Asphalt is a paving material used for all sorts of outdoor projects, including airports, golf courses, superstores, parking lots, and tennis courts. According to the Canadian government, the country’s factories produce more than 30 million tonnes of the material annually.
Asphalt is made of bitumen, a thick, sticky fraction of crude oil, unsuitable for internal combustion engines. Engineers mix it with an assortment of binders and glue to give it various properties. Some asphalt formulations offer better noise absorption, while others have superior surface run-off properties.
Asphalt is popular for many reasons. Chief among them is the material’s durability. Asphalt is long-lasting. It takes a while for it to show signs of wear and tear. With proper seal coating, it can last fifteen years or more.
It is also low maintenance. Weeds find it tremendously challenging to grow up through cracks and potholes, meaning that your driveway will stay looking new for longer.
Finally, it’s super affordable (regardless of the type of asphalt you choose). The cost of paving comes in at much less than concrete driveways.
But which are the three best paving materials for asphalt and why? You’re about to find out.
Cold mix asphalt
Cold mix asphalt is a common type of asphalt used on low-traffic roads and farm tracks. Thanks to its chemical composition and the way that engineers lay it, it is exceptionally durable in low-temperature environments.
Cold mix asphalt is made of a blend of proprietary oil and a quarter-inch chip. This formulation keeps it soft and helps it repel water. While most asphalt requires heating, cold mix, as the name suggests, does not. Engineers can lay it immediately, reducing energy costs.
Incredibly, cold mix asphalt remains soft for around six months. This property means that people can easily store it and then deploy it when they need to use it (perhaps to repair an existing asphalt surface). A cold patch is a smart way to fix a pothole yourself while waiting for a professional company to provide full repairs.
If you want to harden a cold mix asphalt patch quickly, you can. Simply blow hot air over the material until you can’t press into it easily. Keep going for as long as it takes for it to cure
Even though cold mix asphalt is durable by itself, sealing products may enhance its longevity. Most engineers recommend applying a sealant product 48 hours or more after laying.
Experts estimate that noise pollution costs Canadians between $345 million and $3 billion per year, thanks to its effect on health and well-being. Because of this, the race is on to find asphalt paving that produces less noise.
So-called “quiet pavement” is a possible contender for a solution. The concept of restoring road surfaces aims to reduce tire and pavement noise.
Quiet pavement asphalt is not made in the same way as dense graded asphalt. Instead, the mixture contains more gaps to make it easier for air to escape when vehicles travel over the surface. The sound-deadening effect targets wavelengths in key harmonic bands that cause harm to people living or working close by.
Currently, quiet pavements are still a relatively new concept. However, trials are underway across North America to see whether they can successfully reduce noise. So far, the early indications are that they can, and rather successfully.
Traditionally, asphalt pavements lasted between ten and fifteen years before requiring replacement. But with the perpetual pavement concept, they could last much longer.
Perpetual pavements build up asphalt in multiple, flexible layers. The approach reduces the risk of cracks and makes it less likely that the material’s bottom layer will become irrevocably damaged.
Deposition begins with the first layer on top of the sub-base. Then contractors add the middle layer which remains permanent. On top of that comes the “driving layer,” the part that is exposed to the elements.
Like conventional asphalt pavements, the driving layer will only last ten to fifteen years or so. However, with perpetual pavements, the bottom and middle layers remain unharmed. Because of this, engineers can get away with using less material to re-cover the road in the future.
Other materials, such as porous and hot mix asphalt exist, but they are less innovative than those described above. These paving materials promise to not only make laying surfaces cheaper but better, too.