CEM II Portland Composite Cement | Baumaschinen Glossary

CEM II — Portland Composite Cement

Portland cement with 6–35 % blast furnace slag, fly ash, limestone or other supplementary cementitious materials. Reduces CO₂ footprint compared to CEM I by up to 30 %.

CEM II is Portland composite cement according to EN 197-1. It contains 6–35 % supplementary cementitious materials such as blast furnace slag, fly ash, limestone, silica fume or pozzolanas in addition to Portland clinker.

Sub-classes range from CEM II/A (6–20 % supplementary material) to CEM II/B (21–35 %). Commonly used: CEM II/B-M (V-L) — a combination of fly ash and limestone, as found in Heidelberg evoBuild and Holcim ECOPact.

Compared to CEM I, CEM II reduces the CO₂ footprint by 15–30 %. The same requirements apply for structural, exposure and compressive strength classes according to DIN EN 206.