Calcium aluminate cement should not be mixed on site with any other kind of cement. Levelling screeds made with calcium aluminate cement concrete may be used on hardened Portland cement concrete bases.
The total water/cement ratio of calcium aluminate cement concrete should not exceed 0.40 by mass and the cement content should not be less than 400 kg mp3. It is most important that this concrete should be effectively cured during the first 24 h so that its very rapid rate of hardening can proceed normally without deleterious effects on the strength and durability.