WO2023111558A1

WO2023111558A1 - Floor structure

Info

Publication number: WO2023111558A1
Application number: PCT/GB2022/053224
Authority: WO
Inventors: Edward Harry Piers CROFTON
Original assignee: Thornton Tomasetti Limited
Priority date: 2021-12-17
Filing date: 2022-12-14
Publication date: 2023-06-22
Also published as: CA3223053A1; GB2609681A; GB2609681B

Abstract

A floor cassette assembly comprising: a structural bottom panel having an upper surface and a lower surface, a plurality of spaced apart upstanding rib members attached to the upper surface of said panel, wherein adjacent spaced apart rib members define a void between said adjacent rib members, and support means located intermediate adjacent spaced apart rib members, the support means configured to support particulate material within the voids defined by the respective adjacent rib members at a location that is vertically spaced from the structural bottom panel.

Description

FLOOR STRUCTURE

Field of the Invention

The present invention relates to floor structure, in particular to a floor cassette assembly.

Background to the Invention

The floors make up the majority of the mass of most buildings and thus consume the greatest proportion of the materials of a building’s structure. As a result, floor structures have the greatest environmental impact. Floors are also often the most time-consuming building elements to construct.

Existing floor typologies often use concrete as part of their construction. While concrete construction is advantageous in terms of fireproofing and prevention of sound transmission, such floors are heavy, have a high environmental impact and are often slow to construct due to the time required for the concrete to cure.

Alternative floor types make use of lightweight wooden or steel joists but while such floors are economical, they require extensive additional fireproofing and acoustic insulation. Such prior art floors do not span very far, and so large numbers of beams, or compromises to a building’s architectural layout, are required.

Heavy timber floors constructed with cross-laminated timber (CLT), nail laminated timber (NLT) and other similar products have a relatively good structural and fire performance but use large quantities of timber, are expensive and often require additional measures to improve their performance against sound and footfall induced vibration.

There also exists a number of cassette-type floor products, also known as box girders or sandwich panels. These are very efficient structurally, and some perform adequately in fires. However, these typically require additional measures to improve their performance against sound and footfall-induced vibration. Various attempts have been made to produce economic, low-carbon floor cassettes that maximise span, fire protection and performance against footfall induced vibration in a minimum depth/thickness of cassette, however these attempts have resulted in floor cassette designs which only partially address the aforementioned deficiencies.

A known method of providing floor soundproofing, often referred to as “Ash Deafening”, that has found use in Scotland since the end of the 19^th Century employs granular material suspended on a shelf suspended between timber floor joists. This method is effective but suffers from being time consuming to build and does not provide effective fire resistance without additional ceiling finishes. Furthermore, Ash Deafening is not suitable for use in clean areas such as kitchens as the granular material may fall through the floor to contaminate surfaces below.

CH 695 318 A5, discloses a wood box-type cassette structure, within which solid masses supported by a spring-like material provide a sound damping means. In practice, this cassette arrangement is combined with a heavy floating floor, often constructed using concrete, and so the resulting floor system is relatively complicated, resulting in increased cost and slowing construction. In addition, the disclosed floor cassette arrangement has no provision to prevent the accidental ingress of water into the cassette, which may then become trapped and result in damaging mould or fungal growth.

As disclosed in in EP 3 543 416 A1 and EP 3 272 961 A1 , other examples of a floor cassette consist of “Double II” construction, with a solid wood bottom panel and vertical wood stiffening elements. The gaps between the stiffening elements are partially filled with granular or cement-bound ballast that provide mass. This ballast rests on the bottom panel. The mass of the ballast improves acoustic performance and reduces the response to footfall-induced vibration. While simple, this type of floor does not span as far as a box-type floor element for a given depth and is vulnerable to water collecting between the stiffening elements which can result in damaging mould or fungal growth. It is therefore an object of the present invention to provide an improved timber cassette that mitigates the disadvantages of the prior art described above.

Summary of the Invention

In accordance with an aspect of the invention, there is provided a floor cassette assembly comprising: a structural bottom panel having an upper surface and a lower surface, a plurality of spaced apart upstanding rib members attached to the upper surface of said panel, wherein adjacent spaced apart rib members define a void between said adjacent rib members, and support means located intermediate adjacent spaced apart rib members, the support means configured to support particulate material within the voids defined by the respective adjacent rib members at a location that is vertically spaced from the structural bottom panel.

