Patent Application
20240183153
The present invention relates to the field of construction, and more specifically relates to the elaboration of a floor deck structure and of a composite floor deck. The present invention also relates to a process for assembling such a floor deck structure and such a composite floor deck.
Composite floor decks are well known in the field of construction, and they typically comprise a corrugated/profiled metallic sheet, a wire mesh and concrete encompassing the wire mesh and fastened to the profiled metallic sheet by chemical bonding and/or mechanical or frictional interlocking.
The composite floor decks are particularly interesting because the metallic sheet acts as a working platform before concrete pouring and, after concrete hardening, gets incorporated into the concrete slab, working as full or part of tension reinforcement of the slab. As such, the composite floor decks reduce the amount of propping during concrete pouring.
The floor deck resistance depends on the height of the corrugations, and the higher the corrugations are, the more resistant the deck is. However, in some circumstances, the height of the deck has to be limited due to construction specific needs/requirements/National Standards. For example, there are locations where decks are limited in height to 75 mm, limiting their use to short spans. This leads to a limited composite floor deck resistance and span and the deck needs to be propped up during the concrete pouring phase.
It is an aim of the present invention to remedy the drawbacks of the prior art by providing a floor deck structure and a composite floor deck which can reach sufficient spans without the need for propping up.
The present invention also provides a process for assembling the floor deck structure and the composite floor deck of the invention.
For this purpose, a first object of the present invention consists of a floor deck structure, comprising:
The floor deck structure according to the invention may also have the optional features listed below, considered individually or in combination:
A second object of the invention consists of a composite floor deck, comprising:
A third object of the invention consists of a process for assembling a floor deck structure, wherein the process comprises at least the following steps:
A fourth object of the invention consists of a process for assembling a composite floor deck, wherein the process comprises at least the following steps:
Other characteristics and advantages of the invention will be described in greater detail in the following description.
The invention will be better understood by reading the following description, which is provided purely for purposes of explanation and is in no way intended to be restrictive, with reference to:
It should be noted that the terms “lower”, “upper”, “above”, “bottom” . . . as used in this application refer to the positions and orientations of the different parts of the floor deck structure and composite floor deck when they are lying down on the ground. The terms “substantially perpendicularly” define an angle of 90°+/−15° and the terms “substantially parallel” define an angle of 0°+/−15°.
The invention relates to a floor deck structure 1. According to
This profiled metallic sheet 2 comprises a plurality of upper portions 7 separated by a plurality of grooves 3, thus forming a corrugated metallic sheet. As an example and as depicted in
Further in the description, the combination formed by an upper portion 7 and the two opposite lateral walls 13, 14 linked to said upper portion 7 will be further called a longitudinal element 6.
The distance H between the base 5 of any groove 3 and the adjacent upper portion 7, which will be further called groove height H, is for example and preferentially comprised between 30 millimeters and 80 millimeters. Preferably, the ratio of the distance between the first and the second lateral walls 13, 14 of a groove 5, further called width of the base 5, to the groove height H is lower than 5 and is more preferably comprised between 0.5 and 3.5. In addition, the ratio of the width & of the profiled metallic sheet 2 to the groove height H is preferably lower than 25 and more preferably comprised between 10 and 20, said width & of the profiled metallic sheet being its transverse dimension. Typically, the width & of the profiled metallic sheet 2 is comprised between 0.5 meters and 1.5 meters, preferentially around 0.75 meters. Thanks to these ratios, the rigidity of the profiled metallic sheet and thus the resistance of the composite floor deck is further increased.
Advantageously and in order to further improve the rigidity of the profiled metallic sheet 2, said profiled metallic sheet may comprise additional stiffeners 15 arranged in the base 5 of the principal grooves 3 of the metallic sheet 2, and optionally along the lateral walls 13, 14 and along the upper portions 7. These stiffeners are preferably in the form of longitudinal ribs. Their height is small compared to the groove height H and the ratio of the groove height H to the stiffener height is preferably above 4 and more preferably between 5 and 100.
Regarding
Finally, the profiled metallic sheet 2 may comprise one or several longitudinal plates, each plate comprising a longitudinal side that is fastened to the base 5 of the corresponding groove 3 and extending substantially perpendicularly to said base 5. The plates enhance the mechanical resistance of the floor deck structure 1 and improve the interlocking of the profiled metallic sheet with concrete.
