Meant to evoke the unique form of a desert rose in windblown crystallized gypsum, the facade of the National Museum of Qatar by Ateliers Jean Nouvel consists of some 130 concrete discs that interlock and bisect one another at almost every angle. Ranging in diameter from three to 10 metres, the discs were fabricated from a multitude of angular panels that accentuate the crystalline aesthetic. In all, there are over 96,800 individual panels, their combined surface area totalling 120,000 square metres. Astonishingly, though, their concrete skin can be as thin as 40 millimetres.
Danish firm Contec Group was given the formidable task of manufacturing the panels to a tolerance of plus or minus one millimetre using ultra-high-performance fibre-reinforced concrete (UHPFRC). “The main difference, compared to traditional concrete or glass fibre–reinforced concrete (GFRC), is the extreme density combined with very high strength in compression, flexural strength and overall durability,” says Bo Serwin, Contec Group’s CEO. “On this project, for instance, a minimum compressive strength of 115 newtons per square millimetre (N/mm2) was required; GFRC is normally 30 to 45 N/mm2.”
The panels were manufactured in Abu Dhabi by spraying liquid UHPFRC into the double-curved moulds. Once on site in Qatar, the gigantic jigsaw puzzle of panels was locked in place on a steel frame, supported by needle beams on the main structural steel skeleton of the building. The relative slimness of the UHPFRC panels reduces the overall weight dramatically and minimizes the amount of concrete and sand used in their construction.
“Our main challenges were the number of different moulds and the logistical test of controlling all of the panels,” says Serwin. “However, the results are amazing. Due to their improved strength, the panels can be slimmer and more elegant, while still having a very dense, durable surface – the technology actually derives from the original Roman idea of adding pozzolana to concrete.” Adopting an ancient technique to bring to life a building that houses ancient artifacts for future generations is fitting: It speaks to the intended longevity of the project – and allows for minimum maintenance to boot. jeannouvel.com