The Race to Decarbonise Concrete at Scale: Breakthroughs, Challenges, and the UK’s Global Role
With the production of cement, the primary component of concrete, now accounting for around 7-8% of global emissions, decarbonising concrete production is critical to reducing emissions across the construction sector and achieving global climate targets.
The urgency for reducing carbon emissions generated during the production of cement and concrete has intensified, and the race is on to decarbonise concrete at scale.
The Cement and Concrete Breakthrough initiative was launched in 2023 at COP28 to accelerate the transition to net-zero cement and concrete production by 2050. With a focus on international co-operation, technological innovation and investment, the initiative is led by Canada and the UAE with active participation from countries including the UK, Germany and Japan.
Meanwhile, China, which produces more than half the world’s cement, is moving to bring cement into its national carbon emissions trading scheme (ETS), with formal inclusion announced in early 2025 to accelerate the adoption of low-carbon technologies.
Where does this leave the UK in the race to decarbonise concrete at scale? In 2020, the UK concrete and cement industry launched a ‘roadmap to beyond net zero’ to become net negative by 2050. The UK’s cement and concrete production now accounts for just 1.5% of the nation’s carbon emissions, a considerably lower percentage than the global figure of 7-8%. However, there remains an urgency to capitalise on early gains and reduce emissions beyond net zero.
Bringing low carbon concrete alternative materials and processes into mainstream construction standards will be key to measurable climate impact and influencing other nations to follow suit. So, based on progress to date, could the UK take a strategic leadership role in the acceleration of carbon neutral, or carbon negative concrete production, at an industrial scale?
Concrete’s Carbon Problem
According to the World Economic Forum, concrete is globally the second most-widely used material after water. Annual global production currently stands at approximately 14 billion m³ and is forecast to rise to around 20 billion m³ by 2050 — an increase of roughly 6 billion m³,or 43%. Unless large-scale innovation in decarbonising concrete production intervenes, carbon emissions from the sector will increase.
So, what is it about concrete production that causes such a carbon problem?
Cement production involves the chemical decomposition of limestone, this accounts for 50% of the carbon emissions tied to concrete.
Concrete remains one of the most difficult materials to decarbonise because of the energy intensity and chemistry involved in producing cement – its key ingredient. Portland Cement (PC) requires kiln temperatures of 1,400–1,500°C to form clinker, the material that gives cement its strength. At present, these extreme temperatures can only be achieved consistently using fossil fuels such as coal or natural gas.
Researchers and manufacturers are now exploring electrified kiln technologies – systems that replace fossil fuel combustion with electric resistance or plasma heating to reach the required temperatures. However, these methods are still at pilot stage and their carbon benefit depends entirely on using renewable electricity. If powered by fossil-based energy, their net emissions would remain comparable to conventional kilns.
Compounding the challenge, even if renewable electricity were used, the chemical decomposition of limestone (calcination) during clinker production releases large quantities of process CO₂, which cannot be avoided without alternative materials or carbon capture technologies.
Concrete’s carbon problem is intensified by the UK’s heavy reliance on the material for infrastructure and building projects. As one of the most versatile and durable construction materials, it plays an important economic role, contributing around £1 billion annually through production across 10 cement plants and two blending facilities. However, the challenge is not to reduce concrete use, but to reduce its carbon profile – maintaining its structural value while accelerating the transition to low-carbon and carbon-negative alternatives.
The concrete industry has already taken steps to reduce clinker content by using supplementary cementitious materials (SCMs). Traditionally, these have included industrial by-products such as fly ash from coal-fired power stations and ground-granulated blast-furnace slag (GGBS) from iron and steel production. However, as energy systems decarbonise and steel recycling increases, supplies of these materials are rapidly diminishing.
More recently, Portland Cement in the UK is commonly blended with around 15% limestone, helping to lower emissions further. Yet while these substitutions reduce carbon intensity, they cannot achieve the deep decarbonisation required to meet net-zero targets. The industry is therefore accelerating the search for new alternative binders and advanced materials capable of replacing clinker at scale.
