"[[w:Superplasticizer|[S]uperplasticizers]], if used to reduce w/c, do not cause separation or water separation. The use of a clogging micro filler (for example, finely ground limestone or quartz sand) helps to reduce... water separation... [T]he micro filler [may create] an additional "stability framework," which increases... resistance to segregation..."
January 1, 1970
https://en.wikiquote.org/wiki/Foam_concrete