viscosity grading (asphalt)

is the classification system for asphalt cement, defined in American Association of State Highway Transportation Officials (AASHTO) Specification M 226, and based on tests for viscosity, flash point, ductility, purity, etc., as outlined in test method ASTM-D-3381. There are five standard grades, from softest to hardest: AC-2.5, AC-5, AC-10, AC-20, AC-40. Asphalt cement is also classified by penetration grading.

Also see viscosity (asphalt).

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