Engineers of DU, do bridges and roads last longer in a warm climate than cold?

[raccoon]

See also https://www.democraticunderground.com/10142452810

[unblock]

1. i'm not that kind of engineer, but i thought it was *changes* in temperature that's the big problem

it's the expansion and contraction that causes the damage, not heat or cold in and of itself.

highways and bridges in texas are always in great condition, but the pennsylvania turnpike always has large stretches under repair.

i don't think there's any great disadvantage to constant cold, it's just that we don't really have that in america. maybe some parts in northern alaska?

[backscatter712]

5. Cold is pretty brutal on roads.

Particularly when there's water in the ground freezing - the freeze-thaw cycles will over time reduce asphalt and concrete to gravel.

[unblock]

6. right - changes in temperature

would it be a big problem for a road if it were always below freezing? not that even antarctic is always below freezing anymore....

but i guess fair point, changes in temperature damages road, but if those changes cross the freezing point of water back and forth, even more so.

[backscatter712]

8. Yep. Even up in Alaska & the Yukon, it crosses the freezing point of water repeatedly.

The frequent freeze-thaw cycles will destroy the roads, so they have to be constantly maintained.

But if you want to somewhere even colder, like Antarctica, things actually last a loooong time down there because they're always below freezing.

[The River]

2. Too Many Variables

to say. It's more a factor of age, load, original construction quality
and upkeep.

[Arger68]

3. Not an engineer

but I would definitely say yes. I live in Minnesota and when the ground under the roads freezes in the winter it heaves the road surface upward, then it falls again in spring when it gets warmer. This causes lots of cracks in the road surface which then get water in them if they're not patched right away. Then that freezes and thaws also which expands and contracts causing potholes and other problems.

[genxlib]

4. Engineer here

Some of the other earlier responders have noted the effects of temperature changes and freeze/thaw effects.

But the biggest factor that has yet been mentioned is salt. It raises hell on steel. That includes steel bridge structures as well as the steel inside concrete structures. That is mostly seen in road salt up north so the southern most states don't have to worry about that. However, coastal environments have their own salt exposure from the sea water.

Severe heat can be detrimental to asphalt but it is less of a factor.

[unblock]

7. maybe tangential, but i've seen road signs warning "low salt area".

why should i care?

does this just mean i should be more worried in that area if there's ice on the road? but then, why wouldn't they salt those areas when there's snow/ice? or is that the warning, that they *don't* salt those areas when there's snow for some reason?

[genxlib]

9. Sorry, I live in the subtropics so I have limited experience with road salting in practice.

My guess/interpretation would be that they are under utilizing the salt in that area to curb degradation or save on maintenance costs.

[Throckmorton]

10. Often public water supply watersheds have salt restrictions. N/T

[genxlib]

11. That makes total sense. thanks