Advanced mechanical connection system for mixed floor, allowing quick assembly and disassembly of the mixed floor and reuse of its components, and corresponding mixed floor

Abstract

The invention relates to a mechanical connection system (1) for linking at least one concrete slab (D) to a steel beam, which system (1) comprises at least one connector body (C) including a smooth rod (2) having a proximal end intended to be fixed to the beam, a free distal end (2b), and a female coupling part (20) opening at least at the free distal end (2b), and, for each of the at least one connector body (C), a removable connector head (4, 5, 6) comprising a sealed housing part (4) including a housing body (40), a base (41) and a removable cover (42) delimiting a sealed compartment, and a male coupling part (5) adapted to be housed in the sealed compartment and to pass through an opening (410) in the base (41), the male coupling part (5) being configured to be coupled in the female coupling part (20).The invention also relates to a composite floor in which at least one concrete slab (D) is joined to at least one steel beam using this connection system (1).

Description

[0001] The present invention relates to the field of composite floors, and in particular to a mechanical connection system for linking a prefabricated concrete slab to a steel beam in a way that allows for easy and quick assembly and disassembly, as well as at least reuse of the slabs and dry production for greater respect for the environment, and to a composite floor using this connection system.

[0002] A composite floor consists of several concrete slabs resting on steel beams of a metal frame.

[0003] In order to guarantee the quality of the composite floor and reduce installation time and costs, it has been proposed to use prefabricated slabs that are joined on-site to the beams by a continuous keying system using grout. This system fills a cavity defined by the edges of two adjacent slabs and contains dowel-type connectors attached to the respective beam. The German utility model DE 20 2007 005 523 U1 can be cited as an example of such a solution.

[0004] However, this keying is permanent and it is not possible to reuse the slabs and structural elements.

[0005] As part of a general trend towards greater respect for the environment in the field of construction, solutions enabling the dismantling of composite floors for the purpose of reusing / recycling the slabs have been sought.

[0006] The invention that is the subject of international application PCT WO 2016 / 135512 A1 aims to provide a solution allowing the dismantling of a composite floor, while ensuring a connection allowing the transfer of longitudinal shear forces between the slab and the beam, preventing the lifting of the slab and reducing the slippage between the slab and the beam.

[0007] This solution consists of a composite floor comprising: at least one steel beam from the top surface of which extend several stud-type connectors, namely longitudinal connectors, threaded or unthreaded; at least one concrete slab comprising several through-recesses in the shape of a truncated pyramid with a rectangular base, tapering from the top surface to the bottom surface, the slab or each slab being positioned relative to the at least one beam such that at least one connector extends into the recess or each recess;several intermediate pieces called "plugs", truncated conical, made of concrete, each comprising a through hole extending along its axis, each plug being received in a recess and configured to bear against the upper surface of the beam with a connector extending into the through hole and projecting out of it at the top, the diameter of the through hole being greater than that of the connector so as to leave a space between them; several fixing devices each coupled by screwing to the upper end region of a connector, projecting from a plug, so as to prevent the plug from being removed from the recess and to apply a prestress to the plug against the beam;and sealing concrete which fills the free space in each recess, as well as the space between the through hole and the connector, by which the slab is secured to the beam through the keying by the sealing concrete and the connection system composed of connectors, plugs and fasteners. ;

[0008] According to this invention, the assembly of the composite floor would be easy and quick, since the steel beams, concrete slabs and plugs can be prefabricated.

[0009] Dismantling would also be easy, since the plugs can be removed simply by loosening or breaking the fasteners, and possibly destroying the sealing concrete, allowing the steel beams and slab to be separated cleanly.

[0010] To facilitate the separation of the plugs from the sealing concrete, it is also proposed to surround each plug with a similarly truncated conical sleeve made of a detachment material, for example a polymer material, the sleeve having the sole function of preventing direct contact between the fixing block and the sealing concrete.

[0011] The push-out test results are reported in application WO 2016 / 135512 A1, which show an improvement in mechanical performance compared to the theoretical values ​​for a connection by welded studs with equivalent diameter heads.

[0012] One explanation is that the prestressing applied by the fasteners on the plugs against the beam produces a frictional force between the lower surfaces of the plugs and the upper surface of the beam. This frictional force must be overcome before the slab and beam begin to slide relative to each other; in other words, sliding is delayed until a higher load is reached. At higher loads, shear strength would result from a combination of this frictional force and a dowel effect between the connectors and the concrete plugs.

[0013] In order to achieve these improved mechanical performances, the plugs were made using very high performance concrete, notably having a compressive strength of 73.87 MPa, in order to increase the load required to initiate local deformation of the plug concrete by the connector.

