# Potholes and salt: freeze-thaw cycle? **URL:** \ **Category:** Factual Questions\ **Created:** [January 26, 2025, 1:50am UTC](https://boards.straightdope.com/t/potholes-and-salt-freeze-thaw-cycle/1013409 "2025-01-26T01:50:45Z")\ **Posts on this page:** 13\ **Page:** 2
**Author:** ![Exapno\_Mapcase](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/exapno_mapcase/32/1051_2.png) [@Exapno\_Mapcase](https://boards.straightdope.com/u/Exapno_Mapcase)\ **Post date:** [January 26, 2025, 11:06pm UTC](https://boards.straightdope.com/t/potholes-and-salt-freeze-thaw-cycle/1013409/21 "2025-01-26T23:06:51Z")
Cities have experimented with a range of materials from sand to manufactured chemicals in order to prevent the long-term problems cause by salt. Salt has the advantage that it works better than sand and is far cheaper than chemicals. Makes it easier for cities to approve its use. ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [January 26, 2025, 11:33pm UTC](https://boards.straightdope.com/t/potholes-and-salt-freeze-thaw-cycle/1013409/22 "2025-01-26T23:33:29Z")
Are those chemical alternatives ones aimed at reducing the infrastructure (pot holes) or the ecological and health long term harms? It seems to me that any product that lowers the melting point and dissolves will do the same infrastructural harms that road salt does. The more costly alternative products can be more effective with less used, less harm to plants, pets, and even humans, maybe, and may even have less impact on metal corrosion, but pot holes reduction? ---
**Author:** ![jjakucyk](https://avatars.discourse-cdn.com/v4/letter/j/3d9bf3/32.png) [@jjakucyk](https://boards.straightdope.com/u/jjakucyk)\ **Post date:** [January 27, 2025, 12:10am UTC](https://boards.straightdope.com/t/potholes-and-salt-freeze-thaw-cycle/1013409/23 "2025-01-27T00:10:03Z")
Calcium chloride is better as a pre-treatment and it works at colder temperatures than salt. It needs to be mixed into a brine and sprayed onto the road with a tanker truck, rather than just being piled into a dump truck, and it’s more expensive. Beet juice is much less corrosive to metals, so it’s favored on at-risk bridges, especially those with large metal expansion joints, or roads with streetcar tracks. It’s sticky so it works well as a pre-treatment, but it tends to track red goo into buildings on people’s shoes, and like calcium chloride it’s not as good as a post-treatment. Many places use mixtures of all of them depending on the temperature and other conditions. I agree though that it’s not going to make much difference for potholes. ---
**Author:** ![Railer13](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/railer13/32/9742_2.png) [@Railer13](https://boards.straightdope.com/u/Railer13)\ **Post date:** [January 27, 2025, 1:10am UTC](https://boards.straightdope.com/t/potholes-and-salt-freeze-thaw-cycle/1013409/24 "2025-01-27T01:10:08Z")
> [@Exapno\_Mapcase](#): > > Cities have experimented with a range of materials from sand to manufactured chemicals in order to prevent the long-term problems cause by salt. But has anyone tried creole seasoning? [NEW ORLEANS RESIDENT USES “CREOLE SEASONING” INSTEAD OF SALT TO MELT AWAY SNOW -](https://whatstheword.tv/2025/01/23/new-orleans-resident-uses-creole-seasoning-instead-of-salt-to-melt-away-snow/) ---
**Author:** ![Joey\_P](https://avatars.discourse-cdn.com/v4/letter/j/919ad9/32.png) [@Joey\_P](https://boards.straightdope.com/u/Joey_P)\ **Post date:** [January 27, 2025, 1:13am UTC](https://boards.straightdope.com/t/potholes-and-salt-freeze-thaw-cycle/1013409/25 "2025-01-27T01:13:28Z")
A town in Iowa used garlic salt. > **[Facing Ice, Snow, Iowa Town Looks To ... Garlic Salt](https://www.npr.org/2008/12/19/98529510/facing-ice-snow-iowa-town-looks-to-garlic-salt)** > > Al Olson, public works administrator for Ankeny, Iowa, talks about the city's use of 9,000 tons of donated garlic salt to melt snow and ice on its streets. ---
**Author:** ![Exapno\_Mapcase](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/exapno_mapcase/32/1051_2.png) [@Exapno\_Mapcase](https://boards.straightdope.com/u/Exapno_Mapcase)\ **Post date:** [January 27, 2025, 1:24am UTC](https://boards.straightdope.com/t/potholes-and-salt-freeze-thaw-cycle/1013409/26 "2025-01-27T01:24:05Z")
The damage salt does to roads, vehicles, infrastructure, the environment is so serious and widespread, I can’t find anything specific about something as comparatively minor as potholes. [You can look at this worksheet](https://sustainabletechnologies.ca/app/uploads/2020/03/Alternatives-to-salt-technical-brief.pdf) that spells out the advantages and disadvantages for several alternatives. They all work down to different temperatures, so maybe someone can figure out whether that would have an impact on the freeze/thaw cycle and in what temperature bands. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [January 27, 2025, 1:47am UTC](https://boards.straightdope.com/t/potholes-and-salt-freeze-thaw-cycle/1013409/27 "2025-01-27T01:47:24Z")
A lot of commercial “seasoning mixes” are mostly salt, anyway, and what’s not salt is often largely sugar, so that probably would work. It’s a lot more expensive, of course, but if you only need a little, and it’s what you have at hand… ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [January 27, 2025, 1:49am UTC](https://boards.straightdope.com/t/potholes-and-salt-freeze-thaw-cycle/1013409/28 "2025-01-27T01:49:43Z")
