AU2022215262B2 - Expansion joint element and system - Google Patents

Abstract

A method of manufacturing one or more expansion joint elements comprising: extruding a length of metal section having an upper surface and a lower surface, 5 wherein one side length of the section is an anchoring side; cutting an intermeshing profile along an opposite side of the section or along a middle portion; and forming fixing means in the anchoring side. 18957736_1 (GHMatters) P100939.AU.2 11/08/22

Description

EXPANSION JOINT ELEMENT AND SYSTEM

This application is a divisional application of Australian Application No. 2016262776, the original disclosures of which are incorporated herein by reference, in their entirety. The present invention relates to expansion joint elements and expansion joint systems particularly of the cantilevered teeth type used for bridge expansion joints.

Background

Expansion joint elements and the systems incorporating expansion joint elements are used in structures where an expansion joint is required. Such structures include bridges or large spanning platforms where variations in the movement of the ground or structures to which the bridges or platforms are connected require the bridges or platforms to compensate for the variations in movement by way of expansion joints. Variations in movement between structures to which the expansion joints are connected may result from earth movement, heat induced expansion, vibration and the like. Expansion joints are commonly found in buildings, bridges, footpaths, railway tracks and other such structures.

Bridge expansion joints in particular are designed to allow continuity in traffic regardless of the variations in gap between sections of a bridge. Bridge expansion joints have a pair of independent expansion joint elements cast of an aluminium alloy and having intermeshing teeth (typically of triangular profile). The elements are placed facing each other in a cantilevered fashion across an expansion gap and are each anchored to a structure on either side of the expansion gap.

Problems with expansion joints of the cantilevered-type used for bridges is that under repetitive loading over a number of years the expansion joint elements have been known to crack under fatigue and fail. Teeth can break or bend, or the element itself can dislodge from its position. Not only does this reduce the useful life of the expansion joint but can potentially be dangerous if expansion joint failure creates traffic hazards.

The present expansion joint element and system is intended to provide a more reliable,

19201946_1 (GHMatters) P100939.AU.2 24/01/24 longer life expansion joint element and system.

The above description should not be taken as an admission of the state of the common general knowledge in the art in Australia or elsewhere.

Summary

According to the present invention there is provided a method of manufacturing one or more bridge expansion joint assemblies comprising an expansion joint element and a lower support element, the method involving: extruding a length of metal section having an upper surface and a lower surface, including extruding a first engagement profile on the lower surface; cutting an intermeshing profile along a side of the length of the section, or along a middle portion of the section, to form the or each expansion joint element, wherein an opposing side of the length of the or each expansion joint element is an anchoring side; separately extruding a lower support element that aligns for attachment with the or each intermeshing joint element, including extruding a second engagement profile on an upper part of the lower support element that corresponds to the first engagement profile; and forming fixing means in the anchoring side.

The method can be used to either form a single expansion joint element or a pair of expansion joint elements. In the case of the pair of expansion joint elements a monolith length of metal section is first extruded and then it is cut (typically forming a saw-tooth profile cut) down the middle to separate the halves of the monolith and form the pair of expansion joint elements.

Depending on the application of the expansion joint system, and the size of the system, the expansion joint elements may be extruded to integrally include lower support portions, which are adapted to line, or form a skirt, along the upper edge of a structure (eg. concrete bridge section) on one side of the expansion gap. In other embodiments the lower support portion may be provided as a separately formed component, ie. a lower support element, on top of which the expansion joint element is cantilevered and fixed.

In a preferred embodiment the metal section that is extruded is an aluminium or

19201946_1 (GHMatters) P100939.AU.2 24/01/24 aluminium alloy section, but could be formed of another metal, metal alloy or composite sufficiently strong to bear repetitive loading of, for example, vehicular traffic.

In a preferred embodiment the intermeshing profile is cut to form teeth in plan view, and namely a 'saw tooth' shaped profile. The intermeshing profile can be in the form of triangular teeth, long slender finger-like profile, curved wave-form. Furthermore, the intermeshing profile can be cut with a left or right hand bias or lean in plan view, for example to accommodate movement of different skew angles on a bridge.

