This Design Specification provides material, design, and construction requirements for concrete silos, stave silos, and stacking tubes for storing granular materials, including design and construction requirements for cast-in-place or precast and conventionally reinforced or post-tensioned silos.Silos and stacking tubes require design considerations not encountered in building structures. While this Design Specification refers to ACI 318 for several requirements, static and dynamic loading from funnel, mass, concentric, and asymmetric flow in silos; special loadings on stacking tubes; and seismic and hopper bottom design are also included.