Clinker Factor

The proportion of Portland cement clinker in a cement, expressed as a mass fraction. The primary indicator for carbon footprint.

The clinker factor describes the mass fraction of Portland cement clinker in a cement. Since clinker production accounts for the lion's share of CO₂ emissions in the cement industry, the clinker factor is the central lever for decarbonization.

Reference values: CEM I = 95–100 %, CEM II/B = 65–79 %, CEM III/B = 20–34 %. The roadmap of the German cement industry (VDZ) foresees an average clinker factor of below 65 % by 2030. See CO₂-neutral concrete.