AU2010214742B2

AU2010214742B2 - Expansion joints

Info

Publication number: AU2010214742B2
Application number: AU2010214742A
Authority: AU
Inventors: Robert Urquhart Connell
Original assignee: Illinois Tool Works Inc
Current assignee: Illinois Tool Works Inc
Priority date: 2009-09-03
Filing date: 2010-08-31
Publication date: 2016-11-10
Anticipated expiration: 2030-08-31
Also published as: AU2010214742A1

Abstract

C:NRPorblVDCC\PLWu3149553_I DOC-27/08/200 - 13 An expansion joint for installation at adjacent edges of concrete sections, the joint having an installation system comprising adjustable jacking screws co-operable with the concrete 5 sections to set the joint at a desired height relative to the sections, and locators for temporarily locating the joint in position for installation of anchors for fastening the rails to the concrete sections. 38 6 12 22 8 30 G42b 38 * *4 04q CY) ~~ ~ INIy)

Description

C \NRPonbl\DCOPL\W 14955ί_I DOC-27rtW2llΙΟ 2010214742 31 Aug 2010 - 1 -

EXPANSION JOINTS

The present invention relates to expansion joints for installation into concrete decking, and more particularly to a system for facilitating installation of such joints. 5

In the construction of large areas of suspended concrete deck structures such as airport concourses, multi-storey shopping or exhibition spaces, hospitals, bridges 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 temperature 10 variation within the structure and in some cases wind loading under high wind forces which cause 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 15 for this purpose 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 rails throughout the range of anticipated movement. Although the adjacent edges of the adjacent deck sections are spaced to accommodate the movement, the joint itself is usually 20 installed within a rebate formed for that purpose along the edge portion of each section, although in some installations where a thick floor covering is to be applied to the sections, rebates for the joint may not be required.

While the basic principle of operation of a typical expansion joint as described above is 25 very sound, its actual performance in practice will depend on the quality of its installation. Poor quality installation can result in premature joint failure. Existing methods of installation are highly labour intensive and the effectiveness of the installation will usually depend on the skill of the installer. Current installation methods do not ensure that the joint is properly bedded down and supported along its complete length by mortar or other 30 bedding material, and because of the incorporation of packing shims beneath the joint to set the joint to the finished floor height, the joint is not firmly fixed to the concrete which H:\sbt\Interwoven\NRPortbl\DCC\SBT\l 0284431 _1 .doc-13/10/2016 2010214742 13 Oct 2016 -2- allows the joint to move and flex during service. As a result the joint may not work properly and may become loose or buckle under load. It may also cause cracking in adjacent floor finishes such as tiles. 5 Moreover, when rebates are required there also seems to be no systematic process in place for forming the rebates at the edges of the concrete sections to receive the joint. In practice the rebates are usually formed by whatever formwork the concreter can find on site and this is rarely the right size and often requires the joint installer to reform the rebate in certain respects. 10

According to a first aspect of the present invention, there is provided an expansion joint for installation at adjacent edges of concrete sections, the joint having an installation system comprising adjustable jacking screws co-operable with the concrete sections to set the joint at a desired height relative to the sections, and locators for temporarily locating the joint in 15 position for installation of anchors for fastening the rails to the concrete sections, wherein the temporary locators are in the form of removable pins which, when anchor holes have been drilled into the concrete sections, engage within the holes and locate the joint.

According to a second aspect of the present invention, there is provided an expansion joint 20 for installation at adjacent edges of concrete sections, the joint comprising opposed substantially parallel rails mounted for substantially parallel contraction and expansion movement upon contraction or expansion of the space between the two concrete sections, and a cover plate system spanning a gap between the two rails, and an installation system associated with the rails for installing the joint, the installation system comprising 25 adjustable jacking screws co-operable with the concrete sections to set the joint at a desired height relative to the sections, and locators for temporarily locating the joint in position for installation of anchors for fastening the rails to the concrete sections, wherein the temporary locators are in the form of removable pins which, when anchor holes have been drilled into the concrete sections, engage within the holes and locate the joint. 30

According to a third aspect of the present invention, there is provided a method of 2010214742 20 Oct 2016 H:\plw\Interwoven\NRPortbl\DCC\PLW\l 1796562_ I .doc-20/10/2016 -2a- installing an expansion joint as defined above, comprising setting the joint to a required height relative the concrete sections by means of the jacking screws, drilling anchor holes into the concrete sections with the anchor holes being located in predetermined positions relative to the joint, inserting locating pins into the holes and, with the locating pins 5 remaining within the anchor holes and the joint removed, applying bedding mortar or other bedding material for the joint, fitting the joint back onto the concrete sections with correct location being ensured by co-operation between the joint and the locating pins, removing the pins and inserting anchors into the anchor holes thereby vacated via the voids thereby formed in the bedding material and tightening the anchors to lock the joint into the position 10 previously determined by the co-operation between the pins and the joint.

According to an embodiment of the present invention, there is provided a form for producing a rebate in the edge of the concrete section for receiving an expansion joint, the form comprising a mounting engageable over formwork for forming the corresponding 15 edge of the panel, and structure for forming the rebate opening onto that edge.

