Asphalt, also known as bitumen, is a sticky, black, and highly viscous liquid, or semi-solid form of petroleum. Asphalt is man's earliest organic engineering material. Its application as an adhesive and waterproof material dates to the dawn of civilization. The asphalt market thrives today largely for road building, roofing, and various types of repair work where its water-proofing qualities are required, as well as in rubber and adhesive compounds.