GB2640540A

GB2640540A - An elongate box beam

Info

Publication number: GB2640540A
Application number: GB2405705.1A
Authority: GB
Inventors: Gill Bow; Carter Roger; Boxall Steve
Original assignee: Polibeam Ltd
Current assignee: Polibeam Ltd
Priority date: 2024-04-23
Filing date: 2024-04-23
Publication date: 2025-10-29
Also published as: WO2025224441A1; GB202405705D0

Abstract

A cuttable elongate box beam comprising: a first elongate wall defining a first exterior surface; a second elongate wall defining a second exterior surface; a first elongate side wall defining a first side, exterior surface; a second elongate side wall defining a second side, exterior surface; at least one elongate internal side wall, wherein the first elongate wall, the second elongate wall, the first elongate side wall, the second elongate side wall and the at least one elongate internal side wall define multiple elongate enclosed cells of different sizes. The beam may be locatable via edge formations and may be rotationally symmetrical in two degrees.

Description

TITLE

An elongate box beam

TECHNOLOGICAL FIELD

Examples of the disclosure relate to an elongate box beam. Some example relate to a plastic elongate box beam for use in building construction.

BACKGROUND

Elongate beams are often used in construction. They are often made from metal and have an I or H cross-section. The "beam and block" construction method is commonly used to create ground level flooring during construction of a building. A series of blocks, usually concrete, is supported by beams. Insulation material is laid over the blocks, followed by flooring material. Pipes and cables required to be installed in the flooring are usually laid beneath the insulation material.

BRIEF SUMMARY

According to various, but not necessarily all, embodiments there is provided a elongate box beam comprising: a first exterior surface; a second exterior surface; a first side, exterior surface; a second side, exterior surface; wherein the first exterior surface has, at a first lateral edge, a first surface recess of lower relief; and the first exterior surface, at a second lateral edge opposing the first lateral edge, defines an exterior surface of a first projecting lug, wherein the first recess and first projecting lug are correspondingly sized.

In some but not necessarily all examples, the elongate box beam is formed from polymer. n some but not necessarily all examples, the elongate box beam extends lengthwise parallel to a longitudinal axis and has a constant cross-sectional profile suitable for extrusion.

n some but not necessarily all examples, a cross-sectional profile of the first recess comprises a slope that is at an angle relative to an adjacent first flat portion of the first exterior surface and wherein a cross-sectional profile of the first projecting lug comprises a slope that is at the same angle relative to an adjacent second flat portion of the first exterior surface that is in a common plane with the first flat portion of the first exterior surface. n some but not necessarily all examples, the angle is less than 30.

In some but not necessarily all examples, the elongate box beam extends lengthwise parallel to a longitudinal axis, wherein the a cross-sectional profile of the first surface recess, in a plane perpendicular to the longitudinal axis, is substantially the same as a cross-sectional profile of the first projecting lug, in the same plane.

In some but not necessarily all examples, the first surface recess and lug are correspondingly sized such that in use the first surface recess is sized and positioned to receive a lug of a first elongate box beam similar to the elongate box beam located adjacent the elongate box beam at the first lateral edge and the first projecting lug is sized and positioned to be received by a recess of a second elongate box beam similar to the elongate box beam located adjacent the elongate box beam at the second lateral edge.

n some but not necessarily all examples, the second exterior surface has, at the second lateral edge, a second surface recess of lower relief; and the second exterior surface, at the second lateral edge opposing the first lateral edge, defines an exterior surface of a second projecting lug, wherein the second recess and second projecting lug are correspondingly sized, the second recess and first projecting lug are correspondingly sized and the first recess and second projecting lug are correspondingly sized.

In some but not necessarily all examples, the elongate box beam extends lengthwise parallel to a longitudinal axis, and has a constant exterior cross-sectional profile, in planes perpendicular to the longitudinal axis, that has rotation symmetry of order two. In some but not necessarily all examples, the elongate box beam has a constant interior cross-sectional profile, in planes perpendicular to the longitudinal axis, that has rotation symmetry of order one.

In some but not necessarily all examples, the elongate box beam comprises: a first elongate end wall defining the first exterior surface; a second elongate end wall defining the second exterior surface; a first elongate side wall defining the first side, exterior surface; a second elongate side wall defining the second side, exterior surface; at least one elongate internal side wall, wherein the first elongate end wall, the second elongate end wall, the a first elongate side wall, the second elongate side wall and the at least one elongate internal side wall define multiple elongate enclosed cells.

In some but not necessarily all examples, the at least one internal side walls extend between the first end wall and the second end wall.

In some but not necessarily all examples, the at least one internal side walls are substantially parallel and extend for at least 200mm between the first end wall to the second end wall thereby creating a cavities for receiving push fit cellular polystyrene insulation blocks.

In some but not necessarily all examples, each of the elongate cells has a substantially rectangular constant cross-section in planes perpendicular to the longitudinal axis, wherein a depth of a cell between the first and second end walls is greater than a width of a cell perpendicular to the depth and the longitudinal axis.

In some but not necessarily all examples, the elongate box beam comprises multiple internal side walls defining multiple enclosed elongate cells having a common depth but different widths.

In some but not necessarily all examples, a first elongate cell has a width of 45mm, second elongate cell of width of 145mm and a third cell of width of 90mm wherein the second cell is adjacent the first and third cells.

In some but not necessarily all examples, the elongate box beam comprises double-sided adhesive membrane attached to at least one of the first side, exterior surface and the second side, exterior surface.

In some but not necessarily all examples, the first exterior surface is a substantially flat and has a textured surface comprising a crenelated pattern in cross-section and the second exterior surface is a substantially flat and textured surface comprising a crenelated pattern in cross-section.

In some but not necessarily all examples, there is provided an insulated elongate box beam comprising: an elongate box beam as claimed in any preceding claim having one or more elongate, hollow cells; one or more removable elongate push-fit blocks of insulating material positioned within the one or more elongate, hollow cells.

In some but not necessarily all examples, there is provided a set of parts for creating an insulated elongate box beam comprising: an elongate box beam as claimed in any preceding claim having one or more elongate, hollow cells; and one or more elongate push-fit blocks of insulating material sized to be positioned within the one or more elongate, hollow cells.

In some but not necessarily all examples, there is provided a tensioned elongate box beam comprising: an elongate box beam as claimed in any preceding claim comprising multiple internal elongate hollow tubes for housing respective tendons; a first end plate abutting the elongate box beam at one end of its length; a second end plate abutting the elongate box beam at the other end of its length; and multiple tendons each extending, under tension, between a respective fixture at the first end plate to a respective fixture at the second end plate through a respective one of the multiple internal elongate hollow tubes.

In some but not necessarily all examples, there is provided a building or building product comprising: multiple elongate box beams as claimed in any preceding claim, arranged parallel, side-by-side, projecting lug into recess.

In some but not necessarily all examples, there is provided a building comprising: a floor comprising: multiple elongate box beams as claimed in any preceding claim, arranged parallel, side-by-side, projecting lug into recess.

In some but not necessarily all examples, the floor is 1-span and the multiple elongate box beams are supported by a first hanger at their first longitudinal extremities and by a second hanger at their second longitudinal extremities.

In some but not necessarily all examples, there is provided amethod of on-site construction comprising: on-site cutting of elongate box beams as claimed in any of claims 1 to 19; positioning the cut elongate box beam on supports; repeatedly positioning next cut elongate box beam by: placing the next cut elongate box beam on the supports and sliding the next cut elongate box beam laterally into parallel side-by-side abutment with the positioned cut elongate box beam such that a projecting lug of the next cut elongate box beam slides into a recess of the abutted positioned cut elongate box beam.

In some but not necessarily all examples, there is provided a method as claimed in claim 25, comprising on-site cutting to reduce a length of elongate box beams and/or on-site cutting to reduce a width of one or more elongate box beams.

According to various, but not necessarily all, embodiments there is provided a cuttable elongate box beam comprising: a first elongate wall defining a first exterior surface; a second elongate wall defining a second exterior surface; a first elongate side wall defining a first side, exterior surface; a second elongate side wall defining a second side, exterior surface; at least one elongate internal side wall, wherein the first elongate wall, the second elongate wall, the first elongate side wall, the second elongate side wall and the at least one elongate internal side wall define multiple elongate enclosed cells of different sizes.

In some but not necessarily all examples, the at least one internal side walls extend between the first elongate wall and the second elongate wall and is substantially perpendicular to both the first exterior surface and the second exterior surface. In some but not necessarily all examples, the at least one internal side walls are substantially parallel and extend for at least 200mm between the first end wall to the second end wall thereby creating cells for receiving push fit cellular polystyrene insulation blocks.

In some but not necessarily all examples, each of the elongate enclosed cells has a substantially rectangular constant cross-section in planes perpendicular to a longitudinal axis, wherein a depth of a cell between the first and second walls is greater than a width of a cell perpendicular to the depth and the longitudinal axis.

