Yes, but your first question is far too broad. I could type for a week, still not cover the topic evn briefly and bore everybody else with a wall of text too.
Give an engineer a speciifc issue - we're detail people.
Casting swimming pool walls, approx 1 meter high.
Cannot fit a vibrator down one side, as rebar for the gutter is bent along it, encased in polystyrene for later chipping and bending into place.
Down the other side is 30mm cover with an extra 12mm between the vertical bars. Assuming perfect...
That was the assumption I was working under.
As it is, the one set of cols they cast this way had the worst set of honeycombing so far, with two or three needing deep chipping and repairing at the join.
The contractor has quietly gone back to the old approach of chip, clean and cast.
The site I'm on is casting pad foundations and sub-columns in two stages.
So we cast the pad foundation, leave a few days to harden, chip the joint area back a bit for a nice solid interlock, put the sub-col formwork up and cast away.
For the majority of the work done so far, no bonding agent...