The profiled metallic sheet 2 may have different transverse shapes, as depicted in
According to
The profiled metallic sheet 2 may have a transverse shape that is not depicted in the figures and still stays within the scope of the invention. As an example, each longitudinal element 6 may be cylindrical with an opened circular transverse shape.
Generally speaking, the profiled metallic sheet 2 has a unique transverse shape.
Regarding
The number of rebar trusses 10 can be adjusted depending on the desired mechanical resistance of the composite deck 11. According to a preferred embodiment, a rebar truss 10 extends in each and every groove 3. According to another embodiment, rebar trusses 10 extend in every other groove 3. According to another preferred embodiment, the rebar trusses extend at least over the entire length of the profiled metallic sheet. They can extend over the length of the profiled metallic sheet. Alternatively, they can extend over several profiled metallic sheets or over internal supports of the building. This further improves the strength and stiffness of the composite floor deck.
Typically, each rebar truss 10 comprises a plurality of substantially parallel metallic rebars 10a, 10b, 10c, typically a first 10a, a second 10b and a third metallic rebar 10c. The first and the second longitudinal rebars 10a, 10b are assembled with a first corrugated rod 17, while the first 10a and the third longitudinal rebars 10c are assembled with a second corrugated rod 17 having a periodic triangular pattern, so that the rebar truss 10 has a triangular transverse shape. Other shapes of rebar trusses are possible as long as the base of the rebar truss is designed so that it can be connected to the connector and as long as its upper part can be embedded in concrete. An example of other shape is a rebar truss having four longitudinal rebars and a rectangular transverse shape. More preferably the shape of the rebar truss is such that some parts of it can block the relative movement of the rebar truss with respect to the connectors described below.
Regarding
Overall, each connector 9a, 9b comprises fastening means to the profiled metallic sheet 2 and fastening means to the rebar truss 10.
In a first embodiment depicted in
The edges 20 are designed so that they form fastening means to the profiled metallic sheet 2. In particular, the edges at least partially match the shape of the groove 3 in which the connector 9a is inserted. More precisely, while the connector 9a is located inside the groove 3, with its lower face above the base 5 of the groove 3, the external face 25 of each edge 20 is in contact with the considered lateral wall 13, 14 of the groove 3 and thus matches the shape of said lateral wall 13, 14. The external face 25 of each edge 20 is thus curved. Thanks to this design and in combination with a re-entrant transverse shape of the profiled metallic sheet 2, the connector 9a is maintained in place along the Z axis (vertical) and Y axis (transversal). Consequently, the profiled metallic sheet 2 and the connector 9a form an assembly and one piece will not move relative to the other along the Y and Z axes during the use of the composite deck floor 11. In this embodiment, the external faces 25 of the edges 20 of each connector 9a are pressed against the considered lateral walls 13, 14 of the grooves 3. The rebar trusses 10 are thus fastened to the considered grooves 3 of the profiled metallic sheet 2 thanks to the connectors 9a.
The connector 9a is preferably unmovingly fastened to the profiled metallic sheet. By “unmovingly fastened”, it is meant that a first piece cannot move with respect to a second piece in any direction. In particular, the connector cannot move with respect to the profiled metallic sheet in any direction. In other words, an unmoving fastening prevents the relative movement of the connector with respect to the profiled metallic sheet. Accordingly, the connector 9a can further comprise means for unmovingly fastening the connector to the profiled metallic sheet. These means for unmovingly fastening can comprise holes in the connector, through which fastening means, such as screws or bolts, can be inserted so that the connector is screwed or bolted to the profiled metallic sheet. Alternatively, the connector 9a can be welded to the profiled metallic sheet to prevent its relative movement with respect to the profiled metallic sheet. Any other type of bonding is also possible.
Similarly, the rebar trusses are preferably unmovingly fastened to the connectors. In that case, the rebar trusses cannot move with respect to the connectors in any direction. In other words, the unmoving fastening prevents the relative movement of the rebar trusses with respect to the connectors. Accordingly, some parts of the rebar truss can block the relative movement of the rebar truss with respect to the connectors, and thus with respect to the profiled metallic sheet. In the example of
In a second embodiment depicted in
The connector 9b also comprises two opposite lateral notches 21b respectively managed in each lateral extremity of the main body 19b, said notches 21b forming fastening means to the rebar trusses 10. More precisely, the shape of each notch 21b matches the cross-sectional shape of one of the metallic rebar 10b, 10c of the rebar truss 10.