In some but not necessarily all examples, the cuttable elongate box beam comprises multiple internal side walls defining multiple enclosed elongate cells having a common depth but different widths.

In some but not necessarily all examples, a first elongate cell has a width of 45mm, a second elongate cell has a width of 145mm and a third cell has a width of 90mm wherein the second cell is adjacent, width wise, the first and third cells.

In some but not necessarily all examples, the cuttable elongate box beam as claimed in any preceding claim, formed from polymer.

In some but not necessarily all examples, the cuttable elongate box beam extends lengthwise parallel to a longitudinal axis, and has a constant cross-sectional profile suitable for extrusion.

In some but not necessarily all examples, the cuttable elongate box beam extends lengthwise parallel to a longitudinal axis, and has a constant exterior cross-sectional profile, in planes perpendicular to the longitudinal axis, wherein the constant exterior cross-sectional profile has rotation symmetry of order two.

In some but not necessarily all examples, the cuttable elongate box beam has a constant interior cross-sectional profile, in planes perpendicular to the longitudinal axis, wherein the constant interior cross-sectional profile has rotation symmetry of order one.

According to various, but not necessarily all, embodiments there is provided examples as claimed in the appended claims.

While the above examples of the disclosure and optional features are described separately, it is to be understood that their provision in all possible combinations and permutations is contained within the disclosure. It is to be understood that various examples of the disclosure can comprise any or all the features described in respect of other examples of the disclosure, and vice versa. Also, it is to be appreciated that any one or more or all the features, in any combination, may be implemented by/comprised in/performable by an apparatus, a method, and/or computer program instructions as desired, and as appropriate. The description of a function should additionally be considered to also disclose any means suitable for performing that function

BRIEF DESCRIPTION

Some examples will now be described with reference to the accompanying drawings in which: FIGs 1, 2, 3A, 3B illustrate external features of an elongate box beam; FIGs 4A & 4B, 5A & 5B, 6A & 6B illustrate side-by-side interconnection of elongate box beams in the same or different rotational orientations; FIGs 7A & 7B, 8A & 8B, 9A & 9B, 10A & 10B illustrate internal features of an elongate box beam including cells, and longitudinal cell-by-cell cutting of the elongate box beam; FIGs 11A & 11 B, 12A & 12B, 13A & 13B illustrate adhering side-by-side interconnected elongate box beams; FIGs 14A & 14B, 15 illustrate an insulated elongate box beam, the push fit insulation blocks used for insulation of an elongate box beam to form an insulated elongate box beam and friction features used to retain the push fit insulation blocks used for insulation within cells of the elongate block beam; FIGs 16 illustrates a full length of an elongate block beam; FIGs 17A & 17B illustrate floors formed from interconnecting elongate box beams; FIGs 18 illustrates a wall formed from interconnecting elongate box beams; FIGs 19A & 19B, 20A & 20B, 21 illustrate different mechanisms for supporting elongate box beams to form a floor; FIGs 22 and 23 illustrate more detailed examples of the elongate box beam; FIG 24 illustrate external features of an elongate box beam having a different external profile; FIGs 25A & 25B illustrate tensioning of an elongate box beam.

The figures are not necessarily to scale. Certain features and views of the figures can be shown schematically or exaggerated in scale in the interest of clarity and conciseness. For example, the dimensions of some elements in the figures can be exaggerated relative to other elements to aid explication. Similar reference numerals are used in the figures to designate similar features. For clarity, all reference numerals are not necessarily displayed in all figures.

In the following description a class (or set) can be referenced using a reference number without a subscript index (e.g. 10) and a specific instance of the class (member of the set) can be referenced using the reference number with a numerical type subscript index (e.g. 10_1) and a non-specific instance of the class (member of the set) can be referenced using the reference number with a variable type subscript index (e.g. 10_i).

DETAILED DESCRIPTION

The following description relates to an elongate beam 10. An example of a full length of an elongate beam 10 is illustrated in FIG 16. The beam 10 extends lengthwise (L) parallel to a longitudinal axis 4.

A common cartesian coordinate system is used in the FIGs defined by a width wise direction W, a height wise direction H and a lengthwise direction L. The lengthwise direction L is parallel to a longitudinal axis 4 of the elongate beam 10. The width wise direction W, height wise direction H and lengthwise direction L are mutually orthogonal, with H= W x L (vector product).

The elongate beam 10 comprises a first exterior surface 20_1 and an opposing second exterior surface 20_2 and comprises a first side, exterior surface 22_1 and an opposing second side, exterior surface 22_2.

In use the first side, exterior surface 22_1 and the second side, exterior surface 22_2 form side (lateral) surfaces of the beam. In use one of the first exterior surface 20_1 and the second exterior surface 20_2 forms an upper (top) side of the beam and the other one of the first exterior surface 20_1 and the second exterior surface 20_2 forms a lower (bottom) side of the beam. The beam is designed to transmit a load first exterior surface 20_1 and the second exterior surface 20_2 and they can be referred to as first exterior load surface 20_1 and the second exterior load surface 202 or first exterior end surface 20_1 and the second exterior end surface 202 if it is necessary to further differentiate them from the first side, exterior surface 22_1 and the second side, exterior surface 22_2.

The elongate beam 10 is a box beam meaning that the first side, exterior surface 22_1 and the opposing second side, exterior surface 22_2 are separated and are not closely spaced as in an I-beam or H-beam. In some examples, the separation between the first side, exterior surface 22_1 and the opposing second side, exterior surface 22_2 is similar to or greater than a separation between the first exterior surface 20_1 and the opposing second exterior surface 20_2.

In at least some examples, the first exterior surface 20_1 has, at a first lateral edge 23_1, a first surface recess 40_1 of lower relief and the first exterior surface 20_1, at a second lateral edge 23_2 opposing the first lateral edge 23_1, defines an exterior surface of a first projecting lug 30_1. The first surface recess 40_1 and the first projecting lug 30_1 are correspondingly sized.

The term 'lower relief as applied an exterior surface 20 means an area that is displaced from (lower than) the exterior surface 20 when the exterior surface 20 is upward facing.

In at least some examples, the elongate box beam 10 is a cuttable elongate box beam 10 comprising multiple elongate enclosed cells 62 of different sizes. A first elongate end wall 72_1 defines the first exterior surface 20_1 and a second elongate end wall 72_2 defines the second exterior surface 20_2. A first elongate side wall 74_1 defines the first side, exterior surface 22_1 and a second elongate side wall 74_2 defines a second side, exterior surface 22_2. at least one elongate internal side wall 60. The first elongate end wall 72_1, the second elongate end wall 72_2, the first elongate side wall 74_1, the second elongate side wall 74_2 and at least one elongate internal side wall 60 define multiple elongate enclosed cells 62 of different sizes.

In at least some examples, the elongate box beam 10 is formed from polymer for example man-made polymer. The polymer can, in at least some examples be or comprise recycled polymer.

In at least some examples, the elongate box beam 10 is formed from plastic or plastics for example a thermoplastic. An example of a suitable plastic is polyvinylchloride (PVC) which is also a polymer. The plastic can, in at least some examples be or comprise re-cycled plastic or plastics.

In at least some examples, the elongate box beam 10 is formed by extrusion and the elongate box beam 10 is an extrudate comprising at least some artefacts from the extrusion process.

In at least some examples, the elongate box beam 10 has a design that facilitates extrusion. In at least some examples, the elongate box beam 10 has a constant cross-sectional profile (external profile and internal profile), in planes perpendicular to the longitudinal axis, suitable for extrusion.

In at least some examples, the elongate box beam 10 has cross-sectional profile (external profile and internal profile) where cross-sectional corners are rounded corners.

FIG 1 illustrates a perspective view of an example of the elongate box beam 10 highlighting its exterior surfaces. The FIG illustrates exterior surfaces and does not illustrate internal structure of the elongate box beam 10. The absence of an illustration of an internal structure of the elongate box beam 10 does not necessarily indicate an absence of an internal structure. Later FIGs focus on possible internal structures which may or may not be present. FIG 2 illustrates a cross-sectional view of the example of the elongate box beam 10 in FIG 1. The cross-section is in a plane that is perpendicular to a longitudinal axis 4 of the elongate box beam 10 illustrated in FIG 1. FIG 3A is a magnification of the portion of FIG 2 showing the first projecting lug 30_1. FIG 3B is a magnification of the portion of FIG 2 showing the first surface recess 40_1.

The elongate box beam 10 comprises a first exterior surface 20_1 and an opposing second exterior surface 20_2 and comprises a first side, exterior surface 22_1 and an opposing second side, exterior surface 22_2.

