Concrete has more in common with a sponge than you might at first think. Pores are formed as the the concrete cures and the water, which made the concrete pourable, evaporates. As the water exists the concrete, it creates tiny holes or pores. Then, as the the concrete absorbs water from the ground below it, this water travels through these same holes as it evaporates and exits the concrete. While pores are normal in concrete, under some conditions they can cause spalling, and when that happens, you need to take steps to immediately fix the problem.
What Is Spalling?
When small, thin chunks of concrete separate from the surface of your concrete, you have spalling. If you have one piece of concrete that has separated, you don't need to take steps to fix the problem. On the other hand, if you have holes that grow in size and number as time goes by, you need to make repairs.
How to Repair Spalling
You should see spalling as a sign that at least the top layer of your driveway is not structurally sound. You can fix this problem by applying a concrete overlay to your driveway. An overlay is really nothing more than a 1/2 inch thick concrete slab made from equal parts concrete and sand. Because the concrete layer you are adding to your driveway is so thin, you don't want to use large gravel because it could create an irregular surface. While you can pour your own concrete overlay, it is heavy, dirty, time-sensitive work. If you think you are not ready to resurface your driveway for whatever reason, you should call in the professionals to make sure that the job is done right.
How to Avoid Future Spalling
Spalling is typically a sign that water is penetrating the top layer of your driveway and then freezing. As the water freezes inside the pores in your driveway, it expands and breaks the concrete apart. To keep your spalling in check, shovel snow back away from your driveway so that meltwater can seep into the ground as the snow melts. Also, use rock salt sparingly as it melts snow, and the salt water can then leak into the spores in your driveway.
If you live in an area that does not get a lot of snow or freezing temperatures, you may never have to worry about spalling. On the other hand, if you have to contend with a lot of snow and freezing, then you need to make sure that take steps to prevent spalling and to deal with it if it occurs.
Talk to a professional, such as from D & R Masonry Restoration, Inc., for more information