Well the OP was specifically about “potholes”, so it _is_ the relevant point of thread. How salt increases the freeze thaw cycle that breaks down roads. And the process is basically all of which degrades the street structure, the physical breakdown of it. Seriously that is not minor. Yes there is also infrastructure that is metal, especially on bridges. And definitely yes there are huge environmental and health impacts that these products might reduce, if they can be applied effectively (often meaning ahead of time) and afforded. Here’s some information I could find on real world experience in Canada. Pretreated salt seems to win out from what it says. > **[Alternatives-to-salt-technical-brief.pdf](https://sustainabletechnologies.ca/app/uploads/2020/03/Alternatives-to-salt-technical-brief.pdf)** > > 1844.10 KB ---
**Author:** ![Exapno\_Mapcase](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/exapno_mapcase/32/1051_2.png) [@Exapno\_Mapcase](https://boards.straightdope.com/u/Exapno_Mapcase)\ **Post date:** [January 27, 2025, 1:57am UTC](https://boards.straightdope.com/t/potholes-and-salt-freeze-thaw-cycle/1013409/29 "2025-01-27T01:57:30Z")
Adobe won’t let open the file for some problem I’ve never seen before. I’ll try again later. ---
**Author:** ![hogarth](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hogarth/32/1773_2.png) [@hogarth](https://boards.straightdope.com/u/hogarth)\ **Post date:** [January 27, 2025, 2:20pm UTC](https://boards.straightdope.com/t/potholes-and-salt-freeze-thaw-cycle/1013409/30 "2025-01-27T14:20:32Z")
> [@Joey\_P](#): > > But if this is the reason, the implication is that temperature is more likely to fluctuate above and below 15 than it is to fluctuate above and below 32. If your daily low temperature is just a bit below freezing, then you probably wouldn’t need to use much road salt, would you? ---
**Author:** ![ZurBob](https://avatars.discourse-cdn.com/v4/letter/z/71e660/32.png) [@ZurBob](https://boards.straightdope.com/u/ZurBob)\ **Post date:** [January 28, 2025, 3:01am UTC](https://boards.straightdope.com/t/potholes-and-salt-freeze-thaw-cycle/1013409/31 "2025-01-28T03:01:24Z")
**HALLELUJAH**!!! I think you have a bingo here! On reflection, I remember reading a DOT study referring to varying salt concentrations based upon depth over time in pavement and soil from a single application. I just never connected the dots till your post. It makes perfect sense! Thank you very much. ---
**Author:** ![md-2000](https://avatars.discourse-cdn.com/v4/letter/m/9d8465/32.png) [@md-2000](https://boards.straightdope.com/u/md-2000)\ **Post date:** [January 28, 2025, 1:37pm UTC](https://boards.straightdope.com/t/potholes-and-salt-freeze-thaw-cycle/1013409/32 "2025-01-28T13:37:15Z")
> [@DSeid](#): > > I think the missing point is that salted water has different freezing/melting points depended on its concentration of salt. > > Salt on the road creates a _range_ of salt concentrations from some areas that have no salt in the water, to fully saturated. These include areas immediately adjacent to each other. That means the range of freezing/melting points goes from 0 C down to -21.1 C. > > Any and every temperature fluctuations within that range will result in freeze thaw cycles of some of the water, which then seeps into other spaces … Not only the freeze thaw at going above and below 0 C. > [@jjakucyk](#): > > I think there may be a survivor-bias-esque situation here. In a place where there’s enough snow or ice on the streets to need salting, then the climate is likely cold enough that water in would-be potholes would have stayed frozen solid if it weren’t for the salt This is the key. If the temperature range is 35-25 (for those quaint Farenheit people) then it’s unlikely salt would be much in use because the ice would be gone in the daytime. For those in the 25-10 areas, salt would be exactly what is used, because it would make the ice into water - hence the road safer - except in the dead of night. And it would be used for more of the winter, and linger- only to be diluted to almost unsalty (via precipitation) when the temperature improves and salt is not called for, so now you have freshwater freeze-thaw as an added bonus. ---
**Author:** ![ZurBob](https://avatars.discourse-cdn.com/v4/letter/z/71e660/32.png) [@ZurBob](https://boards.straightdope.com/u/ZurBob)\ **Post date:** [January 28, 2025, 9:38pm UTC](https://boards.straightdope.com/t/potholes-and-salt-freeze-thaw-cycle/1013409/33 "2025-01-28T21:38:29Z")
> [@md-2000](#): > > This is the key. > > If the temperature range is 35-25 (for those quaint Farenheit people) then it’s unlikely salt would be much in use because the ice would be gone in the daytime. Exactly the notion folks in central Arkansas had, when I lived there as a kid. 6" of ice and snow? No problem…let God take care of it. The trouble was (is) under the conditions you describe, the entire region may become paralyzed for up to a week. In fairness, they aren’t equipped to effectively handle that kind of weather but I’m happy now that I live up north, under those circumstances the road crews are out in force, plowing and scattering salt like a priest throwing holy water at mass. [Previous page](https://boards.straightdope.com/t/potholes-and-salt-freeze-thaw-cycle/1013409.md?page=1)