The second and third metallic rebars 10b, 10c of the rebar truss 10 are thus located inside the opposite notches 21b of said connector 9b.
The edges 20b are thus designed so that they form fastening means to the profiled metallic sheet 2. In particular, while the connector 9b is located inside the groove 3, with its lower edge 23 above the base 5 of the groove 3, the external face of each leg 24 is in contact with the considered lateral wall 13, 14 of the groove 3 and thus matches the shape of said lateral wall 13, 14. In particular, the external face of each leg 24 forms an acute angle with the lower edge 23 of the connector 9b. Thanks to this design and in combination with a re-entrant transverse shape of the profiled metallic sheet 2, the connector 9b is maintained in place along the Y and Z axes.
Consequently, the profiled metallic sheet 2 and the connector 9b form an assembly and one piece will not move relative to the other along the Y and Z axes during the use of the composite deck floor 11. In this embodiment, the external faces of the legs 24 of each connector 9b are pressed against the considered lateral walls 13, 14 of the grooves 3. The rebar trusses 10 are thus fastened to the considered grooves 3 of the profiled metallic sheet 2 thanks to the connectors 9b.
The connector 9b is preferably unmovingly fastened to the profiled metallic sheet. Accordingly, the connector 9b can further comprise means for unmovingly fastening the connector to the profiled metallic sheet. These means for unmovingly fastening can comprise holes in the connector, in particular in the legs 24, through which fastening means, such as screws or bolts, can be inserted so that the connector is screwed or bolted to the profiled metallic sheet. Alternatively, the connector 9b can be welded to the profiled metallic sheet to prevent its relative movement with respect to the profiled metallic sheet. Any other type of bonding is also possible.
Similarly, the rebar trusses are preferably unmovingly fastened to the connectors, as described above with reference to the first embodiment of the connectors.
Other shapes of connectors are possible as long as part of the connector is designed for, and capable of, fastening the connector to the profiled metallic sheet 2 and as long as part of the connector is designed, and capable of, fastening the rebar truss 10 to the connector. In particular, other shapes of connectors designed for, and capable of, preventing the relative movement of the connector with respect to the profiled metallic sheet are possible. Also, other shapes of connectors designed for, and capable of, preventing the relative movement of the connector with respect to the rebar truss are possible.
Overall, the connectors are preferably fastening the rebar trusses to the profiled metallic sheet so that the relative movement of the rebar trusses with respect to the profiled metallic sheet is prevented. It has been observed by the inventors that the unmoving fastening of the rebar trusses on the profiled metallic sheet significantly improves the performances of the composite floor deck. This unmoving fastening provides a full shear connection, which increases the bending resistance (strength) and the displacements under serviceability (stiffness), which allows for larger unpropped spans.
A process for assembling a floor deck structure 1 according to the invention will now be described.
In a first step, it is provided a profiled corrugated metallic sheet 2 comprising at least a first, a second and a third upper portion 7 separated by a first and a second longitudinal groove 3 comprising a base 5, a first lateral wall 13 linking the base 5 to one of the upper portions and a second lateral wall 14 linking the base 5 to an adjacent upper portion 7. In the example illustrated on
In a second step, at least a first and a second rebar truss 10 as described above are provided. In a third step, they are respectively positioned in and/or above at least the first and second longitudinal grooves 3.
In a fourth step, the first and second rebar trusses are fastened to the profiled metallic sheet using connectors 9a, 9b.
According to one variant of the invention, in-between the first and second steps, a plurality of connectors 9a, 9b are provided and fastened to the profiled metallic sheet. In particular, they are inserted inside the first and second grooves 3, in particular above the bases 5 of said grooves 3. If the connectors 9a are those depicted in
According to this variant, the fourth step consists in fastening the first and the second rebar trusses to the connectors. In particular it consists in inserting the rebar truss 10 in the notches 21a, 21b of each connector 9a, 9b. In particular, two metallic rebars 10b, 10c of each rebar truss 10 are respectively inserted in the opposite notches 21a, 21b of each connector 9a, 9b, in order to fasten said rebar truss 10 to the profiled metallic sheet 2. Preferably, the rebar trusses are unmovingly fastened to the connectors. As described above, it can be done notably by positioning some nodes of the rebar truss in contact with a connector so that the relative movement of the rebar truss with respect to the connectors is prevented. This further improves the strength and stiffness of the composite floor deck.
