This specification covers the materials, manufacturing practice, and corresponding test methods for wet-cast precast modular retaining wall units cast from first-purpose concrete with or without the inclusion of steel reinforcement. The precast units covered by this specification are machine-placed units intended for use in the construction of dry stacked modular retaining wall systems. First-purpose concrete used for the production of precast modular retaining wall units under this specification shall be ready-mixed or central-mixed concrete. Other materials covered by this specification include cementitious materials, aggregates, admixtures, steel reinforcement, and lifting devices.

This specification also covers ordering information that the purchaser shall specify, physical properties (compressive strength, air content), sampling, frequency of tests, specimen preparation, inspection, certification, product marking, and workmanship, finish, and appearance.