AU2004222848A1

AU2004222848A1 - Expansion Joint Closure

Info

Publication number: AU2004222848A1
Application number: AU2004222848A
Authority: AU
Inventors: Scott Robinson
Original assignee: INTEDEV Pty Ltd
Current assignee: INTEDEV Pty Ltd
Priority date: 2003-10-27
Filing date: 2004-10-26
Publication date: 2005-05-12

Description

ORIGINAL

Australia Patents Act 1990 Complete Specification for the Invention Entitled EXPANSION JOINT CLOSURE The invention is described in the following statement: 2

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0 EXPANSION JOINT CLOSURE This invention relates to covers or closures for expansion joints, 00 which are normally provided between massive component parts of large 00 concrete structures.

In large concrete structures, such as dams, bridges, wharves, ,I roadways and the like, it is normal for expansion joints to be provided between massive component parts. Expansion joints permit accommodation of movement between such massive component parts resulting from thermal expansion, low level seismic activity, elastic deformation due to transient loadings and vibratory disturbance resulting from the effects of machinery or traffic. Where relative movement between parts of a structure is relatively small, the most common form of closure takes the form of caulking with a compound which is suitably elastomeric in its cured state. Alternatively, an insert of a suitable elastomeric material is provided, positioned at the opening of an expansion joint. Typical of such inserted closures are those taught by United States patents, Nos. 6,039,503 and 5,888,017.

Where relative movement between parts of a structure are relatively large, more complex closures are employed. In the simplest of these, an external cover plate is provided over the opening of an expansion joint, said cover plate being anchored at one end and free-moving at the other or, alternatively, retained in place by some form of centralising mechanism. Typical of such covering closures are those taught by United 3 States patents Nos. 6,527,467, 5,799,456 and 6,014,848. While such

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Ssimple cover plates have the advantage of low cost of manufacture and

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installation, they are generally unable to provide a flush closure.

0C- Consequently, they impede floor sweeping, may trip pedestrian personnel 00 and cause disturbance of vehicles, such as forklifts, passing over them.

Flush expansion joint closures are provided by plates attached to N the two parts of a joint, fingers or projections on. said plates being interdigitated across the joint opening. Alternatively, closures having articulated elements which extend across the opening of a joint are employed. Typical of these are those taught by United States patents Nos.

5,887,308, 5,964,069 and 6,022,169. Such closures are costly, may be difficult to clean and may be subject to physical blockage as a result of the entry of stones, concrete and other road surfacing material and debris.

The object of the present invention is to provide means of closing the opening of expansion joints which are inexpensive, which are easy to install during construction, which provide a more or less flush closure, which may readily be cleaned, which may be employed for drainage purposes, which may be rendered watertight and which will accommodate relatively small movement between parts of a structure.

According to the present invention, channel members are provide along adjacent edges of the opening of an expansion joint, their outer surfaces being flush with adjacent surfaces. Where structural members meeting at said expansion joint are made of concrete, said channel members are preferably cast into place and are provided with suitable O4

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anchoring elements which extend into the concrete and prevent said 0 Ichannel members becoming loosened, for example, by the passage of vehicular traffic over them. Cheek plates are removably fixed to said 00 channel members, the outer surfaces of said cheek plates being flush with 00 said channel member outer surfaces. The adjacent edges of said cheek plates are separated by a distance suitable to accommodate the maximum

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Nmovement to be experienced by said expansion joint and are tapered from a minimum thickness at said adjacent edges. A closure element having tapered surfaces complementary to those of said cheek plates is positioned in the cavity formed beneath said cheek plates and between said channel members and is urged into abutment with said cheek plates by suitable spring means beneath it, the force generated by said spring means being sufficient to maintain said closure element in place against said cheek plates when loaded by the pressure of vehicle wheels and the like. The cooperation of said tapered surfaces of said closure element with said complementary tapered surfaces of said cheek plates acts to maintain said closure element centralised between said cheek plates, regardless of their movement. Locating elements are optionally provided on the inner surface of said closure element to maintain said spring means in correct positional relationship with said closure element.

Said spring means are suitably compressed by said cheek plates being drawn into position by suitable fastenings passing through them being screwably inserted into said channel members, urging said closure element against said spring means. Suitable apertures are optionally

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provided in said concrete substrate to accommodate the length of said fastenings.

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The various aspects of the present invention will be more readily 00 understood by reference to the following description of preferred 00 5 embodiments given in relation to the accompanying drawings in which: Figure 1 is a transverse cross-sectional view of said expansion joint closure through a plane passing through said spring means, said fastenings and said anchoring elements; Figure 2 is a transverse cross-sectional view through drainage means provided in an expansion joint, said closure means having been removed for the purposes of clarity; Figure 3 is a transverse cross-sectional view through an alternative form of said expansion joint closure having an inverted arrangement of said cheek plates and said closure element; Figure 4 is a transverse cross-sectional view through an alternative form of said expansion joint closure adapted to be rendered watertight.

