A question to all you county patrol and or rock road maintenance operators? What size of road stone do you put down for a top coat on a rock road that already has a good base to it, and how many ton per mile. We have been required to put down 1 inch road stone for years, finally got them to let us use 3/4 class A (lots of fines) on some roads 500 ton to the mile at the most. The only reason they can give us is that they don't like buying all that lime, our argument is that we need the lime to tie every thing down and build a seal to make the water shed off the road. Our county has a little over 700 miles of rock roads at times I think we a just chasing our tales, I'd like to here how other county's take care of there rock roads. THANKS
well we dont have lime in n minnesota but we do use mndot class one with 8 to12 percent passing the 200 seive. IF you been putting down this material for so many years where did it all go? Dont know to much about your situation but maybe you got to subcut your base down to remix what you have? We usually put a 2 inch lift on tired base. figures out to about 750 ton/mile on a 24ft road top. Hope this helps a bit littleroadgrade. If you think about it 1.5 inches deep of 3/4 inch material allows you to put two rocks on top of each other to make the 1.5 inches. Explain it to the powers to be that way and see if that makes sense to them better.
Most road base I ever used was 3/4 minus, with a percentage of fines and some clay as a binder. TPM varied per engineer specs or decision of country road supt. Don't want too much fines or too much clay as they will either turn road into dust bowl or mud pit. Generally put down 2-8" lifts depending on application. Michigan used to like brine as a dust suppressant, don't know if it's legal there now or not. I've used sugar cane juice as well. Smelled like hell and didn't last beyond the first rain.
Mineral well brine is still legal and quite popular due to price. Some use liquid calcium chloride - produced in Ludington and Midland by Dow - more expensive but lasts a little longer
Here's a good site to check out. Lot's of good info. http://www.mnltap.umn.edu/Publicati...ce/documents/GravelRoadMaintenance-Manual.pdf