Locally owned since 1996, S.B. Cox Ready Mix supplies Virginia with high-quality ready mix concrete and aggregate materials to customers in the Richmond metro area and surrounding counties for over 29 years. Our concrete plants are VDOT and NRMCA certified and our ACI-certified technicians are available to ensure the highest level of quality control from start to finish. S.B. Cox Ready Mix has nine ready mix plants in Virginia including Goochland-Rockville, Sandston, Powhatan, Doswell, Blackstone, Meherrin, Smithfield, Chesapeake, and Gloucester. S.B. Cox Ready Mix has four stone yards located in Goochland-Rockville, Sandston, Smithfield and Gloucester, open to the public stocked with stone, sand, mulch, and more. When Performance Counts.