This industry comprises establishments, such as batch plants or mix plants, primarily engaged in manufacturing concrete delivered to a purchaser in a plastic and unhardened state. Ready-mix concrete manufacturing establishments may mine, quarry, or purchase sand and gravel.
Operating sand or gravel pits--are classified in U.S. Industry 212321, Construction Sand and Gravel Mining; and Manufacturing dry mix concrete--are classified in U.S. Industry 327999, All Other Miscellaneous Nonmetallic Mineral Product Manufacturing.