The contractor has struck a deal with supplier Capital Concrete and its key binder supplier Wagners to exclusively use Earth Friendly Concrete in the UK.
Keltbray has committed to use 11,000 cu m of EFC® by the end of June 2021, helping to ensure continued development of low carbon concrete in more critical parts of construction.
The deal comes after Keltbray’s in-house design consultancy Wentworth House Partnership agreed to specify EFC on all of its temporary works projects.
On its Charterhouse Place site, WHP has used EFC® on all temporary works including vault infills, thrust blocks for raking props and wind post foundation bases.
Keltbray is already a certified EFC provider having installed the first-ever pile using Wagners concrete in London earlier in the year.
A 900mm diameter, 25m deep anchor pile was installed at the Keltbray site at Landsec’s Nova East, London Victoria project using Wagners EFC®.
Earth Friendly Concrete
EFC is a product manufactured by Australian firm Wagners and is a zero cement, geopolymer concrete supplied by Capital Concrete in London.
The concrete offers a 50% saving in embodied carbon over and above standard piling mixes.
EFC has all the performance characteristics of Portland cement-based traditional concrete but uses a geopolymer binder system made from the chemical activation of blast furnace slag and fly ash.
Keltbray has been working with leading Forensics Engineer, Royal Academy of Engineering Professor, Peter Robery, from Birmingham University to review of the testing data.
Over the last 10 years, the product has undergone rigorous lab testing and received accreditation to German Standard DIN 206.
This means subject to project-based testing, the product can be considered a fully compliant alternative to conventional materials for both temporary and permanent works.
Keltbray believes the engineering and construction properties of the environmentally friendly concrete are as good, and in some areas better, than normal concrete.
Significant performance advantages include improved durability, lower shrinkage, earlier strength gain, higher flexural tensile strength and increased fire resistance.
Stuart Norman, Managing Director for Piling at Keltbray, said: “We have been using EFC for temporary works elements over the last 10 months with great success.
“EFC is particularly suited for permanent works use within piled foundations, and Professor Robery has been assisting us in the review of the technical data we have.
“Having learned some practical lessons along the way, we are now extremely confident in the performance and durability of EFC and are actively recommending its use for permanent works foundation piles.”
Luke Smith, Managing Director at Capital Concrete, said: “We anticipate this environmentally friendly concrete solution to soon become the construction product of choice for the London market.”
