Concrete application of clinker-efficient cements

The performance of clinker-efficient cements with granulated blast-furnace slag (GGBS) and limestone beyond the limits of the current DIN EN 197-1 was examined. Fresh, mechanical and durability properties of concretes made with laboratory and plant cements were determined. It can be stated that cements with a clinker content of about 50 wt% using GGBS and a limestone content of up to 20 wt% are suitable, in principle, for producing structural concretes. These cements gave fresh concrete properties as used in practice, good mechanical properties and, with the exception of the freeze–thaw resistance, admissible durability properties within the framework of the currently valid description deemed to satisfy rules in Germany. Concretes made with cements outside the currently envisaged extension of DIN EN 197-1 with a clinker content of about 20 to 35 wt% and a limestone content of up to 50 wt% can also exhibit admissible durability properties, if exacting concrete technology measures (low water–cement ratio and corresponding addition levels of admixtures) are applied in the concrete production.