[0014] These improved mechanical performances can also be attributed, in part, to the presence of a countersink at the exit of the hole through the beam flange, through which the connector passes, a countersink which will be filled with sealing concrete, which would force the connector to deform along a double plastic hinge, thus increasing the energy absorbed.

[0015] Thus, the solution according to request WO 2016 / 135512 appears satisfactory in that it effectively allows at least the dismantling of the slab and its reuse.

[0016] However, the gain provided by this connection system to the shear strength of the connector appears rather modest, on the order of 20%, which assumes the use of a connector made of a high-performance material, even though high-performance concrete is used for the plug.

[0017] The present invention therefore aims to provide a demountable connection system, the assembly and disassembly of which are very quick and easy, which allows reuse of the slabs and most of the connection components, and whose design leads to a greater contribution in terms of shear resistance of the connector, in order to allow the use of less efficient materials while meeting regulatory requirements in terms of strength and ductility.

[0018] The present invention therefore relates to a mechanical connection system for linking at least one prefabricated concrete slab to a steel beam, the slab or slabs having at least one recess through their thickness and whose cross-section gradually decreases from the upper surface of the slab to its lower surface, by which the slab rests on an upper surface of the beam, the connection system comprising, for each of the at least one recess, at least one connector body intended to be fixed to the upper surface of the beam and to extend into the respective recess from the upper surface of the beam, characterized in that the connector body or bodies comprise a smooth rod having a proximal end intended to be fixed to the beam and a free distal end opposite the proximal end, the rod having a female coupling portion opening at least at the free distal end,the connection system further comprising, for each of at least one connector body, a removable connector head, the connector head(s) comprising a watertight housing portion having a housing body, a base and a removable cover delimiting a watertight compartment, and a male coupling portion suitable for being housed in the watertight compartment and passing through an opening in the base, the male coupling portion being configured to be coupled to the female coupling portion in order to fix the watertight housing portion to the respective stem, with the base of the housing portion opposite the free distal end of the stem.

[0019] Such a sealed housing part allows, in use, to hide and protect the male coupling part when pouring a filling material into the recess, and thus to fill the recess with filling material in order to obtain a very good quality of keying, while allowing access to the male coupling part for disassembly.

[0020] The case body and the base can be formed as a single piece.

[0021] The case body, base and lid may have a circular cross-section.

[0022] Advantageously, the cover is of the capping type and comprises a top wall and a side wall, the internal diameter of the side wall of the cover corresponding to the external diameter of the peripheral skirt of the housing body.

[0023] The smooth rod may have a straight cylindrical cross-section.

[0024] In one particular embodiment, the female coupling part is a tapped axial bore, and the male coupling part is a screw having a head with a diameter larger than the bore and adapted to be received in the sealed compartment, and a screw shank adapted to pass through the opening in the bottom and whose thread is adapted to cooperate with the tapped axial bore. Thus, the assembly of the connector head and the connector body is easy and quick, requiring only a simple screwing operation.

[0025] Advantageously, the screw head is a hexagonal head with a slotted recess.

[0026] Advantageously, the smooth rod and the screw are made of steel, in particular galvanized mild steel.

[0027] Advantageously, the waterproof casing part is made of plastic, in particular by plastic injection.

[0028] Preferably, the axially tapped bore is a blind bore whose bottom is configured to cooperate with the free end of the screw shank.

[0029] Preferably, the connector head or heads further comprise a washer suitable for being arranged between the underside of the screw head and the free distal end of the smooth shank and around the screw shank.

[0030] The washer can be fitted into the compartment and extend between the underside of the screw head and the bottom of the housing around the screw shank. Thus, in use, the washer bears against the free distal end of the smooth shank.

[0031] Advantageously, the washer is an annular washer whose outer diameter corresponds to the inner diameter of the peripheral skirt of the housing body.

[0032] Alternatively, said washer may equally be suitable for placement between the lower face of the bottom of the housing part and the free distal end of the smooth rod and around the screw rod, the diameter of said washer being greater than the diameter of said bottom.

[0033] In a particular embodiment, the system further comprises, for each connector head, a pull-out demolding aid element adapted to pass through a passage provided in the housing body such that a so-called gripping section of the element is housed within the sealed compartment and a so-called protruding section extends out of the housing portion into the respective recess. Such a pull-out demolding aid element allows the block of filling material to be easily demolded from the recess by simply pulling on the gripping section accessible in the housing.

[0034] The pull-type release aid can be, for example, a loop of cable or wire. In particular, for cost reasons, a rigid, bent steel wire may advantageously be the pull-type release aid.

[0035] In a particular alternative embodiment, the system further comprises, for each connector body, a pressure-release element suitable for placement around the smooth rod in its proximal end region and for covering the upper surface of the beam within a respective recess. This element is adapted to define a cavity suitable for filling with an expanding material. Such a pressure-release element allows for easy removal of the filling material block from the recess by simply filling the cavity with an expanding material.