According to another variant of the invention, the fourth step comprises providing a plurality of connectors 9a, 9b and inserting them between the rebar truss 10 and the profiled metallic sheet 2. Once inserted, they are fastened both to the profiled metallic sheet 2 and to a rebar truss 10. Preferably, they are unmovingly fastened both to the profiled metallic sheet 2 and to a rebar truss 10.
Once the rebar trusses 10 are all fastened to the corresponding connectors 9a, 9b, the floor deck structure 1 is assembled.
Optionally when the metallic sheet 2 comprises longitudinal plates, additional metallic rods (not depicted) may be provided and transversally inserted through openings arranged in said plates. Those additional metallic rods enhance the mechanical resistance of the floor deck structure 1.
Regarding
According to one variant of the invention, the floor deck structure 1 and concrete are assembled on site during building construction to form the composite floor deck 11.
In another variant of the invention, the floor deck structure 1 and concrete are pre-assembled, for instance in a shop, and then transported in anticipation of future work.
The floor deck structure 1 and corresponding composite floor deck 11 of the invention are of particular interest in the field of construction for several reasons.
Firstly, the assembling of the profiled metallic sheet 2, the rebar trusses 10 fastened to the metallic sheet 2 thanks to connectors 9a, 9b, and the concrete structure 12 embedding the rebar trusses 10 and anchored to the metallic sheet provides a composite floor deck 11 that offers good resistance capabilities in tension (due to the metallic sheet 2 and to the rebar trusses 10) and in compression (due to reinforced concrete structure 12).
Secondly, the composite floor deck 11 remains thin. This means it can be used with respect to most building regulations.
Thirdly, the association of the profiled metallic sheet 2, the rebar trusses 10 and the connectors 9a, 9b increases the self-supporting capabilities of the floor deck structure 1. In other words, during assembling on site, the floor deck structure 1 do not need to be propped up as much as the corresponding profiled metallic sheet alone.
More precisely, floor deck structures 1 and profiled metallic sheets 2 of different span have been tested: two meters, four meters and six meters. The graph shows six curves illustrating deflection in millimeters of the structure 1/sheet 2 measured at midspan versus deflection pressure applied in Kilonewtons. To sum up:
It appears that when rebar trusses 10 are connected to the profiled metallic sheet 2 in order to form the floor deck structure 1, the deflection 8 is lesser. In other words, deflection 8 is higher for the profiled metallic sheet 2 alone than for the floor deck structure 1.
The gain in stiffness is calculated for each span L by dividing the stiffness of the floor deck structure 1 by the stiffness of the profiled metallic sheet 2 of same length, and by subtracting 1 to the result. It appears that the gain is:
Those results show that the presence of rebar trusses 10 increases stiffness compared to the profiled metallic sheet 2 alone. In addition, resistance loads are always higher for the floor deck structure 1 than for the profiled metallic sheet 2 alone. It also appears that the floor deck structure 1 is less deformable that the profiled metallic sheet 2 alone having same span L.
The deflection calculation took into account dead loads arisen from the profiled metallic sheet, wet concrete and rebar trusses, which represented 1.20 KN/m of applied load. The connectors were reproduced as rigid elements linking the rebar trusses to the profiled metallic sheet. In model A, they were only transferring vertical forces while, in model B, they were also transferring the shear stress (longitudinal forces).
The maximum unpropped span was calculating knowing that the maximum deflection in serviceability had to respect the following limit, where L is the slab span in millimeters:
Results show that the maximum serviceability limit of 20 mm is obtained in model B with a maximum unpropped span of 4800 mm whereas it is obtained in model A with a maximum unpropped span of 4000 mm. By preventing the longitudinal relative movement of the rebar trusses with respect to the profiled metallic sheet, unpropped spans can be increased by 20%.
| Number | Date | Country | Kind |
|---|---|---|---|
| PCT/IB2021/052830 | Apr 2021 | WO | international |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/IB2022/053205 | 4/6/2022 | WO |