In at least some examples, in the plane perpendicular to the longitudinal axis 4 (L), the first lateral edge 23_1 is separated from the second lateral edge 23_2 by a distance that is substantially the same as a distance separating the first side, exterior surface 22_1 and an opposing second side, exterior surface 22_2. This can be observed in FIG 3. The size w1 of the first projecting lug 30_1 in the width wise direction (VV) is the same as the size w1 of the first surface recess 40_1 in the width wise direction (VV). The size wl of the first projecting lug 30_1 in the width wise direction (VV) can be the same as the size w1 of the first surface recess 40_1 in the width wise direction (W) while still being slightly smaller. The term implies a similarity to achieve a close-fitting of lug into recess of an adjacent beam 10.

In the example illustrated, but not necessarily all examples, in the plane perpendicular to the longitudinal axis 4 (L), the first side, exterior surface 22_1 and an opposing second side, exterior surface 22_2 extend in parallel. In the example illustrated, but not necessarily all examples, in the plane perpendicular to the longitudinal axis 4 (L), the first side, exterior surface 22_1 and an opposing second side, exterior surface 22_2 extend in parallel predominantly or exclusively in the height wise direction (H). They may in some examples extend to some extent also in the width wise direction (see FIG 23).

In the example illustrated in FIG 2, but not necessarily all examples, in the plane perpendicular to the longitudinal axis 4 (L), the first side, exterior surface 22_1 and an opposing second side, exterior surface 22_2 extend in parallel perpendicularly to the longitudinal axis 4 (L) in a height wise direction (H).

In the example illustrated, but not necessarily all examples, the first exterior surface 20_1 is substantially flat and extends in the width wise direction (VV) and the lengthwise direction (L). The first exterior surface 20_1 can be smooth or have surface configuration. If it has surface configuration then the surface configuration can be formed from variations in relief from a flat plane. The variations in relief from the flat plane can form a regular relief pattern.

As illustrated in FIG 1, the first surface recess 40_1 is elongate and extends, with the same cross-sectional profile in the lengthwise direction (L).

As illustrated in FIG 1, the first projecting lug 30_1 is elongate and extends, with the same cross-sectional profile in the lengthwise direction (L).

The first surface recess 40_1 and the first projecting lug 30_1 are correspondingly sized such that in use the first surface recess 40_1 is sized and positioned to receive a projecting lug 30 of a first elongate box beam 10 similar to the elongate box beam 10 located adjacent the elongate box beam 10 at the first lateral edge 23_1 and the first projecting lug 30_1 is sized and positioned to be received by a surface recess 40 of a second elongate box beam 10 similar to the elongate box beam 10 located adjacent the elongate box beam 10 at the second lateral edge 23_2.

In at least some examples, a close-fitting of lug into recess of an adjacent beam 10 is achieved.

In the examples illustrated, but not necessarily all examples, the cross-sectional profile of the first surface recess 40_1, in a plane perpendicular to the longitudinal axis 4, is substantially the same as a cross-sectional profile of the first projecting lug 30_1, in the same plane. The term 'same' implies a similarity to achieve a close-fitting of lug into recess of an adjacent beam 10 In this example, but not necessarily all examples, the cross-sectional profiles (across the lengthwise direction (L), in the height wise direction (H) and the width wise direction (VV)), of the first surface recess 40_1 and the first projecting lug 30_1 are sized such that the shape of additional material of the first projecting lug 30_1 substantially matches the shape of the is absence of material of the first surface recess 40_1. The cross-sectional profile of the first surface recess 40_1 is the negative of the cross-sectional profile of the first projecting lug 30_1. The term 'matches' implies a similarity to achieve a close-fitting of lug into recess of an adjacent beam 10.

As illustrated in FIG 3B, a cross-sectional profile (across the lengthwise direction (L), in the height wise direction (H) and the width wise direction (VV),) of the first surface recess 40_1 comprises a slope that is at an angle 50_2 relative to the width wise direction (VV). In this example, the angle 50_2 is relative an adjacent first flat portion of the first exterior surface 20_1. In at least some examples, the angle 50_1 is less than 3°.

The slope slopes upwards from a larger depth h2 furthest from the first lateral edge 23_1 (at the first side, exterior surface 22_1) to a depth h1 nearest the first lateral edge 23_1. In this example, the cross-sectional profile of first surface recess 40_1 is a trapezium shape. The two parallel sides of the trapezium shape are formed by a virtual line between the first lateral edge 23_1 and the end of the upward slope and a parallel line extending through the start of the upward slope (at the first side, exterior surface 22_1).The slope forms a side of the trapezium shape. In this example the trapezium is a right trapezium and the two parallel sides of the trapezium are perpendicular to the fourth side of the trapezium which is in the plane of the first exterior surface 20_1.

As illustrated in FIG 3A, a cross-sectional profile (across the lengthwise direction (L), in the height wise direction (H) and the width wise direction (VV),) of the first projecting lug 30_1 comprises a slope that is at an angle 50_1 relative to the width wise direction (VV). In this example, the angle 50_2 is relative an adjacent second flat portion of the first exterior surface 20_1 that is in a common plane with the first flat portion of the first exterior surface 20_1. In at least some examples, the angle 50_1 is less than 3°. In at least some examples, the angle 50_1 is the same as the angle 50 2.

The slope slopes upwards from a larger depth h2 furthest from the second lateral edge 23_2 (at the second side, exterior surface 22_2) to a smaller depth h1 nearest the second lateral edge 23_2. In this example, the cross-sectional profile of the first projecting lug 30_1 is a trapezium shape. The two parallel sides of the trapezium shape are formed by a virtual line between the second lateral edge 23_2 and the end of the upward slope and a parallel line extending through the start of the slope at the second side, exterior surface 22_2.The slope forms a side of the trapezium. In this example the trapezium is a right trapezium and the two parallel sides of the trapezium are perpendicular to the fourth side of the trapezium which is in the plane of the first exterior surface 20_1.

The trapezium shape of the first projecting lug 30_1 matches the trapezium shape of the first surface recess 40_1. The term 'matches' implies a similarity to achieve a close-fitting of lug into recess of an adjacent beam 10.

In the example illustrated, but not necessarily all examples, the second exterior surface 20_2 has, at a first lateral edge 25_1, a second surface recess 40_2 of lower relief; and the second exterior surface 20_2, at a second lateral edge 25_2 opposing the first lateral edge 25_1, defines an exterior surface of a second projecting lug 30_2. The second surface recess 40_2 and the second projecting lug 30_2 are correspondingly sized.

In addition, the second surface recess 40_2 and the first projecting lug 30_1 are correspondingly sized and the first surface recess 40_1 and the second projecting lug 30_2 are correspondingly sized.

The description provided above for the first projecting lug 30_1 and the first surface recess 40_1 can also apply to the description of the second projecting lug 30_2 and the second surface recess 40_2.

As illustrated in FIG 1, the second surface recess 40_2 is elongate and extends, with the same cross-sectional profile in the lengthwise direction (L). As illustrated in FIG 1, the second projecting lug 30_2 is elongate and extends, with the same cross-sectional profile in the lengthwise direction (L).

The second surface recess 40_2 and the second projecting lug 30_2 are correspondingly sized such that in use the second surface recess 40_2 is sized and positioned to receive a projecting lug 30 of a first elongate box beam 10 similar to the elongate box beam 10 located adjacent the elongate box beam 10 at the first lateral edge 25_1 and the second projecting lug 30_2 is sized and positioned to be received by a surface recess 40 of a second elongate box beam 10 similar to the elongate box beam 10 located adjacent the elongate box beam 10 at the second lateral edge 25 2.

The cross-sectional profile of the second surface recess 40_2, in a plane perpendicular to the longitudinal axis 4, is substantially the same as a cross-sectional profile of the second projecting lug 30_2, in the same plane (and also substantially the same as a cross-sectional profile of the first projecting lug 30_1 and the first surface recess 40_1, in the same plane).

In this example, but not necessarily all examples, the cross-sectional profiles (across the lengthwise direction (L), in the height wise direction (H) and the width wise direction (VV)), of the second surface recess 40_1 and the second projecting lug 30_2 are sized such that the shape of additional material of the second projecting lug 30_2 substantially matches the shape of the and absence of material of the second surface recess 40_2. The cross-sectional profile of the second surface recess 40_2 is the negative of the cross-sectional profile of the second projecting lug 30_2 (and of the first projecting lug 30_1).

The cross-sectional profile (across the lengthwise direction (L), in the height wise direction (H) and the width wise direction (VV),) of the second surface recess 40_2 comprises a slope that is at an angle relative to the width wise direction (VV). The angle is relative an adjacent first flat portion of the second exterior surface 20_2. In at least some examples, the angle is less than 3°. In at least some examples, the angle is the same as the angle 50_1 and the angle 50_2.

