Bitumen is a sticky, black, viscous substance obtained from the distillation of crude oil or as a by-product in oil refining. This substance is used in many industries and applications due to its adhesive and waterproof properties. Bitumen is generally used in construction, road construction, and various industries.

Types of bitumen are generally divided into two main categories: natural bitumen and synthetic bitumen.

1. Natural bitumen: This type of bitumen occurs naturally in nature and is mainly found in places such as tar lakes, oil rocks, or areas with oil resources. Natural bitumen is obtained in semi-solid or liquid form and, after extraction, is processed for use in various industries.

2. Synthetic bitumen: This type of bitumen is obtained from the distillation of crude oil or the refining of petroleum products. Synthetic bitumen is mainly divided into two categories:

- Pure bitumen: which is obtained in the direct distillation process of crude oil and is produced in terms of viscosity and structure according to the specific needs of the industry.

- Emulsion bitumen: Bitumens that dissolve in water and are marketed in the form of an emulsion.

The applications of bitumen are very wide, including:

- Road construction and asphalt: Bitumen is used as the main ingredient in the manufacture of asphalt for roads, streets and airport runways. Its adhesive property helps to create a solid surface for vehicle traffic.

- Insulation: Bitumen is used in the manufacture of moisture insulation for buildings, roofs, tunnels and basements. This waterproof property of bitumen makes it very suitable for preventing moisture penetration.

- Petrochemical industry: Bitumen is used in the production of some petrochemical products as a material with heat-resistant properties and resistance to harsh environmental conditions.

- Making coating and protective materials: Bitumen is used to coat pipes, tanks, and structures against corrosion and rust.

Given the wide applications of bitumen in various industries, this material plays a very important role in the construction and maintenance of infrastructure and the protection of structures.