The house next door...or how to NOT build a house

[Frank S]

You mentioned you didn't see a single vibrator For a pour that high they must have used super plasticizers and maintained a very low air entrainment factor with small to medium aggregate not more then 1" the plasticizers would allow for a high workability with a high slump without the need to have a very wet mixture.
You also mentioned they were still adding more bracing could they also have been slapping the forms to settle the concrete. I doubt if I will ever understand why here in the states contractors use that OSB panel instead of Phenolic film plywood for their forms. I guess it boils down to cost and availability here in the USA.
We tend to think of it as an exotic form of plywood while in many countries it is considered the norm to be used as forming materials. One thing is for sure the 18mm phenolic plywood will yield a glass smooth finish to the pour.

[DIYSwede]

One thing is for sure the 18mm phenolic plywood will yield a glass smooth finish to the pour.

Amen to that, Frank. Not only will the surface finish be smooth, but also when cutting these sheets,
the edges and its splints are sharp like razor wire, and won't easily bend or break away,
and these mothers will cut right thru your glove and into your hand like a surgeon's scalpel if you're not attentive.