In one of the most extensive uses of advanced composites in the architectural industry to date, Saudi Arabia’s $7 billion Al Haramain high-speed rail project includes four passenger stations with a total of more than 160,000 square meters of fiber-reinforced plastic (FRP) roof panels. The 275-mile railway – the first high-speed rail in the Middle East – will link Jeddah, King Abdullah Economic City and the Muslim holy cities of Mecca and Medina. Travelling at nearly 200 mph, the high-speed trains are expected to reduce congestion during the annual Haj, when millions of Islamic pilgrims from around the world visit Mecca.
The expansive project was a collaboration between the architectural firm Foster + Partners and the civil and structural engineering company Buro Happold in Abu Dhabi. Each rail station will include quarter-mile long platforms, mosques, helipads, shops and restaurants. The roofs are being built using modular construction, with 65 FRP panels assembled into 27 x 27 meter modules before being lifted onto the supporting steel structure.
Panels for the 28,000-square-meter Medina station roof are currently being produced and installed by Premier Composite Technologies of Dubai. Premier joined the project in 2009 when Foster + Partners and Buro Happold were exploring material options for the roofs. During this phase, Premier worked with material supplier Gurit and the designers to conduct feasibility studies, model structural behavior using finite element analysis and finalize the concept design.
Participating in this preliminary stage is critical to the success of composites in architectural projects, says Mark Hobbs, senior engineer at Gurit. “Although composites have been used for almost 50 years in facades and things, they are still seen as quite a novel material in that industry,” he says. “As a result, designers aren’t really very familiar with composites, what they can do or how to best use them.”
The design team opted to use composite panels for the rail station roofs because they provide numerous advantages over traditional materials like concrete. Foremost, composite panels are lightweight. The Medina station roof weighs just 750 tons, resulting in a lighter supporting steel structure and smaller foundations. This, in turn, offers a significant cost savings.
Prefabricated composite panels also allow for quick installation, which was a key requirement for this fast-paced project. The fire-resistant FRP panels also integrate aluminum-framed windows, reflective light shafts, suspension systems for cleaning cradles, roof cappings and external walkways, providing a turnkey solution.
Premier Composites is producing 2,048 panels for the Medina station, the largest of which measures 9 ½ x 2 meters. These advanced FRP sandwich panels feature a structural foam core between two skins of glass reinforced epoxy. Laminated female molds are first layered with quadraxial E-glass fabric that has been impregnated with Gurit’s Ampreg 21FR (fire retardant) epoxy resin.