Carbon-storing concrete undergoing trial

Full-scale trials of ultra-low and carbon-storing concrete mixes have been carried out at London’s Canary Wharf, as part of an industry collaboration aimed at assessing next-generation materials under real construction conditions.

The programme, led by developer Canary Wharf Group (CWG) with input from building materials supplier Holcim UK and a consortium of engineers, contractors and academic institutions, has tested a series of alternative concrete formulations incorporating biochar, graphene and low-carbon cementitious materials.

Trial pours were undertaken in April and September 2025, including a test slab at CWG’s Wood Wharf site and two-metre-deep raft foundations at its Bank Street site. The works follow earlier smaller-scale applications, including underwater counterweights for the ‘Whale on the Wharf’ public art installation.

One of the primary mixes utilised biochar derived from coppiced timber and spent coffee grounds collected from Canary Wharf coffee shops. According to project data, the initial formulation achieved an 80% reduction in net global warming potential (GWP) (A1–A3) compared to a standard CEM 1 concrete, resulting in a projected combined fossil and biogenic GWP of 69 kgCO₂e/m³.

Subsequent optimisation of the mix resulted in a calculated net GWP (A1–A3) of –14 kgCO₂e/m³, when accounting for both fossil emissions and biogenic carbon storage. The negative value reflects the sequestration of carbon captured during the biomass growth phase and retained within the concrete matrix.

A separate mix incorporating graphene demonstrated a reduction in embodied carbon of more than 50% compared to a CEM 1 control, alongside improvements in compressive strength and durability performance, thereby potentially reducing the amount of concrete required in certain applications and improving cover of reinforcement (such as rebar).

Materials will be subject to a two-year monitoring phase to evaluate in-situ performance, durability and long-term carbon outcomes. 

UK’s first hydrogen-fuelled asphalt production

Hydrogen has been successfully used to decarbonise asphalt production on an industrial scale for the first time in the UK, at Heidelberg’s Criggion plant in Powys, Wales.  

During the trial, hydrogen replaced liquid fossil fuels powering production of more than 1,300 tonnes of asphalt, without any impact on the quality or performance of the material, the company claims.  

The project demonstrated hydrogen as a viable alternative to fossil fuels in asphalt production, achieving a 76% reduction in Scope 1 (direct) emissions equating to a 23% reduction in the overall carbon footprint of the asphalt produced.   
 

In total, 4,522 kg of hydrogen was used during the trial, saving 25,105 kg of CO₂. If scaled across the UK asphalt industry, savings could reach 450,000 tonnes of CO₂ a year.

The Criggion trial is part of the UK government’s Industrial Hydrogen Accelerator programme and received part-funding from the Department for Energy Security and Net Zero. 

Hydrogen was used to replace liquid fossil fuels to produce more than 1,300 tonnes of asphalt at Heidelberg’s Criggion plant in Powys, mid Wales  
Heidelberg 

UK Net Zero Carbon Buildings Standard Version 1 launched

The first full version of the UK Net Zero Carbon Buildings Standard has been launched, said to provide a unified framework for defining and verifying net zero carbon performance across the built environment.

Developed through a collaboration of industry bodies including CIBSE, RIBA and the UK Green Building Council, the free-to-access technical standard aims to eliminate ambiguity around net zero claims while aligning building performance with the UK’s legally binding climate targets.  

Version 1 builds on a pilot released in September 2024 and sets out requirements covering performance targets, evidence, reporting and verification. It also introduces several new annexes, including guidance for landlord- or tenant-only assessments, a completion tracker and alignment with existing schemes such as NABERS UK and Passivhaus.

Katie Clemence-Jackson, Chief Executive of the UK Net Zero Carbon Standard, said the framework would provide ‘much-needed clarity and consistency’ while helping the industry measure and reduce emissions in line with climate goals.

The updated version also includes revised performance limits, refined following industry feedback, while maintaining alignment with a 1.5°C pathway.

Verification of buildings against the standard is expected to become available in 2Q2026. Once in place, projects will be able to undergo independent assessment to achieve ‘net zero carbon aligned’ status.