|
(11) | EP 0 480 592 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
|
|
|
|
|||||||||||||||||||||||||||
| (54) | Improvements in or relating to decking profiles for composite floors |
| (57) A profiled castellated metal sheet has secondary features 4 surmounting its flat-topped
areas 3 which run parallel to the castellations and which are upstanding from the
flat-topped areas 3 in use and have a maximum open width of 25 mm. These secondary
features 4 are used to support a mesh when the sheet is used as a decking for a composite
steel/concrete floor, and avoid the need to support the mesh on separately provided
mesh support stools. The use of such a castellated sheet therefore decreases both
the time and cost involved in construction of such composite floors, and also increases
the structural integrity of the floors so formed. |
[0002] Composite flooring utilises profiled steel sheeting which acts as permanent formwork for the concrete slab poured on top. The profiled steel sheeting also combines structurally with the concrete so as to act as positive tensile reinforcement in the cured concrete slab.
[0003] Composite flooring profiles may be trapezoidal, re-entrant (or dovetail) shaped or a combination of these. In standard composite flooring construction a light reinforcing fabric is required which acts as anti-crack mesh and as reinforcement to maintain structural integrity in the slab for a specified period in the case of a fire.
[0004] The mesh reinforcement has to be placed near the top of the concrete slab, in fact a minimum of 15 mm and a maximum of 45 mm from the top of the slab. Standard practice is to place the mesh on wire stools to the correct dimension, which support the mesh at the right height.
[0005] In one aspect this invention consists of a castellated profiled metal sheet, for use in composite concrete/steel floor sections, wherein secondary features are formed in flat-topped areas of the sheet, which features run parallel to the castellations, are upstanding from the flat areas in use and have a maximum open width of 25 mm.
[0006] Preferably the secondary features are of dovetail shape, inverted U-shape or of inverted V-shape in section.
[0008] The secondary features allow a mesh to be supported without the use of stools. The open width maximum of 25 mm is chosen to restrict the upward passage of heat into the concrete slab, in case of fire.
ADVANTAGES
[0010]
1. Cost of support stools is avoided.
2. Labour of placing support stools is avoided.
3. Speed of construction is enhanced.
4. Mesh cannot be dislodged from its position by construction foot traffic etc, as is commonly the case when using support stools.
5. Mesh cannot so easily be deflected downwards by being bent by construction foot traffic etc, as is commonly the case when using support stools.
6. The system thus provides increased economy, speed and reliability.
[0011] In a further aspect the invention consists of a composite concrete/metal floor wherein a profiled metal sheet, as defined above is used to support a mesh which is embedded in concrete.
[0012] The invention will now be further described by reference to the 3 figures of diagramatic drawing (Figures 1-3) which each show a section through a steel sheet according to the invention.
[0013] With reference first to Figure 1, a profiled sheet according to this invention is of generally trapezoidal shape with sloping walls 1 and 2 and a flat top 3. This top is formed with secondary features of dovetail section 4 which runs parallel to the main sheet profile, and is used to support a mesh 5 which acts as a reinforcement when the sheet is used as a decking for a concrete floor. The concrete is poured through the mesh and bonds with the underlying steel profiled sheet. The secondary feature 4 should be not more than 25 mm wide at its open end and should be between 13 and 31 mm in height.
[0014] With reference to Figures 2 and 3, (in which parts are numbered as for figure 1) the same considerations apply except that secondary features 4 are of different geometrical shapes, although they still serve the same purpose (to support the mesh reinforcement). They can be formed in the flat areas of the sheet by rolling or pressing operations.
1. A castellated profiled metal sheet having flat-topped areas (3), characterised
in that secondary features (4) are formed in the flat-topped areas (3) of the sheet,
which features (4) run parallel to the castellations, are upstanding from the flat-topped
areas (3) in use and have a maximum open width of 25 mm.
2. A sheet according to claim 1, characterised in that the secondary features (4)
are substantially of dovetail shape in section.
3. A sheet according to claim 2, characterised in that the dovetail shaped secondary
features (4) have a width which increases in dependence on the distance from the flat-topped
areas (3).
4. A sheet according to claim 1, characterised in that the secondary features (4)
are substantially of inverted-U shape in section.
5. A sheet according to claim 1, characterised in that the secondary features (4)
are substantially of inverted-V shape in section.
6. A sheet according to any preceding claim, characterised in that the height of the
secondary features (4) is between 13 and 31 mm.
7. A sheet according to any preceding claim, characterised in that the secondary features
(4) are open-bottomed where they join the flat-topped areas and the openings at their
bottoms have a constant width along their lengths of not more than 25 mm.
8. A sheet according to any preceding claim, wherein the sheet has a generally trapezoidal
profile.
9. A composite concrete/metal floor wherein a castellated profiled metal sheet having
flat-topped areas (3) is used to support a reinforcement mesh which is embedded in
concrete, characterised in that secondary features (4) are formed in the flat-topped
areas (3) of the sheet, which features (4) run parallel to the castellations, are
upstanding from the flat-topped areas (3) in use and have a maximum open width of
25 mm.