[0036] The pressure demolding aid element may include a hollow piece internally delimiting the cavity and equipped with a pouring chimney opening, at one end, into the cavity and, at the other end, above the reservation.

[0037] Advantageously, the said hollow piece also includes a vent chimney opening, at one end, into the cavity and, at the other end, above the reservation.

[0038] The hollow part can be a thermoplastic part, molded by injection or by injection-blowing.

[0039] Alternatively, the pressure demolding aid element may include a solid part complementary to the cavity to be delimited and capable of being dissolved, and equipped with a pouring chimney, and possibly a vent chimney.

[0040] Advantageously, for economic reasons, the solid part is made of polystyrene. It should be understood that the solid part could be made of any other very low-density material.

[0041] Preferably, the pressure release aid also includes a metal ring, in particular a steel ring, suitable for placement around the cavity. The placement of such a ring prevents the slab from cracking when the block of filling material is removed from the cavity.

[0042] Preferably, the system further includes, for each connector body, a sleeve-forming tube suitable for placement around the smooth rod in a respective recess, the inner diameter of the tube corresponding to the outer diameter of the rod and the length of the tube corresponding to the length of the rod. Thus, this sleeve-forming tube is in sliding contact with the rod, to facilitate disassembly.

[0043] Advantageously, the sleeve tube is a split tube to allow for a tight fit to the rod. Alternatively, this sleeve tube could be a round tube.

[0044] Advantageously, the sleeve-forming tube is made of zinc-plated steel. Alternatively, the smooth rod could be coated with a release agent.

[0045] Preferably, to facilitate disassembly, the connection system also includes a release mechanism to be positioned between each recess and the block of filling material within said recess. This release mechanism may be a solid coating, a textile coating, or a chemical coating. For example, the solid coating may be a plastic part, thermoformed or produced by an injection or injection-blowing process, or a metal part, suitable for placement within a respective recess and in contact with its walls, across the entire thickness of the slab. The textile coating may be a piece of elastic textile material such as tubular jersey, Lycra®, or elastane.In the case of a chemical coating, the inner walls of the or each reservation could be coated with a film-forming and / or non-stick material, for example an oil, a grease, polyvinyl acetate, or a polymer-based solution.

[0046] In an embodiment where at least one opening leads to both the top surface of the slab and one side of the slab, thus defining, with at least one corresponding opening opposite an adjacent slab, a pair of adjacent connecting openings communicating with each other, the system further comprises, preferably for each pair of connecting openings, a tie ring configured to surround the connector bodies intended to extend into said adjacent connecting openings. Such a tie ring enables a transverse connection between two adjacent slabs.

[0047] Advantageously, the chaining ring is made of metal, particularly steel, and is closed by welding. Therefore, it is understood that such a ring is not likely to open under load.

[0048] The chaining ring can be an oval ring.

[0049] The present invention also relates to a composite floor comprising at least one prefabricated concrete slab and at least one steel beam to which the at least one slab is connected by a mechanical connection system, the at least one slab having at least one recess through its thickness and whose cross-section gradually decreases from the upper surface of the slab to its lower surface, by which the slab rests on an upper surface of the beam, the composite floor being characterized by the fact that the connection system is as defined above, for each of the at least one recess, the at least one connector body being fixed to the upper surface of the beam and extending into the respective recess from the upper surface of the beam, the removable connector head being coupled to said connector body, and a filling material, such as concrete or sealing mortar,filling at least part of the space in the reservation, whereby at least one slab is secured to at least one beam by means of the keying through the filling material and the connection system.

[0050] In particular, the filling material may fill the space between the bottom of the recess and a plane located below the lower edge of the lid.

[0051] Advantageously, the filling material can be a low-shrinkage sealing mortar.

[0052] Preferably, the proximal end of the stem of at least one connector body is secured to the beam by welding.

[0053] Preferably, the floor comprises at least two slabs joined on one side, each of these two adjacent slabs having at least one pair of associated openings. Each pair is defined by two openings that open onto both the upper surface and the adjacent side of the slabs. For each pair, the tie ring surrounding the connector bodies extends into the associated openings and is sealed within the infill material. Thus, unlike conventional inter-slab connections using transverse reinforcing bars sealed on both sides of the slabs, the inter-slab connections using tie rings according to the invention allow for the dismantling of the slabs.

[0054] Preferably, each recess in a pair of associated recesses comprises a conical portion whose cross-section gradually increases from the bottom of the recess and whose axis extends perpendicularly to the plane of the slab, and a semi-oval portion into which the conical portion opens. This semi-oval portion flares out towards the upper surface of the slab and is open on the side and the upper face of the slab. Alternatively, the conical portion could be shaped like a truncated pyramid with a rectangular base.

