Fitz wrote:
I've got a big pile of old concrete I've taken up from a knackered path
that was cracking and ugly. I'm wondering whether I can save the money
I might pay for a) a skip and b) 'crusher run'/bulk bag of hardcore for
the planned patio by crushing all the left over concrete.

I've found one passing reference on this group in an old message
suggesting that stone crushing is not a DIY task. Short of starting my
own chain gang and smashing the lot with a trusty old sledgehammer I'm
a bit stuck.

It's not too hard to DIY it... Lidl even have a hammer that
looks suitable for this for a couple of quid. Support the
lumps on a pile of others, and start bashing away.... in a
surprisingly short time, it'll all be little pieces! Use
the big hammer for big bits, little one to reduce the size
of them, as you can swing it nice and quickly!

Speaking from experience...