Holcim: How measurable is the decarbonization strategy in the cement business?

The Holcim Group is increasingly positioning itself as a pioneer for sustainable cement and climate-friendly building products. Given that the cement industry is globally responsible for approximately eight percent of CO2 emissions, the pressure on manufacturers is enormous. Yet while marketing messages sound green, the question arises: How concrete are the technical measures and what measurable results does the group actually deliver? An analysis shows that while the transformation has been initiated, central challenges remain unsolved – with far-reaching consequences for construction companies and competitors.

Clinker efficiency: The core problem of the cement industry

The CO2 footprint of cement is created approximately 60 percent through the chemical process of decarbonating limestone into clinker, the main component of Portland cement. The remaining 40 percent comes from the fuel requirements for rotary kilns, which must reach temperatures of up to 1,450 degrees Celsius. This is where Holcim steps in: The group systematically reduces the clinker content in its cements through the use of additives such as blast furnace slag, fly ash, or calcined clays.

Calcined Clay and Limestone, or LC3 technology for short, is considered a promising approach. Burnt clays and limestone powder are used as partial clinker replacements. The advantage: the firing temperature for clays is significantly lower than for clinker, which saves energy. At the same time, process-related CO2 emissions from limestone decarbonation are partially eliminated. Holcim has introduced this technology in several plants, for example in India and Latin America. In Europe, however, the availability of reactive clays is limited, which makes scaling difficult.

Another problem: standards are lagging behind. Portland cement with reduced clinker content must be approved for use in load-bearing structures. While CEM II and CEM III cements are already established, newer formulations with higher substitution rates require long-term studies on durability. For construction companies, this means: planning certainty is only limited as long as normative framework conditions are not clarified.

Alternative fuels: Between efficiency and availability

Holcim is increasingly replacing fossil fuels such as coal and petroleum coke with alternative energy sources – waste oils, plastic waste, biomass, or meat meal. The group states that it has already achieved a substitution rate of over 80 percent in some European plants. While this reduces direct fossil CO2 emissions, it does not solve the process-related problem of limestone decarbonation.

In addition: the availability of alternative fuels varies greatly by region. In markets with weak waste infrastructure, Holcim remains dependent on fossil energy sources. Furthermore, not all substitute fuels are climate-neutral – plastic waste often contains fossil components. The actual CO2 reduction therefore depends heavily on the composition of the substitute fuels. However, transparent balances of actual emission reductions per ton of cement are largely lacking.

For smaller competitors like Buzzi or Vicat, access to alternative fuels is a strategic challenge. They compete with waste incineration plants and other energy-intensive industries for limited resources. Holcim's market power gives the group an advantage here – with potentially competition-distorting consequences.

Cement replacement materials: Dependence on third industries

The strategy of reducing the clinker content through blast furnace slag or fly ash faces a structural problem: both materials are byproducts of the steel and coal industries respectively. With the decline of European steel production and coal phase-out, the availability of these materials is also declining. Holcim and other manufacturers must in the long term resort to other substitutes – or organize their supply chains globally, which increases transport emissions.

Here a conflict of objectives becomes apparent: the decarbonization of the cement industry is partly linked to the transformation of other sectors. As long as sufficient alternatives such as reactive clays or synthetic additives are not available on an industrial scale, CO2 reduction remains limited. While Holcim invests in research, concrete production capacities for new substitutes are not communicated.

Carbon Capture: Technology with open questions

In the long term, Holcim is banking on Carbon Capture and Storage (CCS) to capture and store process-related CO2 emissions directly at the plant location. Pilot plants are already running, for example in Germany. However, the technology is cost-intensive and energy-intensive. The question of CO2 storage – geologically in caverns or through use in other industries – remains politically and technically unresolved.

For construction companies that must balance their Scope 3 emissions, what is critical: is the captured CO2 permanently stored or only temporarily bound? How is the additional energy for CCS generated? As long as these questions remain unanswered, the climate balance of CCS-based cement remains unclear. While Holcim communicates pilot projects, concrete emission reductions per ton of cement are not reported.

Strategy change or market positioning?

The question of whether Holcim is truly a pioneer or merely anticipating regulatory pressure cannot be definitively answered. The group has created a broad range of concrete solutions for different sustainability requirements with the introduction of ECOPact, a product line with a reduced carbon footprint. At the same time, however, transparent, independently verified CO2 balances for individual products are lacking.

Compared to Heidelberg Materials and CEMEX, Holcim is at a similar technological level. All three groups rely on clinker substitution, alternative fuels, and CCS. Competition takes place less at the technology level than over the speed of scaling and regional availability of green cements. Holcim's global presence gives the group an advantage here – smaller, regionally active manufacturers struggle more to make comparable investments.

Consequences for the supply chain: What construction companies need to know now

For construction companies that must decarbonize their supply chains, Holcim's strategy means above all one thing: increasing complexity. Sustainable cements are more expensive, their availability varies by region, and their technical properties may differ from conventional products. Those who use concrete with a reduced carbon footprint must carefully examine processing times, strength development, and durability.

At the same time, industry-wide standards for CO2 accounting of building products are lacking. Holcim uses its own methods, which are not necessarily compatible with those of other manufacturers. For buyers and planners, this means: comparability is only limited. Those who want to build sustainably must develop their own evaluation criteria and insist on transparent Environmental Product Declarations (EPDs).

Another problem: the availability of green cements is limited. Holcim often prioritizes large projects with high visibility, while smaller construction projects must rely on conventional products. This reinforces a two-tier society in the construction sector – between climate-friendly prestigious projects and broad residential construction, which continues to rely on conventional materials.

Interim conclusion: Transformation initiated, but not completed

Holcim's sustainability strategy in the cement business is ambitious, but incomplete in key respects. The technical measures – clinker substitution, alternative fuels, CCS – are known and being implemented. However, the decisive question is: at what pace and with what commitment? As long as concrete, measurable CO2 reduction targets per ton of cement are lacking and the scaling of green products remains limited, the transformation is more evolutionary than revolutionary.

For the industry as a whole, this means: competition for sustainable cements will intensify. Smaller manufacturers come under pressure because they struggle more to make the necessary investments. Construction companies must actively manage their supply chains and can no longer rely on green products being automatically available. And policymakers are called upon to create normative framework conditions that enable innovation without jeopardizing supply security.

Whether Holcim is truly a pioneer or merely the least sluggish will become clear in the coming years. What will be decisive is how quickly the group converts its production to climate-friendly cements – and whether these become available and affordable for the broad mass of construction projects. Until then, the question of greenwashing remains justified.