If you are wondering which surfacing material to use on a small roadway, driveway, or other projects, getting some basic knowledge and looking at the differences between them will be a great place to start.
Asphalt is something most of us are familiar with. We drive on it nearly every day. But there may be a few things to learn. In some cases, tarmac is a name that gets used to describe a paved area. Airports are an example of this, even when tarmac may not be the actual material used.
We will try and clear that up here.
Tarmac and Asphalt: The Basics
Before jumping into the differences, let’s start by taking a closer look at what each of these materials is.
What Is Tarmac?
Tarmacadam, commonly called tarmac, is a road surfacing material made of tar, sand, and crushed stone or aggregate. In some cases, Portland cement is combined with tarmac for additional strength.
Tarmac was invented in the early 1900s and was used to replace the compacted stone macadam used in previous years. It provided a more durable and dust-free roadway solution.
Tar is manufactured from intensely heating organic material such as wood under low oxygen conditions. Several stages of distillation take place during the heating process. After the first couple of liquid byproducts, the final result is a thick, dark substance called pitch or tar.
Since coal tar has become much more expensive and difficult to produce than bitumen, tarmac is not as common as it used to be. Traditional tarmac still has a reputation for being one of the highest quality roadway materials known for its longevity.
Tarmac is not used commonly for large roadways due to the lower production rate and higher cost. However, some people still prefer it to asphalt and use it on private roads and driveways.
What Is Asphalt?
The bonding agent used in asphalt is bitumen, which is a product of distilling crude oil. Once the lighter crude oils are removed, the heavier crude bitumen is left. This bitumen is mixed with a combination of aggregates and filler such as crushed stone, sand, and some other recycled materials to create the durable substance that we drive on daily.
Asphalt pavement is incredibly resilient to weather and heavy wear, which explains why it covers more than 94 percent of roads in the US. That is over 18 billion tons of asphalt pavement.
There are three main types of asphalt:
- Hot asphalt: This is the most common type we see being laid on roadways and in commercial construction. It is the toughest and most resilient type. When hot asphalt cools, it becomes as hard as a rock surface.
- MC cold mix: This is a more workable mix usually used in temporary situations. It is most commonly used for road repairs in colder conditions due to the slower dry time. It is not ideal for heavy traffic areas, as it just does not develop the durability of hot asphalt.
- UPM: This is a very durable pavement that can be applied in hot or cold conditions and it can also withstand traffic almost as soon as it is laid.
Similarities of Tarmac and Asphalt
Both tarmac and asphalt contain crushed aggregates and a strong bonding agent. Also, both materials create an extremely durable and weatherproof surface and look quite similar.
Lastly, the preparation and application of tarmac is similar to that of asphalt. Both materials need a rough and heavier aggregate used without the liquid bonding agent as a base layer. That base layer provides a high friction solid bed for the fine material laid on the surface.
Differences Between Tarmac and Asphalt
First, the bonding agent used in each material comes from different sources.
Tarmac traditionally uses tar, which is derived from burning organic materials, and distilling the liquids, as previously mentioned. Asphalt uses bitumen as its bonding agent. Bitumen is the leftover crude oil product from the production and distillation of gas and diesel. It is a product higher in demand and less expensive, which results in a much higher production.
As for the cost, that greatly depends on the size of the project. For large-scale jobs, it is more cost-effective to use asphalt. On small repair projects, it may be less expensive to use tarmac. That does depend on your location and material cost in your region.
The maintenance and upkeep could be considerably less with a tarmac surface. Sealing is not necessary as tarmac naturally develops a watertight surface.
Tarmac vs. Asphalt: Which of the Two Should You Use?
Tarmac has a long history, especially in Europe, of being a top-quality road surfacing material that outlasts other methods. It is essentially maintenance-free and it does not require a sealer. It maintains an even, solid black surface that is attractive and extremely durable.
If you want a traditional road or driveway surface that will last for a very long time and not require updating or refinishing, tarmac could be a top choice. It’s also easily installed.
If you have a larger pavement project and want to keep the cost lower, asphalt will still give you a solid, beautiful surface that lasts for many years. It may require occasional maintenance, though less than a traditional concrete drive.
Asphalt is considered to be more environmentally friendly than tarmac. This is because after its lifespan, it can be broken up and reused.
Summary
Though the terminology is sometimes used interchangeably, there is a difference between tarmac and asphalt. As we’ve discussed, there are distinctions in the ingredients and surface quality.
Cost and availability will vary based on what region of the world you live in, but hopefully knowing some facts about these materials will be helpful if you are trying to decide which type to use for your project.