Climate‐Friendly Cements and Concretes: Properties, Applications, and Labeling

Abstract

In Germany, the clinker factor in cement recently reached 67% ‐ a historically low figure that underscores the industry's progress toward climate neutrality. This development is remarkable because the average clinker content in the product portfolio had remained more or less constant for several years. In particular, the momentum in CEM II/C cements (ternary cements with a minimum clinker content of 50%) has led to a 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 application rules for clinker‐efficient cements. These rules facilitate market access in parallel with the process of obtaining general building authority technical approvals (abZ) from the DIBt. With a view to the years 2024 and 2025, the number of such approvals has increased significantly to more than 70 ‐ in addition to the use of Portland composite cements CEM II/C‐M, Portland‐limestone‐slag 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 been approved by the building authorities. Clinker‐efficient, climate‐friendly cements can be used in all exposure classes in many cases. Ultimately, the goal is to further significantly reduce the clinker factor to about 53% by 2045. The availability of suitable clinker substitutes is a limiting factor here. In the future, calcined clays, limestone, and recycled powders from crushed concrete and masonry are expected to play a role. To take this development a step further, 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 launched in early 2025, giving cement manufacturers the opportunity to transparently disclose their CO ₂ footprint to customers and in tenders, in addition to product properties. The CO ₂ footprint is externally audited and verified by the label. Some labels have already been awarded.