EP2340339A1

EP2340339A1 - Firestop screen suspended ceiling

Info

Publication number: EP2340339A1
Application number: EP09781856A
Authority: EP
Inventors: Denis Zago; Romain Keiser
Original assignee: ArcelorMittal Dudelange SA
Current assignee: Liberty Liege Dudelange LU SA
Priority date: 2008-09-10
Filing date: 2009-08-14
Publication date: 2011-07-06
Also published as: LU91476B1; WO2010028928A1

Abstract

The invention relates to a firestop screen suspended ceiling including panels with an insulating non-combustible core and having lower and upper surfaces each covered by a metal sheet. At least one edge of the core includes a connection key made of a reinforced mineral material and along which extend the edges of two metal sheets. Two panels are arranged so that two connection keys face each other, thus defining lower and upper connection grooves separated by the connection keys. A metal profile is provided in each of said two connection grooves and is connected to at least one of the two connection keys and covers the seam between the two connection keys. The connection metal profile secured in the upper connection groove is used as a fastener for a suspending means.

Description

SUSPENDED CEILING FORMING A FIREWALL SCREEN

Technical area

The present invention relates to a suspended ceiling forming a fire screen.

State of the art

Suspended ceilings forming a firewall under a load-bearing structure of wood or metal of a floor or a frame of a roof have been known for a long time. Such suspended ceilings are made of fireproof panels, most often plasterboard, screwed on a metal or wooden frame, which is itself suspended load-bearing structure of the floor. To enhance the fire resistance of such a ceiling it is known to stack several fire resistant panels with staggered joints and / or to cover the upper surface and the framework for fixing a layer of mineral wool. The construction of such a suspended ceiling is still today a craft work. Its effectiveness as a fire screen and its mechanical stability are largely dependent on the experience and know-how of the craftsmen who build it. In addition, such a ceiling is easily damaged by depressions or overpressure inside the building, which are for example due to explosions, the triggering of fire extinguishing or smoke extraction.

Object of the invention

An object of the present invention is to provide a suspended ceiling forming a fireproof screen which can be fully assembled using standard prefabricated elements, while having a high mechanical stability and a high degree of fire.

According to the invention, this objective is achieved by a suspended ceiling according to claim 1. General description of the invention

A suspended ceiling forming a fire screen according to the present invention comprises at least two panels suspended from a supporting structure using suspension means. Each of these two panels comprises an insulating core and non-combustible, the lower face and the upper face are each coated with a metal sheet provided with flanges partially covering the edges of the core. At least one of these songs of the core then comprises a connecting key made of a reinforced mineral material, which is bordered by the edges of the two metal sheets. The two panels are arranged to have two wrenches facing each other, thereby forming a lower connection groove below the wrenches and an upper connection groove above the wrenches. In each of these two connecting grooves is arranged a metal connecting section, which is fixed, preferably with bolt-type screws, to at least one of the two connection keys and which covers the joint between the two keys of the connector. connection. The metal fitting section fixed in the upper connection groove then serves as a fastener for said suspension means.

It will be appreciated that the panels and fittings parts can be prefabricated standard elements, which can be assembled on site without particular craftsmanship. The panels with their insulating core provided with a lower and upper metal casing, without thermal bridge between them, and the assembly of these panels using a lower and upper connection profile thermally separated by the two keys of connection, provide a good mechanical stability of the ceiling and guarantee a high fire resistance. It will also be appreciated that the ceiling panels can be relatively large in size. Thus, a panel may for example have a surface greater than 2 m ² (for example: 120x200 cm panel is perfectly possible), while having a high mechanical stability and a reasonable weight (for example of the order of 400 to 600 Wm ² ). These large panels not only allow rapid ceiling mounting but also result in a reduction in the total length of joints between panels, which naturally has a favorable effect on the fire resistance of the ceiling. One of the two connecting keys is preferably wider than the other. The metal connecting profiles are then attached to the widest key, which increases the mechanical stability of the ceiling.

In a preferred embodiment, the metal fitting section has a central section "U", the base is fixed with screws to at least one of the two keys and covers the seal between the two keys.

