GB2451092A

GB2451092A - Modular building structures with reclosable fasteners

Info

Publication number: GB2451092A
Application number: GB0713861A
Authority: GB
Inventors: Paul Plummer
Original assignee: WACO UK Ltd
Current assignee: WACO UK Ltd
Priority date: 2007-07-17
Filing date: 2007-07-17
Publication date: 2009-01-21
Also published as: GB0713861D0

Abstract

A volumetric unit 22 comprises a base 12 and a roof 10. At least one of a lower surface 26 of the base 12 and an upper surface 28 of the roof 10 comprises a reclosable securing means 38. Two or more of the volumetric units 22, 24 can be stacked to form a building. A building 20 comprising at least two volumetric units 22, 24 is also disclosed in which a second one 24 of the said at least two volumetric units is stacked on top of a first one 22 of the said at least two volumetric units 22, 24. The reclosable securing means 38 can be a fastener having a pair of interacting surfaces, with one part secured to each of the units, such as hook and loop fastener, an adhesive layer on one of the units, means to increase the coefficient of friction between units.

Description

1 2451092 Title: Building Structures

Description:

This invention relates to building structures and in particular, but without limitation to, temporary and/or prefabricated building structures.

It is known to assemble a temporary building, such as a site office, or accommodation block, by the appropriate positioning of prefabricated building modules. Each module can be fitted out for a particular purpose, e.g. office space, living space, catering etc, and different numbers of the different types of module can be arranged to create a temporary building, or in the case of larger projects, so-called "site villages".

Where the available footprint is limited, it is known to stack building modules on top of each other. However, this approach has a number of drawbacks.

To reduce costs, each module is only designed to be self-supporting -that is to support its own weight and to carry a specified, evenly-distributed roof weight (equivalent to a certain depth of snow I water). As such, the roof of each module tends to be designed to be weaker than the floor, which is designed to carry people, furniture, equipment etc. When the modules are not stacked, the floor is supported periodically on foundations. Therefore, the maximum floor span between foundations is quite small, which means that the floor itself does not need to be particularly strong to withstand high loads.

The problem that arises when modules are stacked on top of each other is thatthe floor ofan upper module is not supported on foundations, hence the floor span between support points is quite high. Unless the floor is reinforced, it may have a tendency to sag when loaded.

A known solution to this problem is to bolt the floor of the upper module to the roof of the lower module. Such an arrangement creates a composite or compound beam structure in which the roof and floor of stacked modules reinforce one another. This approach suffers the disadvantages of requiring accurate drilling of the holes for the bolts and accurate positioning of the modules relative to one another if the holes of respective modules are to align.

In practice, this is difficult to achieve, especially in a site environment. The present invention aims to provide a solution to one or more of the above problems.

According to a first aspect of the invention there is provided a volumetric unit comprising a base and a roof, wherein at least one of a lower surface of the base and an upper surface of the roof comprises a reclosable securing means.

The reclosable securing means is preferably arranged to prevent relative movement of the surfaces of adjacent volumetric units when stacked on top of one another.

The volumetric unit may comprise a building module or a prefabricated building. The volumetric unit may additionally comprise spacer means (e.g. vertical support beams or side walls) that are adapted to substantially rigidly maintain the base and roof in a spaced-apart relationship to one another.

According to a second aspect of the invention, there is provided a building comprising at least two volumetric units, a first one of the said at least two volumetric units being stacked on top of a second one of the said at least two volumetric units, wherein at least one of a lower surface of the first volumetric unit and an upper surface of the second volumetric unit comprises reclosable securing means for inhibiting or preventing relative movement of the said lower and upper surfaces.

According to a third aspect of the invention, there is provided a method of assembling a building comprising the steps of: providing at least two volumetric units, applying a reclosable securing means to at least one of a lower surface of the a first one of the at least two volumetric units and an upper surface of a second one of the at least two volumetric units; and placing the said first volumetric unit at least partially on top of the said second volumetric units.

The reclosable securing means is preferably adapted to prevent or inhibit lateral movement, e.g. slippage, of one surface relative to the other.

The reclosable securing means is preferably surface-mounted. The reclosable securing means may comprise a layer of adhesive applied to a surface of the volumetric unit. The adhesive, where provided, is re-stickable to permit the volumetric units or beams to be separated and re-stuck to one another.

The reclosable securing means preferably comprises a releasable fastening means, such as a hook and loop-type fastener (e.g. Velcro RTM) or a reclosable mushroom fastener (e.g. 3M RIM Dual Lock RTM or Duotec RIM) The term "reclosable mushroom fastener" is used herein to signify any reclosable fastener having mushroom-shaped projections that inter-engage to form a mechanical connection, for example as described in United States Patent No US6,558,602 to Minnesota Mining and Manufacturing.

Additionally or alternatively, the reclosable securing means may be adapted to increase the coefficient of friction between the surfaces. Where this is so, a layer of adhesive may be provided, the adhesive having a hard particulate substance, e.g. sand, admixed thereto.

Additionally or alternatively, the reclosable securing means may comprise a pair of opposing toothed or notched elements that together inhibit or prevent relative lateral movement, but allow axial movements.