With reference to Figure 1, channel members 1, 2 are provide along adjacent edges of the opening of expansion joint 3 with their outer surfaces 4, 5 being flush with adjacent surfaces. Where structural members meeting at said expansion joint are made of concrete, said channel members are preferably cast into place and are provided with suitable anchoring elements 6 which extend into concrete 14, 15 and prevent said channel members becoming 6

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loosened, for example, by the passage over them of vehicular traffic.

O Cheek plates 7, 8 are removably fixed to said channel members, the outer surfaces of said cheek plates being flush with said channel 00 member outer surfaces. The adjacent edges of said cheek plates are 00 1 5 separated by a distance sufficient to accommodate the maximum movement to be experienced by said expansion joint and their exposed inner surfaces 31, 32 are tapered to have a minimum thickness at said adjacent edges. In the preferred embodiment, the tapering angle of said cheek plates is in the range 100 to 350 and said minimum thickness of said adjacent edges is in the range 2 millimetres to millimetres. A closure element 9 having tapered surfaces complementary to those of said cheek plates is accommodated in the cavity formed beneath said cheek plates and between said channel members and is urged into abutment with said cheek plates by a plurality of suitable spring means 10 provided beneath it and acting against rails 33 formed on the inner edges of said channel members, the force generated by said spring means being sufficient to maintain said closure element in place against said cheek plates when locally loaded by the pressure of vehicle wheels and the like. The cooperation of said tapered surfaces of said closure element with said complementary tapered surfaces of said cheek plates acts to always maintain said closure element centralised between said cheek plates regardless of their movement. Locating elements 11 are optionally provided on the inner surface of said closure element to maintain said O7 spring means in correct positional relationship with said closure 0 element, said locating elements. optionally extend through gap 12

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between rails 33 of said channel members. Where said locating 00 elements are deleted, suitable recesses 13 is provided in the inner 00 (N 5 surface of said closure element and the outer surfaces of rails 33 (not shown) to better locate said spring means in correct positional

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relationship with said closure element. Said closure element is made sufficiently thick and strong to sustain all normal traffic loads applied to it and, in the preferred embodiment, has a maximum thickness in the range 15 per cent to 40 per cent of its width.

In the preferred embodiment, said tapered faces of said cheek plates and said closure element are made from materials which are non-corrosive and which will operate in hard sliding contact without binding or galling. In an alternative embodiment, said tapered faces are suitably coated to prevent corrosion, binding and galling.

Said spring means are suitably compressed by said cheek plates being drawn into position by suitable fastenings 16 passing through them being screwably inserted into threaded bores provided in said channel members, urging said closure element against said spring means and thereby compressing them. Suitable apertures 17 are optionally provided in said concrete, substrate to accommodate the length of said fastenings, said apertures being created by the insertion of suitably shaped pieces of expanded polystyrene foam (not shown) during the process of casting said concrete. To maintain said channel 8 members in accurate juxtaposition during said concrete casting

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IND process, a jig plate (not shown) is screwably attached to them, said jig plate being removed after curing of said concrete. To create the void 3 0C. of said expansion joint, a sheet of expanded polystyrene foam (not 00 shown) of suitable thickness is placed in the formwork, the edge of said sheet being clamped in gap 12 between the lower ends of channel Smembers 1, thereby preventing the intrusion of concrete into the void between said channel members. Said polystyrene foam is removed after curing of said concrete with the use of high pressure water jetting or the like.

In operation, closure movement of expansion joint 3 results in a small downward vertical displacement of closure element 9, the reverse occurring during opening movement of said expansion joint.

In an alternative embodiment in which said expansion joint void is employed for drainage purposes, suitable apertures (not shown) are provided passing through said closure element to permit escape of liquid. In a further alternative embodiment, a plurality of shallow, narrow, transverse grooves (not shown) is provided in the tapered faces of one or other of said closure element or said cheek plates to permit a flow of liquid between the two said components.

With reference to Figure 2, in an alternative embodiment, a drainage channel 18 is cast into said expansion joint beneath said channel members. In the preferred embodiment, said drainage channel is fabricated from a thin, non-corrosive sheet metal material and its 9 open ends are provided with turned-down edges 19 which ensure their 0 secure embedding in concrete 14, 15. Movement of expansion joint 3

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is accommodated by flexing of said drainage channel. In an 0C. alternative embodiment, said drainage channel is made from a stiff, 00 dense but elastic polymer material. In the preferred embodiment, during the process of casting said channel members and said drainage I channel into said concrete, said drainage channel is bonded to the lower surfaces of said channel members, thereby preventing the intrusion of concrete into the void between said channel members and the void 20 within said drainage channel.

