Asphalt Over Concrete

Does concrete provide a solid base.

Asphalt over concrete.

Homeowners can benefit from this whitetopping technique to reduce labor costs and time when replacing worn asphalt driveways. Brick and stone pavers come in wide variety of patterns colors and textures but since they re labor intensive installing a brick paver or cobblestone driveway costs between 10 and 70 per square foot. Laying asphalt over concrete will likely lead to this new asphalt forming cracks in the same spots that the concrete expansion joints have cracked below. This will most commonly occur during expansion and contraction due to heat and or freeze thaw cycles.

An asphalt overlay is cheaper to install than replacing concrete and can provide a smooth ride over deteriorating concrete. But there are issues as you might expect. To save time and money many states and municipalities use a road repair technique known as whitetopping the process of pouring concrete over asphalt rather than removing the existing asphalt. Laying asphalt over concrete creates two layers to worry about.

In fact many miles of concrete roads are paved over with asphalt every year. Asphalt paving contractors frequently use asphalt over concrete on interstates state highways and city streets concrete provides an excellent base for the asphalt which must have a well compacted stable foundation to yield superior results. Take a look below. How do brick and stone pavers compare to concrete.

The unprepared sub base. When concrete deteriorates it draws and holds moisture. However it is important that you understand there are potential side effects and things to watch out for when paving over concrete. Concrete itself is very stable and strong so no matter what it is poured over the slab is going to be solid when it hardens.

Asphalt requires a well prepared stable subbase otherwise the resulting pavement will be subject to instability and cracking. The truth about asphalt over concrete. In addition you do have an alternative paving method that may surprise you. Concrete paved surfaces are not compressed and compacted like asphalt is rather the concrete adheres and fills voids and irregularities with the soil and subgrade beneath it.

Blacktop can be successfully installed over concrete. Unfortunately when asphalt driveways are poured over concrete resting on an unstable base the resulting asphalt pour is prone to instability. One positive aspect of installing blacktop over concrete is the concrete provides a firm base for the flexible asphalt paving. Applying an asphalt overlay to a concrete surface is a common practice.

Concrete is a great base material because it is stable and allows for excellent compaction of the asphalt above. Therefore concrete is often used as a bridge over unstable ground. Asphalt lasts 20 25 years while concrete lasts 30 40 years.