[0055] To better illustrate the object of the present invention, we will describe below, by way of illustration and not limitation, a particular embodiment thereof, with reference to the attached drawings.

[0056] In these drawings: [ Fig. 1 ] is a top perspective view of a portion of a composite floor according to an embodiment of the present invention, showing a portion of the connection system. Fig. 2 ] is an exploded perspective view of the connection system. Fig. 3 ] is a perspective view, in longitudinal section, of a connector body of the connection system. Fig. 4 ] is a side view of a removable connector head of the connection system. Fig. 5 ] is a top perspective view of a housing body alone, with its base, and the removable connector head. Fig. 6 [ ] is a side view of a removable connector head, a pull-out aid element, and a sleeve-forming tube of the connection system. Fig. 7 ] is a vertical cross-sectional view through a cutout in the slab, showing the connection system in its operating position. Fig. 8 ] is a top perspective view of a reservation, showing the connection system without the cover, washer, and screw. Fig. 9 ] is a view analogous to that of the Figure 8 , only the lid is omitted. Fig. 10 ] is a top-down perspective view of a pair of associated reservations between two adjacent slabs, forming a tie ring of the connection system. Fig. 11 ] is a vertical cross-sectional view through a slab opening, showing a variant for the demolding aid element.

[0057] If we refer to the Figure 1 , we can see that a part of a composite floor according to the present invention has been represented there, showing in particular a beam P and a slab D supported on the upper surface P0 of the beam P and connected to the latter by a connection system 1 according to the present invention.

[0058] In the embodiment shown, slab D has a plurality of through openings D1 and D2, notably at the edge of slab D, and slab D is positioned relative to beam P such that each opening D1 and D2 opens onto the upper surface P0 of beam P. The plurality of openings D1 and D2 includes conical openings D1 and openings D2 defining a pair of associated openings D2.

[0059] As can be seen more on the Figures 8 et 9 Each conical recess D1 has the shape of a hollow truncated cone and includes two circular openings that define the larger and smaller bases of the truncated cone. The larger base, with a diameter greater than that of the smaller base, is located on the upper surface D0 of slab D, while the smaller base is located on the lower surface of slab D. When slab D is positioned on beam P, the central axis of each conical recess D1 is perpendicular to the upper surface P0 of beam P.

[0060] As can be seen more on the Figures 2 And 10Each reservation D2 in a pair of associated reservations D2 comprises a conical portion D20, analogous to the conical reservation D1, and a semi-oval portion D21. The conical portion D20 has a lower circular opening that defines the smaller base of the truncated cone and is located on the lower surface of the slab D, and an upper circular opening that defines the larger base of the truncated cone and opens into the semi-oval portion D21. The semi-oval portion D21 has a semi-oval cross-section whose cross-section gradually decreases from the upper surface D0 of the slab D. The semi-oval portion D21 is defined by a lateral wall open to the side of the slab D and by a lower wall at the level of which the upper circular opening of the conical portion D20 is located.Thus, each reservation D2 of a pair of associated reservations D2 opens onto the upper surface P0 of the beam P and onto the respective associated reservation D2 of an adjacent slab D.

[0061] In the embodiment shown, the beam P is a conventional I-beam on the upper surface P0 of which a series of connector bodies C of the connection system 1 are provided and distributed such that each connector body C is located within a respective recess D1, D2. As can be seen on the Figures 2 , 3 And 7The connector bodies C are cylindrical smooth rods 2, comprising a circular proximal end 2a by which they are welded to the beam P and an opposite annular free distal end 2b. Preferably, the smooth rod 2 is made of steel, particularly galvanized steel. In the welded state, the longitudinal axis of the smooth rod 2 is orthogonal to the plane of the upper surface P0 of the beam P. A female coupling portion 20 is formed inside the smooth rod 2 and opens at the free distal end 2b to allow coupling with the other parts composing the connection system 1. The female coupling portion 20 is a threaded, blind axial bore. More specifically, the longitudinal axis of the bore 20 is coaxial with the longitudinal axis of the smooth rod 2, and the bore 20 has a bottom 200 distant from the free distal end 2b of the rod 2 and a circular opening 201 opening at the free distal end 2b.

[0062] The D slabs are prefabricated concrete D slabs, and the P beams are made of steel, as is well known in the field. The various components of the connection system 1 are received within the recesses D1 and D2.

[0063] In the preferred embodiment, the connection system 1 further comprises, for each connector body C, a sleeve tube 3, a removable connector head 4, 5 and 6 and a demolding aid element 7 or 9 and, for each pair of associated reservations D2, a chaining ring 8.

