What can I mix with rubble to make a hardcore base ??

[Meadows maniacs]

So I have bought a metal shed and have some 60cmx 60cm reinforced slabs to lay…

My plan was to do a hardcore mix (whacker plate) followed by a dry mix and slabs…

However for the hardcore mix what I plan to reuse lots of old rubble, mainly chunks, that I already have (see pic) however what should I mix with the rubble to make it more compact …
I will be using a whacker plate afterwards
Thanks

 

[blup]

Those bricks look small enough to be whacked down on their own.

Blup

 

[Mottie]

More rubble.