The slope slopes from a larger depth h2 furthest from the first lateral edge 25_1 (at the second side, exterior surface 22_2) to a depth h1 nearest the first lateral edge 25_1. In this example, the cross-sectional profile of second surface recess 40_2 is a trapezium shape. The two parallel sides of the trapezium shape are formed by a virtual line between the first lateral edge 25_1 and an end point of the slope and a parallel line extending through the other endpoint of the slope (at the second side, exterior surface 22_2).The slope forms a side of the trapezium. In this example the trapezium is a right trapezium and the two parallel sides of the trapezium are perpendicular to the fourth side of the trapezium which is in the plane of the second exterior surface 202.

The cross-sectional profile (across the lengthwise direction (L), in the height wise direction (H) and the width wise direction (W),) of the second projecting lug 30_2 comprises a slope that is at an angle relative to the width wise direction (W). The angle is relative an adjacent second flat portion of the second exterior surface 20_2 that is in a common plane with the first flat portion of the second exterior surface 20_2. In at least some examples, the angle is less than 3°. In at least some examples, the angle is the same as the angle 50_1 and the angle 50_2.

The slope slopes from a larger dimension h2 of the second projecting lug 30_2, furthest from the second lateral edge 25_2 (at the first side, exterior surface 22_1), to a smaller dimension h1 of the second projecting lug 30_2 nearest the second lateral edge 25_2. In this example, the cross-sectional profile of the second projecting lug 30_2 is a trapezium shape. The two parallel sides of the trapezium shape are formed by a line between the second lateral edge 25_2 and the nearest endpoint of the slope and a parallel line extending through the other endpoint of the slope at the first side, exterior surface 22_1.The slope forms a side of the trapezium. In this example the trapezium is a right trapezium and the two parallel sides of the trapezium are perpendicular to the fourth side of the trapezium which is in the plane of the second exterior surface 20_2.

The trapezium shape of the second projecting lug 30_1 matches the trapezium shape of the second surface recess 40_2 ( and matches the trapezium shape of the first projecting lug 30_1, and matches the trapezium shape of the first surface recess 40_1). The term 'matches' implies a similarity to achieve a close-fitting of lug into recess of an adjacent beam 10.

As illustrated in FIG 4A and 4B, the first surface recess 40_1 and the first projecting lug 30_1 are correspondingly sized such that in use the first surface recess 40_1 of the elongate box beam 10 is sized and positioned to receive a projecting lug 30_1 of a first elongate box beam 10_1 (similar to the elongate box beam 10) located adjacent the elongate box beam 10 at the first side and the first projecting lug 30_1 is sized and positioned to be received by a surface recess 40_1 of a second elongate box beam 10 similar to the elongate box beam 10 located adjacent the elongate box beam 10 at the second side.

The side-by-side, abutting elongate box beams 10_2, 10, 10_1 form a substantially continuous and flat upper surface from the closely fitting first exterior surfaces 20_1 of the abutting elongate box beams 10_2, 10, 10_1.

The second surface recess 40_2 and the second projecting lug 30_2 are also correspondingly sized such that in use the second surface recess 40_2 of the elongate box beam 10 is sized and positioned to receive a projecting lug 30_2 of a second elongate box beam 10_2 (similar to the elongate box beam 10) located adjacent the elongate box beam 10 at the second side and the second projecting lug 30_2 of the elongate box beam 10 is sized and positioned to be received by a surface recess 40_2 of the first elongate box beam 10 (similar to the elongate box beam 10) located adjacent the elongate box beam 10 at the first side.

The side-by-side, abutting elongate box beams 10_2, 10, 10_1 form a substantially continuous and flat lower surface from the closely fitting second exterior surfaces 20_21 of the abutting elongate box beams 10_2, 10, 10_1 The overlap provided by the projecting lugs 30 of an elongate box beam with respect to the surface recesses 40 of the adjacent and abutting side-by-side elongate box beams 10_1, 10_2 can provide a seal or barrier for the transfer of liquids and/or gases through the interconnected arrangement of elongate beams.

The projecting lugs 30_1, 30_2 of an elongate box beam fit into the surface recesses of the surface's adjacent and abutting side-by-side elongate box beams 10_1, 10-2 and a fixing, for example a screw, can be screwed through the a projecting lug 30_1, 30_2 of an elongate box beam into the abutting, adjacent elongate box beams 10_1, 10 2.

The corresponding slopes of the projecting lugs 30 and surface recesses 40 facilitate the sliding engagement of lug 30 into surface recess 40.

FIG 5A illustrates an exterior cross-sectional profile of the elongate box beam 10 in a first rotational orientation with respect to a central longitudinal axis 4. In this first orientation the first exterior surface 20_1 is an upper surface and the second exterior surface 20_2 is a lower surface.

FIG 5B illustrates an exterior cross-sectional profile of the elongate box beam 10 in a second rotational orientation with respect to the central longitudinal axis 4. In this first orientation the first exterior surface 20_1 is a lower surface and the second exterior surface 20_2 is an upper surface.

The transformation between the first rotational orientation and the second rotational orientation is a 180° rotation about the central longitudinal axis 4.

The elongate box beam 10, as previously described, extends lengthwise (into the page) parallel to the central longitudinal axis 4 with a constant exterior cross-sectional profile. The exterior cross-sectional profile has rotation symmetry of order two about the central longitudinal axis 4. The shape of the exterior cross-sectional profile in FIG5A is the same as the shape of the exterior cross-sectional profile in FIG 5B.

FIGs 6A and 6B are similar to FIGs 4A and 4B and illustrate that an interconnected arrangement of elongate beams can be formed where all of the side-by-side elongate box beams 10 has the same first orientation(FIG 4A and 4B) but also when any one or more of the side-by-side elongate box beams 10 have a second orientation.

The projecting lug 30_i of one beam can fit into the surface recess 40_j of an adjacent beam and vice versa.

An elongate box beam 10 to be added to another elongate box beam 10 to form or extend an interconnected arrangement of elongate box beams can therefore be used in either the first rotational orientation or the second rotational orientation.

FIG 7A is similar to FIG 5A. Not only does FIG 7A illustrates an exterior cross-sectional profile of the elongate box beam 10 in the first rotational orientation with respect to a central longitudinal axis 4 but it also illustrates an example of an interior structure for the elongate box beam 10.

FIG 7B is similar to FIG 5B. Not only does FIG 7B illustrates an exterior cross-sectional profile of the elongate box beam 10 in the second rotational orientation with respect to a central longitudinal axis 4 but it also illustrates the same interior structure for the elongate box beam 10 as illustrated in FIG 7A.

The interior structure for the elongate box beam 10 has a first rotational orientation in FIG 7A and a second rotational orientation in FIG 7B. The shape of the interior cross-sectional profile in FIG7A is not the same as the shape of the interior cross-sectional profile in FIG 7B.

The interior structure for the elongate box beam 10 in this example is defined by a constant interior cross-sectional profile, in planes perpendicular to the longitudinal axis 4. The elongate box beam 10 extends lengthwise (into the page) parallel to the central longitudinal axis 4 with a constant interior cross-sectional profile that has rotation symmetry of order one about the central longitudinal axis 4.

The exterior cross-sectional profile has rotation symmetry of order two about the central longitudinal axis 4.

In this example but not necessarily all examples, there are multiple cells 62 of different widths (in the width wise direction \/1/).

In this example but not necessarily all examples, there are multiple cells 62 centrally aligned such that a virtual line in the width wise direction (VV) bi-sects each cell in the height wise direction (H).

In this example but not necessarily all examples, there are multiple cells 62 centrally and symmetrically aligned such that a virtual line in the width wise direction (VV) bisects each cell in the height wise direction (H) and the portion of a cell on one side of the virtual line has reflection symmetry in that line with the portion of the same cell on the other side of the line.

In this example but not necessarily all examples, there are multiple cells 62 edge aligned such that the extremities of the cells in the height wise direction (H) are aligned along two parallel virtual lines in the width wise direction (VV).

In this example but not necessarily all examples, the maximum depth of the cells 62 in the height wise direction is substantially the same.

In this example but not necessarily all examples, the median depth of the cells 62 in the height wise direction is substantially the same.

In this particular example, there are three (closed) cells 62_1, 62_2 and 62_3 of different widths (in the width wise direction \AO. The cells 62_1, 62_2 and 62_3 have respective widths a, b, c.

In FIG 7A, the cells 62_1, 62_2 and 62_3 are in order 62_1, 62_2 and 62_3 in the page. This ordered set of cells 62 has a respective ordered set of widths {a, b, In FIG 7B, the cells 62_1, 62_2 and 62_3 are in order 62_3, 62_2 and 62_1 in the page. This ordered set of cells has a respective ordered set of widths {c, b, a}.

The cells are separated from each other by one or more internal walls 60.