[0064] If we refer more specifically to Figures 2 , 6 And 7As can be seen, the sleeve tube 3 is a hollow cylindrical piece defining an internal space intended to receive the smooth rod 2. In particular, the smooth rod 2 and the sleeve tube 3 are dimensioned for assembly by a sliding joint, with the circumferential wall of the smooth rod 2 in contact with the inner wall of the sleeve tube 3. In other words, the outside diameter of the smooth rod 2 corresponds approximately to the inside diameter of the sleeve tube 3. The sleeve tube 3 is open at both its ends 3a and 3b. The length of the sleeve tube 3 is equal to that of the smooth rod 2. Thus, one end 3a of the sleeve tube 3 rests on the upper surface P0 of the beam P, while the other end 3b is located at the free distal end 2b of the smooth rod 2. The sleeve tube 3 may be a round tube, or advantageously, a slotted tube.The tube forming the sleeve 3 may advantageously be made of steel, in particular zinc-plated steel or steel coated with a release agent.

[0065] If we refer more specifically to Figures 2 , 4 And 7 , we can see that the removable connector head 4, 5 and 6 includes a waterproof housing part 4, a male coupling part 5 and a washer 6.

[0066] The watertight housing portion 4 comprises a housing body 40, a base 41, and a cover 42. The housing body 40 and the base 41 may be formed as a single unit. Alternatively, the housing body 40 and the base 41 could be two separate parts joined together, for example by screwing. In the embodiment shown in the Figure 5 The housing body 40 is a tubular body defined by a peripheral skirt 400 with a circular cross-section, having a circular opening at one end and a circular base 41 at the other end. The base 41 has a circular opening 410 in its center. The central axis of the opening 410 is coaxial with the central axis of the housing portion 4.

[0067] The cover 42 has a capped upper portion 420 from which a side wall extends at a right angle, forming a peripheral rim 421. The capped portion 420 is disc-shaped, and the peripheral rim 421 has an annular cross-section. The internal diameter of the peripheral rim 421 corresponds to the external diameter of the peripheral skirt 400, such that the cover 42 is able to hermetically seal the circular opening of the housing body 40. The cover 42, the housing body 40, and the base 41 define an internal volume.

[0068] The circular opening 410 through the bottom 41 has a diameter corresponding to the outer diameter of the sleeve tube 3. Thus, when the sleeve tube 3, mounted around the smooth rod 2, passes through the bottom 41, the internal volume delimited in the watertight housing part 4 defines a watertight compartment 43. The watertight housing part 4 can be made of plastic material, thus reducing costs.

[0069] The male coupling part 5 is a simple screw 5 comprising, conventionally, a screw head 50 and a screw shank 51. The head 50 has a polygonal external shape, here hexagonal, and a recess 500, here a slotted recess 500, for use with a screwing tool to screw the screw 5 into the smooth shank 2. The dimensions of the head 50 are chosen to allow it to be housed in the watertight compartment 43. The shank 51 has an external thread suitable for engaging with the tapped bore 20. The diameter of the shank 51 is chosen to allow the screw shank 51 to be screwed into the smooth shank 2 from inside the housing part 4. In other words, the diameter of the screw shank 51 corresponds to the diameter of the bore 20 and is therefore smaller than the diameter of the opening 410 in the bottom 41. The screw 5 can be made of steel, especially galvanized steel.

[0070] Washer 6 is an annular washer with a central circular opening 60. The outer diameter of washer 6 corresponds to the inner diameter of the skirt 400 of the housing body 40, so that washer 6 is housed in the watertight compartment 43 and bears against the base 41. The central opening 60 of washer 6 is axially aligned with the opening 410 in the base 41. The diameter of the central opening 60 of washer 60 is smaller than the diameter of the opening 410 in the base 41 and corresponds to the diameter of the screw shank 51. Thus, the screw shank 51 passes through washer 6, centered by it, and the screw head 50 bears against the upper surface of washer 6.In other words, the washer 6 will be interposed between the screw head 50 and the bottom 41 of the housing part 4, the lower surface of the washer 6 resting on the free distal end 2b of the smooth rod 2 and the upper end 3b of the sleeve-forming tube 3.

[0071] In the illustrated embodiment, the smooth rod 2 has an outside diameter of 18.3 mm, the washer 6 has an inside diameter of 12 mm, an outside diameter of 40 mm and a thickness of 6 mm, and the screw 5 has a shank 51 of 12 mm diameter and 20 mm length.

[0072] If we refer more specifically to Figures 2 , 6 , 8 et 9 We can see that the demolding aid element is a traction demolding aid element 7, which may be in the form of a loop of cable or wire. In other words, it may be a flexible cable looped or a rigid metal wire bent into at least one loop. The dimensions of the pull-out aid element 7 will be chosen so that it is able to pass through a passage 401 provided through the skirt 400 of the housing body 40. Thus, in the assembled state, this element 7 has a gripping section 70 housed in the sealed compartment 43 and accessible from the top of the housing part 4 and a projecting section 71 extending out of the housing part 4 and therefore into the space delimited by the walls of the recess D1 and D2 and intended to be filled with a filling material M. The projecting section 71 can surround the sleeve-forming tube 3.

