Why is it so expensive and is there an alternative out there that won’t break so easily especially in the winter? My state is spending like a billion dollars a year on roads that they’ll probably have to fix in 5 years, it really seems like a huge waste of money.
Good Public transportation would fix a lot of these costs I know but what other road materials/solutions are out there?
Thank you for the answers and for putting up with my follow up questions. I’m learning a lot!
Thanks, I had no idea asphalt was a byproduct of petroleum. Is concrete just rocks?
Not technical definitions:
Asphalt is for roads is small rocks held together by petroleum byproducts.
Concrete is small rocks held together by cement.
Concrete is gravel, sand, cement, lyme, and water, mixed in various ratios.
There’s a lot of variations and additives that can change how quickly it cures, often to speed it up or slow it down to account for weather (temperature and humidity play a huge part in how it cures), or to modify the pace of how it cures so you can keep building on it if you’re building vertically.
It’s a simple concept that gets incredibly complicated very quickly.
Big rocks, little rocks, cement, water.
Like the other comment says, concrete is rocks of various sizes (called “aggregate”) mixed with a cement and other additives to change its particular properties.
The cement is the really important point, because once water is added to the cement, it undergoes a chemical reaction which hardens it. Saying cement “dries” isn’t quite correct - yes, it stops being wet, but some of the water actually ends up incorporated into the molecules of the final cement. This is also why cement is really hard to recycle - you have to undo that chemical reaction, as opposed to asphalt which stays the same material.
Fun fact: When concrete is mixed at a big plant, it begins curing immediately. Concrete being carried in those big mixer trucks needs to be delivered before it cures in the truck!