In this example, but not necessarily all examples, the N cells 60 are arranged side-by side width wise and are separated by N-1 interior walls. In this example, N=3, but N can be a different value in other examples.

In this example, but not necessarily all examples, interior walls 60_1, 60_2 are parallel walls.

In this example, but not necessarily all examples, interior walls 60_1, 60_2 extend parallel with the height wise direction (H) and perpendicular to the width wise direction (VV).

The interior walls 60_1, 60_2 extend from a first end wall 72_1 that defines the first exterior surface 20_1 to a second end wall 72_2 that defines the second exterior surface 20_2.

In this example, but not necessarily all examples, the cells 62 have the same depth in the height wise direction (H) and different widths in the width wise direction (VV).

In this example, but not necessarily all examples, each cells 62 has a depth in the height wise direction (H) that is greater than its with in the width wise direction (VV).

In this example, but not necessarily all examples, each cell 62 comprises opposing parallel elongate sides and opposing parallel elongate ends. The opposing parallel elongate sides and opposing parallel elongate ends are orthogonal to each other. The opposing parallel elongate sides and opposing parallel elongate ends lie on a rectangle and, while there may be additional features (2, 64 see FIG 15, 22, 23) the profiles of the cells 62 are substantially rectangular.

In this example, a first elongate closed cell 62_1 is formed by parallel end walls 72_1, 72_2 and parallel side walls 74_2, 60_1 one of which is an exterior side wall defining a second side, exterior surface 22_2 and one of which is a first interior wall 60_1 separating the first elongate closed cell 62_1 from a second elongate closed cell 62_2.

The second elongate closed cell 62_2 is formed by parallel end walls 72_1, 72_2 and parallel side walls 60_1, 60_2 one of which is the first interior wall 60_1 separating the second elongate closed cell 62_2 from the first elongate second closed cell 62_1 and one of which is a second interior wall 60_2 separating the second elongate closed cell 62_2 from a third elongate closed cell 62_1.

The third elongate closed cell 62_2 is formed by parallel end walls 72_1, 72_2 and parallel side walls 60_2, 74_1 one of which is the second interior wall 60_2 separating the third elongate closed cell 62_3 from the second elongate closed cell 62_2 and one of which is an exterior side wall defining a first side, exterior surface 22 1 An elongate box beam 10 can therefore comprise: a first elongate end wall 72_1 defining the first exterior surface 20_1; a second elongate end wall 72_2 defining the second exterior surface 20_2; a first elongate side wall 74_1 defining the first side, exterior surface 22_1; a second elongate side wall 74_2 defining the second side, exterior surface 22_2; at least one elongate internal side wall 60, wherein the first elongate end wall 72_1, the second elongate end wall 72_2, the first elongate side wall 74_1, the second elongate side wall 74_2 and the at least one elongate internal side wall 60 define multiple elongate enclosed cells 62.

In this example, the at least one internal side walls 60 extend between the first elongate end wall 72_1 and the second elongate end wall 72_2. Each of the elongate cells 62 has a substantially rectangular constant cross-section in planes perpendicular to the longitudinal axis 4, wherein a depth h of a cell 62 between the first and second end walls 72_1, 72_2 is greater than a width a, b, c of a cell 62 perpendicular to the depth h and the longitudinal axis 4.

FIGs 8A, 8B, 9A, 9B, 10A, 10B illustrate different options for cutting the elongate box beam 10.

The cuts illustrated are longitudinal cuts in planes perpendicular to the width wise direction, that is in the plane defined by the lengthwise direction (L) and the height wise direction (H).

In this example the cuts are made in, at or adjacent to side wall 74_1 (FIG 8A), side wall 74_2 (FIG 8B), side wall 60_2 (FIG 9A, 10B), side wall 60_1 (FIG 9B, 10A).

In this example the cut elongate box beams are in the first rotational orientation in FIGs 8A, 8B, 8C and the first cell 62_1 is always retained. The cut elongate box beams 10 are in the second rotational orientation in FIGs 9A, 9B, 9C and the third cell 62_3 is always retained.

In FIG 8A the elongate box beam has been cut adjacent the second side, exterior side wall 74_1 removing the second projecting lug 30_2 along the length of the elongate box beam 10. The three closed cells 62_1, 62_2, 62_3 are retained. The cut elongate box beam is used in the first rotational orientation. In FIG 9A the elongate box beam has been cut adjacent the first side, exterior side wall 74_2 removing the first projecting lug 30_1 along the length of the elongate box beam 10. The three closed cells 62_1, 62_2, 62_3 are retained. The cut elongate box beam is used in the second rotational orientation.

In FIG 8B the elongate box beam 10 has been cut adjacent the second interior side wall 60_2 removing the third cell 62_3 along the length of the elongate box beam 10. The two closed cells 62_1, 62_2, are retained. The cut elongate box beam 10 is used in the first orientation.

In FIG 9B the elongate box beam 10 has been cut adjacent the first interior side wall 60_1 removing the first cell 62_1 along the length of the elongate box beam 10. The two closed cells 62_3, 62_2, are retained. The cut elongate box beam 10 is used in the second orientation.

In FIG 8C the elongate box beam 10 has been cut adjacent the first interior side wall 60_1 removing both the second cell 62_2 and the third cell 62_3 along the length of the elongate box beam 10. The first closed cells 62_1 is retained. The cut elongate box beam 10 is used in the first orientation.

In FIG 9C the elongate box beam 10 has been cut adjacent the second interior side wall 60_2 removing the both the first cell 62_1 and the second cell 62_2 along the length of the elongate box beam 10. The third closed cells 62_3 is retained. The cut elongate box beam 10 is used in the second orientation.

As the widths of the cells 60_1, 60_2, 60_3 are different, the widths of the cut elongate box beams 10 that retain different combinations of cells are different.

In FIGs 8A and 9A, the first, second and third cells 60_1, 60_2, 60_3 are retained (widths: a+ b +c).

In FIG 9A the first and second cells 60_1, 60_2 are retained (widths: a+ b). In FIG 10A the first cell 62_1 is retained (widths: a).

In FIG 9B the third and second cells 60_3, 60_2 are retained (widths: c+ b).

In FIG 10B the third cell 62_3 is retained (width: c).

It is therefore straightforward to re-size an elongate box beam 10 at a construction site. An elongate box beam 10 can be cut to a suitable length by making a transverse cut, for example with a rotary saw. An elongate box beam 10 can be cut to a suitable width by making a longitudinal cut, for example with a rotary saw.

As illustrated in FIGs 8A, 8B, 9A, 9B, 10A, 10B different longitudinal cuts can be made while still retaining an external box structure with closed cell(s) 62 by making cuts adjacent an interior side wall 60. In FIGs 8A, 8B, 9A, 9B, 10A, 10B the cut surface forms a flat plane in the height wise direction (H) and the lengthwise direction (L) that extends from the first exterior surface 20_1 to the second exterior surface making 20_2. There are no overhangs, the planar cut surface meets the exterior surfaces 20-1, 20_2 are right angles.

The illustrated elongate box beam 10 is a cuttable elongate box beam 10 comprising multiple elongate enclosed cells 62 of different sizes. A first elongate end wall 72_1 defines the first exterior surface 20_1 and a second elongate end wall 72_2 defines the second exterior surface 20_2. A first elongate side wall 74_1 defines the first side, exterior surface 22_1 and a second elongate side wall 74_2 defines a second side, exterior surface 22_2. The first elongate end wall 72_1, the second elongate end wall 72_2, the first elongate side wall 74_1, the second elongate side wall 74_2 and at least one elongate internal side wall 60 define multiple elongate enclosed cells 62 of different sizes.

FIGs 11A, 11B; 12A, 12B; 13A, 13B illustrates different examples of using an adhesive membrane 80 at exterior elongate side wall(s) 74 or at a cut surface (not illustrated). The adhesive membrane 80 can be pre-attached to the first side, exterior surface 22 of exterior elongate side wall(s) 74 or attached on site. The adhesive membrane 80 can be attached on site to a cut surface, for example a cut surface as illustrated in FIGs 8A, 8B, 9A, 9B, 10A, 10B. The adhesive membrane can, for example, be a double-sided adhesive membrane.

In FIG 11A and 11B, an adhesive membrane 80 is attached to the first side, exterior surface 22_1 (defined by the first elongate side wall 74_1) but is not attached to the second side, exterior surface 22_2 (defined by the first elongate side wall 74_1). FIG 11A illustrates two side-by-side elongate box beams 10 before adhesive interconnection. FIG 11 B illustrates the two side-by-side elongate box beams 10 after adhesive interconnection. In FIG 11B, the adhesive membrane 80 at the first side, exterior surface 22_1 of one elongate box beam 10 is adhered to the second side, exterior surface 22_2 of the adjacent beam 10. Both beams have the same rotational orientation.

