What Type of Asphalt Is Used for Roads?

type of asphalt
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Asphalt is one of the most widely used paving materials in the entire world—and with good reason. It’s made from high-quality, flexible, and long-lasting resources. On top of that, asphalt is also one of the most versatile paving materials on the market today. In varying capacities, it can be used for commercial parking lots, residential driveways and even road construction. Of course, choosing the right type of asphalt is imperative to getting the most out of any paving project. Different climates, pavement conditions, and other specifications all play a role in determining what type of asphalt is needed. Keep reading to learn more about the different types of asphalt, how to select the right one for your needs, and what makes asphalt superior to concrete.

Types of Asphalt

The type of asphalt mixture that’s needed for any given paving or repair project depends largely on the type of work that needs to be done, the regional climate, and the extent of the damages.

There are three main types of asphalt to choose from: native, asphalt rock, and asphaltites.

Native Asphalt

Also referred to as natural asphalt, native asphalt is asphalt that occurs naturally in any given part of the world. Native asphalt can often be found in a semiliquid or liquid state. There are only five known natural asphalt deposits in the entire world; three are in California and one is in Venezuela. But the largest and most famous one is Pitch Lake in Trinidad. It spans approximately 100 acres and is estimated to be about 250 feet deep.

Rock Asphalt

Rock asphalt is typically composed of grainy crushed sandstone and fortified with a higher concentration of bitumen than other types of asphalt. That’s what gives it its signature coarse and rough texture. Ideal for highways, high-impact and high-volume roads, rock asphalt has the strength and durability required to withstand all kinds of weather conditions and the weight of heavy vehicles. Bitumen content can vary from trace amounts to complete saturation anywhere from 3% to 15%. Kentucky is considered to be one of the leading producers of rock asphalt, but other states like Texas and Alabama are quickly catching up. Government initiatives in Canada have also encouraged more companies to mine and produce asphalt here as well.

Asphaltites  

Asphaltites, which are also referred to as gilsonite, asphaltum, and uinttahite are a naturally occurring solid hydrocarbon. This is a type of bitumen that has an extremely high melting temperature and is largely produced in Utah and Colorado. When mixed with certain oil solutions like CS2 and TCE, asphaltites are classified as soluble materials. Although carbon is one of the key components of asphaltites, they also contain a number of other elements including sulfur and nitrogen. Aside from asphalt, asphaltites are listed as core ingredients in a number of other commercial products including dark coloured-printing inks, dark coloured paint, various chemical products, and mud and cement used for oil well drilling.

Types of Asphalt Mixtures Used for Roads

Rolled Asphalt  

As with all other types of asphalt, hot rolled asphalt (HRA) has a number of different uses, including road work and roofing. HRA is comprised of several mineral aggregates including sand, filler, and bitumen to bind it all together. Varying in density depending on the use, this mixture typically contains a high concentration of sand to prevent air pockets from forming during the compaction process. The result is a highly durable, smooth, flexible, long-lasting, impervious, and skid resistant asphalt aggregate that’s ideal for exit and entry ramps on highways and commercial properties.  

Mastic Asphalt  

According to many industry experts, mastic asphalt is considered to be one of the toughest and most watertight asphalt aggregates on the market. This is largely because of the fact that it’s mostly made of crushed limestone. Due to its impressive durability, flexibility, and structural integrity, mastic asphalt is typically used for paving minor side roads and commercial parking lots that get a lot of traffic. Since modern mastic asphalt is composed of Polymer materials, it can be used for a wide range of construction applications, whether its repairs, repaving, or installation. While mastic asphalt isn’t compactable, the application process of spreading it while it’s hot with a hand float rather than rolling it out is what gives it its smooth finish.

Compressed Rock Asphalt  

Considering asphalt is one of the most recyclable materials in the world—particularly in the paving industry—there’s pretty much nothing it can’t do. When it comes to repaving or repairing roadways and commercial parking lots, most commercial contractors often source the very asphalt they’ve removed from the property to perform these jobs. Hence, compressed rock asphalt is born. The damaged asphalt that’s extracted from these jobsites is melted down to the desired consistency, mixed in with a base aggregate, and then reused to repair and restore the pavement to its former glory.  

Why Are Asphalt Roads Replacing Concrete?

Two of the biggest benefits of asphalt compared to concrete are its flexibility and versatility. Even if there are imperfections in the substrate, asphalt won’t crack or crumble as easily as concrete does when it dries. Concrete, on the other hand, doesn’t have the structural capability to withstand all of the same pressures, weight, and temperature changes that asphalt successfully combats on a daily basis. Concrete becomes stiff and completely unyielding once it dries and this limits its longevity. It’s also more prone to cracking and breakage.

Although both concrete and asphalt are composed of aggregates, the ingredients used in these mixtures are vastly different and therefore offer different performance levels.

The aggregate used in concrete is composed of crushed rock and sand, which is then mixed with cement (the binding agent) and water. Asphalt is also composed of the same aggregate as concrete. The core difference is that bitumen is used as a binder instead of cement. Bitumen is a dark, sticky substance that’s derived from crude oil.

Other advantages to using asphalt instead of concrete paving is that it’s completely recyclable, imperious to water and debris erosion, and it can withstand more weight from vehicles even if the foundation isn’t completely stable.

Additionally, asphalt pavement repairs are relatively simple and can often be completed in a matter of hours. Concrete repairs, on the other hand, take much longer and are often cost-prohibitive.

Why Choose Sure-Seal Pavement Maintenance Inc.?

When it comes to choosing the right asphalt for your road or parking lot, trust the experts at Sure-Seal Pavement Maintenance Inc.! Our services include commercial asphalt repairs, installation, and maintenance. Contact us today to learn more!