Cutting the intermeshing profile may be carried out using profile cutting machinery such as waterjet cutting machines, plasma or laser cutting machines, CNC (computer numerical control) machines, or oxy cutters.

The fixing means may include forming fixing holes through the anchoring side. The holes may be formed at an angle of 0° to 9 0 °relative to the upper surface, and preferably between 45 to 90°.

In preferred embodiments the method includes extruding an anti-skid surface pattern into the upper surface.

As discussed above, in another embodiment there may be extruded a second element, namely a lower support element that, in use, is fixed against the lower surface of the expansion joint element. The lower support element comprises in cross section two arms angled relative to each other, where an upper arm abuts the lower surface at the anchoring side of the expansion joint element, while a lower arm in the form of a skirt descends downwardly below the intermeshing side of the joint. To accommodate alignment of the expansion joint element with the lower support element, a first engagement profile may be extruded in the lower surface of the expansion joint element, and a second, corresponding engagement profile is extruded in the upper arm of the lower support joint.

A seal retaining recess may also be extruded into the lower support element into which a part of a seal can be retained. Alternatively, the seal retaining recess may be extruded into the lower surface of the expansion joint element.

The expansion joint element is adapted to be used in pairs to form an expansion joint system in a reinforced concrete structure, such as a bridge, platform or pavement

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(such as an airport pavement), or movable deck. In use, the expansion joint elements are cast into the concrete forming part of the structure requiring an expansion joint.

In accordance with the invention there is further provided an expansion joint system comprising at least two expansion joint elements formed by the above method, wherein the intermeshing profiles of the joint elements intermesh with each other to provide variable gaps between the expansion joint elements.

In particular, the variable gaps are caused as the elements, in use, move toward and away from each other as a result of the structure into which the joints are cast moves.

In an embodiment the system comprises an elastomeric or flexible thermoplastic seal. The seal is fixed between the two joint elements and below the intermeshing profile. The seal may be a multi-chamber seal or single layer membrane trough.

Bolts may be provided for insertion through the fixing holes. The bolts can be tensioned or passive. Commonly, where the joint elements are cast into a concrete structure the bolts are post-tensioned after the concrete has set. Anchoring ferrules are used at the end of the bolts against which the bolts are tensioned.

Anchoring means such as bolts, bar elements, loops and ferrules may also be provided to assist in anchoring the joint elements to the concrete structure. In one instance of using loops as an anchor, an open ended loop can be fixed to the joint element by bolting the two ends of the open loop through one or more fixing holes in the joint element. Once set in concrete the ends of the loop anchor may be post tensioned to increase the stiffness of the anchor.

Brief Description of the Drawings

Embodiments of the present invention will now be described by way of example only with reference to the accompanying drawings in which:

Figure 1a is a perspective view of an expansion joint system in use between sections of a road structure;

Figure 1b is a perspective view of one unit of an expansion joint system;

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Figure 2a is a cross-section of an embodiment of the expansion joint system anchored to structures across an expansion gap;

Figure 2b is a cross-section of another embodiment of the expansion joint element anchored to a structure;

Figures 3a, 3b and 3c illustrate steps in a method of manufacturing a single expansion joint element;

Figure 4a is an enlarged isometric view of an embodiment of the expansion joint element;

Figure 4b is an isometric view of an embodiment of a lower support element on top of which the expansion joint element of Figure 4a aligns and is attached;

Figure 5 is a closer cross section view of the expansion joint system of Figure 2a anchored into the structure;

Figure 6a is a side sectional view of another embodiment of an expansion joint system in which the expansion joint elements are extruded with a lower support portion;

Figure 6b illustrates an isometric view the expansion joint elements of Figure 6a prior to cutting and separating the elements from a monolithic section;

Figure 7a is an isometric view of yet another embodiment of the expansion joint system; and

Figures 7b, 7c and 7d illustrate steps in the method of making the expansion joint system of Figure 7a in which the cantilevered expansion joint elements are formed as a single component and then saw-tooth cut into separate joint elements.

