The Impact of Climate Change on Asphalt: Why We Need Climate-Resilient Roads

Climate change is raising temperatures globally, and our infrastructure is feeling the heat—literally. Asphalt is particularly vulnerable to high temperatures over long periods of time. Understanding how these temperatures impact asphalt and the subsequent effects on public roads and runways, as well as private parking lots and driveways, is crucial for developing climate-resilient infrastructure.

The Temperature Threshold

Asphalt is designed to withstand a range of temperatures, but there is a critical threshold beyond which it begins to deteriorate: 120°F (49°C) for extended periods. During extreme heat waves, surface temperatures can exceed this limit, causing significant damage to roads.

What Happens to Asphalt When It's Too Hot for Too Long?

1. Softening and Rutting: Prolonged exposure to high temperatures causes asphalt to soften, losing its structural integrity. This softening leads to rutting, where depressions form in the wheel paths, making the road uneven and hazardous for vehicles. Rutting is particularly problematic as it can cause water to pool on the road, increasing the risk of hydroplaning.
2. Thermal Cracking: While asphalt expands in the heat, it contracts when temperatures drop, leading to thermal cracking. Repeated cycles of heating and cooling can cause these cracks to widen and deepen, compromising the road's surface. This not only shortens the lifespan of the road but also increases maintenance costs.
3. Oxidation and Hardening: High temperatures accelerate the oxidation of the asphalt binder, causing it to become brittle over time. This hardening process reduces the asphalt's flexibility, making it more susceptible to cracking and other forms of damage. Brittle asphalt is less capable of absorbing the stresses of traffic, leading to more frequent repairs.
4. Aggregate Stripping: Extended exposure to heat can weaken the bond between the asphalt binder and the aggregate (the stones and sand mixed with asphalt). This weakening, known as stripping, results in the aggregate being pulled out of the road surface, creating potholes and further degrading the road's condition.

The Need for Climate-Resilient Roads

Given the increasing frequency and intensity of heat waves, it is essential to develop and implement climate-resilient asphalt technologies. Here are a few strategies to enhance the durability of asphalt roads in the face of rising temperatures:

1. Heat-Resistant Asphalt Mixtures: Developing asphalt mixtures that can withstand higher temperatures is crucial. These mixtures may include modified binders and additives that enhance the thermal stability of the asphalt, preventing it from softening and rutting under extreme heat.
2. Reflective Coatings: Applying reflective coatings to asphalt surfaces can help reduce surface temperatures by reflecting more sunlight. This can significantly lower the risk of heat-induced damage and extend the lifespan of the road.
3. Regular Maintenance and Monitoring: Implementing proactive maintenance strategies and monitoring road conditions can help identify and address issues before they become severe. Regular inspections and timely repairs can mitigate the effects of high temperatures on asphalt roads.

The impact of climate change on asphalt is a growing concern that requires immediate attention.

As temperatures continue to rise, traditional asphalt will struggle to maintain its structural integrity, leading to safety hazards and increased maintenance costs. By investing in climate-resilient asphalt technologies and proactive maintenance strategies, we can ensure our roads and runways remain safe and durable in the face of a changing climate.

For more information on developing climate-resilient asphalt and our latest innovations in the industry, visit Modern Asphalt.