The reclosable securing means are preferably provided at the area of maximum shear stress, or typically towards the ends of the volumetric units or beams.

The volumetric units may comprise a support frame. Walls, floors and roofs may be attachable to the support frame to create building modules of various types.

A yet further aspect of the invention, provides a composite/compound beam comprising a first elongate beam and a second elongate beam arranged, in use, to overlie the first elongate beam, and reclosable securing means located between the first and second beams adapted to inhibit or prevent movement of an upper surface of the first beam relative to a lower surface of the second beam.

Preferred embodiments of the invention shall now be described, by way of example only, with reference to the accompanying drawings in which: Figure 1 is a schematic side view of a pair of stacked beams under load; Figure 2 is a schematic side view of the beams cojoined and under load; Figure 3 is a schematic side view of a two-storey building structure in accordance with the invention, building modules making up the structure being shown slightly spaced apart for the sake of clarity; Figure 4 is a partial cross-section of Figure 3 on plane A; Figure 5 is a schematic cross-section through the fastener shown in Figure 3; Figure 6 is a perspective view of a h igh friction connection element; and; Figure 7 is a cross-section of Figure 6 on Vll-Vll.

In Figure 1, a first elongate beam 10 sits on a pair of point supports 14, 16. A second beam 12 rests on top of the first beam 10. A downward point load F is applied at the centre of the second beam. The load F is transferred through the second 12 and first beams 10 to the point supports 14, 16. The effect of the load F is to cause both beams 10, 12 to deflect.

Since the first 10 and second beams 12 are not secured to one other, they slide relative to one another. Specifically, the upper surface 18 of the first beam 10 appears to contract 20 relative to the lower surface 22 of the upper beam, which apparently expands 24.

A much stiffer arrangement can be obtained, as shown in Figure 2, if the upper surface 18 of the lower beam 10 is secured to the lower surface 22 ofthe upper beam 12 using connectors (not shown). Thus, instead ofthe opposing surfaces 18, 22 of the beam being able to move relative to one another thereby enabling the beam to deflect, the connectors carry a shear force t, which reduces significantly the amount of flexure. In effect, by connecting the beams to one another, the second moment of area of the composite beam is much greater, and hence its stiffness is much greater, than the sum of the stiffness of the two beams 10, 12 individually.

In Figures 3 and 4, a two-storey building structure 20 is formed by stacking an upper building module 22 on top of a lower building module 24.

Each building module 22, 24 comprises a volumetric unit of generally cuboidal shape, each having a floor deck 26, a roof deck 28 which is mono-pitched -higher at one end of the module than the other - and upright side and end walls 30, 31.

Along the longitudinal vertices of each building module 22, 24 run respective "C" channel sectioned members. In the drawings, the channel members along the lower vertices of each module are designated lOa, lOb and the channel members along the upper vertices of each module are designated 12a, 12b. It can be seen in Figure 4 that inwardly turned portions 13, 15 of the channel members provide surfaces through which one building module 22 can rest upon the other 24.

Figure 4 is a partial section through the assembled building structure 20, including only those parts seen within a square A in Figure 3 -i.e. this drawing includes only the upper channel members 12a, 12b of the lower building module 24 (and certain associated parts) and the lower channel members l0a, lOb of the upper building module 22 (and again, the drawing also shows certain associated parts secured to these channel members). The drawing has also been considerably foreshortened laterally for the sake of clarity. It can be seen that the roof deck 28 of the lower module 24 is mounted between channel members 12a, 12b. In this embodiment the roof deck 28 is a composite insulated panel whose contoured upper face 33 is seen in the drawing due to the pitch of the roof, the ridge of the roof being indicated at 35. Roof joists 37 are provided, extending between the channel members 12a, 12b and being welded to them, at intervals along the length of the channel members.

The lower channel members lOa, lOb of the upper module 22 are connected through floor joists 39, which again are provided at intervals along the length of the building module and are welded to the channel members.

The floor deck 26 is supported on upper surfaces of the lower channel members 12a, 12b.

It can be seen in Figure 4 that the inwardly turned portions 13 of the channel members lOa, lOb of the upper module 22 rest upon the corresponding inwardly turned portions 15 of the channel members 12a, 12b of the lower module 24. Also visible in this drawing are reclosable fastener arrangements 38 through which these portions of the channel members engage with one another.

According to the present embodiment, the reclosable fastener arrangements 38 comprise strips of mushroom fasteners applied to the channel portions 13, 15. The locations of the strips of mushroom fasteners on the lower building module 22 can be seen in Figure 3 at 38a-38d. In the present embodiment they are each approximately 1 metre in length and are positioned within 1.2 metres of the ends of the channel members. Note that corresponding fasteners are provided on the undersurface of the upper building module 22, although these are not seen in Figure 3. By resisting longitudinal motion of one channel member relative to the other in these regions, the fastener arrangements 38 cause the channel members together to serve as a composite or compound beam structure with improved stiffness.