The metal fitting section arranged in the upper connection groove advantageously has two outer lateral wings resting on the metal sheet.

In a preferred embodiment, the suspension means comprise at least one fixing rod and at least one fixing plate. The latter is fixed by means of screws on the metal connecting profile in the upper connection groove and comprises at least one fixing point for the fixing rod.

The metal fitting section arranged in the lower connection groove preferably has a section "U" with two inner wings serving as a support for a cover plate, which is screwed onto the metal fitting section. This cover plate is preferably a carbon steel plate coated with an alloy composed of aluminum and zinc, with an intumescent band fixed on the upper surface of the cover plate. It protects the screw heads attaching metal profile fitting to the fitting key against fire heat.

The metal sheet serving as envelope to the core is advantageously a thin sheet (thickness of about 0.6 to 1.3 mm) of carbon steel, which is coated with an alloy composed mainly of aluminum and zinc. Preferably this alloy comprises between 53 and 57% of aluminum, 41 and 46% of zinc and 1 and 2% of silicon. A preferred alloy comprises 55% aluminum, 43.4% zinc and 1.6% silicon. It will be appreciated that under the effect of the high heat of a fire, the aluminum and zinc coating behaves in "millefeuille", that is, it swells by forming thin, separate solid layers by layers of air. This "millefeuille" coating then constitutes a layer of thermal insulation, which delays the heating of the carbon steel sheets.

The insulating core of a panel advantageously comprises a sandwich structure having: on the side of the underside, a non-load bearing panel fuel, cement-based or silico-calcareous, fiber-reinforced, having good resistance to bending and compression; and on the upper side side, a non-combustible thermal insulation layer, based on cellular glass, having low thermal conductivity and low density. The carrier panel and the thermal insulation layer are preferably assembled by bonding using an elastic adhesive. Such a panel provides not only excellent thermal insulation and high mechanical strength, but is also made of easily recyclable materials (steel and mineral materials).

The sandwich structure of the core is preferably framed by framing members of a reinforced mineral material. These frame members, which form the edges of the core with the connecting keys, are advantageously glued to the edges of the sandwich structure with the aid of an elastic adhesive.

The carrier panel and the framing members are advantageously products based on cement or silico-limestone, reinforced with fibers, having a good resistance to bending and compression.

The metal sheets are advantageously bonded to the insulating core using an elastic adhesive.

The elastic adhesive used for assembling the various elements of a panel is preferably an organic adhesive including a hydrated mineral filler. This glue has sufficient elasticity to compensate for the differential expansions of different materials of a panel under the effect of fire heat. In addition, the hydrated mineral filler slows the transfer of heat through the panel by slowly evaporating under the action of fire heat. Then, the organic binder chars, which also seems to slow down the heat transfer through the panel. It will also be appreciated that the bonding of the various elements of the panel improves its lift and its mechanical stability significantly.

The frontal surfaces of the keys are preferably provided with an intumescent paint layer. This intumescent paint seals the joint between two keys when the suspended ceiling is exposed to a fire. Brief description of the drawings

Other features and characteristics of the invention will become apparent from the detailed description of an advantageous embodiment presented below, by way of illustration, with reference to the accompanying drawing. This one shows:

Fig. 1: a cross section through a suspended ceiling according to the present invention.

Description of a preferred execution

[0020] FIG. 1 shows a seal between two panels 10 and 10 'according to the present invention. Such a panel normally has a square or rectangular shape. Typical dimensions are for example: 60x60 cm, 80x80 cm, 90x90 cm, 120x120 cm, respectively 60x90 cm, 80x120 cm or 120x200 cm, with a preference for panels having large dimensions. In FIG. 1, we see only a right end of the panel 10 and a left end of the panel 10 '.

Each of these panels 10, 10 'comprises a core 12, 12' insulating and non-combustible, the lower face 14 and the upper face 16 are each coated with a metal sheet 18, 20 provided with flanges 22, 24 partially covering the edges of the core 12. This core 12 comprises a sandwich structure having as a bottom layer, a non-combustible carrier panel 28 having a good flexural strength, and as the upper layer, a non-combustible thermal insulation layer 26, having low thermal conductivity and low density.