In FIG 12A and 12B, an adhesive membrane 80_1 is attached to the first side, exterior surface 22_1 (defined by the first elongate side wall 74_1) and an adhesive membrane 80_2 is attached to the second side, exterior surface 22_2 (defined by the first elongate side wall 74_1). The adhesive membranes 80 can, for example, be attached off-site, for example by a manufacturer or attached after manufacture, for example, on-site. FIG 12A illustrates two side-by-side elongate box beams 10 before adhesive interconnection. FIG 12B illustrates the two side-by-side elongate box beams 10 after adhesive interconnection. In FIG 12B, the first adhesive membrane 80_1 at the first side, exterior surface 22_1 of one elongate box beam 10 is adhered to the second adhesive membrane 80_2 at the second side, exterior surface 22_2 of the adjacent beam 10. Both beams 10 have the same first rotational orientation. In FIG 13A and 13B, the elongate box beams 10 of FIGs 12A, 12B are in the same second rotational orientations. Both beams 10 have the same second rotational orientation. An adhesive membrane 80_1 is attached to the first side, exterior surface 22_1 (defined by the first elongate side wall 74_1) and an adhesive membrane 80_2 is attached to the second side, exterior surface 22_2 (defined by the first elongate side wall 74_1). The adhesive membranes 80 can, for example, be attached off-site, for example by a manufacturer or attached after manufacture, for example, on-site. FIG 13A illustrates two side-by-side elongate box beams 10 before adhesive interconnection. FIG 13B illustrates the two side-by-side elongate box beams 10 after adhesive interconnection. In FIG 13B, the second adhesive membrane 80_1 at the first side, exterior surface 22_1 of one elongate box beam 10 is adhered to the second adhesive membrane 80_2 at the second side, exterior surface 22_2 of the adjacent beam 10.

In other examples, adjacent elongate box beams 10 of FIGs 12A, 12B are used in different rotational orientations-one in the first rotational orientation and one in the second rotational orientation. A first adhesive membrane 80_1 at a first side, exterior surface 22_1 of one elongate box beam 10 is adhered to the first adhesive membrane 80_1 at the second side, exterior surface 22_2 of the adjacent beam 10 or a second adhesive membrane 80_2 at a second side, exterior surface 22_2 of one elongate box beam 10 is adhered to a second adhesive membrane 80_2 at the second side, exterior surface 22_2 of the adjacent beam 10.

FIGs 14A and 14B illustrate how the closed cells 62 of the elongate box beam 10 can be filled with insulation.

FIG 14A illustrates an elongate box beam 10 with elongate closed cells 62. In this example there are three closed cells 62_1, 62_2, 62_2 as previously described.

The cells 62_1, 62_2, 62_2 have a constant-cross sectional profile in cross-sectional planes perpendicular to the longitudinal axis of the elongate box beam 10.

The elongate cells are configured to receive insulation. In this example, the insulation is in the form of push fit insulation blocks 90.

In at least some examples, a push fit insulation block 90_i has a constant-cross sectional profile in cross-sectional planes perpendicular to the lengthwise direction (L) i.e. the longitudinal axis of the elongate box beam 10. In at least some examples, the cross-sectional profile of the insulation block 90_i is configured to fit within the cross-sectional profile of a respective cell 62_i. In at least some examples, the cross-sectional profile of the insulation block 90_i is configured to snugly fit within the cross-sectional profile of a respective cell 62_i. The fit is selected so that the insulation block 90_i can be push-fitted within the respective elongate cell. The fit can be selected so that the insulation block 90_i is retained, by friction, within the respective elongate cell 62_i. The cross-sectional profile of the insulation block 90_i can therefore depend upon the compressibility and coefficient of friction of the insulation block 90_i.

The friction between the insulation block 90_i and its respective cavity can be controlled by controlling the reaction force between the elongate box beam 10 and the fitted insulation block 90, the size of the contact area between the elongate box beam 10 and the fitted insulation block 90, and the coefficient of friction at the contact area. Friction features can therefore be added to the walls of the cells 62 or to insulation block 90 to increase or reduce friction.

For example, although the exterior surface of the insulation block 90 is illustrated as smooth it can be configured to increase friction (e.g. larger cross-sectional profile, rougher surface, larger contact area) or it can be configured to decrease friction (e.g. smaller cross-sectional profile, smoother surface, smaller contact area for example by having contact and non-contact areas) For example, although the walls of the cells 62 are illustrated as smooth they can be configured to increase friction (e.g. different profile, rougher surface, larger contact area) or can be configured to decrease friction (e.g. smooth surface, smaller contact area).

FIG 15 illustrates an example, where the side walls of the cells 62 have friction features 64 that control friction. In this example, the friction features 84 are pointed protuberances from the side walls in the constant cross-sectional profile. The protuberances extend lengthwise along the cells. The protuberances have a substantially triangular cross-sectional shape.

The protuberances in a cell 62 are designed to contact the push fit insulation block 90 inserted into the cell 62.

In some examples, this contact can be in addition to contact between the side walls of the cell 62 and the push fit insulation block 90.

In some examples, this contact can be the only contact between the side walls of the cell 62 and the push fit insulation block 90.

The protuberances are blades/retainers.

In FIGs 14A, 14B, 15 the internal side walls 60 are substantially parallel and extend for at least 200mm between the first elongate end wall 72_1 to the second elongate end wall 72_2 thereby creating cells 62 (cavities) for receiving push fit cellular polystyrene insulation blocks 90 having a depth in the depth wise direction (D) of at least 200mm. The depth of cells 62 and insulation block 90 can be designed to achieve target thermal insulation targets.

The internal side walls 60 are extend for at least 200mm between the first elongate end wall 72_1 to the second elongate end wall 72_2 thereby creating cells 62 (cavities) for receiving push fit cellular polystyrene insulation blocks 90 that have a depth in the height wise direction of at least 200mm.

The push fit insulation block 90 once inserted into a cell by pushing can be removed from the cell by pushing. The push fit insulation block 90 is therefore independently recyclable from the elongate box beam 10.

For the foregoing it will be appreciated that FIG 14B illustrates an insulated elongate box beam 10 comprising: an elongate box beam 10 having one or more elongate, hollow cells 62; and one or more removable elongate push-fit blocks 90 of insulating material positioned within the one or more elongate, hollow cells 62.

The elongate box beam 10 and the insulation block 90 sized for the cells of the elongate box 10 can be sold together or separately.

In some examples, a set of parts for creating an insulated elongate box beam 10 comprises: an elongate box beam 10 having one or more elongate, hollow cells 62; and one or more elongate push-fit blocks 90 of insulating material sized to be positioned within the one or more elongate, hollow cells 62.

FIG 16 illustrates an elongate box beam as manufactured. The dimensions in the lengthwise direction are much greater than the dimensions in the width wise direction or the height wise direction.

The elongate box beam can be cut to a required length on-site or off-site.

In this example, the length of the elongate box beam is at least three times a width of the elongate box beam. In some examples, the length of the elongate box beam is at least 15 times a width of the elongate box beam.

The elongate box beam 10 is a construction beam designed to take a transverse force in the height wise direction (H) and distribute to 1-span supports at opposing ends of the elongate box beam 10.

The elongate box beams 10 can be interconnected to create a floor 100 as illustrated in FIG 17A and 17B. The elongate box beam 10 can therefore be used horizontally (x-y plane) with or without an underlying air cavity.

The floor in FIG 17A can be laid horizontally (x-y plane) by sliding a new elongate box beam 10 that extends lengthwise in the y-direction into place from right to left (-x direction) or from left to right (+x direction).

The floor in FIG 17B can be laid horizontally (x-y plane) by sliding a new elongate box beam 10 that extends lengthwise in the x-direction into place from right-to-left (y direction) or from left to right (-y direction).

FIGs 17A and 17B also illustrate a building comprising: a floor comprising: multiple elongate box beams 10, arranged parallel, side-by-side, projecting lug into recess.

The elongate box beams 10 can be used vertically. The elongate box beams 10 can be interconnected to create a vertical wall 102 as illustrated in FIG 18. The wall 102 in FIG 18 can be laid vertically (z-y plane) by positioning a new elongate box beam 10 that extends lengthwise in the y-direction into place (-z direction). The elongate box beams 10 can therefore be used to form a wall or panel.

FIGs 17A, 17B and 18 illustrate examples of a building or building product 100 comprising: multiple elongate box beams 10 arranged parallel, side-by-side, projecting lug into recess.

The elongate box beams 10 are therefore sub-components of a building component (floor/wall/panel) and are not themselves a floor/wall/panel. Multiple elongate box beams 10 are interconnected to form a floor/wall/panel.