With reference to Figure 3, an alternative embodiment is shown of the arrangement depicted in Figure 1 in which the tapered surfaces of cheek plates 7, 8 and closure element 9 are inverted. In the preferred embodiment, said closure element is urged into contact with said cheek plates by a plurality of spring means in the form of bow springs 23, the ends of which bear against the inner surfaces of said cheek plates, stem 21 being fixed to the inner surface of said closure element and passing through a suitable aperture provided in the mid point of said bow spring, the mid point of said bow spring bearing against flange 22 formed on the end of said stem. In an alternative embodiment, individual members of said plurality of bow springs are joined at adjacent edges to create a single long spring element. In operation, narrowing of expansion joint 3 results in a small upward vertical displacement of closure element 9, the reverse occurring during widening of said expansion joint. During installation of said

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expansion joint closure, all members are maintained together in correct

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positional relationship by suitable jig plates (not shown), said jig plates 00 being removed following curing of said concrete.

00 With reference to Figure 4, an expansion joint closure similar in arrangement to that in Figure 1 is depicted, but adapted to render the closure watertight. In this alternative embodiment, channel members 1, 2 are provided with key grooves 25 along their outer surface edges and cover 24 extends fully across said closure with necked ribs 26 along each of its edges sealing engaged in said key grooves. In the preferred embodiment, said cover is made from a tough, flexible, cutresistant polymer material, such as polyurethane. The lower, outer edges 28 of said channel members are optionally deepened to better accommodate said key grooves. In the embodiment depicted, said spring means take the form of short, stiff coil springs 30. Stem 11 is provided fixed to the inner surface of said closure element and a guide sleeve (not shown) is provided filling the annular space between said stem and said spring means to positively locate said spring means. In an alternative embodiment, said stem and said guide sleeve are deleted and recesses 13 are provided in the inner surface of said closure element and the outer surface of rails 33 to locate the ends of said spring means. In the preferred embodiment, said channel members are provided along their outer edges with upraised flanges 29, the outer edges of which are level with the outer surface of said cover. Said 11 channel members and said cheek plates are preferably made from non-

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IDcorrosive materials or are treated to render them non-corrosive. Where (,i the surfaces surrounding said expansion joint closure are required to 00 be protected from corrosion as is the case, for example, in an abattoir, 00 (i 5 a durable, impervious coating 27 is applied level with the outer edges of said upraised flanges, said flange outer edges being used to provide C-i a depth reference for coverings applied to said surfaces adjacent said closure means. The said embodiment is otherwise installed and assembled in the manner described in relation to Figure 1. A suitable sealant is optionally applied to said key grooves and said necked ribs during installation of said cover.

In all said embodiments, said spring means optionally takes the form of short, stiff coil springs, stacks of thick Belleville washers or stiff bow springs in discrete or conjoined form.

With reference again to Figures 1 and 4, in an obvious alternative embodiment (not shown) in which said closure element is made in wider form, said spring means are optionally provided in two longitudinal rows situated along either side of said closure element. In such embodiment, in which said wider closure element may be susceptible to bending by spot loads, medially-located locating elements 11 are optionally replaced by a medial stiffening web of suitable depth fixed to the inner surface of said closure element and extending for more or less its full length. Locating elements to locate said spring means are also provided in longitudinal rows situated on 12 either side of said closure element.

0 Where used herein, the term, 'outer' is intended to imply located at

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or adjacent or directed towards the outer surface of said structure and 00 the term, 'inner' is intended to imply located inwardly and remote 00 c N 5 from or directed away from the outer surface of said structure.