The thermal insulation layer 26 is advantageously made up of alumino-silicate cellular glass plates, having a thermal conductivity of approximately 0.04 W / mK, a density of the order of 120 kg / m 3, a compressive strength of the order of 0.7 MN / m2 and a flexural strength of the order of 0.4 MN / m2. Such plates, which are completely inorganic and are formed without binders, are for example sold by the company "PITTSBURGH CORNING EUROPE SA" under the designation "FOAMGLAS ® T4". To achieve a fire resistance of 120 minutes, plates 80 mm thick will normally be used. The noncombustible carrier panel 28 is advantageously a cement-based panel or silico-limestone, reinforced with fibers. It has for example a thickness of the order of 12 mm and a density of the order of 1000 kg / m3. This panel may be a poor thermal insulator (thermal conductivity of the order of 0.25 W / mK) but must be incombustible and have good resistance to bending and compression, that is to say a resistance to bending of the order of 6-12 MN / m2 and a compressive strength perpendicular to the surface of the plate of the order of 10-20 MN / m2.

At least one of the edges of the core 12, 12 'comprises a connecting key 30, 30' of a reinforced mineral material, which is bordered by the flanges 22 and 24 of the two metal sheets 18, 20, respectively the flanges 22 'and 24' of the two metal sheets 18 ', 20'. Normally each edge that is to be connected to another panel includes such a fitting key 30, 30 '. Preferably, two opposite edges of the same panel have keys of different width. In FIG. 1, we see for example that the key 30 of the right edge of the panel 10 is wider than the key 30 'of the left edge of the panel 10'.

The sandwich structure of the core 12, 12 'is framed by frame members 32, 32' of a reinforced mineral material. These frame members 32, 32 'form the edges of the core 12, 12' with the connecting keys 30, 30 '. They are glued to the edges of the sandwich structure using an elastic adhesive. These frame members 32, 32 'are preferably fiber-reinforced cementitious or sand-lime-based elements, as is the support panel 28.

The panel 10 is for example assembled as follows. The cellular glass plate 26 is glued on the carrier panel 28. Then, the frame members 32, 32 ', which form the edges of the core 12, 12' with the connecting keys 30, 30 'are glued on the four Finally, the metal sheets 18, 20 are bonded to the upper or lower surface of the core 12. It will be noted that the flanges 22, 24 of the metal sheets 18, 20 contribute to maintaining the elements of the core. frame 32, 32 'firmly in place on the sandwich structure edges. A second flange 34, 36 at least partially covers the lower surface, respectively upper part of the connection key 30 and thus contributes to further stabilizing the connection key 30.

As glue assembly is preferably used an adhesive composed of an organic elastic binder, for example a resin of the family of polyols containing usual amounts of plasticizers, adhesion promoters, stabilizers, catalysts, to which is added a hydrated inorganic filler, for example trihydrated alumina, and a polymerization reagent. Such elastic adhesives are for example described in the patent application EP 1283310. The organic binder must provide sufficient elasticity to compensate or absorb the deformations of a slab 10, 10 'when it is loaded in normal use. and, in the event of a fire, to compensate as much as possible for the differential expansions of the different materials of a slab 10, 10 'under the effect of the fire heat. Hydrated mineral filler slows thermal transfer by evaporating slowly under the action of fire heat. Then, the organic binder is carbonized, which also seems to retard the heat transfer through the slab 10, 10 '.

