Durability of blended cements with several main components

The European cement standard EN 197-1 defines Portland composite cements (CEM II-M) which are characterized by two or more main constituents in addition to clinker. The real advantages of this type of cement are in the combined use of the individual strength of well-established materials. Basic requirement for the application of these cements, which are new in several markets, is the verification of durability of concrete.
In an extensive test program the most important durability aspects were investigated (carbonation, freeze-thaw resistance, frost-de-icing salt resistance, chloride penetration). The program focuses on cements with the combination of granulated blast furnace slag (gbfs) and limestone, but also other combinations (gbfs/fly ash, fly ash/limestone) were included.
The test results clearly indicate that Portland composite cements in the range of the investigated compositions show a high durability. In comparison to ordinary Portland cements and well-known blended cements the results of tested parameters were on a similar level. Thus the existing applications rules can be transferred to Portland composite cements without changes.

Author: R. Härdtl, M. Dietermann, K. Schmidt

Section: Application of cement

Keywords: cement standard; durability; Portland composite cement; granulated blast furnace slag