What is Asphalt?
Asphalt can come as a thick and sticky liquid or as a semi-solid form. It is mixed with aggregates such as sand, gravel or crushed stone and combined with a bitumen binder. The biggest difference between asphalt and tarmac is the binder, with tarmac using tar instead of bitumen.
The name asphalt comes from the Greek word, ‘asphaltos’ which means secure.
Tarmac used to be the main choice for surfacing roads, however asphalt is more commonly used today due to it being more durable and easier to maintain.
Asphalt is used for a variety of services including roads, motorways, car parks and driveways.
What is Tarmac?
Tarmac is short for tarmacadam, and is a highly durable substance which was originally used for surfacing roads. It is made by crushing a layer of stones or aggregate which is then coated and mixed with bitumen.
It is named after John Loudon McAdam, who created the “macadamizing” method in 1820. This method involves adding a layer of gravel on top of a regular pavement. However, this isn’t the entire story. The “tar” in tarmac comes from an extra layer of tar that a businessman named Edgar Purnell Hooley added to McAdam’s macadamized pavement in 1901.
Tarmac can be used for a number of different things, including car parks, driveways, sports courts and even on playgrounds when it’s a soft tarmac.
Key Differences Between Asphalt and Tarmac
Composition:
- Asphalt: Made from aggregates and mixed with bitumen.
- Tarmac: Made from a range of sizes of aggregates and mixed with bitumen.
Strength and Durability
- Asphalt: Resistant to extreme weather conditions. Able to withstand heavy traffic and requires a lot less maintenance compared to tarmac.
- Tarmac: Not as durable as asphalt and more likely to wear down quicker.
Main Uses:
- Asphalt: The majority of UK roads are made from asphalt. Commonly used on motorways, airport runways, car parks and drives.
- Tarmac: Commonly used for playgrounds and footpaths.
Surface features:
- Asphalt: Surface can vary from smooth to coarse.
- Tarmac: A rough and coarse surface which helps with grip. It is also impermeable and water resistant.
Recyclability:
- Asphalt: Can be fully recycled and used again for a new road surface.
- Tarmac: Able to be recycled as unbound aggregate or through cold recycling technology but is a less sustainable option than asphalt.
Conclusion
It is easy to see why people confuse asphalt and tarmac. Although they look similar, both have different compositions. Asphalt is more durable, making it better suited for modern roads. It takes longer to wear down from traffic and harsh weather conditions and can be easily patched.
If you’re interested in asphalt or tarmac for your next project, contact our expert team today. We’ll be able to advise you on the best materials so you get the highest quality results.
FAQs: Asphalt vs Tarmac
Which is More Environmentally Friendly?
Asphalt is better for the environment compared to tarmac as it does not contain tar. Asphalt can also be easily reused making it a far more sustainable option.
Which is More Durable, Asphalt or Tarmac?
Asphalt is more durable than tarmac, making it the ideal choice for roads that experience heavy traffic. It will also withstand changing weather conditions better. Tarmac is more prone to wear and tear.
Why Do People Often Confuse Asphalt and Tarmac?
The names asphalt and tarmac are often used interchangeably by people, even though they are different. This is due to both being used for very similar purposes. Airport runways are still referred to as “tarmac” even though today, they are made from asphalt. It’s things like this which help fuel the confusion between both surfaces.
Is Asphalt or Tarmac Easier to Maintain?
Asphalt is easier to maintain. It is more durable and will usually only require small areas patching. Tarmac needs additional maintenance as it wears down quicker.
