Intended purpose of crushed limestone with fines

Question

I'm fixing up some logging roads in the bush in Eastern Ontario. The roads have muddy ruts that I want to fill in with gravel to avoid getting my truck stuck.

I have been using 3/4" clear crushed limestone from a local landscaping company, which has worked well to fill in low spots. I get a half yard in my truck each time I'm in the area.

But the landscaping company has run out of 3/4" clear and only have the following products left for purchase:

• Limestone Screenings
• Washed Beach Sand
• 3/8″ Peastone
• 5/8″ Minus Crushed Limestone
  

I'm considering using the 5/8″ minus crushed limestone as an alternative to fill in the ruts. But I'm wondering if the fines will retain water and not drain properly, resulting in tire tracks filled with water.

This leads me to ask: What is the intended purpose of crushed stone with fines? Is it just cheaper to produce than clear stone? If that's the case, I wonder why it's the same price as the clear stone. Or are there cases where crushed stone with screenings is preferred?

Answer 1

The crushed stone with fines gives you a good gradation of stone. The 3/4" by itself won't compact, so the stone will move over time (both from wheels traveling on it, and pushing it into the ground). The fines help fill the space between the stones so they don't move.

Answer 2

The landscape company says the 5/8″ minus crushed limestone is used for bases like driveways, under patio slabs, etc., where high compaction is needed. Compacted with a tamper or by hand. They said it does hold some water.

They said the 3/4" clear limestone is used more for drainage.

In the past, I've used 3/4" clear for bases. It seems to compact well with a tamper. It turns into a solid mass, almost like concrete but with holes. So I'm still not really sure why someone would want the 5/8″ Minus Crushed Limestone, since 3/4" clear drains better and can also be compacted. They are the same price.

With that said, the landscape company did say they think the 5/8″ minus crushed limestone would work for filling in muddy ruts.

Answer 3

From a colleague:

Crushed stone is typically used for road and driveway bases. Clear stone is used more for backfill behind retaining walls and around perforated pipe.

The best base choice often depends on the percolation rate of the subsoil.

Clear stone isn’t typically used for driveways or roads because it is easily displaced when used in this manner. Snow Plows tend to push it into the ditch and sides of the road.