Detailed Description of Embodiments

The drawings illustrate various embodiments of expansion joint elements 10 forming part of expansion joint systems 12 where pairs of expansion joint elements 10 are anchored across an expansion gap 15 to structures 20a and 20b on either side of the gap 15, which can vary in size depending on movement between structures 20a and

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20b.

Figure 1a illustrates a road 11 having sections defining structures 20a, 20b divided by an expansion gap 15 across which expansion joint elements 10 are arranged in pairs facing each other to form an expansion joint system 12, and units of the expansion joint system are arranged end-to-end to form and expansion joint across the structure 20a, 20b.

Figure 1b illustrates a single expansion joint system 12 unit. Each element 10 in the pair is anchored to one or the other structure 20a, 20b to be cantilevered to extend part way across the gap 15. The side length of the expansion joint element that is anchored to the structure is the anchoring side 17 and the side length that cantilevers to extend into the expansion gap 15 is the intermeshing side 18. The intermeshing side 18 of each expansion joint element 10 comprises an intermeshing profile 22, which in the drawings is illustrated as substantially triangular teeth 23, and namely a saw-tooth profile, so that opposing and facing expansion joint elements in each pair intermesh with each other at close distance whereby the teeth 23 of one element 10 intermeshes with the teeth in the opposite element 10 by moving into the recesses 24 in between the teeth 23 of the opposite element.

The expansion joint elements 10 each have an upper surface 13 and a lower surface 14, where the upper surface 13 is exposed, namely to pedestrian or vehicle traffic, and the lower surface 14 is fixed to the structure or exposed to the expansion gap 15 between structures 20a, 20b. The joint elements 10 are provided in lengths of variable sizes, for example of approximately 3.5 metres in length, although the lengths may vary between 0.5 metres and 12 metres. Figure 1a illustrates the expansion joint elements placed end to end in length to create a long expansion joint across the width of the road 11.

Figure 2a illustrates an expansion joint system 12 comprising two opposing expansion joint elements 10 shown in cross section and each anchored to a structure 20a, 20b on either side of the expansion gap 15. The structures 20a, 20b may be sections of road as illustrated in Figure 1 or may be other similar structures such as sections of bridges, footpaths or other pedestrian, vehicle or rail crossings or platforms where movement between structures requires an expansion joint.

The anchoring side 17 of each expansion joint element 10 includes fixing holes 26 for

19201946_1 (GHMatters) P100939.AU.2 24/01/24 accommodating bolts 28 or other anchoring elements to fix the expansion joint elements 10 to each structure 20a, 20b. Typically, where the structures are formed from concrete poured on site the expansion joints are cast into formed block outs defined by formwork panels 31. Expansion joint elements are fixed to the structures by casting the joint elements 10 during the pouring process. Bolts 28 are positioned through the fixing hole 26 to extend through into the area to be poured with concrete, which is defined by formwork panels 31 and that is reinforced with steel reinforcement 29. As shown in Figure 2a, the upper surface 13 is arranged so that when the concrete structure dries the top 33 of the concrete structure 20a, 20b is flush with the upper surface 13. The concrete structure 20a, 20b is a smaller recessed part of a larger structure, such as road 11 and the structure beneath the road 11.

Before pouring concrete C to create structures 20a, 20b a void former (not shown), by way of polystyrene block or other removable or sacrificial formwork, is placed in the expansion gap 15 on an underside of the expansion joint elements 10. The void former sets a desired gap distance at the time of installation and is selected to be an appropriate size for the particular project. Namely, the expansion gap selected should be large enough to accommodate foreseeable movement between the two structures 20a, 20b yet small enough to ensure the maximum expansion gap has no detectable impact on the pedestrian or vehicle thoroughfare over the expansion joint. The length of the teeth 23 in the intermeshing profile 22 is similarly selected having consideration to the specifications of the project and desired size range for the expansion gap 15.