Optionally, the support means configured to support the particulate material is a non- rigid support means

Optionally, the support means configured to support the particulate material is a resilient support means.

Optionally, the support means configured to support the particulate material comprises a shelf.

Optionally, the shelf is a flexible shelf.

Optionally, the shelf spans substantially across the width of the void defined between adjacent rib members.

Optionally, the shelf is mounted along its respective side edges upon support means provided on the respective rib members.

Optionally, the side edges of the shelf are spaced apart from the respective rib members. Optionally, the shelf is formed from suitable wood, metal, or plastic material.

Optionally, the support means configured to support a particulate material comprises a resilient pad.

Optionally, the resilient pad substantially fills the portion of the void intermediate the particulate material supported thereon and the structural bottom panel.

Optionally, the resilient pad is formed from any one or more of neoprene, mineral wool, cellulose fibre, expanded polystyrene.

Optionally, the support means for supporting the particulate material is configured to provide vibration damping due to friction of the particles of the granular material located thereon in response to footfall-induced vibration of the cassette assembly.

Optionally, the particulate material comprises any one or more of sand, crushed concrete, crushed glass, saw dust or a mixture thereof.

Optionally, the particulate material is contained within a bag or bags.

Optionally, the particulate material is a granular particulate material.

Optionally, the floor cassette assembly comprises a top panel, wherein the top panel spans across the upper ends of the rib members.

Optionally, the top panel is a load-bearing panel.

Optionally, the top panel is a non-structural panel.

Optionally, the floor cassette assembly comprises a compressible material located intermediate the particulate material supported on the support means and the top panel.

Optionally, the compressible material comprises a mineral wool. Optionally, the floor cassette assembly comprises one or more end panels configured to enclose the voids defined between the rib members and the structural bottom panel.

Optionally, the structural bottom panel and the rib members are of wood construction.

Optionally, the structural bottom panel is fire resistant.

Optionally, the structural bottom panel further comprises a fire protective layer, coating or finish.

Optionally, the top panel is of wood construction.

Optionally, the top panel is of plasterboard construction.

The various aspects of the present invention can be practiced alone or in combination with one or more of the other aspects, as will be appreciated by those skilled in the relevant arts. The various aspects of the invention can optionally be provided in combination with one or more of the optional features of the other aspects of the invention. Also, optional features described in relation to one aspect can typically be combined alone or together with other features in different aspects of the invention. Any subject matter described in this specification can be combined with any other subject matter in the specification.

Various aspects of the invention will now be described in detail with reference to the accompanying figures. Still other aspects, features, and advantages of the present invention are readily apparent from the entire description thereof, including the figures, which illustrates a number of exemplary aspects and implementations. The invention is also capable of other and different examples and aspects, and its several details can be modified in various respects, all without departing from the scope of the present invention. Accordingly, each example herein should be understood to have broad application, and is meant to illustrate one possible way of carrying out the invention, without intending to suggest that the scope of this disclosure, including the claims, is limited to that example. Furthermore, the terminology and phraseology used herein is solely used for descriptive purposes and should not be construed as limiting in scope. In particular, unless otherwise stated, any dimensions and numerical values included herein are presented as examples illustrating one possible aspect of the claimed subject matter, without limiting the disclosure to the particular dimensions or values recited. All numerical values in this disclosure are understood as being modified by "about". All singular forms of elements, or any other components described herein are understood to include plural forms thereof and vice versa.

Language such as "including", "comprising", "having", "containing", or "involving" and variations thereof, is intended to be broad and encompass the subject matter listed thereafter, equivalents, and additional subject matter not recited, and is not intended to exclude other additives, components, integers or steps. Likewise, the term "comprising" is considered synonymous with the terms "including" or "containing" for applicable legal purposes. Thus, throughout the specification and claims unless the context requires otherwise, the word “comprise” or variations thereof such as “comprises” or “comprising” will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.

Any discussion of documents, acts, materials, devices, articles and the like is included in the specification solely for the purpose of providing a context for the present invention. It is not suggested or represented that any or all of these matters formed part of the prior art base or were common general knowledge in the field relevant to the present invention.

