BWP-71 system cross-section of the building: a) building with cantilevered ceilings and a basement, b) building without a basement without supports; 1 — slup, 2 - bolt, 3 - ceiling slab, 4 - roof plate, 5 - sub-wall beam, 6 - wall plate, 7 - ramp plate, 8 - retaining wall, 9 - foot.
The structural system of the multi-storey industrial building is shown in the figure. This drawing shows two sections of buildings, one building with cantilevers and a basement, the second one without supports and without a basement.
The structure of the building is: socket-type ceilings, poles, ceiling and roof bolts as well as ceiling and roof slabs.
In the BWP-71 system, buildings with a height of up to 5 floors with a basement and no basement.
Column grids used (n·6,0×6,0) m; (n·7,5)x6,0 m; (n·9,0) x 6,0 m or (6,0 + 3,0 + 6,0) x 6,0 m; (7,5 + 3,0 + 7,5) x 6,0 m.
Basic- the structural elements of the system are poles, bolts and floor slabs. The reinforcement protruding from the columns is used to connect the columns and transoms in the node. The pillars of the ground floor and cellars are set in the chalices of the foundation footings.
Rigid knots are obtained by filling with concrete the space between the transoms on the mullion and the space between the boards on the transom. Due to the monolithic connection of prefabricated elements, frames with rigid nodes are obtained, oriented in the transverse direction of the building. The longitudinal stiffness of the building is achieved by making monolithic longitudinal ribs between the plates in the axis of the columns.
External walls can be made of reinforced concrete slabs with an insulating layer or of aerated concrete slabs.
Figure d shows the detail of the connection of the external wall with the column and the ceiling.
Connections of columns with transoms and floor slabs: a) vertical section, b) actionometry, c) bolt bracket, d) view of the connection between the wall and the column; 1 - bolt, 2 - pole, 3 - a half-timbered floor slab, 4 — nadbeton, — 5 - bars protruding from the transoms and mullions, 6 - bars protruding from the plate, 7 - stirrups protruding from the bolt, 8 - reinforcement of a monolithic bracket, 9 - extreme pole, 10 - a cover plate anchored in the column.
In the BWP-71 system, the possibility of making transoms is also provided (substrings) monolithic concrete blocks concreted on site. Steel forms of bolts can be used for production, which are attached to prefabricated poles. Most of the columns are made with a fixed cross-section without cantilevers. The reinforcement protruding from the column merges with the reinforcement of the rafter (substring), and after concreting, a rigid frame node is obtained.
After the concrete is sufficiently strong, the steel forms of the bolt are transferred to another storey.
The principle of using assembly transoms as steel forms is widespread in all types of construction.