In many ceiling solutions, prefabricated composite slabs are used as the load-bearing formwork element for the composite – monolithic – ceiling structure. Standard composite (non-stressed) slabs are produced with a thickness of 7 to 8 cm of a prefabricated slab and a span of up to approx. 9 m. Such ceilings require additional support from a certain span (determined by the statics of the object) during assembly and during the maturation of the filling concrete. When using pre-stressed composite slabs, the thickness of the prefabricated element exceeds 10 cm, and the spans of these slabs reach up to 12 m. For most pre-stressed prefabricated slabs, assembly support is not provided as it is for unstressed elements.

 

Different types of cross-sections

Hybrid beam in combination with a single-span monolithic floor on prefabricated slabs

 

Hybrid beam with the continuing of the reinforcement of the concrete topping embedded in the side surface of the beam

 

Hybrid beam in a multi-span slab floor

 

Hybrid beam protruding above the upper edge of the floor

 

Raised support of a prefabricated panel

 

Suspended support of a prefabricated slab for composite floors

 

1 – hybrid beam
2 – composite reinforced concrete or pre-stressed slab
3 – reinforcement connecting the beam and ceiling
4 – concrete topping
5 – possible execution of the front plate of the floor slabs with a choice of h = -15 mm for the so-called hidden slab support
6 – reinforcement screwed in (or bent) at the construction site to be pulled down with top reinforcement of concrete topping
7 – concrete topping top bars built into the construction site
8 – integrating reinforcement with concrete topping embedded in the beam
9 – elevation of the hybrid beam above the upper edge of the floor slab
10 – concrete of longitudinal raised support for hollow-core slab