100% for anything structural don't touch recycled as it's just not possible to know if the 20 or 40mm aggregate is made of acceptable strength concrete, plus bits of brick etc alwags find their way in.Last time I checked recycled aggregate in concrete meant the concrete didn't meet British Standard regs. Hence why the big boys only use primary aggs and the volumetric etc use recycled
Some suppliers actively use utility work to get rid of landfill waste and save money- Ive seen plastic being added back into 6f2.Any recycled 6f5 or type 1 I've ever had has been either:
A. Full of plastic, glass, old aa batteries, mobile phones, nails, kids action figures, d1ldos
B. 15% incinerator ash/dust
C. Mixed with wet muck/stinking soil
When you ring the supplier, they all state "I'm allowed 5% deleterious material"
So now its a rule of thumb, any recycled material is checked per load on arrival.