Use of two‐stage mixing to further improve the performance of composite cements

Clinker‐ and resource‐efficient composite cements, with their great variety of concrete technology advantages, suffer most from early compressive strength. The literature postulates that the early cement hydration can be increased by more intensive two‐stage mixing.

The extent to which different two‐stage mixing processes can increase the early hydration reactions and thus accelerate the compressive strength development of ternary composite cements containing granulated blast furnace slag and limestone was systematically investigated. In addition, the effects of a reduced w/c ratio were determined. Concrete durability was tested.

The results show that reducing the w/c ratio improves the performance of composite cements much more significantly than energy‐intensive and more complex two‐stage mixing processes.