Breakthrough Innovations in Carbon-Negative Concrete
Research and innovation around carbon negative concrete have gathered pace. Reducing clinker content, implementing carbon capture processes and finding low-carbon alternatives to concrete are just some of the breakthrough innovations driving change.
Geopolymer concrete
As an alternative to traditional Portland Cement, geopolymer concrete (GPC) uses silica and alumina rich industrial byproducts, such as ash or slag, mixed with an alkali solution to produce a strong, robust material.
Rather than being a replacement cement, geopolymer systems operate as an alternative class of SCM-based binders, reducing reliance on clinker-based Portland cement.
Beyond substantial carbon reductions, geopolymer concretes can match or exceed Portland cement performance in specific applications, although durability depends on precise formulation and robust quality assurance and control.
A 2023 case study conducted by civil engineers at Liverpool John Moores University demonstrated the potential of an aluminium-geopolymer composite to construct the ‘skeleton’ of a building to a similar level of performance as traditional concrete.
Research into alternative SCM-based concrete systems has shown promising structural results in controlled applications. A recent study evaluated 24 stub columns and 12 beams constructed using aluminium hollow sections infilled with one-part geopolymer concrete, comparing them against both bare sections and Portland-cement-filled equivalents under uniform compression and uniaxial bending. The geopolymer-filled sections achieved very similar strength performance to Portland-cement systems, demonstrating the technical potential of geopolymer technology when correctly formulated and quality-controlled.
However, geopolymer concretes are not direct alternative binders — they are alternative SCM-based systems, typically reliant on industrial by-products such as GGBS or fly ash. This creates competition for limited SCM supply as other decarbonisation strategies also depend on these materials. In addition, one-part geopolymer systems mitigate some handling issues, but high-alkali activation requirements currently limit in-situ use, meaning deployment at scale remains most feasible in precast and controlled manufacturing environments.
Alternative SCMs and binder systems
The use of alternative SCM-based cement systems is widely considered to be a viable way of reducing carbon emissions at scale. The RIBA Journal article refers to high hopes for future binders based on calcined clay. Heating clays containing the common clay mineral kaolinite to 650-750°C can produce effective supplementary cementitious materials, which when blended with limestone can achieve clinker replacement of 50%. While kaolinitic clays are abundant worldwide, high-quality deposits are sparse in the UK. A collaboration between the University of Leeds, Imperial College London, the University of Bath and the British Geological Survey, together with numerous industrial partners, is sourcing over 60 clays from across the UK to assess their suitability for widespread application in concrete.
Recent research has also highlighted the potential of biochar as a carbon-negative material in concrete. Rather than acting as an alternative binder, biochar functions primarily as a fine aggregate or additive, produced by heating organic waste in the absence of oxygen. A critical review of biochar-enhanced construction materials found that incorporating biochar into concrete mixes can enable carbon-neutral, and in some cases carbon-negative, performance, while also supporting circular economy goals by valorising biomass waste streams. The study noted that biochar demonstrates “tremendous promise” for large-scale application in low-carbon and carbon-negative construction materials.
Caron Utilisation and Mineralisation in Concrete
The high alkalinity of cement and concrete makes them strong candidates for carbon capture and utilisation (CCU). In this process, captured CO₂ is chemically converted into stable carbonate minerals, which can then be incorporated into concrete. This permanently stores carbon and can also reduce clinker demand when carbonated materials act as fillers or partial binders.
One current pathway is CO₂-curing, particularly in precast applications. Here, fresh concrete reacts with CO₂ to form calcium carbonates, delivering strength gains and measurable reductions in net embodied carbon.
Beyond curing technologies, CO₂ can also be mineralised into carbonated aggregates and fines, which are then used as constituents in concrete mixes. Early research further shows promise for carbonated recycled concrete paste, which has potential to behave as a near-carbon-neutral SCM – supporting both carbon sequestration and circular economy objectives.
