Asphalt vs. Bitumen vs. Tar: What are the Differences?
More often than not, only the most discerning eye can differentiate between bitumen, asphalt, and tar.
Due to their similarities, these three names can be used interchangeably. Due to their dark colour and sticky nature, they are suitable for road building. However, they have distinctive qualities that must be considered before use.
The similarity in some of their qualities make asphalt, bitumen, and tar materials to be frequently used as construction materials for pavements.
In this post, the variances between asphalt, bitumen, and tar are examined, as well as their types and comparisons of their qualities.
What is Asphalt?
Asphalt is a composite material made by combining bitumen with aggregates like sand, gravel, crushed stone, alumina, lime, and silica. These ingredients are mixed in an asphalt plant, where the bitumen acts as a binder to hold the aggregates together. While asphalt commonly refers to the final mixture of bitumen and aggregates outside the United States, in American English, it often refers to asphalt cement, a refined form of bitumen.
Asphalt’s strength, flexibility, and durability make it ideal for road construction. It can withstand heavy traffic and temperature variations, ensuring long-lasting pavement for roads, parking lots, and pathways.
Various Forms of Asphalt
Asphalt is available in the following forms:
- Cutback asphalt (Asphalt cement dissolved in a solvent, making it fluid for easier application.)
- Asphalt emulsion (Asphalt mixed with water and emulsifying agent to create a stable suspension for cold applications.)
- Asphalt cement (A by-product of crude oil refining, used as the primary binder in paving.)
- Mastic asphalt (Asphalt cement mixed with fine aggregates and solvent, used in flooring, roofing, and waterproofing.)
What is Bitumen?
Bitumen is a by-product of crude oil refining, produced when crude oil is heated to temperatures between 300 and 350 degrees Celsius and passed through an atmospheric distillation column.
In this process, lighter oil fractions vaporize and separate, while the heavier components remain as a thick, sticky residue, known as the vacuum bottom. This residue is further refined to produce bitumen, which meets specific performance standards for applications such as road construction and waterproofing.
Bitumen is also found naturally in deposits, such as bitumen from lakes (40-70% purity) or oil sands (5-15% bitumen), requiring extraction and refining for use. Its adhesive, waterproofing qualities make it versatile for various industrial uses.
Various Forms of Bitumen
There are typically five different types of bitumen.
- Cutback bitumen (Bitumen dissolved in a solvent to reduce viscosity for easier application at lower temperatures.)
- Bitumen emulsion (Bitumen mixed with water and an emulsifier, creating a stable suspension for cold applications.)
- Plastic bitumen (Modified bitumen with additives to increase viscosity and elasticity, used for road paving.)
- Blown bitumen (Bitumen oxidized by air to increase hardness and viscosity, commonly used in roofing and waterproofing.)
- Straight run bitumen (Bitumen obtained directly from crude oil distillation without further modification, used in road construction.)
What is Tar?
Tar is a thick, black liquid produced by distilling organic materials like coal or wood. Known for its excellent sealing and waterproofing properties, it has been used in construction and industrial applications for centuries. While tar and bitumen look similar, tar has a higher carbon content, making it more adhesive and heat-resistant.
However, bitumen is more commonly used in road construction due to its consistency and fewer environmental concerns. Tar is mainly used for waterproofing and sealing, such as in roofing and coatings.
Various Forms of Tars
These are some common types of tar.
- Coal tar (Obtained through the destructive distillation of coal.)
- Wood tar (Created through the distillation of wood)
- Mineral tar (obtained through the distillation of certain types of petroleum or crude oil)
Difference between Bitumen and Asphalt
These two terms are interchangeable everywhere in the world. We must be conscious of the fact that bitumen is a sticky petroleum.
It bonds other construction materials effectively to prevent mistakes. This compound is ideal for mixing with sand to form asphalt because of its special adhesive properties. As a result, bitumen and sand are combined to make asphalt. Road paving is done with asphalt plant.
A factory that heats, dries, and combines sand, bitumen, and gravel into a composite mix produces asphalt. Then, in relation to the ultimate use, it is put through a paving machine on the job site as a solid material at a designated or required thickness.
Compared to a bitumen-sealed road, asphalt creates a smoother and more resilient asphalt road surface.
Difference between Bitumen and Tar
When coal or wood is distilled, tar—a viscous, black liquid—is produced. Because of tar's remarkable properties as a sealing and waterproofing agent, we employ it. Despite having very similar appearances, bitumen and tar are very distinct substances.
Tar melts at a higher temperature than bitumen, has more carbon than bitumen, and is a superior adhesive. However, tar is only sometimes utilized in place of bitumen while constructing roadways. Tar is used for various purposes, including skin care, coating wood, and waterproofing.
Difference between Asphalt and Tar
You will spend significant time on the runway while waiting for departure when traveling by airline. One of the most annoying aspects of modern air travel may be getting stuck on the tarmac.
But at least you can be sure that once you're moving again the tarmac will provide you with a flawless transition to the skies.
Tar is a naturally occurring compound made from raw materials such as peat, coal, and wood. On the other side, petroleum is used to create bitumen. Small pebbles, stones, sand, and other filler materials are combined with bitumen as a binding agent to create asphalt.
Conclusion
Asphalt is required to pave or resurface a driveway, parking lot, hardstand, or commercial space. Asphalt is a composite material. Asphalt provides a durable surface for automobiles, trucks, and other heavy machines.
Only commercial vendors utilize bitumen as a glue or sealer for other goods. Tar is used for various purposes, including skin care, coating wood, and waterproofing.