Bitumen content refers to the percentage of bitumen present in asphalt or other bituminous mixtures, which is a critical factor in determining the material's durability, stability, and flexibility. Accurate measurement of bitumen content ensures that the mixture meets specified standards for strength and longevity, preventing issues such as cracking or raveling. Testing methods typically involve extracting and quantifying the bitumen from the mixture, such as through the ignition method or solvent extraction, to ensure optimal performance of the asphalt in road construction and other applications.