That is a very cool idea that seems likely to be broadly implemented.

CrispyCrete

High level process review article

Good idea in general. If they already use forms to cast blocks, that could continue and this could complement the system. Blocks for a large returned load, treated concrete for the rest.

I have a good friend who has a concrete crushing yard.

Depending on spec needed he can grind everything from 1/4” chunks to 5” rock. He resells for anything from road beds to oyster beds

Everything goes through multiple stage screens and sorted by size. Magnets pull the steel out. This he amasses until the recycling price is right then he cashes it in also

He can’t get enough waste to fill his orders often

I would expect a trademark infringement lawsuit from Crispy Kreme pretty shortly.

Concrete is my career. If the foreman or project manager has a half a clue as to what thy are doing there will be less than half a yard of concrete remaining after a pour. We will either line our concrete debris dumpster with some plastic and have he truck wash out there or build a box for it. Either way the dumpster of leftover concrete and debris gets sent to a recycler for a minimal charge.
Regular garbage costs about $50 a yard to dispose of.
Concrete debris in a separate dumpster costs $8 a yard to dispose of. It is always crushed and reused.