The temporary locators are in the form of removable pins which, when anchor holes have been drilled into the concrete sections, engage within the holes and locate the joint, the temporary locating pins when installed into the holes remaining in position when the joint 20 is removed to allow application of bedding mortar or other bedding material for the joint without penetration of the material into the holes, and the locating C \NRPonbf\DCC\PLWU149553.1 DOC-27A)V2ll 10 2010214742 31 Aug 2010 -3 - pins thereafter allowing correct relocation of the joint into the rebates. The locating pins are then removed to permit location of the anchors through the voids thereby formed in the bedding material and into the holes previously drilled into the sections. 5 In a preferred embodiment of the invention, the jacking screws are carried by brackets spaced along the rails of the joint, the brackets also having apertures for receiving upper parts of the locating pins. The apertures facilitate drilling location for the anchor holes in the concrete sections and then location of the joint when lower parts of the pins are temporarily engaged within the anchor holes and upper parts of the pins are within the 10 apertures in the brackets. Advantageously the brackets are formed separately from the rails and are then clipped to the rails.

Usually, the joint will be installed into rebates at adjacent edges of the concrete sections and in that case the anchor holes are drilled into the base of the rebates. 15 A further aspect of the invention provides a form for producing the rebate in the edge of the concrete section, the form comprising a mounting engageable over formwork for forming the corresponding edge of the panel, and structure for forming the rebate opening onto that edge. 20

In a particularly preferred embodiment, the mounting is provided by a downwardly-opening channel engageable over the formwork.

The form may be shaped to provide keying grooves extending along the base of the rebate 25 for improved keying of the bedding material thereto and/or it may be configured to form the base with a downwards inclination towards the upright wall of the rebate to facilitate retention of the bedding material within the rebate.

According to a further aspect of the invention there is provided a method of installing an 30 expansion joint as defined above, comprising setting the joint to a required height relative the concrete sections by means of the jacking screws, drilling anchor holes into the C\NRPonbr\OCC\PLWUU9SJJ.l DOC-27/0IV2010 2010214742 31 Aug 2010 -4- concrete sections with the anchor holes being located in predetermined positions relative to the joint, inserting locating pins into the holes and, with the locating pins remaining within the anchor holes and the joint removed, applying bedding mortar or other bedding material for the joint, fitting the joint back onto the concrete sections with correct location being 5 ensured by co-operation between the joint and the locating pins, removing the pins and inserting anchors into the anchor holes thereby vacated via the voids thereby formed in the bedding material and tightening the anchors to lock the joint into the position previously determined by the co-operation between the pins and the joint. 10 In practice, if required the jacking screws are adjusted to provide final height adjustment of the joint relative to the concrete sections prior to curing of the bedding material. Prior to curing the anchors are tightened to an extent sufficient to provide preliminary anchorage of the joint and to compress the bedding material, with final tightening to a prescribed anchoring torque occurring after curing. 15

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

Figure 1 is a fragmentary perspective view showing adjacent edge portions of concrete deck sections, with an expansion joint in accordance with an embodiment of the 20 invention installed within rebates formed along those adjacent edge portions;

Figure 2 is a schematic exploded section corresponding to Figure 1;

Figure 3 is a perspective view of a locating and anchoring bracket engageable with the rails of the expansion joint;

Figure 4 is an end view of the bracket shown in Figure 3; 25 Figure 5 is an end view of a form for producing the rebate during casting of the concrete decking section;

Figure 6 is an end view similar to Figure 5 but showing the rebate form engaged with formwork for the concrete decking section;

Figure 7 is a fragmentary perspective view corresponding to Figure 6; 30 Figure 8 is an end view similar to Figure 5 but showing an alternative design of rebate form; and C:\NRPonbl\DCC\PLWOl49553J DOC-27rtW2mi 2010214742 31 Aug 2010 -5-

Figure 9 shows a modified version of the rebate form, the form being illustrated in its in use configuration following casting of the rebate.

Figures 1 and 2 of the accompanying drawings show adjacent edge portions of concrete 5 decking sections 2, 4, each formed with a rebate 6, 8 into which expansion joint 10 is fitted; it will be understood that to facilitate illustration, Figure 1 is only showing a short length of the decking sections and also of the expansion joint. The expansion joint 10 comprises a pair of parallel longitudinal rails 12, 14 in the form of extrusions. The rails 12, 14 are coupled by pivotal links 16 spaced along the length of the rails. Each link 16 10 comprises a strut 18 having a ball 20 at each end. The balls 20 are pivotally and slidably mounted within part-cylindrical passages in the two rails. The strut 18 is inclined at approximately 45° to the axis of the two rails whereby the two balls 20 of the link are laterally offset. The series of links 16 spaced along the length of the joint maintain the two rails 12, 14 in substantially parallel relationship while allowing the rails to move towards 15 and away from each other upon contraction and expansion of the joint. The gap between the two rails 12, 14 is spanned by a cover plate 22 which engages the upper surface of the two rails and which is secured to the struts 18 at their centre points whereby upon contraction and expansion of the joint by movement of the rails 12, 14, the cover plate 22 will remain centrally located between the two rails. To this basic extent, the design of the 20 joint is substantially conventional, although the rails 12, 14 themselves are of a special design to accommodate brackets 30 which have an important function in the installation of the joint as will be explained.

The brackets 30 are shown in greater detail in Figures 3 and 4 and are mounted at spaced 25 intervals within outer channels of the two rails 12, 14. