Asphalt is much like human skin. When freshly laid, asphalt is strong, flexible, and very appealing. However, as it ages, and with continuous exposure to natural elements and weather, just like our skin, signs of stress and decline start to show. Here and there, you will begin to see cracks, discolorations and fading, sagging, and pockmarks. You will also notice that more vegetation start growing out of cracks and potholes after each winter. Don’t wait until your asphalt pavement is completely destroyed before taking action.
Here are 4 of the most common signs of deterioration on asphalt, and our experts’ recommended methods of restoration.
Type I – Oxidation.
As asphalt ages and gradually loses its bituminous binder due to continuous exposure to wind, weather and UV rays from the sun, it fades and begins to turn gray. This process is called oxidation. Although naturally unavoidable, oxidized asphalt is not only unpleasant-looking, it also means that your pavement has weakened considerably, and will be prone to more damage if left untreated. Oxidized asphalt is brittle due to lack of sufficient binding agent, and will easily crack under constant pressure from traffic, moisture seepage, and the yearly freeze-thaw cycle.
The Fix – Sealcoating.
Oxidized asphalt appears faded, with uneven discoloration. This can be fixed by applying a coat of sealer after thoroughly cleaning and prepping the pavement surface. Aside from returning the aesthetic beauty of asphalt, sealcoating also protects it from further damage due to moisture and exposure to the elements. Visit our sealcoating resource page for more tips, guides and techniques.
Type II – Cracks and Minor Potholes.
Moisture from rain, melted snow, runoff from lawn sprinklers and hoses, spills from engine coolants, etc. can seep below the surface of unsealed asphalt and get trapped underneath. Trapped moisture freezes during winter, causing the subgrade to expand.
Newer asphalt can flex and move to accommodate expansions since it still has relatively more bitumen content. However, older asphalt is brittle and can no longer flex and contract accordingly. Once frozen moisture expands, it causes the brittle surface to split and crack. If left unrepaired, cracks can eventually grow larger and form potholes.
The Fix – Crack Sealing and Pothole Patching.
Check the weather in your area to make sure that no rain is in forecast within 24 to 48 hours before scheduling crack and pothole repairs. The asphalt surface must be prepared and cleaned thoroughly to ensure that crackfill and pothole patches adhere properly. Use a gas-powered sidewalk edger and crack cleaner to remove vegetation from cracks and curbs. Remove loose debris and fine sand from cracks using a walk-behind blower or high-quality stiff-bristle broom. Wash the entire asphalt surface by power-washing or using a garden hose fitted with a spray nozzle until the area is thoroughly clean. Allow the cleaned asphalt to dry completely, at least overnight, before applying crackfill.
Cracks that are ½” wide or smaller should be filled with a cold-pour crackfiller, while those that are 1” or larger should be sealed with rubberized hot-pour crackfill. If the cracks are shallow and widespread and appears like a spider web or alligator skin, use Gator Patch by applying with a trowel, putty knife or squeegee.
Potholes that are 1” deep or less should be patched with the year-round cold patch for asphalt that come in 20-kg. bags. For larger gaping holes, we recommend using the permanent pothole repair, as this product can be used on both cold or hot temperature. This product also works wonderfully on low-lying sections of the pavement where water will most likely pool or puddle.
To better understand how and why cracks and potholes form and how you can keep them in check, visit our resource page. For a more in-depth guide on crack repair and pothole patching, check out the linked guides.
Type III – Large Holes, Ruts and Uneven Depressions.
Cracks and potholes have a tendency to grow and worsen over time if not repaired in a timely manner. Unusually high traffic movement cause asphalt to distress and sag, which result in depressions, ruts, and ultimately, sinkholes. These types of damage are too large and extensive for crack filling or pothole patching, and must be repaired differently.
The Fix – Cut, Patch, and Sealcoat.
Sinkholes and very large potholes mean that not just the asphalt surface has grown weak and damaged. This means that even the foundation or subgrade had shrunk or had been corroded to some extent, leaving the surface “floating” on empty air. In these cases, it is recommended to cut out the sunken sections and refill the eroded foundation with a layer of soil and aggregate base. Tamp down using a metal tamper (or, if the area is really wide, a vibrating plate compactor) to ensure an even compaction before adding pothole patch or new asphalt. After adding the patching material, tamp down again until flush. Let the patch cure overnight, or up to 24 hours, before applying sealcoat to further protect the asphalt surface and restore its aesthetic appeal.
Type IV – Crumbling Asphalt.
If you are sweeping through your driveway or parking lot and notice that pieces of aggregate come loose and get swept along with the other debris, this means that the asphalt has deteriorated completely and must be replaced ASAP.
The Fix – Repaving Critically Damaged Asphalt.
For relatively small sections of crumbling asphalt, you can opt to repair it by using an infrared asphalt heater. To use, place the infrared heater over the damaged section and heat the asphalt for 5 to 10 minutes until the surface is of mixing consistency. Use a metal rake or shovel to spread out the reheated asphalt until evenly distributed. Tamp down with a tamper or vibrating compactor until firmly compressed. Allow the refreshed asphalt to set and cure before sealcoating.
On the other hand, if the disintegrated asphalt is too wide and extensive for DIY methods, contact a professional to assess and create an action plan to restore your pavement.
Repairing asphalt can be quite expensive, based on the severity of deterioration, that is why we recommend that cracks and potholes be checked and filled regularly. Applying a fresh coat of sealer every 2 to 3 years after prepping the pavement surface is ideal, as it helps prolong the life of asphalt while preventing larger issues in the long run.