[0073] We now refer to the Figure 7 , on which the connection system 1 is shown in cross-section in its operating position, suitable for connecting slab D to beam P. Prior to this, for each conical recess D1 in slab D, a smooth rod 2 will be welded to the upper surface P0 of beam P, and slab D will be positioned on beam P as illustrated in the Figure 1 , namely with a smooth rod 2 extending through each conical reservation D1. Once the slab D is positioned in this way, a sleeve tube 3 is placed around each smooth rod 2, with the lower circular end 3a of the sleeve tube 3 resting on the upper surface P0 of the beam P. A removable connector head 4, 5, and 6, carrying a pull-out release aid element 7, is then coupled to each smooth rod 2. For this purpose, a housing body 40 is positioned with its bottom 41 opposite the free distal end 2b of the smooth rod 2 and the sleeve tube 3, a washer 6 is positioned at the bottom of the housing body 40, and the shank 51 of a screw 5 is inserted through the washer 6 and through the bottom 41 and screwed into the tapped bore 20 of the smooth rod 2, until the free end of the screw shank 51 abuts against the bottom 200 of the bore. 20.The cover 42 is then fixed to the housing body 40 to hermetically seal the connector head. The washer 6, the screw 5, and the gripping section 70 of the pull-release aid 7 are then protected inside the sealed compartment 43. Next, for each recess D1, the free space between the side wall of the recess D1 and the outer walls of the sleeve tube 3 and the sealed housing portion 4 is filled with a filler material M, in particular sealing concrete, for example up to the peripheral rim 421 of the cover 42. The recess D1 can then be closed by means of a hatch or other finishing strip or covering (not shown). The slab D is thus secured to the beam P by keying (sealing concrete M) and by the connection system 1.

[0074] We now refer to the Figure 10 Figure 1, shown in a top view, depicts the connection system 1 for linking two adjacent slabs D connected to the same beam P, in addition to the connection of the slabs D to the beam P. This inter-slab connection allows, in particular, the creation of a membrane effect over an entire floor slab comprising multiple slabs D. The components of the connection system 1 are the same as those described previously for the conical recesses D1. Each smooth rod 2 is welded to the upper surface P0 of the beam P such that when the adjacent slabs D are positioned on the beam P, the smooth rods 2 extend to the center of the conical sections D20 of the associated recesses D2. In addition to the aforementioned components, the connection system 1 includes, for each pair of associated recesses D2, a tie ring 8. The tie ring 8 may be an oval ring with a circular cross-section, made of steel.Each chaining ring 8 is placed against the bottom of the semi-oval portion D21 of the associated recesses D2, thus in a plane orthogonal to the longitudinal axis of each smooth rod 2, and so as to surround the two opposing connector bodies C. Then, as before, for each pair of associated recesses D2, the free space within the recesses D2 is filled with the filler material M. The chaining ring 8 is therefore embedded in the filler material M, in the same way as the protruding section 71 of the traction release aid elements 7.

[0075] Thus, the connection system 1 can be in the form of a kit comprising at least one connector body C and, for each of the at least one connector body C, a housing body 40 with a base 41, a cover 42, a washer 6, a screw 5, a sleeve tube 3, and a demolding aid element 7, and for each pair of associated reservations D2, a chaining ring 8.

[0076] The assembly of the connection system 1 is very easy and quick. Indeed, once the smooth rods 2 are welded to the beams P, it is simply a matter of screwing a removable connector head 4, 5 and 6 into each smooth rod 2. This screwing is done from above, and no operation from below, which is more tedious for the operators, is required.

[0077] The connection system 1 is also very easy and quick to disassemble. For each removable connector head 4, 5, and 6, simply remove the cover 42, unscrew the screw 5 using a suitable tool, and then remove the washer 6, thus separating the connector head from the connector body C. To remove the mold, simply pull on the gripping section 70 of the pull-out release aid 7, which is accessible in the housing body 40. This pull releases the block of filling material M from its recess. This removal operation is facilitated by the flared shape of the recess and by the presence of the sleeve tube 3, which ensures proper sliding at the interface between the smooth rod 2 and the filling material M. To further facilitate removal, the inner wall of the recess can also be coated with a release agent, such as oil.In the case of a conical recess D1, the filling material block M will be a conical block. In the case of two adjacent recesses D2, the joint between the two adjacent slabs D will be sawn, and the tie ring 8 may also be sawn. In this case, the two filling material blocks M, filling each recess D2 of the pair, will be demolded one after the other by simple traction using the traction demolding aid element 7.