The metal sheets 18, 20 forming the facing of the panels 10, 10 'are preferably thin sheets (0.6 to 1, 3 mm thick) of carbon steel coated with an alloy composed of aluminum and zinc in substantially equal proportions and a trace of silicon. Such sheets are for example marketed by ArcelorMittal under the name ALUZINC ® sheets. The ALUZINC ® sheet coating alloy comprises approximately 55% aluminum, 43.4% zinc and 1.6% silicon. The well-known advantages of these sheets are their remarkable resistance to corrosion and the fact that the natural color and gloss of the coating are preserved for a long time. However, during fire resistance tests carried out on elements equipped with ALUZINC ® facing sheets, it was found that thin sheets significantly and unexpectedly increase the fire resistance of the elements tested. It is thought that this phenomenon can be explained as follows. Under the effect of high heat, the aluminum and zinc coating behaves in "millefeuille", that is to say, it swells by forming thin solid layers separated by layers of air. This coating "millefeuille" then seems to be a layer of thermal insulation, which delays warming of the elements tested. In FIG. 1 it can be seen that the two panels 10, 10 'are arranged so as to have the two connection keys 30 and 30' facing each other, thus forming a lower connection groove below the connection keys 30 , 30 'and an upper connecting groove above the connecting wrenches 30, 30'. In each of these two connecting grooves is arranged a metal connecting section 40, 42. The latter is fixed by means of lag screws 44, 46 to the coupling key 30 and covers the joint between the two. keys 30 and 30 '.

The metal connecting section 40 arranged in the upper connection groove has a central section "U" 48, of width substantially identical to the width of the upper groove, with two outer lateral wings 50, 50 ', which are resting on the metal sheet 20, respectively 20 ', along the upper groove. The base 52 of the central section 48 in "U" is fixed by means of the screws of the laggable type 44 to the key 30. A fixing plate 54 is fixed on the metal connecting section 40, using self-drilling screws 56, 58, so as to close the central section 48 in "U" upwards. The self-drilling screws 56 pass through the fixing plate 54, the base 52 of the central section 48 "U" of the metal connecting section 40 to be screwed through the second flange 36 of the sheet 18 in the key 30. The self-drilling screws 58 pass through the fixing plate 54 and the lateral flanges 50, 50 'of the connecting metal section 40 to screw through the sheet 18 in the core 12.

The reference numeral 60 identifies an attachment point for a suspension rod 62. This attachment point 60 is advantageously a nut nut type FABRO-RIVEKLE ® or equivalent, which is placed using a device in a hole in the fixing plate 54, and can even be put in place after having fixed the fixing plate 54 to a metal connecting section 40. The suspension rod 62 then comprises a threaded end which is screwed into the flooded nut 60.

The metal fitting section 42 arranged in the lower connection groove also has a section "U" 64, which has a width substantially identical to the width of the lower groove. Instead of the two outer lateral wings, it has two inner wings 66, 66 'serving to support a cover plate 68. The base 70 of the "U" section 64 is fixed with the help of screws of the pulling type. 72 to the key 30. The cover plate 68, which closes the section "U" 64 downwardly flush with the plates 18, 18 ', is fixed on the two inner wings 66, 66' with self-drilling screws 74. These self-drilling screws 74 pass through the cover plate 68 , the inner wings 66, 66 'and the base 70 of the "U" section 64, to be screwed through the second flange 34 of the sheet 18 into the key 30. The reference sign 76 identifies an intumescent strip which is attached to the upper surface of the cover plate 68.

The two metal connecting sections 40, 42, the fixing plate 54 and the cover plate 68 are preferably coated with an alloy composed of aluminum and zinc, such as ALUZINC ® sheets mentioned above.

It will be appreciated that a suspended ceiling according to the invention may have a classification firestop REI 120 (European standards), which means that with a fire defined in the standard, a seal to the flames, hot gases and toxic is ensured for 120 minutes and that, during the same time, the temperature on the surface opposite the fire does not exceed 140 ⁰ C on average and 180 ⁰ C punctually. In addition, the suspended ceiling can be easily dimensioned to withstand permanent suspended loads of at least 500 N / m ² (eg luminaires or other equipment) and a temporary load of at least 1000 N / m ² ( eg when working in the suspended ceiling vacuum).

It will also be appreciated that it is easy to integrate fire dampers (for ventilation / air conditioning systems) into the panels. It is even possible to deliver panels with fire dampers integrated in the factory, which facilitates assembly on site and guarantees a fitting of the firestop valve according to the rules of art. It is also possible to deliver panels with factory-prepared passages for cable ducts and sanitary conduits.

