Salting ruins gravel roads?

Joined
May 7, 2018
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Northern KY
This is a Facebook post from a county in eastern Kentucky not too far from where I grew up. I’m trying to figure out what mechanism would cause salting a gravel road to do this. The best I can come up with is that the salt is hygroscopic and when it dissolves and seeps into the surface and refreezes it causes frost heave. Except that wouldn’t explain why it wrecks the road upon initial melting, only upon subsequent freeze/thaw cycles.

Does someone have any insight here?

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Lowers the freezing point—but the melt can’t flow away. So the road gets soft and runny when it could be frozen like the ground around it. and when all the ground thaws, then water has a place go.

That’s my uneducated guess.
 
It's more of a side effect of the road being wet due to melted snow. The road likely would have ended up like that when it thawed anyway however due to the amount of traffic it may be in worse shape than nearby roads that didn't stay wet as long. Most of our county looks like this right now as things have started to thaw out.

I own a couple of dump trucks and have a maintenance contract with our county to spread gravel on our local roads. If they will let it dry and firm up a little, dress it with a grader and then cap with base rock or AB-3 it will be fine.

I don't think the county attorney will accomplish anything and it could backfire. Let's say the homeowner requires ingress/egress for some specific reason(ie. medical, etc.) and counter sues for material and labor due to the county not clearing the road.
 
Isn't calcium chloride sometimes used for dust control on dirt and gravel roads too? :unsure:
Sodium Chloride isn’t the same as Calcium Chloride.


I could see how it would ruin it. Thaws the top while the base is still frozen leaving no where for the moisture to go. While it can happen in the spring that comes down more to maintenance of the road beforehand than anything.
 
The definition of road gravel is a bit complex and the design and nomenclature is not consistent across regions. Gravel is different than stone. Gravel is a mix of fines, medium, and coarse materials that can be compacted down: https://lindberginc.com/product/23a-shoulder-gravel/ Ones with more clay can be packed tight to shed water while road base ones are a bit more permeable.

My guess is that the salt attracts water into the mix and disrupts the structure (arrangement) of some mixes causing the structure to break down. Water infiltrates/displaces the minute air spaces of the packed gravel and destroys the packed structure, allowing it to turn into a mucky mess (scientific description).

I imagine some mixes are better designed to handle the salt. I.E., the road gravel shoulders on salted Michigan rural roads tend not to break down during spring thaw. So I disagree with dnewton3 blanket statement. Otherwise, Michigan would not be able to use road gravel shoulders.
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Simple everyday things we take for granted actually have lots of design and engineering back ground: https://ctt.mtu.edu/sites/ctt/files/resources/cew/2024/11-MichiganCEW_2024.pdf
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I've seen this many times back home where gravel roads meet paved highways. When salt it spread, some ends up on the first 15' of the gravel road. The surface of the gravel road won't free between 20-32F so it stays soft and muddy. The mess starts as slop and with enough traffic it gets rutted. When the spring thaw happens most gravel roads get soft and start to rut. It can be a real mess until the road dries out and is graded with a maintainer.
 
Isn't calcium chloride sometimes used for dust control on dirt and gravel roads too? :unsure:
I don't know but here they love mag chloride. It works well to keep dirt roads packed and smooth when dry. It also doesn't really let ice form on paved roads, but it's nasty slimy stuff and will flash rust bare steel in a heartbeat. Supposedly attacks aluminum. Difficult to wash off paint, esp when mixed with our local mud.

I'd much rather just see 'em use sand on ice and deal with broken windshields. Or do nothing except plow more often.
 
Can't speak to gravel, but you can tell where homeowners applied salt on their concrete driveways and sidewalks. Looks like they were shot with a machine gun. Tons of chipped concrete.
 
I think the towns could do a better job if they really cared. I would see the mud roads in upstate NY when the ground surface warmed a little but one foot down its still frozen.

If the town put down a barrier fabric and then crusher run on top then the road would be fine.
 
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