[0078] Slab D can therefore be easily and quickly separated from beam P without damaging slab D, which can then be reused at another site. Similarly, all components can be reused at another site, with the exception of the filler block M and the traction release aid element 7, a section of which is embedded in this block.

[0079] The ability to reuse / recycle D tiles and connection system components promotes the emergence of an environmentally friendly circular economy.

[0080] The solution according to the present invention has other advantages including occupying a small volume, facilitating storage, transport and handling by operators during installation, and not requiring the use of a high-performance material, which further facilitates the industrialization of the manufacture of the connection system 1.

[0081] If we now refer to the Figure 1 As an alternative, the demolding aid element could be a pressure-based demolding aid element 9, rather than a pull-based one. This element 9 could comprise a hollow part 90, a pouring channel 91, and a steel ring 92.

[0082] The hollow piece 90 delimits an annular cavity 90a, defined by an outer cylindrical wall 90b, an inner cylindrical wall 90c, a lower annular wall 90d, which is flat and intended to rest on the beam P, and an upper annular wall 90e, the latter being inclined in such a way that the cross-section of the cavity 90a is not constant.

[0083] The outer diameter of the ring 92 is chosen to correspond to the diameter of the small base of the conical recess D1. The inner diameter of the ring 92 corresponds to the outer diameter of the outer cylindrical wall 90b. The height of the ring 92, along the direction of the central axis of the conical recess D1, is approximately equal to the mid-height of the hollow part 90, namely the height equidistant from the maximum and minimum heights of the upper annular wall 90e. Thus, the cavity 90a can be considered as defined by a region of larger cross-section and a region of smaller cross-section, in which the height of the upper annular wall 90e is greater than, respectively, less than said mid-height. The inner diameter of the inner cylindrical wall 90c is chosen to correspond to the outer diameter of the smooth rod 2 or to the outer diameter of the sleeve tube 3.

[0084] The casting chimney 91 delimits a cylindrical channel having one open end which opens into the cavity 90a, in particular in the region of largest section, and another open end which protrudes at least slightly above the reservation D1.

[0085] We could also provide for a vent chimney similar to the casting chimney 91, namely having one open end which opens into the cavity 90a, in particular in the region of smaller section, and another open end which protrudes at least slightly above the reservation D1.

[0086] In the case of such a pressure-activated demolding aid element 9, for each recess D1, before coupling the removable connector head 4, 5, and 6 to the smooth rod 2, an element 9 is positioned at the base of the conical recess D1. The hollow part 90 and the ring 93 radially fill the space formed between the smooth rod 2 and the side wall of the recess D1 at the bottom of this recess D1. The connector head is then mounted and the recess D1 is filled as described above.

[0087] When it is necessary to demold a block of filler material M filling the space above element 9 as described above, it is sufficient, after removing the access panel or other finishing strip or coating covering the recess D1, to pour an expansive material, for example, a fluid expansive mortar, from the accessible opening of the pouring chute 91 until the cavity 90a is completely filled. Filling the cavity 90a is facilitated by the fact that the pouring chute 91 opens into the region with the largest cross-section of the cavity 90a, which offers a greater volume for the entry of the expansive material. The expansive material then acts in such a way as to tend to expand the volume of the cavity 90a. This expansion then creates sufficient upward pressure to push the block of filler material M out of the recess D1.During this expansion, it is the steel ring 92 which ensures that the pressure exerted by the expansion is directed upwards, in order to avoid the risk of causing the slab D itself to burst.

[0088] In the case where the element 9 includes a solid piece, in particular made of polystyrene, complementary to the cavity to be delimited in place of the hollow piece 90, if it is desired to proceed to demold a block of filling material M filling the space above the element 9, it is necessary first to dissolve the solid piece, for example by pouring a solvent, such as acetone, through the pouring chimney 91, then, once the piece has dissolved, to fill the cavity thus formed with expansive material.

[0089] It is understood that the particular embodiment just described has been given by way of example and not limitation, and that modifications may be made without departing from the present invention.

Claims

1. Mechanical connection system (1) for linking at least one prefabricated concrete slab (D) to a steel beam (P), the slab or slabs (D) having at least one recess (D1; D2) which passes through its thickness and whose cross-section gradually decreases from the upper surface (D0) of the slab (D) to its lower surface by which the slab (D) rests on an upper surface (P0) of the beam (P), the connection system (1) comprising, for each of the at least one recess (D1; D2), at least one connector body (C) intended to be fixed to the upper surface (P0) of the beam (P) and to extend into the respective recess (D1; D2) from the upper surface (P0) of the beam (P), characterized by the fact thatThe connector body (C) comprises a smooth rod (2) having a proximal end (2a) intended to be fixed to the beam (P) and a free distal end (2b) opposite the proximal end (2a), the rod (2) having a female coupling portion (20) opening at least at the free distal end (2b), the connection system (1) further comprising, for each of the at least one connector body (C), a removable connector head (4, 5, 6), the connector head (4, 5, 6) comprising a watertight housing portion (4) having a housing body (40), a base (41) and a removable cover (42) delimiting a watertight compartment (43), and a male coupling portion (5) adapted to be housed in the watertight compartment (43) and to pass through an opening (410) in the base (41),the male coupling part (5) being configured to be coupled in the female coupling part (20) in order to fix the watertight housing part (4) to the respective rod (2), with the bottom (41) of the housing part (4) opposite the free distal end (2b) of the rod (2).