As can be seen from Figure 2a the bolts are inclined relative to the upper surface 13. The bolts may be tension bolts or can be passive bolts. Figure 2a illustrates tension bolts which are post-tensioned after the concrete has set in order to provide a strong interconnection between the expansion joint elements 10 and the structures 20a, 20b. Anchoring ferrules 34 are threaded at the end of the bolts 28 so that the bolts can be tightened by rotating the bolts in tension against the anchoring ferrules that have been set in concrete. The anchoring ferrules 34 may include wings 35 to anchor the ferrules in the concrete and ensure their position is fixed.

Other anchoring means such as reinforcement bar elements 29 and loops 37 may also be used to assist in anchoring the bolts and the joint elements 10 into the concrete structure. The anchoring means loops 29 may be embedded in the concrete in the vicinity of the bolts 28 as shown in Figure 2a. Alternatively, the anchoring means may include an open ended loop 38 as shown in Figure 2b that acts as both a bolt and a

19201946_1 (GHMatters) P100939.AU.2 24/01/24 loop to anchor the joint element to structure 20a. Open ended loop 38 can be fixed to the joint element by bolting the two ends 41 of the open loop through one or more fixing holes 26 in the joint element. Once set in concrete the ends of the loop anchor 38 may be post tensioned to increase the strength of the anchor.

An expansion seal 39 is attached across the expansion gap 15 and to the facing joint elements on either side of the gap 15, or to intermediate elements connected to or close to the expansion joint elements 10 (such as second element 50 discussed in more detail below). The expansion seal 39 avoids the ingress of water into the expansion gap and is fixed in position by interlocking flanges of the seal into seal retaining recesses provided in the joint element 10 or other element, such as second element 50. The expansion seal 39 is an elastomeric or flexible thermoplastic seal that can be in the form of a concertina seal, such as a multi-chambered seal, or a drape or trough seal.

The presently described expansion joint element 10 and system 12 incorporating the expansion joint element provides a reliable and longer lasting expansion joint for applications involving small cantilever joints but also for larger cantilever joints for large structures, such as large capacity, multi-lane bridges. These benefits are achieved because the expansion joint element is extruded into a metal section rather than cast. Typically, aluminium or an aluminium alloy is used, although other metal sections such as steel, could also be used.

It has been found that the casting process for manufacturing expansion joint elements produces imperfections in the metal including tiny gas pores and impurity inclusions that present as microscopic defects. Under repetitive loading the microscopic defects can propagate into larger fatigue cracks and over time the fatigue cracks can fail and cause breakages or deformation, particularly at the weakest point in the structure, such as the teeth. Extrusion of metal produces far fewer microscopic defects.

The method of manufacturing the expansion joint elements, and of the system as a whole, involves the extrusion of components to make one or a combination of the following options, as required:

a) A single expansion joint element 10 without a lower supporting part, as illustrated in Figure 3c. This element will intermesh with a correspondingly formed opposite element;

19201946_1 (GHMatters) P100939.AU.2 24/01/24 b) An extruded monolithic section cut down the middle in a saw-tooth cut (or other tooth profile pattern) to form two separate expansion joint elements 10, as illustrated in Figures 7b to 7d; c) The single expansion joint formed in a) but including an integrally extruded lower support portion that forms a skirt on an inner face of the expansion gap (this embodiment not shown in the figures); d) The pair of expansion joint elements 10 formed from a monolithic component as in b) but each element including an integrally extruded lower support portion 55, as shown in Figure 6a; e) A separately extruded lower support portion in the form of a lower support element 50, as shown in Figure 4b, that can be aligned under and attached with the expansion joint elements 10 formed by a) or b) above.

Which of the above methods and combinations to use will depend on the application of use.

For example, for small sized applications, eg foot bridges or the like, it could be suitable to provide the upper cantilevered expansion joint element formed as a whole with the lower support portion, as outlined in options c) and d) above. An advantage of choosing c) over d) is that cutting a single component down the middle to form two joint elements creates less material wastage than the process of cutting a tooth profile from two separate extruded sections.

For medium and large sized applications, eg. multi-carriageway bridges, it may be suitable to use systems where the upper cantilevered joint elements are separate components to the lower support elements, and namely a combination of options a) +

e) or b) + e).

