Face-mix mixers are primarily used for mixing face-mix concrete for paving stones.
The face-mix mixer reduces the build-up of dry concrete in the mixer and behind the shovels. Dry concrete may be mixed into the face-mix concrete and cause flaws in the surface of the paving stones.
The mixer also prevents the formation of tiny cement spheres by adding water directly into the concrete. The spheres may form if water droplets are mixed with the cement before the cement has been fully incorporated in the aggregates. The cement spheres will dissolve in the surface layer of a paving stone and create tiny holes.
Haarup's face-mix mixers prevent this through a unique system for batching water in the mixer, specially designed shovels and scrapers, and the unique design of the mixers.