My block paving driveway is on a slope. The lower end sunk long ago so the rainwater collects in a big puddle.

 

I am (finally) lifting and shifting the blocks and sand bed with the intention of adding and compressing more material to raise the level, and put them back.

 

I was expecting to find type 1 under there but the sand layer was essentially put straight onto an uneven concrete base.

 

So my question is what material can I use straight onto concrete to compress down and raise this driveway level? At its worse it needs a good few inches. 
 

Some have suggested gravel / much smaller stones than MOT type 1 because that will compress better against the already hard concrete. Then sand compressed, then blocks tampered finally back.

 

Any other suggestions?

Edited October 26, 20241 yr by Diynot
Added photo

Quarry dust (0-5mm typically.) compacts and holds together better than paving sand.

Edited October 26, 20241 yr by Conor

If you use small crushed stone gravel ( not pea gravel) then it will store water in the gaps  and allow it to flow to a drain.

Bash some holes in the concrete base to give water an outlet, unless it already has somewhere to go.

 

The downside is temporary. This stone won't compress well or lay level. So i would put a layer of membrane on it, then sharp sand.