Finally, note that a suspended ceiling according to the invention has a high hygienic and environmental quality. In addition, it can essentially consist of easily recyclable materials (steel and mineral materials). Legend: ⁷ ^ self-drilling screws

76 intumescent band

10, panel 10 '

12, insulating core and not

12 'fuel

14 underside of 12

16 upper side of 12

18, metal sheet 20

22, ledge of 18, 20 24

26 thermal insulation layer

28 carrying panel

30, fitting key 30 '

32, framing elements 32 '

34, second ledge 18, 20 36

40, metal connector profile 42

44, bolt type screw

48 central section in "U" of 40

50, outer side wings 50 '

52 base of 48

54 fixing plate

56, self-drilling screws 58

60 fixing points for 62

62 suspension rod

64 "U" section of 42

66, Inner wings 66 '

68 cover plate

70 basis of 64

72 bolts of the lag bolt type

Claims

claims

1. Suspended ceiling forming a fire screen, comprising at least two panels suspended to a supporting structure using suspension means, characterized in that: each of these two panels comprises an insulating core and non-combustible, the lower face and the upper face are each coated with a metal sheet provided with flanges partially covering the edges of the core; at least one of these songs of the core comprises a connecting key made of a reinforced mineral material, which is bordered by the edges of the two metal sheets; both panels are arranged to have two wrenches facing each other, thereby forming a lower connection groove below the wrenches and an upper connection groove above the wrenches; in each of these two connecting grooves is arranged a metal connector section, which is attached to at least one of the two connection keys and which covers the joint between the two connecting keys; and the metal connector section fixed in the upper connection groove serves as a fastener for said suspension means.

2. Ceiling according to claim 1, wherein one of the two connecting keys is wider than the other and the two metal connection profiles are fixed on the widest fitting key.

3. Ceiling according to claim 1 or 2, wherein: the metal connecting section has a central section "U", whose base is fixed with screws to at least one of the two keys and covers the seal between both keys.

4. Ceiling according to claim 3, wherein the metal fitting section arranged in the upper connection groove further has two outer lateral wings resting on the metal sheet.

Ceiling according to claim 3 or 4, wherein said suspension means comprise: at least one fixing rod; and at least one fixing plate which is fastened with screws on the connecting metal profile in the upper connection groove, and which comprises at least one fixing point for the fixing rod.

6. Ceiling according to claim 3, wherein the metal connecting section arranged in the lower connection groove further has two inner wings serving to support a cover plate, which is screwed onto the metal connecting section.

Ceiling according to claim 6, wherein: the cover plate is a carbon steel plate coated with an alloy composed of aluminum and zinc; and an intumescent strip attached to the upper surface of the cover plate.

8. Ceiling according to any one of claims 1 to 7, wherein: the metal sheet is a thin sheet of carbon steel coated with an alloy composed of aluminum and zinc.

Ceiling according to claim 8, wherein: said alloy comprises between 53% and 57% of aluminum, between 41% and 46% of zinc and between 1% and 2% of silicon.

10. Ceiling according to any one of claims 1 to 9, wherein the insulating and non-combustible core comprises a sandwich structure having: on the side of the underside, a noncombustible carrier board, based on cement or silico-limestone fiber reinforced, having good bending and compressive strength; and on the upper side side, a non-combustible thermal insulation layer, based on cellular glass, having low thermal conductivity and low density; the carrier panel and the thermal insulation layer being assembled by gluing using an elastic adhesive.

Ceiling according to claim 10, the sandwich structure of the core is framed by framing members of a reinforced mineral material; these frame elements, which form the edges of the core with the connecting keys, being glued to the edges of the sandwich structure using an elastic adhesive.

Ceiling according to claim 11, wherein the carrier panel and the framing members are fiber-reinforced cementitious or sand-lime-based products having good resistance to bending and compression.

13. Ceiling according to any one of claims 1 to 12, wherein the metal sheets are bonded to the insulating core and non-combustible with a resilient adhesive.

14. Ceiling according to one of claims 10, 11 or 13, wherein the elastic adhesive is an organic adhesive including a hydrated mineral filler.

15. Ceiling according to any one of claims 1 to 14, wherein the front surfaces of the keys are provided with a layer of intumescent paint.