In this disclosure, the words “typically” or “optionally” are to be understood as being intended to indicate optional or non-essential features of the invention which are present in certain examples but which can be omitted in others without departing from the scope of the invention.

Directional references such as “up”, “down”, “upper”, “lower”, “bottom”, “top”, “vertical”, “horizontal”, “above”, “below”, “left”, “right” are to be understood in the context of the normal orientation of a suspended floor. With reference to the Figures, examples of an improved floor cassette will now be described.

Brief Description of the Drawings

Figures 1a and 1b are schematic vertical cross-section views through exemplary floor cassettes in accordance with the invention;

Figure 2 is a schematic horizontal cross section view through an exemplary floor cassette in accordance with the invention, shown in plan view;

Figure 3 is a schematic cross section view showing adjacent floor cassettes supported by an exemplary structural steel beam;

Figure 4 is a schematic cross section view showing adjacent floor cassettes supported by an exemplary timber framed wall; and

Figure 5 is a perspective view of a floor cassette in accordance with the invention.

Detailed Description

With reference to Figure 5, in accordance with the invention there is provided a floor cassette assembly comprising a structural bottom panel 1 having an upper surface 1a and a lower surface 1b, and a plurality of spaced apart upstanding rib members 2 attached to the upper surface 1a of said panel 1. In an exemplary arrangement, rib members 2 are in parallel alignment. Optionally, rib members 2 provided along opposing side edges of the bottom panel 1 define side members of the floor cassette. Conveniently, the gaps between adjacent spaced apart rib members 2 define voids 10 within the floor cassette assembly.

It will be understood that the bottom panel is a structural panel which contributes significantly to the strength of the overall floor cassette assembly, as opposed to a superficial cover member located at the underside of a floor structure, for example, but not limited to, a ceiling panel. The structural bottom panel 1 is fire resistant. Structural bottom panels of floor cassettes in accordance with the invention may be suitably dimensioned, for example in thickness, to provide various levels of fire resistance, e.g. 30 to 120 minutes, depending on applicable requirements. In an optional arrangement, structural bottom panels may further comprise auxiliary fire protection means, such as fire resistant layer, coating or finish.

In examples, the floor cassette assembly further comprises an upper or top panel 3 that spans across the top of the rib members 2 to which it is attached. Advantageously, the upper or top panel closes the upper ends of the voids 10 formed between adjacent rib members 2.

Optionally, structural bottom panel 1 and rib members 2 are of wood construction.

Optionally, rib members 2 are fixed to the structural bottom panel 1 with a structural adhesive. Alternatively, or in addition, the rib members 2 may be fixed to the bottom panel by suitable fastening means such as, but not limited to, nails and/or screws.

In examples, upper panel 3 is a structural panel of wood construction. In this way, upper panel 3 can be a load-bearing panel, for example for use as a floor surface.

Alternatively, upper panel 3 may be a non-structural panel, for example a plasterboard panel 3a as shown by way of example in Figure 3.

Optionally, upper panel 3 is fixed to the rib members 2 with a structural adhesive.

Alternatively, or in addition, the upper panel 3 may be fixed to the rib members 2 by suitable fastening means such as, but not limited to, nails and/or screws.

Thus, a floor cassette assembly in accordance with the present invention functions in similar manner to an I-beam or T-beam, with corresponding strength and stiffness. With reference to Figure 1a and Figure 1b, which represent section X-X shown by way of illustration in Figure 5, a particulate material 5 is provided within the voids 10 defined between adjacent rib members 2.

In accordance with the invention, the particulate material 5 is located at an upper region of the respective voids 10 defined between adjacent rib members 2. Thus the particulate material is vertically spaced from structural bottom panel 1. Thus the particulate material only partially fills the respective voids 10 formed between the adjacent rib members 2 and the bottom panel 1.

With reference to Figures 1a, 1b, 3 and 4, the particulate material is maintained in spaced apart relationship from the bottom panel 1 by a support means.

Optionally, the support means is a non-rigid support means.

Further optionally, the support means is a resilient support means.

