Abstract: A sectional smokestack wherein each section is assembled from multiple precast concrete segments having aligned vertical ribs. The sections are stacked axially one upon the other during erection of the smokestack. Concentrated reinforcement extends vertically through aligned apertures in each rib from the bottom of the smokestack to the top of the smokestack. Each of the segments which are used to assemble a section have structural tie rods which extend laterally within a segment and extend into the aperture on opposite sides of the concentrated reinforcement to transfer wind loads and heat stress loads to the concentrated reinforcement.

Abstract: A high, self-supporting smokestack or tower having a structure constructed by stacking precast reinforced concrete sections one upon the other, the cross-sectional area of the structure being larger at the bottom than at the top and concentrated reinforcement being provided along the length of the structure to bear the horizontal forces acting upon the smokestack or tower. The structure exhibits ribs provided with concentrated reinforcement and extending longitudinally on the outside of the structure at least along its lower portion, the radial extent of these ribs increasing from the top to the bottom at least so as to correspond essentially to the bending moment progression resulting from the horizontal stress. A mould device for producing precast reinforced concrete parts for such smokestacks or towers, in which mould sections are provided which are radially adjustable for fashioning the front surfaces of the ribs.

Abstract: A dual wall concrete smokestack having a freestanding flue liner in each flue. The smokestack being constructed of preassembled and precast concrete sections axially stacked one upon the other. The preassembled sections have a precast concrete body having a flue aperture. An inner flue liner is carried within the flue aperture spaced inwardly and concentrically from the wall of the flue aperture. The wall of the flue aperture further having a flue liner stop means. The inner flue liner having a bracket for engaging the flue liner stop means to prevent the flue liner from dropping downwardly and out of the concrete body when being transported to the site of construction. The concrete body further having another aperture to be aligned with a corresponding aperture of an adjacent section for receiving reinforcing rods extending from the bottom of the smokestack to the top of the smokestack and for receiving poured concrete as the smokestack is being erected to tie the sections together.