Thor, or should that be Zeus?

[Tom J]

Tom I am not sure you are understanding this way of moulding concrete as it is done with superplasticiser which makes a very fluid mix and MUST NOT be vibrated as it will settle the aggregate to the bottom. The way it works is that it separates all the individual fines and stones in suspension for about half an hour then they come back together for the set.
This explains it better. https://www.youtube.com/watch?v=9ySyaKb2_b0

ok, I was referring to cement mix with coarse sand. Got your point guys