how does snow cause potholes on the road?



I’ve always been pretty confused how there’s always massive pot holes in the road once a massive snowstorm rolls through our valley.

In: Chemistry

Snow melts into water, then freezes causing pressure on the surrounding material that loosens it. Then next time there’s more space for more liquid to get in, and when it freezes again it expands and thus expands the crack/hole more.

It’s the cycle repeated over time that breaks shit up.

Its a combination of two things that come with snow. Freezing temperatures, and snow removal.

When you have a road there are always going to be at least small holes/cracks in the pavement. these holes/cracks let water in/underneath the pavement.

During warm months, this doesn’t really matter and the water eventually drains away. But when there’s water in/under the pavement and freezing temps come along, that water freezes. And when that water freezes, it expands. It expands enough that it can actually break up concrete, especially if there are already small cracks/holes to make bigger.

Since the water is under these pieces of pavement, it also can push these cracked pieces of pavement up, which leads to the next cause.

Snow removal. Snow plows do their best to not tear up the road, but at the same time they’re trying to get as much snow off of the road as possible, so that big metal plow is ideally just skimming the top of the pavement. But say it goes over a cracked up section where the pavement has been pushed up 1/4 of an inch by water freezing beneath it. That big metal plow in front of a 15+ ton vehicle is just going to tear up that already broken up pavement and toss it to the side just like it would snow.

So you get this 1 2 punch of the freezing temperatures breaking up the pavement, and then large vehicles moving that broken up pavement around.