Asphalt surfaces, while durable, are susceptible to damage from high temperatures and UV rays. Understanding how summer weather impacts asphalt can help in maintaining and extending its lifespan. Here’s a breakdown of the primary issues caused by summer heat:
Oxidation
Asphalt oxidation is a form of deterioration triggered by UV rays from the sun. This chemical reaction causes the light oils in the asphalt to mix with heavier oils, reducing the binding oils that provide structural integrity. As oxidation progresses, the asphalt loses its elasticity and becomes brittle, making it prone to cracks, buckling, and failure. This deterioration also causes the asphalt to fade from a dark black to a lighter black-grey hue, affecting the appearance and stripping pavement markings on roads and parking lots. The more UV radiation the asphalt is exposed to, the more severe the oxidation, leading to deep cracks and potholes. While asphalt naturally ages over decades, the sun’s rays can accelerate this process significantly.
Cracking
Cracking in asphalt can result from both solar radiation and oxidation, as well as thermal changes. During extreme heat, such as temperatures over 90°F, asphalt expands. When temperatures drop at night or during rain, the asphalt contracts. This constant expansion and contraction lead to cracks, and in severe cases, the road may buckle. Cracking is common in older asphalt but can also occur in newly installed surfaces if the installation is improper or maintenance is neglected. Heavy traffic on roads and parking lots can exacerbate this issue. Cracking allows water to infiltrate, causing further damage. As temperatures drop, the trapped water can freeze, expanding and damaging the asphalt subbase, making timely repairs crucial.
Raveling
Raveling occurs when water or excess moisture enters cracks in the asphalt, leading to binder cohesion failure within the asphalt mixture. This process causes the asphalt to break apart along with the aggregate and soil, further damaging the surface. Raveling is often due to inadequate compaction or separation of the binder and aggregate, but it typically results from asphalt cracking. The more cracks present, the more susceptible the asphalt is to damage, which can lead to settling, rutting, or base failure from water penetration.
Tracking
Tracking happens when the asphalt absorbs the sun’s heat energy, causing surface temperatures to rise significantly. As a result, the asphalt surface can soften, releasing tiny specks that stick to shoes or tires. Although tracking is not a severe issue, it indicates the asphalt’s inability to withstand extreme heat temperatures. Asphalt’s solar reflectance values range from 0.04 to 0.16, whereas concrete ranges from 0.18 to 0.35, with darker asphalt absorbing more heat.
Preventive Measures
Heat damage to asphalt is inevitable, but you can take steps to minimize its impact and extend the lifespan of your driveway or road. Applying a seal coat and performing regular asphalt repairs are effective ways to protect against excessive damage. Regular maintenance can prevent small issues from becoming significant problems, ensuring a smooth, durable surface for years to come.
Understanding these factors and taking proactive measures will help you maintain your asphalt surfaces in optimal condition, even under the harsh summer sun. Is your driveway cracked, crumbling, discolored or looks neglected? Contact Maisano Bros today at (203) 239-5405 or request a free estimate here!