A material (viscous liquid or rock) of natural origin (natural asphalt) or produced as one of the fractions obtained from crude oil processing (petroleum asphalt). It has a solid or semi-solid consistency and ranges in color from dark brown to black.

Types of Asphalt

Natural Asphalt

Natural asphalt deposits occur in nature, usually near crude oil deposits, in the following forms:

• Bituminous deposits – containing 55–98% pure asphalt.
• Bituminous rocks – most commonly limestone, dolomite, or sometimes sandstone, which have a porous structure saturated with asphalt. The asphalt content in these rocks is approximately 10–15% of the rock’s volume.

Natural asphalt is too hard to be used as a standalone binder. It is added to petroleum asphalt in amounts of 5–15% to enhance its properties.

Petroleum Asphalt

This is the heaviest fraction obtained after crude oil distillation. Depending on the technological modifications applied, the final product is divided into two main groups:

• Road Asphalt – Used for constructing asphalt road surfaces (asphalt layers and asphalt-concrete pavements), road repairs, and spraying freshly made surfaces.
• Insulation Asphalt – Used in the production of waterproofing materials, such as roofing felt, emulsions, adhesives, sealants, and coatings for waterproof insulation.