What Is Asphalt Made of?

Asphalt is also known as bitumen. The majority of asphalt used in the world is for road construction.
Sticky, dark, and highly viscous in nature, asphalt is a form of petroleum that can be found in several
different types of natural deposits, though it can also be refined or manufactured.

Though there are several different forms of asphalt such as liquid asphalt, asphalt binder, and
asphalt cement, they are sometimes referred to as simply “tar”. You might be more familiar with this
term because it’s used significantly more than asphalt in the US. Naturally occurring bitumen might
also be called crude bitumen, whereas refined bitumen generally means the material that is
obtained from the fractional distillation crude oil when boiled at 977F.

Asphalt is a type of pitch.

Pitch is a broader category of materials that are either derived from petroleum or plants (sometimes coal tar). In fact, resin is also a type of pitch (plant-derived). Though there is no consensus on which term among asphalt and bitumen should be used for which type of material (synthetically derived vs. natural), geologists tend to prefer the term asphalt for the derived or manufactured material whereas the term bitumen for the naturally occurring material.

What Is Asphalt Used for?


Around 70% of all asphalt is used for road construction. It’s generally mixed with aggregate particles
and then laid on a foundation to let dry. Asphalt works like a glue that binds these aggregates
together. Once mixed with aggregates, the mixture becomes what’s called “asphalt concrete”, which
is similar to normal concrete in that it can be used as a construction material, though mainly for
roads. Other uses of asphalt include roofing felts and sealing flat roofs because of its waterproof
qualities.