Asphalt is one of the most reliable, durable, and cost-effective options, which can last for many years if installed and maintained properly. However, like any other paving material, asphalt can start to deteriorate as it ages. The constant exposure to heavy loads, weather, and other elements can cause your asphalt to crack.
Asphalt cracks should be taken seriously and should be repaired immediately. Failing to do so can lead to serious problems, such as potholes, which are very costly to repair. In this post, we shall discuss the common causes of asphalt cracks and how to deal with them. Read on for more information.
Different asphalt cracks and their causes
These are longitudinal cracks that occur a few feet from the edges of the asphalt pavement. Edge cracks are mostly caused by a lack of lateral support, settling of the underlying material, or soil drying. Possible culprits can be close to shrubs or trees.
These cracks form as a result of asphalt pavement overlays that are laid over a jointed or cracked pavement structure. Then, there is the movement or shifting of the older pavement. These joints can move from the older pavement to the surface. Typically, reflection cracks tend to be severe, and require a complete replacement of the layer.
Slippage cracks have a crescent shape, and there are numerous factors that lead to their formation. For instance, non-adhesive materials like dirt or water between layers can cause poor bonding between the asphalt surface and materials beneath. Also, deficient, or low-strength asphalt mix can lead to the formation of slippage cracks. According to the ABС Paving, sealcoating contractor from Florida, the solution to such cracks can be to remove the materials surrounding the cracks until you reach the layer with good bonding before repairing the crack.
Also known as alligator cracking because they resemble the alligator skin, fatigue cracks are caused by heavy loads. These cracks can be further aggravated by the deterioration of a weak surface, subgrade, or weak base. Also, poor drainage is another factor that leads to the formation of fatigue cracking. To repair fatigue cracks, the material on the affected area should be removed and replaced with the right asphalt mix.
Typically, these cracks are nearly in line with the center line. The common causes of transverse cracking include the use of the wrong asphalt grade for certain climatic conditions, or because of low temperature thermal cracking. Transverse cracks happen when the asphalt layer shrinks. Although they are not load related, they can be worsened by heavy traffic. Repairing transverse cracks require asphalt sealant or a complete replacement with a fresh overlay.
Preparing the surface
- Before patching the cracks on your asphalt pavement, make sure that the surface is clean and smooth—this makes it easier for the matching material to adhere to the surface.
- If you notice that there are broken asphalt pieces obstructing the crack, use a hammer and chisel to remove them.
- The next step is to use a wire wheel or wire brush mounted on a drill to remove the debris and dirt from the crack.
- To finish preparing the surface, use a shop vacuum or compressed air gun to make sure that all the smaller particles and loose debris have been cleared from the surface. If you don’t have any of these two materials, you can use a garden hose to flush out the debris from the crack. But, if you choose to use a garden hose, don’t attempt to patch the crack until it dries completely.
Now, when cleaning the crack, always wear safety goggles regardless of the equipment you are using—this protects your eyes from debris.
After cleaning the crack in your asphalt pavement, it’s time to start patching it. However, it’s important to note that different crack sizes require different patching materials. With that said, let’s look at the steps that you can follow to fix both small and large cracks on your asphalt pavement.
Patching small cracks (1/8” – 1/2”)
- The best material to use to repair small cracks in your asphalt pavement is rubberized asphalt-emulsion crack filler. When patching the cracks, avoid getting the filter material on unaffected areas because it can easily stain your pavement.
- If possible, use a caulking gun to apply the filler. If you don’t have one, you can pour the filler carefully into the crack.
- Use a trowel or putty knife to smoothen the surface of the repaired crack. If you don’t have a trowel or putty knife, use rubber gloves, and then smoothen the crack using your thumb.
- Always allow the filler to dry following the manufacturer’s instructions before driving on the affected area.
Patching large cracks (>1/2”)
- If the cracks on your pavement are more than two inches deep, you should consider filling up the two-inch crack using crushed angular gravel. Never larger gravel, because it shifts, and doesn’t provide the required base for the filler.
- Next, use a 4 by 4 wooden post or steep tamper to compact the gravel.
- Once done, you can start filling the crack using a cold-press asphalt repair compound like blacktop.
- When you finish pouring the compound, compact it using a 4 by 4 wooden post or tamper.
- Once you finish compacting it, you might need to add more compound or blacktop material and then repeat the tamping process—make sure that you get a consistent, level pavement.