The debate over cement decarbonisation has, until recently, centred on carbon capture, alternative fuels and clinker substitution. However, a report from the European Environmental Bureau (EEB), published earlier this month, suggests that cement standards themselves could become the next battleground.
"A key obstacle is the current standardisation framework. Existing standards conferring automatic access to the EU single market do not exist for most low-carbon binders," states the EEB's report, entitled "Cement It Better: Unlocking Low-Carbon Concrete in Europe".
Specifically, it argues that the EN 197 family of standards remains largely prescriptive, defining cements by their composition rather than simply by their performance.
Consequently, novel binders that do not fit within established cement families may struggle to obtain harmonised certification and unrestricted access to the EU market, regardless of their engineering properties. The EEB advocates a shift towards performance-based standards, under which strength, durability and environmental performance would take precedence over chemistry.
It is true that cement chemistry is evolving rapidly and on an initial glance, the evidence is persuasive. Alongside lower-clinker Portland cements, developers are investigating limestone calcined clay cements (LC3), recycled cement paste, alkali-activated materials and other novel binders. The EEB argues that standards should be sufficiently flexible to accommodate future innovations without requiring entirely new compositional specifications.
However, the report is less convincing in demonstrating that today's standards are materially delaying the technologies currently driving cement decarbonisation.
The EN 197 family of standards has evolved considerably over the past two decades. Limestone cements are now firmly established, while EN 197-5 introduced new cement types such as CEM II/C-M and CEM VI, allowing significantly lower clinker contents through combinations of established constituents. Indeed, the report itself acknowledges that EN 197-5 already accommodates many formulations similar to LC3 and that several are entering commercial production.
More recently, EN 197-6 represents a further step towards incorporating recycled concrete fines (RCF) as a cement constituent, as the standards system continues to evolve.
Moreover, many of the non-Portland binder systems highlighted by the EEB, including alkali-activated materials, remain largely at the research, demonstration or niche commercial stage. Their wider deployment depends not only on standards but also on demonstrating long-term durability, securing reliable raw material supplies and gaining acceptance from designers, contractors and asset owners. Therefore, while the report raises a legitimate strategic concern, it does not convincingly demonstrate that standards are currently the principal barrier to commercial deployment.
The American way
The EEB points to the USA as an example of a more flexible approach. ASTM C1157, which was introduced in the early 1990s, classifies hydraulic cements primarily according to performance rather than composition. In principle, this allows innovative products to be qualified without first creating an entirely new cement family.
That is not to say the US has abandoned compositional standards. Traditional specifications such as ASTM C150 and ASTM C595 remain widely used, while ASTM C1157 operates alongside them rather than replacing them. As is customary, ASTM will review C1157 to ensure it remains suitable for emerging low-carbon cement technologies, while researchers continue to build the long-term durability data needed to support wider adoption.
The US transition to Portland limestone cement (PLC) illustrates the point, albeit this transition has been driven primarily by carbon reduction objectives rather than a move towards performance-based specification. Although ASTM Type IL has become increasingly common, its introduction has been accompanied by extensive research into durability, finishing characteristics and compatibility with admixtures. The debate has not been whether lower-carbon cements should be permitted, but how much evidence is required before engineers are comfortable specifying them for infrastructure expected to last many decades.
The rapid adoption of PLC from 2020 onwards did lead to some site-specific problems, such as longer setting times, although subsequent research has suggested this may be due to the interaction with particular SCMs, admixtures and local cement characteristics.
In short, the jurisdictions in both Europe and the USA remain cautious with regard to cement standards, albeit there are distinctions in where they assign the burden of proof. Europe has traditionally asked whether a cement belongs to an established family, while the USA has been more willing to ask whether it can demonstrate equivalent performance. Neither philosophy is inherently superior.
Standards should not thwart innovation but they are meant to ensure that today's carbon savings do not become tomorrow's durability problems. In that regard, composition-based standards perhaps offer a degree of predictability that purely performance-based testing can’t necessarily replicate with new chemistries.
Therefore, the EEB is right to ask whether European standards can continue to evolve as new technologies emerge. However, the evidence suggests that the EN 197 framework is already adapting to accommodate the principal technologies driving cement decarbonisation today.
The more pertinent question may not be whether Europe's standards are holding back current innovation, but whether they will prove sufficiently agile should a genuinely disruptive, commercially viable non-Portland binder eventually emerge.
