Paver base compaction amount?
 

Does anyone know how much crushed concrete or crushed rock for a brick paver base will compact after running over it with a plate compactor every 2"? I'm shooting for 6" after compaction. I've seen people say it won't compact much and others say 25%. I'm planning on 1/4" minus crushed concrete.

There are many factors...

For stone dust, I've typically experienced about 1"-1.5"+/- compaction on a 6-8" loose stone bed...meaning, you wheelbarrow/tractor in 7"+/- of stone and it will generally compact to about 6"+/-.

The factors are the size of the media, the wetness, and the amount of compaction prior to the plate whacker (ex. walking on it, etc.).

If you are using 1/2 inch to 3/4 inch angular crushed stone or crushed concrete, you will typically not get much more than 10% compaction by volume no matter how hard you tamp. Sometimes you appear to get more, however this may be due to compaction of the underlying soil. Loose soil can often be compacted 30%, occasionally more, but not crushed stone or concrete.