‘World’s longest’ composite bridge debuts in Madrid

The 44m long beam, which manufacturer Acciona claims is the longest in the world, is a load bearing, jointless, single structure made using carbon fibre reinforced polymers. Co-funded by the European Commission, it is part of a new HP Future Bridge project aimed at producing long life and low cost composite bridges for rapid infrastructure renewal. Designed to be as lightweight as possible to meet the transportation, logistics and installation requirements defined for the project, the bridge was created using an epoxy adhesive system with enhanced toughness, chemical thixotropy and low exotherm from Araldite. According to Stefano Primi from Acciona's R&D centre, the bridge was constructed over the Manzanares River in just two hours and took only 30 days to manufacture. "This is the first time in the history of the composites industry that a 44m long, 3.5m wide, structural load bearing bridge beam has been built utilising 12tonnes of carbon fibre," he said. "The surface of the beam is smoother and more aesthetically pleasing than a steel or concrete bridge and it offers excellent corrosion resistance and less maintenance. No painting is required." Primi also said that because no joints, assembly or high capability cranes were needed for either installation or maintenance, the beam allowed for more architectural freedom in design. "By offering huge potential to produce more efficient and cost effective structures, carbon composites could truly revolutionise the construction of long span bridges," he concluded. The company is now working on a 200m single beam bridge in Cuenca, Spain and has plans to further explore the usage of composites in construction across Europe, with a longer term view to undertake similar projects on a global scale.