In the example shown in Figure 1b, the support means may comprise a shelf 8. Optionally, shelf 8 is a flexible shelf. Optionally, the shelf 8 is configured as a leaf spring. Optionally, shelf 8 spans substantially across the width of the void 10 between adjacent rib members 2. The shelf 8 may be formed from any suitable material such as, but not limited to, wood, metal, plastics etc.

As shown by way of example in Figure 1b, shelf 8 may be mounted along its respective side edges upon suitable support members 11 provided on the rib members 2. Support members 11 may comprise elongate battens or corbels or the like. Optionally, the support members 11 are of wooden construction.

Optionally, the side edges of shelf 8 are non-contacting with the rib members 2. By not abutting or otherwise making direct contact with the rib members 2, the shelf maintains its flexibility in use.

In the example shown in Figure 1a, the support means may comprise a pad 6, shown by cross-hatching. The upper surface of the pad 6 is configured to support particulate material located thereon. Optionally, pad 6 is a resilient pad. Optionally, pad 6 is substantially formed from a resilient material. Examples of a suitable resilient material include, but are not limited to, neoprene, mineral wool, cellulose fibres, expanded polystyrene, or the likes.

Optionally, pad 6 substantially fills the portion of the void 10 intermediate the structural bottom panel 1 and the particulate material 5.

The provision of resilient support means 6, 8 to support particulate material 5 allows the mass of said particulate material to act as a damping material as described below.

The particulate material 5 located on the non-rigid support means provides a mass that improves the response of the floor cassette to footfall-induced vibration, as well as to sound transmission. Under vibration, the action of the particles of particulate material 5 rubbing together as they move turns their kinetic energy into heat energy, thereby acting as a damper to improve the response of the floor cassette to footfall- induced vibration.

Advantageously, the provision of a resilient pad 6 or flexible shelf 8 in accordance with examples of the present invention supporting the particulate material enhances activation of the aforementioned damping action, which overcomes the deficiency of prior art cassette-type floors that are known to be too stiff for optimal acoustic performance.

Optionally, the particulate material 5 is non-flammable.

Optionally, the particulate material 5 is inert.

Optionally, the particulate material 5 is a heavy inert particulate material.

Optionally, the particulate material comprises, for example, but is not limited to, sand, crushed concrete, crushed glass saw dust, or a mixture of suitable particulate materials.

Optionally, the particulate material 5 may be in granular form. In examples, the particulate material may be mixed with, or comprise, a saw dust fraction as it has been found that inclusion of a saw dust advantageously mitigates unwanted agglomeration of the particulate material, whether in particulate or granular form.

As shown by way of example using dashed lines in Figure 1a, the particulate material may be encapsulated or enclosed within a bag or bags 7.

Conveniently, the particulate material 5 provides fire protection to the sides of the rib members 2 in the event of the floor cassette being exposed to fire. The particulate material also provides fire protection at the upper in use region of the floor cassette assembly.

As shown by way of example in Figure 1b, 3 and 4, a suitable compressible material 4 such as, but not limited to, stone or mineral wool may be located between the particulate material 5 and the top panel 3, 3a in order to enhance vibration damping.

With reference to Figures 2 and 5, the otherwise open ends of the floor cassette assembly may be closed by an end panel 9. End panels 9 prevents the particulate material 5 from escaping from the cassette assembly. In addition, the particulate material also prevents ingress of water, and/or smoke, and/or heat into the floor cassette assembly. Encapsulation or enclosure of the particulate material in a bag or bags 7 further enhances the prevention of material escape, even if the event of damage or modification of the floor cassette.

As shown by way of example in Figuresla, 1b, 3 and 4, the interfaces between the various floor cassette components may be protected by water resistant elements or coverings 12 such as suitable tapes, strips, pads, patches or the likes.

With reference to Figures 3 and 4, floor cassette assemblies may be supported in use by structural support means, for example, but not limited to, steel beams 13 (Figure 3), walls 130, or the likes. By way of example in Figure 3, where adjacent floor cassettes are shown supported either side of a support beam 13 structural continuity across said support beam may be provided by extending a top panel 3b over the support beam such that is it connected to both cassettes, and/or by providing connecting elements 14 that transfer forces between the bottom panels 1 of the respective cassettes through the support beam 13

In addition to the particulate material 5 provided within the floor cassettes, particulate material 5 of the same or a different type may be used to encapsulate part or all of the structural support beam 13 as shown by way of example in Figure 3. Used in this way, the particulate material provides fire protection and footfall-induced vibration damping in the region of the structural support beam 13.

