures – even for overhead installations. No wonder architects all over the world are so keen to use it: it gives them the greatest freedom to imagine dreamlike aerial and transparent structures. But it’s not a dream: they are real!