There is a really good reason that most roads and parking lots are made from asphalt. This is a material that is created out of limestone aggregate and bitumen. The material is used all over the United States and Canada. Most people do not realize that there is a lot of science and engineering that goes into every aspect of the asphalt that you drive on everyday. This article will go into a little bit of the science behind asphalt, but also why it is such a great material for creating roads and parking lots.
There are a few reasons why limestone has been chosen to be the aggregate in most asphalt. There are many different classifications of limestone, but the one that asphalt companies are after is a hard limestone that has very little microporosity. Porosity is just simply the space between the minerals in the rock. Microporosity is the tiny spaces between the calcium carbonate. When water gets into the tiny spaces then freezes, the water expands and starts to erode the rock away. So, geologists are hired to inspect the rock that is used in the aggregate of the asphalt so it lasts as long as possible. This is a very important aspect of roads because paving a road usually comes out of taxpayer dollars. That means longer lasting roads could give you a tax break in a very roundabout way.
It is important that the foundation where the road or parking lot is going to be is very well built. You do not want to pour the asphalt on a sub par foundation. However, the foundation does not need to be completely flat like it does with concrete. Asphalt has the ability to actually flex and move when it is being pored, and when it is hot. It is able to flex and adapt to different terrain much better than other materials.
Asphalt is also relatively easy to fix if there ever is a crack. The cracks can be filled with a tar or bitumen that can seal up the crack. Or, if the surface is really bad, then it can simply be resurfaced. This is when the asphalt already in existence is used as the foundation and a new surface of asphalt is laid down on top of the old asphalt. This effectively seals up any cracks, but it also makes it so you do not have to replace the entire slab of asphalt.
Check with your local professionals (think Branche Industries) for more information.