In a significant first for the UK, the country’s debut ultra-low carbon concrete has been laid. It has a 70% lower carbon footprint compared with traditional concrete and 50% lower than very low carbon concrete.
It is a significant move for transport, where concrete sees major use in road, rail, maritime and aviation construction projects.
The use of Exegy concrete in the UK follows its use on the Grand Paris Express rail project in France. Vinci Construction created pre-cast tunnel lining segments out of the low-carbon concrete for a pilot project on the new Line 18.
Already used in major projects in Paris, for construction of the athletes’ village for the Paris 2024 summer Olympics, the concrete was developed over four years by Vinci Construction and Ecocem.
They have jointly patented the alkali-activated binder that is key to reducing the use of Portland cement in the mix.
The first UK pour took place this week at EcoPark South in Edmonton, London, isthe first phase of North London Waste Authority’s £1.2bn sustainable management hub and energy recovery facility.
The pilot project intends to ascertain whether the Exegy concrete works adequately when poured into formwork at the pace required for an industrial operation. It will also check how the finished precast segments behave in storage and over time under operating constraints.
Vinci Construction created a concrete formula specifically suited to tunnel lining segment construction. In September last year it created 40 segments – enough to produce five full tunnel rings – for the project. These will be used for full-scale qualification tests including ISO fire tests and load tests.
Vinci Construction is working with partner concrete manufacturers for the production of Exegy concretes.
Société du Grand Paris – the client for the Grand Paris Express – board member Bernard Cathelain said: “We are very proud to be in a position to enable our partners to try out new solutions at our construction sites, as those solutions can benefit the building and civil engineering sector as a whole moving forward.
“We have been encouraging our partners’ initiatives, in particular the ones that reduce our construction projects’ carbon impact, since the beginning of the programme. The use of ultra-low-carbon concrete tunnel lining segments fits perfectly into our approach to reducing CO2 emissions at our worksites. And this is paving the way for using it more extensively. So we will be watching the experiment results particularly closely.
“Innovation is embedded in our DNA at Société du Grand Paris. And the Grand Paris Express, which is a pioneering project for the ecological transition, is a fantastic testing ground.”
Ecocem Northern Europe managing director Micheál McKittrick said: “Our Ecocem Ultra technology is already being used at scale in France, and we’re excited to now see it being adopted in the UK.
“The cement and construction industries are developing and deploying a range of emission reduction technologies to help the UK Government reduce emissions by 78% by 2035, and reach net zero by 2050, and Ecocem will add a further dimension to these efforts.”