Laying concrete with integral surrounding upstand

[Greenbeast]

I need to create a contained wash down bay for our pet food plant.
We already have a 6x1m path, but we need to add to this a vehicle unloading/wash down bay and also extend the slab underneath the doors of both the freezer and the cutting room.
It needs to be so that any dropped/spilled/wash out liquid is caught and fed into a treatment plant

So how can i pour a slab and include an upstand of a few inches?

 

[Derky]

Either using a good fall or use a kerb on the edge.

 

[bitwrx]

Make up a freestanding shuttering frame that supports the inner wall of the upstand from the outer wall. Some ¾” ply, plenty of 4”x2", and a few million screws should do it.

Failing that, stick some pins in the ground to support a bit of wood for the inner face of the upstand, then cut them off afterwards.

Either way, getting the mix right so it consolidates well, but doesn't flow out of the upstand, may be tricky. Maybe put a v dry mix in the bottom of the upstand, then more normal consistency everywhere else.

ETA: Alternatively, maybe just do it in two pours.