Sustainable timber skyscrapers
Using materials like cross-laminated timber (CLT) can also reduce construction time and make it easier to build on difficult sites. At Dalston Lane in Hackney, London, Ramboll has designed what is set to be the world’s tallest and largest CLT building by volume.
“The lighter construction weight of CLT enables smaller foundations, something critical to the Dalston Lane site, which has High Speed 1 and Crossrail passing underneath. The use of CLT at Dalston Lane has also saved 2,400 tonnes of carbon compared to an equivalent block with a concrete frame and so has great potential as a sustainable and quick-to-construct material,” says Gavin White, Director of Ramboll UK.
Andrew Waugh, Director of Waugh Thistleton Architects, adds:
“CLT structures are the only sustainable solution to provide high-quality, high-density housing, and as such, this project – given its scale and ambition – is a seminal piece of architecture.”
Refurbishing an existing flyover
London is investing heavily not only in buildings but also in road and rail, which includes upgrading existing infrastructure to make it fit for purpose. A critical part of Transport for London’s Structures
and Tunnels Investment Programme was work on the Hammersmith Flyover, a vital link in West London carrying over 70,000 vehicles per day.
The post-tensioning system had suffered significant erosion that threatened to close the flyover unless the system was repaired. However, the innovative use of ultra-high performance fibre-reinforced concrete (UHPFRC) has enabled the structure to stay open and extended its life for many years to come.
This phenomenally complex EUR 130-million programme is believed to be the first time an all new pre-stressing system has been installed in a bridge where the original could not be removed. Such techniques and the intelligent use of 3D scanning technology are driving life extension and design efficiency, as well as eliminating programme and safety risks, speeding up repairs and thus minimising disruption to the public.
Managing Director Paul Bottomley from the post-tensioning sub-contractor Freyssinet calls the work unique:
“Replacing, fully, all the old post-tensioning without first removing it on such a significant structure is truly impressive,” he says. Mat McNab, Head of Buildings, Ramboll UK,
“At a time when resource scarcity is at the forefront of our minds, innovations that make the best use of existing infrastructure and building plots will be vital to securing the increased capacity our growing cities need.”