FIIGs 19A and 19B illustrate a 1-span support system for an elongate box beam 10. In this example, the ends of the elongate box beam 10 are supported adjacent walls formed from construction block 120 by hanger 110 supported by the supported walls formed from construction block 120. In this example, a first substantially horizontal support portion of the hanger 110 is placed between construction blocks 120 forming the wall and another second substantially horizontal support portion of the hanger 110 supports an end of the elongate box beam 10. The second substantially horizontal support portion of the hanger 110 is supported by an interconnecting portion of the hanger 110 connected to the first substantially horizontal support portion of the hanger 110. The hanger can be sized to simultaneously support multiple side-by-side elongate box beams 10. The hanger can be configured to provide a slide that allows an elongate box beam 10 to be slid into a side-by-side position next to another elongate box beam 10.

FlIGs 20A and 20B illustrate a 1-span support system for an elongate box beam 10.

In this example, the ends of the elongate box beam 10 are supported within walls formed from construction block 120. The supported end of the elongate box beam 10 lies over a first horizontal layer of construction blocks 120_1 and underneath a second horizontal layer of construction blocks 120_2. At least one reinforcement 112 is placed within at least one end-portion of a cell 62 of the elongate box beam 10. The reinforcement 112 is designed to transfer load from the overlying second horizontal layer of construction blocks 120_2 to the underlying first horizontal layer of construction blocks 120_1.

FIGs 21A and 21 B illustrate a 1-span support system for an elongate box beam 10. In this example, the ends of the elongate box beam 10 are supported adjacent walls formed from construction block 120 by supports formed from construction blocks 120.

The supported end of the elongate box beam 10 lies on the support formed from construction blocks 120. The elongate box beam 10 has no overlying construction block 120.

FIGs 22 and 23 illustrate some example of an elongate box beam as previously described. The elongate box beams 10 have the profiles illustrated consistently along their lengths. The elongate box beams are formed from extruded plastic. The dimensions illustrated are in mm. The dimensions are to scale. To avoid confusion between dimensions and labels, minimum labelling has been used.

The cells 60_1, 60_2, 60_3 have the same maximum depth of 205mm (>200mm).

The width a of the first cell 62_1 is 45mm. The width b of the second cell 62_2 is 145mm. The width c of the third cell 62_3 is 90mm. The width of the walls is 5mm. The elongate cells 62 each has a substantially rectangular constant cross-section in H-W planes perpendicular to the lengthwise direction. Each cell is deeper than it is wide.

The first exterior surface 20_1 is substantially flat and has a textured surface comprising a crenelated pattern in cross-section and the second exterior surface 20_2 is substantially flat and has a textured surface comprising a crenelated pattern in cross-section.

The elongate box beam 10 comprises multiple internal elongate hollow tubes 2. The multiple internal elongate hollow tubes 2 are placed in at least some of the corners of at least some of the cells 62. The multiple internal elongate hollow tubes 2 are placed in all the corners of the second cell 62_2. Multiple internal elongate hollow tubes 2 are placed in the two outermost corners of the third cell 62_3 but not at the two innermost corners of the third cell 62_3.

The internal tubes 2 are approximately square with rounded corners All corners in the cross-sectional profile of the elongate box beam 10 are rounded.

FIGs 25A and 25B illustrate use of the internal elongate hollow tubes 2. The elongate box beam 10 comprises multiple internal elongate hollow tubes 2 for housing respective tendons 200. A tendon can be, for example, a wire such as a steel wire.

A first end plate 202_1 is used to close the elongate box beam 10 at one end of its length and a second end plate 202_2 is used to close the elongate box beam 10 at the other end of its length.

The first end plate 202_1 is used to fix one end of each of multiple tendons 200 and the second end plate 202_2 is used to fix the other end of each of the multiple tendons 200. Each tendon 200 is fixed at one end to the first end plate 202_1 and is fixed at the other end to the second end plate 202_2 and travels through a respective internal elongate hollow tube 2 between the first end plate 202_1 and the second end plate 202_2.

A tensioning mechanism or means (not illustrated) can be provided to create a tension in the tendons 200 and compress the elongate box beam 10 longitudinally between the end plates 202_1, 202_2.

FIG 25B illustrates a tensioned elongate box beam 10. The elongate box beam 10 comprises multiple internal elongate hollow tubes 2 for housing respective tendons 200. A first end plate 202_1 abuts the elongate box beam 10 at one end of its length and a second end plate 202_2 abuts the elongate box beam 10 at the other end of its length. Multiple tendons 200 each extend, under tension, between a respective fixture at the first end plate 202_1 to a respective fixture at the second end plate 202_2 through a respective one of the multiple internal elongate hollow tubes 2.

From the foregoing it will be appreciated that a method of on-site construction can comprise: on-site cutting of elongate box beams 10 to length; positioning a cut elongate box beam 10 on a set of 1-span supports; repeatedly (For i=1 to N-1) positioning a next (i+1) cut elongate box beam 10 by: placing the next cut elongate box beam 10_i on the set of 1-span supports and sliding the next cut elongate box 10_i beam 10 laterally into parallel side-by-side abutment with the last positioned cut elongate box beam 10_i-1 such that a projecting lug 30 of the next cut elongate box beam 10_i slides into a surface recess 40 of the abutted, positioned cut elongate box beam 10_i-1.

In some examples the next cut elongate box 10_i beam 10 and the positioned cut elongate box beam 10_i-1 are fixed by a screw through the a projecting lug 30 into the surface recess 40 or using an adhesive membrane or adhesive between the next cut elongate box beam 10_i and the positioned cut elongate box beam 10_i-1.

In some examples the elongate box 10_i beam 10 comes with insulation and in other examples blocks of insulation are push-fitted into the elongate, internal, closed cells 60 of the elongate box beam 10.

In some examples one or more elongate box beams 10 are cut longitudinally so that the interconnected combination of multiple side-by-side elongate box beams 10 spans a width of a room in the width wise direction (VV).

Any offcuts from the elongate box beams can be recycled to produce more elongate box beams 10.

The elongate box beam 10 has some significant benefits: it can be made from recycled material, such as recycled plastic; unused off-cut portions of the elongate box beam 10 can be recycled to produce new elongate box beams 10; an elongate box beam 10 is light and easily maneuverable and transportable.

The interfacing between the projecting lug 30 of one block and the surface recess 30 of another block provides for parallel self-alignment of side-by-side beams 10. The sloping projecting lugs 30 and the correspondingly sloping surface recess 30 facilitate the proper interfacing of the side-by-side beams 10.

The matching cross-sectional profiles of the projecting lugs 30 and the surface recesses 30 creates a firm exterior surface across the side-by-side beams. The overlap between projecting lugs 30 and the surface recesses 30 reduces fluid passage between the adjacent beams. Adhesive between adjacent beams 10 can further reduce fluid transfer. Adhesive between adjacent beams 10 can also stiffen the composite structure. Fixtures through the projecting lugs 30 into the underlying surface recesses 30 also improves stiffness.

Different depths of cells 60/insulation block 90 can be used to provide different thermal insulation levels.

The two fold rotational symmetry of the exterior cross-sectional profile of the elongate box beams 10 allows them to be used in any of two rotational orientations.

The cellular structure of the interior of the fluid elongate box beams 10 allows them to be cut to different widths. The asymmetric cellular structure of the interior of the elongate box beams 10 allows them to be cut to different widths depending on the rotational orientation while keeping the retained internal cell(s) closed.

The term 'comprise' is used in this document with an inclusive not an exclusive meaning. That is any reference to X comprising Y indicates that X may comprise only one Y or may comprise more than one Y. If it is intended to use 'comprise' with an exclusive meaning then it will be made clear in the context by referring to 'comprising only one...' or by using 'consisting.' In this description, the wording 'connect', 'couple' and 'communication' and their derivatives mean operationally connected/coupled/in communication. It should be appreciated that any number or combination of intervening components can exist (including no intervening components), i.e., to provide direct or indirect connection/coupling/communication. Any such intervening components can include hardware and/or software components.

In this description, reference has been made to various examples. The description of features or functions in relation to an example indicates that those features or functions are present in that example. The use of the term 'example' or 'for example' or 'can' or 'may' in the text denotes, whether explicitly stated or not, that such features or functions are present in at least the described example, whether described as an example or not, and that they can be, but are not necessarily, present in some of or all other examples. Thus 'example', 'for example', 'can', or 'may' refers to a particular instance in a class of examples. A property of the instance can be a property of only that instance or a property of the class or a property of a sub-class of the class that includes some but not all the instances in the class. It is therefore implicitly disclosed that a feature described with reference to one example but not with reference to another example, can where possible be used in that other example as part of a working combination but does not necessarily have to be used in that other example.

Although examples have been described in the preceding paragraphs with reference to various examples, it should be appreciated that modifications to the examples given can be made without departing from the scope of the claims.

Features described in the preceding description may be used in combinations other than the combinations explicitly described above.

Although functions have been described with reference to certain features, those functions may be performable by other features whether described or not.