The advantage of using separate upper and lower components in the expansion joint system in these applications is that in case of damage, which will typically occur on the exposed upper joint element 10, the upper joint element 10 can be quite easily removed and replaced without having to also remove the lower support element 50, which will usually be embedded in concrete.

Figures 3a, 3b and 3c illustrate the steps involved in manufacturing a single expansion joint element 10. Figure 3a illustrates a metal section 40 that has been extruded to a desired elongated shape and includes a length I, a width w and has an upper surface

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13 and a lower surface 14. Extruding the metal section 40 to a desired length I is advantageous because different lengths of joint element sections can be pre-ordered and extruded to size. By comparison, casting different lengths of joint elements would require using different sized casting dies for each desired length.

Figure 3a shows the metal section 40 without the intermeshing profile yet formed. The intermeshing profile 22 will be formed in the intermeshing side 18 along one side length of the extruded metal section 40. The other, opposite side length of the metal section 40 defines the anchoring side 17, in which fixing means such as holes will be formed for anchoring the expansion joint element 10 to a structure.

Certain joint element features can be formed in the metal section during the extrusion process. Such features could include an anti-skid surface pattern 42 defined by a number of closely formed parallel ridges running along the length of the metal section on the intermeshing side 18 and/or the anchoring side 17. Other features formed by extrusion include features formed on the lower surface 14 such as anchoring or engagement profiles 57 and a seal retaining recesses. In the embodiments illustrated a seal retaining recess 46 is shown formed as part of a secondary extrusion element, namely the lower support element 50 discussed above and in more detail below, and not formed with the expansion joint element 10. It is however understood that the expansion joint elements 10 may instead be extruded with a seal retaining recess 46 for retaining an expansion seal between the pairs of expansion joint elements.

The expansion joint element may be extruded with other structural/physical features. For example, the joint element could be extruded to include a channel rebate (not shown) in the upper surface 13. The channel rebate would be designed to accommodate the heads of the bolts 28 to keep them below the running surface of the structure and remove the need to separately counter-bore bolt head holes.

After extruding the metal section 40 an intermeshing profile is cut along the intermeshing side of the metal section 40. This is illustrated in Figure 3b. The intermeshing profile is cut from the rectangular metal section 40 and into the form of teeth, when viewed in plan view, to resemble a saw tooth-shaped profile. It is however understood that while a saw-tooth profile is illustrated in the drawings other intermeshing profiles can be cut including triangular teeth with sharper ends, long finger-like profile, curved wave-formed sinusoidal profile or the like.

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The cutting process can involve cutting the intermeshing profile in two dimensions but could also involve cutting the profile in three dimensions. Three dimensioned cutting is useful, for example, to acquire a "lean in" or bias, or undercut feature in the teeth that may be required, for example, when the pairs of expansion joint elements are installed on a surface that is skewed, such as at the top of an arched bridge or on a curved stretch of road over a bridge where the intermeshing piece needs to be appropriately profiled to accommodate skew angles or curves in order for the teeth to properly mesh together.

The profile cutting process for the intermeshing profile is carried out using profile cutting machinery. Waterjet cutting machines using abrasives and operating on three axis or five axis can be used to cut in two dimensions or three dimensions. Other examples of profile cutting machinery include plasma or laser cutting machines, computer numerical control (CNC) machines or oxy-fuel cutters.

Figure 3c illustrates the metal section 40 cut with the intermeshing profile 22 and with fixing means in the form of holes 26 drilled in the anchoring side 17 of the metal section 40 to form the expansion joint element 10. As best seen in Figure 4a, the fixing holes 26 are drilled and then counter-bored recesses are machined into the metal section 40 and through the anchoring side 17. Counter-boring is not essential but may be desirable if bolt heads are to be located below the running surface (eg. road 11) of the structure 20a, 20b.

The fixing holes 26 are machined either at a 900 angle to the upper surface 13, parallel to the upper surface at 00 or at an inclined angle to the upper surface 13, such as 450, or any angle between 00 to 900, depending on the application. The angle selected allows the bolt 28 to be cast into a concrete structure at an appropriate angle to improve anchoring of the expansion joint element to the structure, 20a, 20b.