2. System (1) according to claim 1, characterized by the fact that the female coupling part (20) is an axially tapped bore (20) and the male coupling part (5) is a screw (5) having a screw head (50) of a larger diameter than the bore (20) and suitable for being received in the sealed compartment (43) and a screw shank (51) suitable for passing through the opening (410) in the bottom (41) and whose thread is suitable for cooperating with the tapping of the axial bore (20).

3. System (1) according to claim 2, characterized by the fact that the axial tapped bore (20) is a blind bore whose bottom (200) is configured to cooperate with the free end of the screw shank (51).

4. System (1) according to any one of claims 2 and 3, characterized by the fact that each connector head (4, 5, 6) further includes a washer (6) suitable for being arranged between the lower face of the screw head (50) and the free distal end (2b) of the smooth rod (2) and around the screw rod (51).

5. System (1) according to any one of claims 1 to 4, characterized by the fact that It further includes, for each connector head (4, 5, 6), a pull-out aid element (7) capable of passing through a passage (401) provided in the housing body (40) such that a so-called gripping section (70) of the element (7) is housed in the sealed compartment (43) and a so-called protruding section (71) extends out of the housing part (4) in the respective recess (D1; D2).

6. System (1) according to any one of claims 1 to 4, characterized by the fact thatIt further comprises, for the connector body or each connector body (C), a pressure release aid element (9) suitable for being placed around the smooth rod (2), in its proximal end region (2a), and for covering the upper surface (P0) of the beam (P) in a respective reservation (D1; D2), the element (9) being suitable for delimiting a cavity (90) suitable for being filled with an expansive material.

7. System (1) according to any one of claims 1 to 6, characterized by the fact that It further comprises, for the connector body or each connector body (C), a sleeve-forming tube (3) suitable for being placed around the smooth rod (2) in a respective recess (D1; D2), the inner diameter of the tube (3) corresponding to the outer diameter of the rod (2) and the length of the tube (3) corresponding to the length of the rod (2).

8. System (1) according to any one of claims 1 to 7, at least one opening (D2) opening onto both the upper surface (D0) of the slab (D) and onto one side of the slab (D) so as to define, with the respective at least one opening (D2) placed opposite an adjacent slab (D), a pair of associated adjacent openings (D2) communicating with each other, characterized by the fact that the system (1) further includes, for the or each pair of associated reservations (D2), a chaining ring (8) configured to surround the connector bodies (C) intended to extend into said adjacent associated reservations (D2).

9. Composite floor comprising at least one prefabricated concrete slab (D) and at least one steel beam (P) to which the at least one slab (D) is connected by a mechanical connection system (1), the at least one slab (D) having at least one opening (D1; D2) which passes through its thickness and whose cross-section gradually decreases from the upper surface (D0) of the slab (D) to its lower surface by which the slab (D) rests on an upper surface (P0) of the beam (P), the composite floor being characterized by the fact thatthe connection system (1) is as defined in any one of claims 1 to 8, for each of the at least one reservation (D1; D2), the at least one connector body (C) being attached to the upper surface (P0) of the beam (P) and extending into the respective reservation (D1; D2) from the upper surface (P0) of the beam (P), the removable connector head (4, 5, 6) being coupled to said connector body (C), and a filling material (M), such as concrete or sealing mortar, filling at least part of the space in the reservation (D1; D2), whereby the at least one slab (D) is attached to the at least one beam (P) by means of the keying by the filling material (M) and the connection system (1).

10. Composite floor according to claim 9, characterized by the fact that the proximal end (2a) of the rod (2) of at least one connector body (C) is secured to the beam (P) by welding.

11. Composite floor according to any one of claims 9 and 10, characterized by the fact that it comprises at least two slabs (D) adjacent by one of their sides, the at least two adjacent slabs (D) having at least one pair of associated reservations (D2), the pair or each pair being defined by two reservations (D2) opening onto both the upper surface (D0) and the adjacent side of the slabs (D), for the pair or each pair, the chaining ring (8) surrounding the connector bodies (C) extending into the associated reservations (D2) and being sealed in the filling material (M).

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