The description of a feature, such as an apparatus or a component of an apparatus, configured to perform a function, or for performing a function, should additionally be considered to also disclose a method of performing that function. For example, description of an apparatus configured to perform one or more actions, or for performing one or more actions, should additionally be considered to disclose a method of performing those one or more actions with or without the apparatus. Although features have been described with reference to certain examples, those features may also be present in other examples whether described or not.

The term 'a', 'an' or 'the' is used in this document with an inclusive not an exclusive meaning. That is any reference to X comprising a/an/the Y indicates that X may comprise only one Y or may comprise more than one Y unless the context clearly indicates the contrary. If it is intended to use 'a', 'an' or the' with an exclusive meaning then it will be made clear in the context. In some circumstances the use of 'at least one' or 'one or more' may be used to emphasis an inclusive meaning but the absence of these terms should not be taken to infer any exclusive meaning.

The presence of a feature (or combination of features) in a claim is a reference to that feature or (combination of features) itself and to features that achieve substantially the same technical effect (equivalent features). The equivalent features include, for example, features that are variants and achieve substantially the same result in substantially the same way. The equivalent features include, for example, features that perform substantially the same function, in substantially the same way to achieve substantially the same result.

In this description, reference has been made to various examples using adjectives or adjectival phrases to describe characteristics of the examples. Such a description of a characteristic in relation to an example indicates that the characteristic is present in some examples exactly as described and is present in other examples substantially as described.

The above description describes some examples of the present disclosure however those of ordinary skill in the art will be aware of possible alternative structures and method features which offer equivalent functionality to the specific examples of such structures and features described herein above and which for the sake of brevity and clarity have been omitted from the above description. Nonetheless, the above description should be read as implicitly including reference to such alternative structures and method features which provide equivalent functionality unless such alternative structures or method features are explicitly excluded in the above description of the examples of the present disclosure.

Whilst endeavoring in the foregoing specification to draw attention to those features believed to be of importance the Applicant may seek protection via the claims in respect of any patentable feature or combination of features hereinbefore referred to and/or shown in the drawings whether or not emphasis has been placed thereon.

I/we claim:

Claims

CLAIMS1. A cuttable elongate box beam comprising: a first elongate wall defining a first exterior surface; a second elongate wall defining a second exterior surface; a first elongate side wall defining a first side, exterior surface; a second elongate side wall defining a second side, exterior surface; at least one elongate internal side wall, wherein the first elongate wall, the second elongate wall, the first elongate side wall, the second elongate side wall and the at least one elongate internal side wall define multiple elongate enclosed cells of different sizes.
2. A cuttable elongate box beam as claimed in claim 1, wherein the at least one internal side walls extend between the first elongate wall and the second elongate wall and is substantially perpendicular to both the first exterior surface and the second exterior surface.
3. A cuttable elongate box beam as claimed in claim 1 or 2, wherein the at least one internal side walls are substantially parallel and extend for at least 200mm between the first end wall to the second end wall thereby creating cells for receiving push fit cellular polystyrene insulation blocks.
4. A cuttable elongate box beam as claimed in claim 1, 2 or 3, wherein each of the elongate enclosed cells has a substantially rectangular constant cross-section in planes perpendicular to a longitudinal axis, wherein a depth of a cell between the first and second walls is greater than a width of a cell perpendicular to the depth and the longitudinal axis.
5. A cuttable elongate box beam as claimed in any preceding claim, comprising multiple internal side walls defining multiple enclosed elongate cells having a common depth but different widths.
6. A cuttable elongate box beam as claimed in any preceding claim, wherein a first elongate cell has a width of 45mm, a second elongate cell has a width of 145mm and a third cell has a width of 90mm wherein the second cell is adjacent, width wise, the first and third cells.
7. A cuttable elongate box beam as claimed in any preceding claim, formed from polymer.
8. A cuttable elongate box beam as claimed in any preceding claim, extending lengthwise parallel to a longitudinal axis, and having a constant cross-sectional profile suitable for extrusion.
9. A cuttable elongate box beam as claimed in any preceding claim, extending lengthwise parallel to a longitudinal axis, and having a constant exterior cross-sectional profile, in planes perpendicular to the longitudinal axis, wherein the constant exterior cross-sectional profile has rotation symmetry of order two.
10. A cuttable elongate box beam as claimed in claim 9, having a constant interior cross-sectional profile, in planes perpendicular to the longitudinal axis, wherein the constant interior cross-sectional profile has rotation symmetry of order one.
11. A cuttable elongate box beam as claimed in any preceding claim, wherein the first exterior surface has, at a first lateral edge, a first surface recess of lower relief; and the first exterior surface, at a second lateral edge opposing the first lateral edge, defines an exterior surface of a first projecting lug, wherein the first recess and first projecting lug are correspondingly sized.
12. A cuttable elongate box beam as claimed in claim 11, wherein a cross-sectional profile of the first recess comprises a slope that is at an angle relative to an adjacent first flat portion of the first exterior surface and wherein a cross-sectional profile of the first projecting lug comprises a slope that is at the same angle relative to an adjacent second flat portion of the first exterior surface that is in a common plane with the first flat portion of the first exterior surface.
13. A cuttable elongate box beam as claimed in claim 11 or 12, extending lengthwise parallel to a longitudinal axis, wherein the a cross-sectional profile of the first surface recess, in a plane perpendicular to the longitudinal axis, is substantially the same as a cross-sectional profile of the first projecting lug, in the same plane.
14. A cuttable elongate box beam as claimed in claim 11, 12 or 13, wherein the first surface recess and lug are correspondingly sized such that in use the first surface recess is sized and positioned to receive a lug of a first elongate box beam similar to the elongate box beam located adjacent the elongate box beam at the first lateral edge and the first projecting lug is sized and positioned to be received by a recess of a second elongate box beam similar to the elongate box beam located adjacent the elongate box beam at the second lateral edge.
15. A cuttable elongate box beam as claimed in any of claims 11 to 14, wherein the second exterior surface has, at the second lateral edge, a second surface recess of lower relief; and the second exterior surface, at the second lateral edge opposing the first lateral edge, defines an exterior surface of a second projecting lug, wherein the second recess and second projecting lug are correspondingly sized, the second recess and first projecting lug are correspondingly sized and the first recess and second projecting lug are correspondingly sized.
16. A cuttable elongate box beam as claimed in any preceding claim, comprising double-sided adhesive membrane attached to at least one of the first side, exterior surface and the second side, exterior surface.
17. A cuttable elongate box beam as claimed in any preceding claim, wherein the first exterior surface is a substantially flat and has a textured surface comprising a crenelated pattern in cross-section and the second exterior surface is a substantially flat and textured surface comprising a crenelated pattern in cross-section.
18. An elongate box beam comprising: a cuttable elongate box beam as claimed in any preceding claim having one or more elongate, hollow cells; one or more removable elongate push-fit blocks of insulating material positioned within the one or more elongate, hollow cells.
19. A set of parts for creating an insulated elongate box beam comprising: a cuttable elongate box beam as claimed in any preceding claim having one or more elongate, hollow cells; and one or more elongate push-fit blocks of insulating material sized to be positioned within the one or more elongate, hollow cells.
20. A tensioned elongate box beam comprising: a cuttable elongate box beam as claimed in any preceding claim comprising multiple internal elongate hollow tubes for housing respective tendons; a first end plate abutting the elongate box beam at one end of its length; a second end plate abutting the elongate box beam at the other end of its length; and multiple tendons each extending, under tension, between a respective fixture at the first end plate to a respective fixture at the second end plate through a respective one of the multiple internal elongate hollow tubes.
21. A building or building product comprising: multiple cuttable elongate box beams as claimed in any preceding claim, arranged parallel, side-by-side width wise, wherein at least one of the multiple cuttable elongate box beams has been cut along its length to remove at least one of the multiple elongate enclosed cells.
22. A building comprising: a floor comprising: multiple elongate box beams as claimed in any preceding claim, arranged parallel, side-by-side width wise, wherein at least one of the multiple cuttable elongate box beams has been cut along its length to remove at least one of the multiple elongate enclosed cells.
23. A building as claimed in claim 22, wherein the floor is 1-span and the multiple elongate box beams are supported by a first hanger at their first longitudinal extremities and by a second hanger at their second longitudinal extremities.
24. A method of on-site construction comprising: on-site cutting of cuttable elongate box beams as claimed in any of claims 1 to 19; positioning the cut elongate box beam on supports; repeatedly positioning next cut elongate box beam by: placing the next cut elongate box beam on the supports and sliding the next cut elongate box beam laterally into parallel side-by-side abutment with the positioned cut elongate box beam.
25. A method as claimed in claim 24, comprising on-site cutting to reduce a length of elongate box beams and/or on-site cutting to reduce a width of one or more elongate box beams.