ᐅ What material should be used to compact the driveway base?

Hello,
I had a large amount of 16/32 mm (0.6/1.3 inch) gravel left over and spread it over the driveway, which is 3 m (10 feet) wide and 10 m (33 feet) long, to create a firmer base. Unfortunately, this didn’t really work. Even compacting it with a vibratory plate compactor didn’t provide enough stability.
Now I’m considering adding clay soil or another material, possibly rolling it in or mixing it with water to solidify the surface.
Does anyone have other ideas or advice on how to strengthen the area?
Any tips would be much appreciated.
Best regards,
Michael

Consider buying a time machine and checking the compaction before installing the filter material.

Adding new material to compensate for the missing zero line makes sense in theory, but in practice, I only see limited benefits because you would then also have to mix the blend. My gut feeling is that simply slurry sealing is not sufficient.

For a pedestrian path, that’s okay. Under vehicle load, it won’t last forever. Maybe it’s better to invest money in the subbase now, so the driveway will be more durable.

What type of soil is found beneath the gravel layer? How thick was the gravel layer installed? This doesn’t matter much if the soil underneath is not sufficiently load-bearing. For good reason, many geotechnical reports recommend replacing several meters of soil before a base layer can be installed. When we were setting angle stones, we encountered a clayey, persistently wet layer. I had it excavated over a large area and replaced with gravel.