What is Asphalt and Why Should I Choose it for My Driveway?

One of the questions we hear often from our clients who are comparing surfaces for a driveway is, “What exactly is asphalt?” Most people can identify an asphalt surface from gravel, concrete, or pavers, but do you know what actually makes up the paving material known as asphalt? It really is an incredible substance, and we’re excited to tell you why!

The Ingredients in Asphalt

Asphalt is made from several key ingredients that each serve a different purpose. Together, they create a surface that is not only durable, but also flexible – a very important factor in our midwestern climate.

1.       Aggregates – usually a mix of crushed stone, gravel, and sand. These mineral components make up the majority of the final substance that is asphalt. They are what help asphalt be able to withstand a significant amount of weight, making it an excellent material for driveways, parking lots, and roads.

2.       Bitumen – the binder for asphalt. Bitumen is a mix of hydrocarbons derived as a byproduct of refining crude oil (petroleum). It is a dark, sticky substance that is extremely beneficial, thanks to its breathability (more on that in a minute). In most modern asphalt applications, bitumen is used instead of tar, as it is a more environmentally friendly material. A fun little history lesson – bitumen’s first use is traced back 40,000 years ago by Neanderthals! Thanks to bitumen's extreme viscosity, it is capable of expanding and contracting with temperature shifts.

3.       Fillers – we’ve only included it here to make sure you know that some companies bring down their costs by adding fillers to their asphalt. We source our asphalt from a local, high-quality, family-owned supplier and know the asphalt mix they provide us does not have fillers. This is one of the reasons the jobs we complete look fantastic for years – the lack of fillers ensures that the asphalt is sturdy and flexible.

The Base Matters

One of the most critical pieces of proper asphalt installation is an adequate and properly compacted base layer. For driveways and parking lots, the base layer typically is a combination of stone and sand, which is then compacted to remove as many gaps as possible. At Pave Tech, our base layer is always at least 3 inches thick; that depth allows for plenty of stability while also acting as a shield from ground water that could reach the underlayer of the asphalt.

The base layer is another area where some companies may deviate from best practice in order to reduce their material cost. But since it is one of the most important components to avoid settling or cracks, reputable asphalt companies will not take shortcuts.

The Magic of Asphalt

We’ve already mentioned that bitumen expands and contracts with temperature shifts. Here in the Midwest, that viscosity is incredibly important. When bitumen is mixed with stone, sand, and gravel to make asphalt, the result is a durable, yet flexible, material that is perfect for driveways, parking lots, and roadways. Asphalt suppliers mix the compounds differently for each unique application, which is another reason having an expert supplier is so important.

If cost is a factor, asphalt is much more cost effective than either concrete or pavers. It’s quite low maintenance, requiring just an occasional sweep and yearly seal coating. While Pave Tech does not provide seal coating services, there are plenty of great companies in the area who do. Just make sure you do your research, get a written estimate, and request a contract before they do the work.

Those who are environmentally conscious may also be pleased to know that asphalt is primarily made of upcycled and recycled materials. The aggregate mixture comes from broken down stone, gravel, and sand. Bitumen is a natural derivative from crude oil production, so while you may be concerned about petroleum, you can feel good knowing that the substance left over is being used in another application.

Preventative Maintenance for Asphalt

Over time, the bitumen in asphalt does break down due to moisture and sun, so it is important to regularly seal coat your driveway or parking lot to slow the deterioration and retain flexibility as long as possible. That is also to best way to prevent cracking.

Moisture is not asphalt’s friend, particularly if it has already started to break down, so you may consider going to the car wash rather than washing your vehicle in your driveway. Low spots where moisture collects are problematic, and that takes us back to the importance of a solid base layer to ensure low spots don’t develop in the first place.

We realize we’re biased, but we think asphalt is a pretty incredible substance. And with our expert application in the western, northwestern, and southwestern Chicago suburbs, you can feel confident your new asphalt driveway or parking lot will be executed perfectly. Get a free, no obligation estimate today by contacting us online or giving us a call at 630.256.0258.