Christoph Müller, VDZ, examines how clinker-efficient cements, updated standards, and new carbon labelling are accelerating the shift towards climate-friendly cement in Germany.
In Germany, the clinker factor in cement was recently only 67% – a historically low value that underscores the industry's progress towards climate neutrality. This development is remarkable because the average clinker content in the product portfolio has been more or less constant for several years. The momentum in CEM II/C cements (ternary cements with a minimum clinker content of 50%) in particular has led to a more significant reduction in the clinker factor. The German concrete standard DIN 1045-2:2023, which is based on the European concrete standard EN 206, is likely to make a significant contribution to the greater market penetration of clinker-efficient cements. This standard defines new rules of application for clinker-efficient cements. These rules facilitate market access, in parallel with the path of building authority technical approvals. The latter have increased significantly in 2024 and 2025 – in addition to the use of portland composite cements CEM II/C-M, portland limestone blast furnace cements with a very low clinker factor and high proportions of unburned limestone, as well as the use of a first CEM VI cement, have also been approved by the building authorities. Ultimately, the goal is to further reduce the clinker factor significantly to around 53% by 2045. The availability of suitable clinker substitutes is a limiting factor here. In future, calcined clays, limestone, and recycled fines from concrete and masonry rubble are likely to play a role. In addition, the public sector is needed as an important driving force and role model for initiating green lead markets. To this end, the ‘Cement Carbon Class CCC’ label was published at the beginning of 2025, which gives cement manufacturers the opportunity to transparently disclose not only the product properties but also the carbon footprint to customers and in tenders. A number of labels have been awarded.
Cement type development
Clinker-efficient cements have been used in Germany for many years. In addition to portland cement clinker, the main constituents used are granulated blast furnace slag (marked with the letter S), natural pozzolan (P), which is essentially trass, siliceous fly ash (V), burnt shale (T), and unburned limestone (LL). Figure 1 shows the development over recent years. According to this, portland composite cements (CEM II) and blast furnace cements (CEM III) are increasingly being produced and used. This contrasts with a reduction in portland cements (CEM I), whose domestic share has more than halved from over 60% at the end of the 1990s to around 24%. Until around 2003, CEM II cements and CEM III contained one further main constituent besides clinker. CEM II/A has a minimum clinker content of 80%, while CEM II/B has a minimum clinker content of 65%. In CEM II cements, all of the above-mentioned main components can be used in addition to portland cement clinker, while in blast furnace cements CEM III with a minimum clinker content of as low as 20%, only granulated blast furnace slag can be used. From 2003 onwards, ternary CEM II-M cements were also produced with two additional main constituents besides portland cement clinker. Since the publication of the VDZ's CO2 roadmap in 2020, portland composite CEM II/M cements have continued to gain in importance. Their market share rose from 6.5% in 2019 to 16% in 2024. Of this, an estimated 790 000 t were accounted for by the new CO2-reduced CEM II/C-M cements with a minimum clinker content of 50%. In the future, a further shift in the market towards clinker-efficient cements, such as CEM II/C-M with a minimum clinker content of 50% or CEM VI with a minimum clinker content of 35%, is planned. As a result, the average proportion of cement clinker in cement is to be reduced from 67% today to around 53% by 2045.
Environmental Product Declaration (EPD) for cement
Information on the environmental impact of construction products used is becoming increasingly important as a basis for assessing the sustainability of buildings. Until now, manufacturers of construction products have preferred to provide this data in the standardised format of the EPD. In an EPD, product manufacturers disclose life cycle assessment-based indicators such as resource use and global warming potential and have them independently verified. VDZ has so far developed five EPDs for cement and had them externally verified.
The EPDs are based on the evaluation of production data from VDZ member companies for the relevant period and assumptions about the composition of the cements.
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