Wall Units A. Precast modular blocks shall be Stone Strong units manufactured under license from Stone Strong LLC. B. Wall units shall conform to ASTM C1776. C. Dimension tolerances for precast modular blocks shall be +/- 1/8 inch (+/-3 mm) for height, +/- 1/8 inch (+/-3 mm) for length (along face), and +1/2 to -1/4 inch (+13 mm to -6 mm) for width (face to tail). D. Concrete for precast modular blocks shall have a minimum 28-day compressive strength of 4,000 psi (28 MPa). Entrained air content shall be between 5 and 7%. E. Internal unit reinforcement or unreinforced units shall be provided according to published Stone Strong engineering guidance. Reinforced units shall be marked with the type of reinforcement. F. The face pattern shall be selected from the manufacturer’s standard molds. The color of the units shall be natural gray. A concrete stain may be field applied to color the units if specified by the Owner. References A. ASTM - American Society for Testing and Materials (AASHTO - American Association of State and Highway Transportation Officials) B. ASTM C33 - Standard Specification for Concrete Aggregates (AASHTO M43) C. ASTM C39 - Standard Test Method for Compressive Strength of Cylindrical Concrete Specimens (AASHTO T22) D. ASTM C136 - Standard Test Method for Sieve Analysis of Fine and Coarse Aggregate (AASHTO T27) E. ASTM C1776 - Standard Specification for Wet-Cast Precast Modular Retaining Wall Units