Figure 5 illustrates in closer detail the expansion joint system 12 incorporating oppositely placed expansion joint elements. The second element, namely the lower support element 50, which is extruded in metal and commonly in aluminium or aluminium alloy, is clearly shown in this view fixed or placed against the lower surface 14 of each expansion joint element 10. Figure 4b illustrates the lower support element 50 on its own. The lower support element 50 defines a skirt 51 that extends along vertical wall 52 of the structure 20a or 20b and faces the expansion gap 15.

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The lower support element 50 is not necessary to the working of the expansion joint system but is optionally used to increase the stiffness of the connection between the joint element 10 and the structure 20a, 20b, particularly in larger sized applications, as the additional metal underneath the bolt head can distribute stresses from the joint element and makes it less likely to become loose from the structure 20a, 20b due to vibration or fatigue. Furthermore, providing an expansion joint system having a second element provides a surface to which formwork or gap former can be fixed, which makes installation of the system faster and more convenient. Still further, and as described above, separating the expansion joint system into an upper component (the cantilevered joint element 10) and a lower component (the lower support element 50) allows for better maintenance access and faster repair times when the upper surface of the expansion system is damaged.

The second element comprises, in cross section, two arms angled relative to each other at about a right angle. A lower arm defines the skirt 51 and an upper arm 53 engages or aligns with the lower surface 14 of the expansion joint element 10. Expansion joint element 10 and second element 50 include corresponding engagement profiles in order to properly align the two parts at installation. Specifically, joint element 10 includes on its lower surface 14 a first engagement profile 57 in the form of a ramped channel that is extruded with the metal section 40 (see Figure 4a). A corresponding second engagement profile 58 is extruded on the upper arm 53 of the second element. The second engagement profile 58 is in the form of a ramped extruded bead (see Figure 4b) that complements and sits in the ramped channel of the first engagement profile. The first and second engagement profiles align to correctly position the joint element 10 with second element 50.

In this embodiment, the lower support element 50 is formed to have a seal retaining recess, or keyway, 46 located at an intermediate portion between the upper arm 53 and skirt 51. The seal retaining recess is shaped to have a locking neck 54 to receive a corresponding engagement lip of an expansion seal 39 located underneath the intermeshing teeth between the expansion joint elements 10. The lower support element 50 is positioned in place against the joint element 10 before casting the concrete structure 20a, 20b. As can be seen in Figure 5, the skirt 51 overlaps with and sits on top of sacrificial formwork 56 and forms part of the formed block out structure into which the concrete structure 20a, 20b is formed.

The fixing means may include more than one type of fixing hole. For example, the

19201946_1 (GHMatters) P100939.AU.2 24/01/24 expansion joint element 10 could have additional screw holes (not shown) in the upper surface to receive screws that fix together expansion joint element 10 and second element 50. In the embodiment shown, the expansion joint element 10 and second element 50 are aligned together then fixed together using bolts 28.

Figure 6a and 6b illustrate the embodiment of option d) described earlier in which the expansion joint element 10 is first formed as a single monolithic extruded structure 60, including integrally formed lower support portion 55. Figure 6b illustrates in upper isometric view the structure before cutting to separate the structure into two opposing expansion joint elements 10. Figure 6a shows in side view the structure of Figure 6b before cutting, where dashed lines 59 indicate the extremities of the saw-tooth cut along a middle portion 61 of the structure 60. The cut structure will appear similar to the embodiment illustrated in Figure 7a, which differs from the embodiment of Figure 6b in that the lower support element 50 is not formed integrally with the upper joint element 10.

The embodiment of the expansion joint elements illustrated in Figure 7a is formed according to the steps illustrated in Figures 7b, 7c and 7d. This embodiment reflects options b) + e) described earlier, which start as a single extruded structure 60 that will form two pairing joint elements 10. Figure 7b illustrates the extruded structure 60, included an anti-skid surface pattern 42. In this embodiment there is no integrally formed lower support portion 55, but rather the underside of each anchoring side 17 of the structure 60 includes a second engagement profile 58 that is adapted to engage with a first engagement profile 57 on a lower support element 50 (as shown in Figure 7a).

