This European Prestandard specifies properties of the constituents of common cements and the proportions in vhich they are to be combined to produce a range of types and classes of cement. It then specifies the mechanical, physical and chemical requirements for these types and classes and states the rules for assessing their conformity to these requirements.
It is recognized that different cements have different properties and performance. Vhere performance tests are available (i.e. setting time, strength and soundness), they have already been taken into account in this European Prestandard. In addition, work is being carried out by CEN/TC 51 to identify any additional tests which are needed to specify further performance of cement. In the meantime, and during the life of this prestandard, it is necessary that the choice of cement, especially the type and/or strength class in relation to the exposure class and type of construction in which it is incorporated, should follow the national standards and other regulations valid in the place vhere the cement is used.
In addition to these requirements, an exchange of additional information betveen the cement producer and user may be helpful. The procedures for such an exchange are not vithin the scope of ENV 197-1 but are to be dealt with in accordance with national standards or regulations or may be agreed between the parties concerned.