# Cement standard

The cement standard SFS-EN 197-1 specifies the consistency and quality demands for common cements and the compliance terms and conditions.

Portland clinker and additives are used in manufacturing cements. The standard groups the cements into five main types based on their composition:

- CEM I Portland Cement
- CEM II Portland Composite Cement
- CEM III Blast-furnace Cement
- CEM IV Pozzolanic Cement
- CEM V Composite Cement

The main types are further divided into different cement types based on the additives used and their amounts. The standard covers altogether 27 different types of cement.

## Cement markings

Cements are marked with a cement type code (+ additive code), a number depicting the strength class and a letter depicting the early strength.

## Strength classes and early strength

Cements are divided into three standard strength classes where the standard strength is the cement’s compressive strength at 28 days. The strength classes are 32.5, 42.5 and 52.5. Each standard strength class also has two early strength classes, where N is the normal early strength and R is the high early strength. The standard defines the cement’s early strength based on the compressive strength values after 48 hours with the exception of the 32.5 N class.

See

The additives used in Finnsementti’s construction cements are blast-furnace slag and limestone, which means that they are marked as follows:

CEM I 52,5 R |
maximum Portland cement additives 5%, standard strength 52.5 MPa, initial strength 2d 30 MPa |

CEM II/A-LL 42,5 R |
main additive of Portland limestone cement is limestone (code LL) a total of 6–20% (code A), standard strength 42.5 MPa and 62.5 MPa early strength 2d 20 MPa |

CEM II/B-M (S-LL) 42,5 N |
Portland composite cement contains several additives (code M), including blast-furnace slag (code S) and limestone (code LL) amounting to a total of 21–35% (code B) standard strength 42.5 MPa and 62.5 MPa, early strength 2d 10 MPa |