I live in an area that has an abundance of river rock and a shortage of crushed stone. Can river rock be used in place of crushed stone as a sub base for foundations, roads, etc. or does the smoothness cause problems when it comes to movement, compaction, settling, etc.?
My gut tells me that the "sharp" edges of crushed stone will result in better interlocking when compacted and thus less shifting/movement. However, I don't have any actual evidence/data to back this up.
Searching around the internet suggests that river rock is used predominately for decorative tasks, but most of the resources are also from the US where I believe river rock is significantly less available (more expensive) than crushed stone and it could just be that people only use it decoratively because it is not economical to use it as a sub base.