AU2010201482B9 - Expansion joints - Google Patents

Abstract

C:\NRPfnblDCC\PLB\2795446_1.DOC-A/04/2010 -9 An expansion joint for installation at adjacent edges of concrete sections, the joint comprising a rail mountable to one of the concrete sections, a cover plate for spanning a 5 gap between the two concrete sections, the rail displacing relative to the cover plate upon expansion/contraction of the two concrete sections whereby a gap between an upright inner face of the rail and an opposed upright face of the cover plate narrows/widens with expansion/contraction of the concrete sections, and a flexible seal mounted within the gap to maintain the gap closed within the range of movement of the expansion joint, the seal 10 comprising a series of spaced parallel vertical legs extending lengthwise along the gap, and flexible transverse webs interconnecting adjacent pairs of legs to permit the effective width of the seal to contract/expand to correspond to the width of the gap, the vertical legs being relatively rigid so as to carry vertical loading to which the seal may be subjected by passage of personnel and equipment across the joint. 4a 14b 14a 20a T ,4 20 20a 14a 8a 24 8b 14c

Description

CANRPonbN)CC\PLB\279544r.J DOC‘MU/2010 2010201482 09 Apr 2010 - 1 -

EXPANSION JOINTS

The present invention relates to expansion joints for installation into concrete decking, and more particularly to a flexible seal between moving components of an expansion joint. 5

In the construction of large areas of suspended concrete deck structures such as multistorey shopping or exhibition spaces, hospitals and so forth it is necessary to incorporate expansion joints between adjacent sections of the deck structure principally to absorb movement of the structure primarily arising from the temperature variation within the 10 structure and in some cases wind loading under high wind forces which causes the structure to sway and seismic loading. The movement between the sections of the deck structure can be a combination of horizontal, vertical, and sideways movement and the expansion joint which is designed to accommodate the anticipated range of movement is installed in a gap between two adjacent sections. Expansion joints for this purpose 15 typically comprise spaced parallel rails which move together and apart while maintaining a substantially parallel relationship, and a cover plate system comprising one or more cover plates extending across and closing the gap between the two concrete sections throughout the range of anticipated movement. 20 Some current designs of expansion joint feature a flexible seal interposed between an edge of the cover plate and a rail coupled to the edge portion of the adjacent concrete section so as to close the gap between those components while allowing the required movement between the rail and cover plate, the upper surface of the seal forming a transition surface between the surface of the cover plate and the surface of the adjacent concrete section to 25 facilitate smooth passage of personnel and equipment across the expansion joint. Existing seals for this purpose are not particularly satisfactory in that they are prone to splitting due to the load applied to the edge sections of the seal by high load traffic such as the wheels of pallet trolleys, maintenance equipment, and heavy medical equipment. Moreover, under such loading the seal tends to depress within its central part thereby impeding smooth 30 transition of the equipment across the expansion joint. 2010201482 26 Sep 2016 -2-

The present invention in its preferred embodiments relates to an expansion joint having an improved design of flexible seal for this purpose.

According to one aspect of the invention, there is provided an expansion joint for 5 installation at adjacent edges of concrete sections, the joint comprising a rail mountable to one of the concrete sections, a cover plate for spanning a gap between the two concrete sections, the rail displacing relative to the cover plate upon expansion/contraction of the two concrete sections whereby a gap between an upright inner face of the rail and an opposed upright face of the cover plate narrows/widens with expansion/contraction of the 10 concrete sections, and a flexible seal mounted within the gap to maintain the gap closed within the range of movement of the expansion joint, the seal comprising a series of spaced parallel vertical legs and flexible transverse webs interconnecting adjacent pairs of legs to permit the effective width of the seal to contract/expand to correspond to the width of the gap, the vertical legs extending along the entire vertical length of the seal and being 15 relatively rigid so as to carry vertical loading to which the seal may be subjected by passage of personnel and equipment across the joint, wherein the flexible seal constituted by the vertical legs and transverse webs is formed as an elastomeric extrusion in one piece, the elastomeric material used to form the legs being of a relatively hard durometer rating and the elastomeric material for forming 20 the transverse webs being of a relatively soft durometer rating.

In a preferred embodiment of the invention, the rail comprises a lower transverse flange which extends across the gap and which is in sliding contact with a lower part of the cover plate, the lower ends of the legs of the flexible seal being supported by engagement with 25 the lower transverse flange. Advantageously, opposed outer legs of the seal lie flush against the opposed faces of the rail and cover plate and are connected to the rail and cover plate by fastenings formed by integral extensions of the outer legs.

