Activated coal gangue is a by-product of coal mining and washing, consisting primarily of silica and alumina with smaller amounts of calcia and iron oxide. Its activation, usually achieved through thermal or chemical methods, enhances its pozzolanic properties, making it suitable for use in cement and concrete. Under ASTM standards, the material is evaluated for properties like particle size distribution, chemical composition, and pozzolanic activity level (e.g., ASTM C618 for pozzolanic materials in cement). These standards ensure that activated coal gangue used in cement and concrete meets specific quality and safety benchmarks, particularly necessary under severe environmental conditions.