Figure 7c illustrates the structure 60 with fixing holes 26 drilled through the anchoring sides 17 of the structure 60.

Figure 7d illustrates the structure 60 with a saw-tooth cut 62 along the middle portion 61 of the structure, which separates the structure 60 into two separate cantilever expansion joint elements 10 as shown in Figure 7a. The cut can be made using a waterjet cutting machine, a plasma cutter, or any other suitable metal-cutting apparatus as described earlier and known to the metal cutting industry.

The expansion joint system 12 described herein includes a pair of expansion joint elements 10 that are adapted to be used facing each other and fixed to structures on

19201946_1 (GHMatters) P100939.AU.2 24/01/24 either side of an expansion gap. The system further includes bolts and expansion seals, as required, in order to properly provide an expansion joint between sections of movable structures. As structures 20a, 20b move toward and away from each other the expansion gap will vary in size and the opposing expansion joint elements 10 will also move toward and away from each other. The intermeshing profile teeth 23 while moving into and out of mesh engagement will always overlap to some extent in order to provide a continuous surface across the teeth and across which vehicle and pedestrian access can be maintained.

Extruding the expansion joint elements from a metal, and metal such as aluminium or aluminium alloy, provides a superior product that can withstand repeated loading from traffic as well as adequately accommodate varying movement between structures and varying widths of expansion gaps.

As the joint elements may be extruded to any size, the system becomes a modular system. Extruding joint elements has the benefit of providing longer unit lengths than that achievable with casting. Longer module lengths will make installation faster by reducing the time required to join elements length to length, as there are fewer lengths to join, but also reduces the preparation required by reducing the number of installation support beams for the joint lengths. Overall, the installation process is simplified and manual adjustments are reduced, which will improve level accuracy and thereby improve vehicle ride.

It will be understood to persons skilled in the art of the invention that many modifications may be made without departing from the spirit and scope of the invention.

In the claims which follow and in the preceding description of the invention, except where the context requires otherwise due to express language or necessary implication, the word "comprise" or variations such as "comprises" or "comprising" is used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention.

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Claims (10)

CLAIMS:

1. A method of manufacturing one or more bridge expansion joint assemblies comprising an expansion joint element and a lower support element, the method involving: extruding a length of metal section having an upper surface and a lower surface, including extruding a first engagement profile on the lower surface; cutting an intermeshing profile along a side of the length of the section, or along a middle portion of the section, to form the or each expansion joint element, wherein an opposing side of the length of the or each expansion joint element is an anchoring side; separately extruding a lower support element that aligns for attachment with the or each intermeshing joint element, including extruding a second engagement profile on an upper part of the lower support element that corresponds to the first engagement profile; and forming fixing means in the anchoring side.

2. The method claimed in claim 1, including forming an anchoring side along both side lengths of the metal section and providing fixing means in each anchoring side; and cutting an intermeshing profile along a middle portion and separating a pair of intermeshing joint elements.

3. The method claimed in claim 1, including cutting an intermeshing profile along an intermeshing side, which is at the opposite side of the anchoring side, to form a single intermeshing joint element.

4. The method claimed in any one of the preceding claims, including extruding an aluminium or aluminium alloy section.

5. The method claimed in any one of the preceding claims, including cutting the intermeshing profile by waterjet cutting.

6. The method claimed in any one of the preceding claims, including extruding an anti-skid surface pattern into the upper surface.

7. An expansion joint system comprising at least two expansion joint elements manufactured according to the method according to any one of the preceding claims,

19201946_1 (GHMatters) P100939.AU.2 24/01/24 wherein the intermeshing profiles of the joint elements intermesh with each other to provide variable gaps between the expansion joint elements.

8. The expansion joint system claimed in claim 7, further comprising an elastomeric or flexible seal fixed between the two joint elements.

9. The expansion joint system claimed in claim 8, further comprising an elastomeric or flexible seal fixed between the two lower support elements.

10. The expansion joint system claimed in any one of claims 7 to 9, wherein anchors are located through the fixing means to anchor the expansion joint system to a structure.

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