What Are the Causes of Asphalt Deterioration on Runways?

Weather

• Asphalt deterioration begins almost immediately after installation, no matter how good a job the contractor did. Sunlight dries binders within the asphalt that hold it together, resulting in cracking that often resembles spiderwebs. Cracking allows water from rain or irrigation to seep under the asphalt. When moisture under the asphalt freezes, it expands, causing the asphalt to heave upward. The frozen water later thaws and soaks into the ground, leaving a void or air pocket under the asphalt. Vehicles traveling over the area cause the asphalt to sink into the air pocket, resulting in a pothole.

Installation Errors

• Improperly prepared ground and incorrectly installed asphalt surfaces begin to show signs of channels, ruts and depressions almost immediately following inadequate installation. Airline runways must endure a large amount of heavy traffic and heavy vehicles on a 24/7 basis. Runway construction, including base compaction, mixture, temperature and drainage, must conform to those demands.

Chemical Spills

• Gas and oil soften asphalt, causing it to deteriorate more quickly than with weather alone. Periodically applied asphalt sealers help reduce damage that chemicals cause but does not eliminate it. Properly deal with chemical spills as soon as possible to avoid costly, premature repairs.

Repairs

• When damage is new and not yet a major problem is the best time to make repairs. Products on the market include quick-setting polymers, allowing for traffic flow in as little as 10 minutes following application. This type of product reduces runway closures due to maintenance. Polymer-based asphalt repair products are durable and can withstand the high-traffic demands at airports. Versions of the product designed for hand application are available for commercial and private use. The product works equally well for cracks and potholes of any size.