Sub-base for patio and path

[Centerblik]

I have an issue with a sub-base that I am hoping someone may have a clever solution to.

 

Having had to look at our back garden that had a combination of rough concrete, loose paving slabs and deteriorating crazy paving for the last 20 years we have finally decided to do something about it. We are replacing all of the "paved" areas with sandstone paving.

I have lifted all the slabs and managed to Freecycle them so they can get a second life.

I have also broken up all the concrete (the concrete path had one layer of concrete on top of another so was raised by about 50mm!!). I have also broken out all the crazy paving. Where I am now is that I have two distinct areas to deal with.

 

1. Where the looses slabs were there is a layer of sharp sand then just soil underneath. That is an easy one - dig out to 150mm then put down MOT type 1 hardcore etc.

 

2. In the second area, is seems as thought the concrete and crazy paving was just laid on a layer of about 50-100mm of concrete ballast. The balast does not seem to be compacted at all but is just loose. I know I should not be using it as the sub-base but I have about 50 sq meters of this. It seems like quite a waste / chore to dig it all out just to replace it with MOT 1 hardcore. Is it sensible to dig it lower then compact it, spread say a 50mm later of MOT 1 hardcore on top?

 

I am preparing myself for the answers that say I should do it properly and dig the lot out, but as a long shot I thought there may be a clever way of reusing it.

 

I would appreciate any suggestions.