Whether you own a commercial parking lot or you care about the condition of your residential street, you may wonder how long the asphalt near you will last.
What is the average lifespan of an asphalt road?
Asphalt roads typically last 25 to 30 years, but factors such as maintenance (or lack thereof) as well as traffic and climate can degrade this lifespan. So too can the soil under the road, especially if it doesn’t drain well.
Ahead, we’ll talk more about the average lifespan of asphalt roads, including a thorough discussion on what can shorten that lifespan. We’ll also provide maintenance tips and suggestions for making your asphalt surfaces last longer. Keep reading.
How Long Does an Asphalt Road Last?
Typically, asphalt comprises mostly aggregates such as gravel, sand, and stone. These ingredients can make up to 95 percent of average asphalt roads. The rest is asphalt cement, about 5 percent.
Those materials sound durable, but asphalt does not last forever. With regular use from pedestrians and mostly vehicular traffic, asphalt roads last between 20 and 30 years.
The Factors That Can Affect the Life of an Asphalt Road
Many factors play a role in how long an asphalt road will last, including some that we touched on in the intro. Let’s elaborate further in this section.
Many asphalt roads start from grassy surfaces. Not all soil is necessarily suitable to build atop of. Soils that are considered weaker include loose saturated sand, peat, silt, and clay.
As we’re certain you know if you’ve taken a barefoot walk on the beach, sand shifts under pressure. Enough particles of sand are sturdy enough that your foot doesn’t sink right into it, but the lack of structural soundness makes sand a poor base for an asphalt road.
Peat, silt, and clay are all soil deposits. They share another thing in common: you find these materials most often by bay perimeters and river mouths. These soil deposits often have high quantities of organic content, and building asphalt roads on them makes the road prone to flooding.
Besides the structural strength of the asphalt road, what also matters when laying down asphalt is how well the soil drains. Soil that can release water as it accumulates is best here. As you can imagine, when soil holds onto water, it can swell, affecting the asphalt.
Thicker asphalt can withstand more daily use and thus ensuing wear and tear. Whether it’s a driveway, a parking lot, or a residential street, the thicker the asphalt used, the more ideal for a longer lifespan.
Most asphalt roads are designed for cars to drive across or park on. Even with that intended purpose in mind, the heavier the traffic an asphalt road receives, the quicker it will need to be repaired or replaced.
The seasons and the climate in which you live can also influence the condition of the asphalt road. In very hot temperatures, cracks can develop in the asphalt. Water seepage then occurs, which can affect any asphalt sub-surface layers. When this happens, air gaps develop across the asphalt surface.
The next time someone drives over one of these roads, the asphalt’s top layer can crumble, collapse, or sag. The result is a pothole, which is dangerous to drive on and a sign of an asphalt road that’s badly cared for.
It’s not only heat that can affect asphalt, by the way, but cold as well. If you often experience bone-chilling winters where the temperature is well under freezing, the asphalt can freeze in two places: underneath and on top. Cracks are likely to follow, as is water when the temperatures are somewhat less frigid.
If the temps dip back down from there and the water freezes again, it will expand. This strains the asphalt and can also contribute to the formation of potholes.
Lack of Maintenance
Potholes are one very serious problem in asphalt roads, cracks are another. Although it’s always annoying to have to take an alternate route to work because an asphalt road near you is being repaired, doing so can keep the road around longer.
Methods for Extending the Life of an Asphalt Road
As we’ve shown you, lots of things can weaken asphalt roads, but you do have options for making asphalt last longer. Here are some suggestions.
Repair Issues Right Away
Small cracks in the asphalt will inevitably get bigger, and sometimes it doesn’t take as long as you would expect. Thus, as soon as you or someone else spots even a small crack in the road, you’ll want to repair it posthaste. You can use more asphalt to seal the cracks before they go deeper or spread wider.
A sealcoat product covers the asphalt, adding a second layer atop it that acts as a protectant. Sealcoats can ward off water damage as well as fading from UV rays and even fluids from passing vehicles.
If the asphalt road in question has a rather faded look from years of use and sun exposure, sealcoat restores the appearance of the asphalt. It’ll almost be like paving anew.
Use a Graphene Additive
In 2017, New Atlas, a science and tech news resource, published a piece about graphene. If you’re not familiar with graphene, it’s a carbon allotrope that stacks in layers. Graphene-based asphalt additives are supposed to make asphalt roads more sustainable and durable.
Graphene does have good thermal conductivity, so it could reduce cold-induced cracking as well as asphalt softening from the heat. The article also mentions that these additives can make asphalt stronger and more elastic, even in high-load situations such as heavy, consistent traffic. Some graphene additives may be to add 12 or 14 years more to an asphalt road’s lifespan.
Asphalt Maintenance Tips
To reiterate what we mentioned in an earlier section, maintaining asphalt roads is one of the most recommended ways to increase the road’s lifespan. Here are some asphalt maintenance tips to use in addition to the information above.
Speaking of high-load situations as we did before, it helps if you can reduce these kinds of scenarios as much as possible. If you have heavy vehicles like commercial-grade trucks, construction vehicles, garbage trucks, and the like, you might limit their parking time in your lot or even encourage them to use another road.
Sweep Asphalt Often
Sweeping, especially if you own a commercial parking lot, is one of the most important parts of a good asphalt maintenance routine. When sweeping, you’re removing all obstructions from your asphalt. This gives you a chance to look at your asphalt objectively. You’re removing sand and other aggregate materials that could degrade the asphalt’s quality as well.
Install a Drainage System
Since water can cause both heat-related and cold-related potholes, if your asphalt road doesn’t have a suitable drainage system, that should be high on your priority list too. Drainage system options include under-drains and drain inlets.
Asphalt roads may last 20 to 30 years, but that fate is not necessarily set in stone. Getting into a good preventative maintenance routine is key, as is tackling cracks and potholes as they arise and keeping the asphalt clean.