Preferably, each fastening comprises a transverse extension at the upper end of the outer 30 leg and flush with the upper edge of the rail or upper surface of the cover plate respectively, and a fixing portion extending downwardly from the transverse extension and engaged within a slot in the rail or cover plate respectively. Advantageously, the engagement is a snap-in engagement. 2010201482 26 Sep 2016 -3 -

According to another aspect of the invention, there is provided a flexible seal for use in an expansion joint for installation at adjacent edges of concrete sections, the seal being of elongate form for incorporation in a gap extending lengthwise of the joint between 5 relatively movable components of the joint, the seal comprising a series of spaced parallel vertical legs and flexible transverse webs interconnecting adjacent pairs of legs to permit the effective width of the seal to contract/expand to correspond to the width of the gap, the vertical legs extending along the entire vertical length of the seal and being relatively rigid so as to carry vertical loading to which the seal may be subjected by passage of personnel 10 and equipment across the joint, wherein the seal is formed as an elastomeric extrusion, the elastomeric material used to form the legs being of a relatively hard durometer rating and the elastomeric material for forming the transverse webs being of a relatively soft durometer rating. 15 An embodiment of the invention will now be described by way of example only with reference to the accompanying drawings in which:

Figure 1 is a section of an expansion joint in accordance with the preferred embodiment of the invention;

Figure 2 is a fragmentary section in perspective view showing a part of the 20 expansion joint to better illustrate the configuration of a flexible seal between a rail and a cover plate of the joint;

Figure 3 is a more detailed view showing the flexible seal and its co-operation between the rail and cover plate; and

Figure 4 is an end view of the seal prior to its incorporation into the joint. 25

Figures 1 and 2 show an expansion joint 2 between two adjacent edge portions of concrete decking sections 4, 6. The expansion joint 2 comprises a pair of parallel longitudinal rails 8, 10 in the form of extrusions, for example of aluminium. The rail 8 is mounted within a rebate formed at the edge portion of concrete section 4, and the rail 10 is mounted within a 30 rebate formed at the edge portion of concrete section 6, the upper edges of the rails 8, 10 being substantially flush with surface covering 4a, 6a applied to the concrete sections 4, 6, C:\NRPortbl\DCOPLBV2795446J.DOC-MM/20|0 2010201482 09 Apr 2010 -4- respectively. The rails 8, 10 are coupled by pivotal links 12 spaced apart along the length of the rails 8, 10. The gap between the two rails 8, 10 is spanned by a cover plate 14 which is secured to the links 12 at their centre points whereby upon contraction and expansion of the joint by movement of the rails 8, 10, the cover plate 14 will remain centrally located 5 between the two rails. In the embodiment shown, the cover plate 14 consists of an extrusion 14a of channel section, likewise of aluminium for example, carrying an insert plate 14b, the upper surface of the cover plate 14 being level with the upper edge of the rails 6, 8. It will be seen from Figures 1 and 2, that the rails 8, 10 each consist of an outer vertical side and a lower, inwardly-directed, wide horizontal flange which supports the 10 cover plate 14 while allowing for sliding movement of the rails 8, 10 relative to the cover plate 14. A flexible seal 18 in accordance with an embodiment of the invention is installed between each of the rails 8, 10 and an adjacent face of the extrusion 14a of cover plate 14. Figure 3 15 shows the installation of one of the seals 18 in enlarged detail and Figure 4 shows the seal 18 prior to installation.

With reference to Figures 3 and 4, the seal 18 is formed as a single extrusion in an elastomeric material and extends for the full length of the gap between the inner face 8a of 20 the vertical side of the rail 8 and the opposite face 14c of extrusion 14a. The seal 18 comprises substantially vertical outer legs 20 and a series of intermediate legs 22 which are parallel to the outer legs. The adjacent pairs of vertical legs 20, 22 are interconnected by upper and lower flexible transverse webs 24. Each of the outer legs 20 is formed at its upper end with an integral outwardly-directed horizontal extension 20a leading into a 25 downwardly-directed fixing portion 20b which lies outwardly of, and parallel to, the leg 20 itself. The vertical sides of the rail 8 and cover plate extrusion 14a are shaped with longitudinal slots to receive the fixing portions 20b of the seal, the fixing portions being locked within the slots by snap-in engagement of locking lips 20c beneath an enlarged shoulder portion at the bottom of the slot. The upper parts of the vertical sides of the rail 8 30 and extrusion 14a are shaped to accommodate the transverse extensions 20a in the manner shown in Figure 3 whereby the upper surfaces of the transverse extensions 20a are C \NRPonbI\DCC\PLB\27y544r._l DOC-8AM/2010 2010201482 09 Apr 2010 -5- substantially flush with the upper edges of the rail and cover plate extrusion. The vertical legs 20, 22 of the seal rest on the lower horizontal flange 8b of the rail 8 which thereby provides load-bearing support for those legs. 5 Each of the legs 20, 22 is formed from a relatively hard durometer elastomeric material which provides good vertical load-carrying capacity whereby the seal will not be prone to depression within its central portion under an applied vertical load as equipment is moved across the expansion joint. As the upper transverse extension 20a of each outer leg 20 is formed from the same hard durometer material and forms the exposed outer edge of the 10 seal, the outer edge is less prone to degradation under loading. The upper and lower transverse connecting webs 24 are of a relatively soft durometer and are shaped to accommodate the lateral contraction and expansion of the seal consequent on the sliding of the rail relative to the cover plate upon expansion/contraction of the associated sections of the concrete deck. 15

In one practical example, the seal 18 is formed from a thermoplastic elastomer such as that sold under the trade mark Santoprene. The legs 20, 22 are formed with a durometer hardness of 50 to 90 with around 87 being particularly preferred, and the transverse webs 24 are formed with a durometer hardness of 10 to 50 with around 35 being especially 20 preferred. The entire seal is formed in a single extrusion using extrusion techniques which will be well understood by those skilled in the art.