As shown in Figure 4, floor cassettes may be supported by a timber wall 130, or similar. In the example of Figure 4 no ancillary means for structural continuity such as a top panel, or no encapsulation with particulate material, is required due to the shorter spans and reduced fire resistance requirements inherent in this form of construction.

Modifications are possible within the scope of the present invention as defined in the appended claims.

Claims

1. A floor cassette assembly comprising:

A structural bottom panel having an upper surface and a lower surface, a plurality of spaced apart upstanding rib members attached to the upper surface of said panel, wherein adjacent spaced apart rib members define a void between said adjacent rib members, and support means located intermediate adjacent spaced apart rib members, the support means configured to support particulate material within the voids defined by the respective adjacent rib members at a location that is vertically spaced from the structural bottom panel.

2. A floor cassette assembly as claimed in claim 1 , wherein the support means configured to support the particulate material is a non-rigid support means.

3. A floor cassette assembly as claimed in claim 1 or claim 2, wherein the support means configured to support the particulate material is a resilient support means.

4. A floor cassette assembly as claimed in any preceding claim, wherein the support means comprises a shelf.

5. A floor cassette assembly as claimed in claim 3, wherein the shelf is a flexible shelf.

6. A floor cassette assembly as claimed in claim 4 or claim 5, wherein the shelf spans substantially across the width of the void defined between adjacent rib members.

7. A floor cassette assembly as claimed in any one of claims 4 to 6, wherein the shelf is mounted along its respective side edges upon support means provided on the respective rib members.

8. A floor cassette assembly as claimed in claim 7 wherein the side edges of the shelf are spaced apart from the respective rib members.

9. A floor cassette assembly as claimed in any one of claims 4 to 8, wherein the shelf is formed from any one of wood, metal, or plastic material.

10. A floor cassette assembly as claimed in any one of claims 1 to 3, wherein the support means configured to support the particulate material comprises a resilient pad.

11. A floor cassette assembly as claimed in claim 10, wherein the resilient pad substantially fills the portion of the void intermediate the granular material supported thereon and the structural bottom panel.

12. A floor cassette assembly as claimed in claim 10 or claim 11, wherein the resilient pad is formed from any one or more of neoprene, mineral wool, cellulose fibre, expanded polystyrene.

13. A floor cassette assembly as claimed in any preceding claim, wherein the support means for supporting the particulate material is configured to provide vibration damping.

14. A floor cassette assembly as claimed in any preceding claim, comprising a particulate material, wherein the particulate material comprises any one or more of sand, crushed concrete, crushed glass, saw dust, or a mixture thereof.

15. A floor cassette assembly as claimed in any preceding claim, wherein the particulate material is a granular particulate material.

16. A floor cassette assembly as claimed in any preceding claim, wherein the particulate material is contained with a bag or bags.

17. A floor cassette assembly as claimed in any preceding claim, further comprising a top panel, wherein the top panel spans across the upper ends of the rib members.

18. A floor cassette assembly as claimed in claim 17, wherein the top panel is a load-bearing panel.

19. A floor cassette assembly as claimed in claim 17, wherein the top panel is a non-structural panel.

20. A floor cassette assembly as claimed in any one of claims 17 to 19, further comprising a compressible material located intermediate the particulate material supported on the support means and the top panel, optionally wherein the compressible material comprises a mineral wool.

21. A floor cassette assembly as claimed in any preceding claim, further comprising one or more end panels configured to enclose the voids defined between the rib members and the structural bottom panel.

22. A floor cassette assembly as claimed in any preceding claim, wherein the structural bottom panel and the rib members are of wood construction.

23. A floor cassette assembly as claimed in any one of claims 17 to 22, wherein the top panel is of wood construction.

24. A floor cassette assembly as claimed in any one of claims 17 to 22, wherein the top panel is of plasterboard construction.

25. A floor cassette assembly as claimed in any preceding claim, wherein the structural bottom panel is fire resistant.

26. A floor cassette assembly as claimed in any preceding claim, wherein the structural bottom panel further comprises a fire protective layer, coating or finish.