WO2022154671A1

WO2022154671A1 - A building element of prefabricated concrete

Info

Publication number: WO2022154671A1
Application number: PCT/NO2022/050011
Authority: WO
Inventors: Ole Gunnar Selvaag
Original assignee: Ogs Seed As
Priority date: 2021-01-12
Filing date: 2022-01-12
Publication date: 2022-07-21

Abstract

A building element of prefabricated concrete (1) comprises a rectangular, elongated top plate (2) with ribs (3, 4) on the underside for forming part of a floor or roof of a building alongside at least one similar building element (1). One (4) of the ribs extends along one longitudinal edge (5) of the top plate, a part (8) of the rib (4) projecting laterally outside the plate (2), while the other longitudinal edge (6) is without a rib and, in use, is to be supported by the laterally projecting part ((8) of a similar adjacent building element (1).

Description

A BUILDING ELEMENT OF PREFABRICATED CONCRETE

The present invention relates to a building element of prefabricated concrete. Concrete floor and ceiling elements with ribs are often produced as double T- beams. The disadvantages of these are that the longitudinal joints between the elements become visible and difficult to fit together due to different deflection and inaccurate execution. This is more so since in the construction industry, the dimensional tolerances varie. These elements must be support at each end by longitudinal joists, which in turn are supported by columns. In addition, the T- beams must have ribs that are relatively close to each other because the lateral rigidity against twisting in the thin top plate is limited.

The present invention aims at alleviating these disadvantages. This is obtained according to the invention by a building element and floor as defined in the claims.

For better understanding of the invention, it is described in the following with reference to the appended drawings, in which

Figure 1 is a perspective top view of a building element according to a first exemplifying embodiment of the invention;

Figurer 2 is a perspective view of the opposite side of the element in Figure 1;

Figure 3 is a view like Figure 1 of a building element according to a second exemplifying embodiment of the invention;

Figure 4 is a plan view of two adjacent building elements of the embodiment shown in Figure 3; and

Figure 5 is a section along line V-V in Figure 4.

Figures 1 and 2 show a building element 1 having a top plate 2, a central longitudinal rib 3 underneath the top plate, and a peripheral rib 4 extending longitudinally along one edge 5 of the top plate 2. The opposite edge portion 6 is without a rib. Transverse ribs 7 extend along the short sides of the element 1. The peripheral rib 4 has a laterally extending part 8 forming a ledge 9 for support of said opposite edge portion 6 of an adjacent building element 1 when in use. The transverse ribs 7 that transfer the load from the element 1 to underlying supports, are strong enough to avoid the usual joist and rest directly on the column. Another way of reducing the vertical dimension of the structure would be to leave out the transverse ribs and the end portions of the ribs 3, 4, so that the plate 2 can rest directly on the joists with its rib-free end portions.

Figure 3 shows a building element 10 like the one in Figure 1 but with symmetrical recesses 11 in the longitudinal edge portion 6 and ledge 9. When two elements 10 are joined to form part of a floor as shown in Figure 4, the recesses 11 form chambers 12 for dowels (not shown). The dowels will provide a mutual shear function so that the elements 10 will function as a complete slab and not slide with respect to each other. This lets the slab transfer lateral forces, e.g. wind forces, to structural walls of the building. Furthermore, the doweling avoids the creep and shrinkage often experienced in joints filled with mortar.

Figure 5 shows a section V-V in Figure 4 with the chamber 12 and a joint 13 between the elements. Evidently, the rib 4 prevents the joint 13 from being seen from below and reduces the impression of any difference in height between the elements. Any suitable material may be used for the dowels, or they may simply be provided by filling the chamber (12) with joint mortar or other castable material.

It will be understood that the invention is not limited to the exemplifying embodiments described in the above but may be varied and modified by the skilled person within the scope of the following claims and equivalents thereof.

Claims

1. A building element of prefabricated concrete (1), comprising a rectangular, elongated top plate (2) with ribs (3, 4) on the underside, for forming part of a floor or roof of a building alongside at least one similar building element (1), characterized in that one (4) of the ribs extends along one longitudinal edge of the top plate, a part (8) of the rib (4) projecting laterally outside the plate (2), while the other longitudinal edge (6) is without a rib and, in use, is to be supported by the laterally projecting part ((8) of a similar adjacent building element (1).

2. A building element according to claim 1, wherein at least one short side edge of the top plate (2) is provided with a rib (7).

3. A building element according to claim 1 or 2, wherein the longitudinal edges of the plate are provided with symmetrical recesses (11) for forming chambers (12) with adjacent building elements (1) for receiving dowels for preventing longitudinal movement in use between the adjacent building elements.

4. A floor of a building comprising a plurality of building elements (1) according to any one of the preceding claims.

5. A floor according to claim 4, wherein the chambers (12) for the dowels are filled with castable material.