Why Asphalt and Concrete Don’t Always Mix

If you’re thinking about replacing your current concrete pavement with asphalt, you may be thinking that it would be a simple matter of installing asphalt right over the top of your existing concrete surface. Although it is possible to do this in certain situations, we don’t recommend it. While it is initially cheaper to pour asphalt over the top of a concrete surface, it can present some problems down the road. The truth is that asphalt and concrete don’t always mix. There are two reasons why we recommend that your existing concrete surface be removed prior to installing asphalt:

• The sub base for asphalt is different than the sub base for concrete. When paving contractors install asphalt, they take great care in preparing the sub base underneath the pavement to ensure that the ground below the surface doesn’t sink or shift. But concrete is a bit different. Although paving contractors do prepare the ground prior to pouring concrete, not as much work is needed in this phase of the installation as is needed for asphalt. If concrete installers are concerned about the ground moving a bit underneath the pavement, they simply pour a thicker slab of concrete. So if you choose to have asphalt poured over an existing concrete surface, there’s really no way of knowing how stable the ground is below the concrete – unless you remove the original pavement. If the sub base under the existing surface isn’t stable enough, the expansion joints in the original concrete will create cracks in the new asphalt surface on top. This can result in having to repeatedly repair the new asphalt surface or, in extreme cases, having to replace it altogether.
• Your new asphalt pavement won’t last as long if it’s installed over an existing concrete surface. While it’s true that it’s cheaper upfront if you simply pour asphalt over an existing concrete slab, it will cost you more in the long run. That’s because your new asphalt will be much more likely to need repairs on an ongoing basis, due to all of the problems we mentioned above. Asphalt surfaces that are built from the ground up, on the other hand, generally require fewer repairs, less maintenance, and last longer than those installed over an existing concrete surface.

To find out more about why asphalt and concrete don’t always mix, call a trusted asphalt contractor and schedule an appointment today. They can assess your needs and recommend the best solution for you.