These approaches highlight the growing role of carbonation in concrete decarbonisation, with continued advances expected as research refines the chemistry and scalability of CCU pathways.
Moreover, according to a recent review of carbon mineralisation, “By utilising CO2 in this manner, the carbonation process is enhanced, leading to increased carbon sequestration within the concrete and reducing the overall carbon footprint of the material.”
Barriers to Scaling Up Decarbonised Concrete
Despite technological advances, systemic challenges continue to hinder widespread decarbonisation.
The Mineral Products Association (MPA) notes that since 1990, the embodied carbon of UK concrete has been reduced by 30% through investment in efficient plants, fuel switching, and the use of by-product materials. Yet, as an article from the University of Manchester highlights, achieving full decarbonisation in the UK requires more robust efforts, and the next ten years will be pivotal for scaling up innovative technologies.
The report calls for sustained R&D investment and cross-sector collaboration to overcome technical, economic, and regulatory barriers, emphasising that “future efforts must focus on improving the cost-effectiveness and efficiency of decarbonisation technologies, as well as enhancing collaboration between industries, government bodies, and academic researchers.”
Other major obstacles include:
- High capital costs for electrified kilns and carbon capture systems.
- Fragmented standardsacross European markets.
- Limited incentivesfor manufacturers to adopt new technologies.
- Cultural resistance to changewithin the construction industry.
Addressing these challenges will require coordinated effort between government policy, industry innovation, and financial support mechanisms to de-risk adoption.
What Happens Next? — Policy, Practice and Industry Action
Progress is emerging on the regulatory front. The UK’s updated BS 8500 standard (BS 8500-2:2023) supports the use of multi-component and low-clinker cement systems, enabling higher levels of SCMs and encouraging more sustainable concrete formulations.
Alongside this, the shift towards performance-based standards is accelerating innovation. The introduction of BSI Flex 350 V2.0 (2024) — Alternative cementitious materials for lower-carbon concrete: Code of Practice — marks a significant move away from prescriptive mix requirements. This framework allows the use of novel SCM-activated and alternative cementitious systems, provided performance, durability, and safety requirements are demonstrated, opening the door to wider adoption of low-carbon technologies at scale.
To accelerate further, policies must go beyond voluntary roadmaps. Strategic interventions could include:
- Tax incentives or grantsfor carbon capture and low-carbon cement projects.
- Revised building codespromoting circular economy principles and waste reuse.
The academic community reinforces the urgency of comprehensive change across materials, standards, and practice. Professor Leon Black, University of Leeds, summarises the challenge:
“Decarbonisation of cement and concrete is imperative. There is no single solution, and success will come from adopting a wide range of approaches. This will certainly include adoption of low-carbon binders and new supplementary cementitious materials. But it will also require changes in standards, such as roll-out of approaches such as BSI Flex 350.”
Knowledge sharing and cross-sector partnerships will also be essential. As the University of Manchester article concludes, the next 10 years will be a critical period of action for decarbonising concrete at scale. Decarbonisation pathways such as the UK cement industry’s decarbonisation roadmap and the action plan for supplementary cementitious materials and carbon capture by 2035, will require sustained research and development to overcome technical, economic, and regulatory barriers.
Where do you stand on the concrete decarbonisation debate?
Is the decarbonisation of concrete achievable? Will net-zero be enough or should we be aiming for a carbon negative future?
Decarbonising concrete is one of the biggest opportunities to achieve net zero. The science is catching up and the innovations are here. Perhaps the question should no longer be if we can decarbonise concrete at scale, but how fast and how boldly we should mobilise to make it happen.
Do you agree? Join the debate! Resources published by the Centre for Construction Best Practice provide key industry insights and food for thought. For information on becoming a member to gain access to cutting edge research and industry experts get in touch or join online.