Since the shear force and/or relative movement of the beams 10, 12 is greatest towards their ends, little additional stiffness is gained by extending the reclosable mushroom fastener 38 towards the centre of the beams 10, 12.

The weight of the upper module 24 presses the respective parts of the reclosable mushroom fastener 38 firmly together.

Reclosable mushroom fasteners have a characteristically high resistance to shear loading, but a relatively low resistance to tensile loading.

Thus, the reclosable mushroom fastener 38 is capable of preventing the relative slippage of the beams 10, 12 depicted in Figure 1, whilst being readily pulled apart to facilitate disassembly of the building structure 10 after use.

In Figure 5, it can be seen that reclosable mushroom fastener strip 38 comprises a support web 40 having on one side, an array stems 42 that each carry a substantially hemispherical engagement head 43. When pushed together, the flat surfaces 44 of the engagement heads 43 engage, thereby creating a mechanical connection between the opposing strips 38.

A strongly self-adhesive layer 46 is provided on the opposite side of the support web 40 to mushroom fastener elements 42, 43, which layer 46 adheres strongly to the under surface 26 of the upper module or the upper surface 28 of the lower module.

In Figures 6 and 7, a high friction connection element 50 is shown which can be used instead of the reclosable mushroom fastener previously described. The high friction element 50 comprises a backing plate 52 having an array of integrally formed protrusions 54 projecting therefrom. The back surface 56 of the high friction element 50 can be glued to a surface of the module using an adhesive layer 46 in the same way as the reclosable mushroom fastener elements previously described.

As can be seen, when two such high friction elements 50 are placed together with their protrusions 54 tessellating, the arrangement is highly resistant to shear loading 58, 60, whilst being free to separate under tensile loading 62.

Claims

Claims: 1. A volumetric unit comprising a base and a roof, wherein at least one of a lower surface of the base and an upper surface of the roof comprises a reclosable securing means.
2. A volumetric unit as claimed in claim 2, wherein the reclosable securing means is surface-mounted.
3. A volumetric unit as claimed in claim I or claim 12, wherein the reclosable securing means comprises any one or more of the group comprising: a layer of adhesive; a releasable fastening means, a reclosable mushroom fastener, a hook and loop-type fastener, means adapted to increase the coefficient of friction between the first and second beams, and a pair of opposing toothed, ridged or notched elements.
4. A volumetric unit as claimed in any of claims 1, 2 or 3, wherein the reclosable securing means are provided substantially at, or near to, the point of maximum shear stress.
5. A volumetric unit as claimed in any of claims 1 to 4, wherein the reclosable securing means are provided at, or towards the ends of the volumetric units.
6. A volumetric u nit as claimed i n a ny p receding claim, further comprising spacer means adapted to substantially rigidly maintain the base and roof in a spaced-apart relationship to one another.
7. A volumetric unit as claimed in claim 6, wherein the spacer means comprise side walls or upright support beams.
8. A volumetric unit as claimed in any preceding claim, wherein the base and/or the roof comprises a deck and a pair of structural elongate members extending along edges of the deck, the reclosable securing means being carried upon outer surfaces of the said members.
9. A building comprising at least two volumetric units, a first one of the said at least two volumetric units being stacked on top of a second one of the said at least two volumetric units, wherein at least one of a lower surface of the first volumetric unit and an upper surface of the second volumetric unit comprises reclosable securing means for inhibiting or preventing relative movement of the said lower and upper surfaces.
1O.A building as claimed in claim 9, wherein the reclosable securing means is adapted to prevent or inhibit slippage of the lower and upper surfaces.
11.A building beam as claimed in claim 9 or claim 10, wherein the reclosable securing means is surface-mounted.
12.A building as claimed in any of claims 9, 10 or 11, wherein the reclosable securing means comprises any one or more of the group comprising: a layer of adhesive; a releasable fastening means, a reclosable mushroom fastener, a hook and loop-type fastener, means adapted to increase the coefficient of friction between the lower and upper surfaces, and a pair of opposing toothed, ridged or notched elements.
13.A building as claimed in any of claims 9 to 12, wherein the reclosable securing means are provided substantially at, or near to, the point of maximum shear stress.
14.A building as claimed in any of claims 9 to 13, wherein the reclosable securing means are p rovided at, or towards the ends of the volumetric units.
15.A building as claimed in any of claims 9 to 14, wherein the lower surface of the first volumetric unit and an upper surface of the second volumetric unit comprises a beam for reinforcing the lower or upper surface.
16.A method of assembling a building comprising the steps of: providing at least two volumetric units, applying a reclosable securing means to at least one of a lower surface of the a first one of the at least two volumetric units and an upper surface of a second one of the at least two volumetric units; and placing the said first volumetric unit at least partially on top of the said second volumetric units.
17.A method as claimed in claim 14, comprising the step of providing at least one volumetric unit according to any of claims 1 to 7.
18.A volumetric unit substantially as hereinbefore described, with reference to and as illustrated in Figures 3 and 4 of the accompanying drawings.
19.A building substantially as hereinbefore described, with reference to and as illustrated in Figures 3 and 4 of the accompanying drawings.