What Is Asphalt Made Of? The Science Behind Blacktop
Asphalt consists of 90-95% mineral aggregates—crushed stone, sand, and gravel—bound by 5-10% bitumen, a viscoelastic hydrocarbon derived from petroleum refining. The bitumen contains four molecular fractions (saturates, aromatics, resins, and asphaltenes) that determine viscosity, adhesion, and aging resistance. Aggregates provide structural integrity through mechanical interlock, while bitumen penetrates pores and forms physicochemical bonds with stone […]