This basic design of the seal allows significant versatility in adapting the design to suit different ranges of expansion movement (by incorporating more or fewer intermediate legs 25 22) and different vertical loading characteristics (by varying the cross-sectional size of the legs and also possibly by varying the spacing between the legs).

Although in the particular expansion joint illustrated, the construction is such that the rails 8, 10 associated with the two adjacent concrete sections will each move, on expansion of 30 the concrete sections, relative to the cover plate, whereby a seal 18 is present between each of the rails and the cover plate to accommodate the anticipated range of movement, in a 2010201482 26 Sep 2016 -6- joint of a similar form but designed for a somewhat reduced range of movement, the cover plate may be fixed to one of the concrete sections and abut firmly against that concrete section thereby obviating the need for a seal at that side of the joint, the seal present at the other side of the joint being sufficient to accommodate the anticipated movement. 5

The flexible seal described may also be utilised in expansion joints of different detailed design to that shown.

The invention has been described by way of non-limiting example only and many 10 modifications and variations may be made thereto without departing from the spirit and scope of the invention.

Throughout this specification and the claims which follow, unless the context requires otherwise, the word "comprise", and variations such as "comprises" and "comprising", will 15 be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.

The reference in this specification to any prior publication (or information derived from it), or to any matter which is known, is not, and should not be taken as an acknowledgment or 20 admission or any form of suggestion that that prior publication (or information derived from it) or known matter forms part of the common general knowledge in the field of endeavour to which this specification relates.

Claims (8)

1. THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:

   1. An expansion joint for installation at adjacent edges of concrete sections, the joint comprising a rail mountable to one of the concrete sections, a cover plate for spanning a gap between the two concrete sections, the rail displacing relative to the cover plate upon expansion/contraction of the two concrete sections whereby a gap between an upright inner face of the rail and an opposed upright face of the cover plate narrows/widens with expansion/contraction of the concrete sections, and a flexible seal mounted within the gap to maintain the gap closed within the range of movement of the expansion joint, the seal comprising a series of spaced parallel vertical legs and flexible transverse webs interconnecting adjacent pairs of legs to permit the effective width of the seal to contract/expand to correspond to the width of the gap, the vertical legs extending along the entire vertical length of the seal and being relatively rigid so as to carry vertical loading to which the seal may be subjected by passage of personnel and equipment across the joint, wherein the flexible seal constituted by the vertical legs and transverse webs is formed as an elastomeric extrusion in one piece, the elastomeric material used to form the legs being of a relatively hard durometer rating and the elastomeric material for forming the transverse webs being of a relatively soft durometer rating.
2. 2. An expansion joint according to claim 1, wherein the rail comprises a lower transverse flange which extends across the gap and which is in sliding contact with a lower part of the cover plate, the lower ends of the legs of the flexible seal being supported by engagement with the flange.
3. 3. An expansion joint according to either one of claims 1 and 2, wherein opposed outer legs of the seal lie flush against opposed faces of the rail and cover plate and are connected to the rail and cover plate by fastenings formed by integral extensions of the outer legs.
4. 4. An expansion joint according to claim 3, wherein each fastening comprises a transverse extension at the upper end of the leg, the extension lying flush with the upper edge of the rail or upper surface of the cover plate respectively, and a fixing portion extending downwardly from the transverse extension and engaged within a slot in the rail or cover plate respectively.
5. 5. An expansion joint according to claim 4, wherein the engagement is a snap-in engagement.
6. 6. A flexible seal for use in an expansion joint for installation at adjacent edges of concrete sections, the seal being of elongate form for incorporation in a gap extending lengthwise of the joint between relatively movable components of the joint, the seal comprising a series of spaced parallel vertical legs and flexible transverse webs interconnecting adjacent pairs of legs to permit the effective width of the seal to contract/expand to correspond to the width of the gap, the vertical legs extending along the entire vertical length of the seal and being relatively rigid so as to carry vertical loading to which the seal may be subjected by passage of personnel and equipment across the joint, wherein the seal is formed as an elastomeric extrusion, the elastomeric material used to form the legs being of a relatively hard durometer rating and the elastomeric material for forming the transverse webs being of a relatively soft durometer rating.
7. 7. A flexible seal according to claim 6, wherein the opposed outer legs of the seal include integral extensions forming fastenings by which the seal can be secured to adjacent components of the expansion joint.
8. 8. A flexible seal according to claim 7, wherein each fastening comprises a transverse extension at the upper end of the leg, and a fixing portion extending downwardly from the transverse extension for engagement within a slot in the adjacent component of the joint.