Bitumen
Bitumen is a highly viscous, sticky, black semi-solid form of petroleum. Chemically, it is a complex mixture of heavy hydrocarbons, used primarily as an adhesive binder in road construction and as a waterproofing agent in roofing.
It consists mainly of large, dense hydrocarbon molecules (asphaltenes and resins), along with trace elements like sulphur, oxygen, nitrogen, and metals. At room temperature it behaves like a soft rubber or thick molasses, but flows when heated, making it easy to mix and apply. It is naturally hydrophobic, making it an excellent barrier against moisture — roughly 85% of all produced bitumen is used in road construction, acting as the “glue” that binds aggregates (sand, gravel, and crushed stone) together to create asphalt.
