Element slabs (also referred to as filigree slabs or semi-prefabricated slabs) are reinforced concrete slabs consisting of precast elements that are supplemented with an additional layer of in-situ concrete as concrete. The prefabricated elements, which are about 5 cm thick and span the room, are used as formwork during the paving process and, together with the concrete layer, contribute statically to the overall cross-section after hardening. The necessary tensile and composite reinforcement has already been concreted into the prefabricated elements. The upper reinforcement is placed on site. The concrete layer is connected to the prefabricated element by means of lattice girders protruding upwards from the precast element and a roughened concrete surface.
During the installation of the concrete until it hardens, the slab is supported by yokes and formwork girders. On exposed sides, formwork must be provided for the concrete layer. Due to the smooth soffit, the ceiling does not have to be plastered, joints are filled. In addition to the most common form as flat slabs, prefabricated slabs can also be produced in the form of ribbed or coffered ceilings with a concrete layer. Prefabricated slabs are generally slackly reinforced, prestressed prefabricated slabs must be regulated in Germany by a general building authority approval in accordance with DIN EN 1992-1-1/NA.
Source: bauwion
