Asphalt pavement is the most common paving material used for paving roads, parking lots, driveways, etc. It comprises a mixture of gravel, sand, and asphalt binder, then compacted. The binder allows the pavement to flex or “give” when traffic drives over it. While asphalt pavement is very durable, it can still experience problems over time.
Birmingham Sealcoat Inc. shares some common problems with flexible pavement in this blog post.
Flexible Pavement v Rigid Pavement
The difference is that a rigid pavement has one layer of concrete on the sub-base, while a flexible pavement has several layers of materials.
Rigid pavement is less common because they are more expensive to install and maintain. However, they last longer than flexible pavement.
Flexible pavement is easy to repair and can be renewed by resurfacing. The flexibility allows it to resist temperature variations.
Causes of Failure in Flexible Pavement
There are many causes of failure in flexible pavement. Some of the most common are:
- Poor drainage
- Lack of compaction
- Improper mix design
- Environmental elements such as UV rays, freezing and thawing, rain, snow
- Vehicular and traffic load
- Aging and deterioration of the pavement
Types of Failures in Flexible Pavement
Alligator Cracking: Also called fatigue cracking, alligator cracking is a series of interconnecting or random cracks that form on the asphalt surface. The cracks resemble an alligator’s skin and hence the name. Repeated traffic load is a significant reason for this cracking.
Block Cracking: Block cracking is a series of large (typically square or rectangular) cracks that form on the asphalt surface. Block cracking is caused by shrinkage of the asphalt due to temperature changes. This type of failure is not load-related.
Edge Cracking: Edge cracking is a linear crack that forms along the inside or outside edge of the asphalt pavement. Edge cracks are usually seen in areas lacking support at the pavement edge and occur due to brittle pavement.
Swelling of Flexible Pavement: This is characterized by an asphalt pavement distortion due to the expansion of soils underneath. An increase in moisture content typically causes this. The swelling can cause cracking, rutting, and potholes.
Rutting: This type of failure is where depressions are formed on the asphalt surface. This usually occurs in the wheel path due to the vehicle load. It is caused by weakening the asphalt binder, which can be due to moisture damage or poor pavement mix.
How to Prevent Flexible Pavement Failures?
Flexible pavement may fail for many reasons; however, a few things can be done to prevent flexible pavement failures. Asphalt installation on a well-prepared base, appropriate thickness of the asphalt layers, good drainage, proper compaction, prompt repairs, and sealcoating can help prevent some of these failures.
The good news is that Birmingham Sealcoat Inc., serving the Lake Orion, MI area, has the expertise and the tools to help you with all your pavement needs. We provide services from installation to maintenance of asphalt.