Asphalt is a versatile material that is used in many construction and building projects. We compare asphalt to concrete and tarmac, two substances it is often confused with. Thereafter, we look at its multiple uses.
What Asphalt Is Not – Concrete
To distinguish asphalt from other substances with similar uses, it is helpful to not only know what it is but also what it is not. Two materials that people often confuse with asphalt are concrete and tar.
For example, a new residential driveway could be constructed from either asphalt or concrete. The similarities between these two substances make it hard to tell them apart. Their compositions are very much alike, both being formed from sand and stone and resting on a gravel base. The key difference is how they are held together. Concrete gets its adhesiveness from cement, whereas asphalt is petroleum-based.
There are six primary differences between concrete and asphalt used to construct a suburban driveway:
- Asphalt is cheaper at $2.00 to $4.00 versus $4.00 to $15.00 (measured per square foot).
- Asphalt requires a lot more maintenance. It must be sealed in the second half of the year after installation and thereafter, every three to five years. While a single seal is preferable for a concrete driveway for aesthetics, it is not essential.
- Cracks in concrete and asphalt both require filling but in the former, they cannot be resurfaced, while an asphalt repair looks a lot better.
- Concrete lasts up to 20 years longer (roughly 50 years) while asphalt has to be replaced after approximately 30 years.
- Concrete lends itself beautifully to tints and stains, allowing for multiple stunning finishes. Asphalt, on the other hand, is mostly black due to the compression and rolling required to install it, making it difficult to color.
- Weather patterns and climate result in the sixth difference between asphalt and concrete. Cracks in concrete occur from extreme cold weather. Asphalt is more negatively impacted by the sun. When it softens, it can adhere to vehicle tires and pedestrians’ shoes.
What Asphalt Is Not – Tarmac
Tarmac has undergone several changes over the years since 1820 when it consisted of a layer of gravel placed on top of a standard pavement with an adherent. The next stage in its history was due to an accidental spillage of tar on a section of tarmac. Gravel had been sprinkled over the tar to protect the workers’ footwear. This combination resulted in a durable surface to which dust did not cling. Businessman Edgar Purnell Hooley was quick to patent this find. Tarmac was trademarked in 1901.
One further change came about when it was realized that the tar component is susceptible to damage from diesel and gasoline. The tar was replaced with a less vulnerable substance, bitumen. This concoction was called ‘bitmac’ but the tarmac name remained too popular for it to take.
The difference between tarmac and asphalt is far more subtle than the contrast between concrete and asphalt. In fact, when used on airport runways, it remains bitmac or tarmac but when used to construct a residential street, it is known as asphalt.
Asphalt combines sand, tiny pebbles, larger stones, and filler material and binds it with bitumen. Bitumen comes from petroleum while tar is formed from coal, peat, or wood. The ratios of the composition of materials are the key difference between tarmac and asphalt.
There are other differences as well. Asphalt is more cost-effective and can thus be used for bigger areas. It is more resilient against weather extremes than tarmac. Tarmac is more expensive to maintain.
Uses of Asphalt
Asphalt is used to surface most of the roads in America. It is also the substance of choice in many driveways on private, residential property, bicycle lanes, playgrounds, and car parking lots. You can learn more about asphalt parking lots here.
Special consideration is given to the exact composition of asphalt when utilized in high-stress areas. For example, heavy-duty vehicles need a firmer, more durable surface than a parking lot frequented by cars doing shopping. Other high-stress places are where trailers’ solid metal feet sit directly on the surface, where drums storing goods are placed, for usage by forklift trucks, and bus lanes.
Asphalt is the surface of choice for many sports arenas, tennis courts, pitches, and netball courts. Likewise, it has found its way into the agricultural and farming industries to provide flooring in animal houses, as a solid base for storing grain and other produce, and on certain farm roads. In the aviation field, perimeter and access roads are usually constructed from asphalt, inside airplane hangars, as well as in the passenger parking areas. Another area where asphalt is found is at vehicle and driver testing facilities.
By knowing what asphalt is used for, it is easier to choose the right materials for any job.