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Claims

2. The closure means of Claim 1 in which said channel members are installed with their outer surfaces positioned more or less flush with those of said structure.
3. The closure means of Claim 1 in which said channel members are provided with anchoring elements providing secure attachment to a cast concrete structure. 14
4. The closure means of Claim 1 in which said cheek plates are drawn O into position on and fixed to said channel members by screw fastenings of suitable length screwed into threaded bores in said 0C. channel members. 00
5. The closure means of Claims 1 and 4 in which the drawing into position on said channel members of said cheek plates by said screw N fastenings acts to compress said spring means.
6. The closure means of Claim 4 in which the excess length of said screw fastenings is accommodated within apertures formed in a said cast concrete structure beneath said channel members by the insertion of suitably shaped pieces of expanded polystyrene foam into formwork during the process of casting said concrete.
7. The closure means of Claim 1 in which said channel members are maintained in accurate juxtaposition during their incorporation into a said cast concrete structure by a jig plate removably attached to them, said jig plate being removed after curing of said concrete.
8. The closure means of Claims 1 and 7 in which, to create the void of said expansion joint in a said cast concrete structure, a sheet of expanded polystyrene foam of suitable thickness is placed in the formwork, the edge of said sheet being clamped in the gap between rails formed on the inner ends of said channel members to prevent the intrusion of concrete into the void between said channel members.
9. The closure means of Claim 8 in which said polystyrene foam is removed after curing of said concrete with the use of high pressure water jetting or the like. O
10. The closure means of Claim 1 in which said closure element is made with a maximum thickness in the range 15 per cent to 40 per cent of its 00 width. 00
11. The closure means of Claim 1 in which said spring means are located "in position by locating elements fixed to the inner surface of said N closure element and extending axially through said spring means.
12. The closure means of Claim 1 in which the inner ends of said spring means bear against adjacent rails formed on the inner edges of adjacent said channel members.
13. The closure means of Claim 1 in which the outer ends of said spring means are located in recesses formed in the inner surface of said closure element and in the rails provided on the inner edges of said channel members.
14. The closure means of Claim 1 in which said spring means take the form of short, stiff coil springs. The closure means of Claim 1 in which said spring means take the form of stacks of thick Belleville washers.
16. The closure means of Claims 11 and 14 in which guide sleeves are proved between said locating elements and the inner surfaces of said coil springs.
17. The closure means of Claim 1 in which said spring means are provided in a single row extending along the centre-line of said closure element.
18. The closure means of Claim 1 in which said spring means are provided 16 in a single row extending along the centre-line of said closure element. O
19. The closure means of Claim 1 in which said spring means are provided in two longitudinal rows situated along either side of said closure 00 element. 00 i 5 20. The closure means of Claim 19 in which a medial stiffening web of suitable depth is fixed to the inner surface of said closure element and ri extends for more or less its full length.
21. The closure means of Claim 1 having a drainage channel provided beneath it in said expansion joint to collect liquid entering through said closure means.
22. The closure means of Claim 21 in which said drainage channel is made from an elastic material to elastically accommodate movement of said expansion joint.
23. The closure means of Claims 1 and 21 in which said drainage channel is made with turned-down edges to facilitate their embedding in a said cast concrete structure.
24. The closure means of Claims 1 and 21 in which said drainage channel is bonded to the inner edges of said channel members prior to their during their incorporation into a said cast concrete structure.
25. The closure means of Claim 1 in which the tapered surfaces of said cheek plates and said closure element are inverted, with said closure element being located uppermost and urged downwardly by suitable spring means into strong co-operating contact with said tapered surfaces of said cheek plates. 17 O 0 form of discrete, short, stiff bow springs, the ends of which bear against the inner surfaces of said cheek plates and the mid points of 00 which bear against flanges formed on the inner ends of stems fixed to 00 (i 5 the inner surface of said closure element, said stems passing through (-i -suitable apertures provided in said bow springs. C, 27. The closure means of Claim 25 in which said bow springs are joined one to another at adjacent ends to create a single long spring element.
28. The closure means of Claim 25 in which the complete assembly of said channel members, said cheek plates and said spring means is maintained in accurate juxtaposition during its incorporation into a said cast concrete structure by a jig plate removably attached to said channel members and said cheek plates, said jig plate being removed after curing of said concrete.
29. The closure means of Claim 1 which is rendered watertight by an impervious cover passing fully across it with its longitudinal edges being sealingly fixed to said channel members. The closure means of Claim 29 in which said impervious cover is sealingly fixed to said channel members by necked ribs formed along the longitudinal edges of the inner surfaces of said cover engaging complementary key grooves provided along the longitudinal edges of the outer surfaces of said channel members.
31. The closure means of Claim 29 in which said impervious cover is made from a tough, flexible, cut-resistant polymer material such as 18 O polyurethhne. (N 32. The closure means of Claim 29 in which said channel members are 0provided along the edges of their outer surfaces with upraised flanges 00 of a height matching the outer surface of said impervious cover, said flanges providing a depth reference for covering material applied to surfaces adjacent said closure means.
33. The closure means of Claim 29 in which a suitable sealant is applied to said key grooves and said necked ribs during installation of said cover.
34. The closure means of Claim 1 in which said expansion joint void is employed for drainage purposes, suitable apertures being provided passing through said closure element to permit escape of liquid. The closure means of Claim 1 in which said expansion joint void is employed for drainage purposes, a plurality of shallow, narrow, transverse grooves being provided in the tapered faces of one or other of said closure element or said cheek plates to permit a flow of liquid between the two said components.
36. The closure means of Claim 1 in which said tapering of said adjacent edges of said cheek plates is in the range 100 to 35'
37. The closure means of Claim 1 in which said adjacent edges of said cheek plates taper to a minimum thickness in the range 2 millimetres to 20 millimetres.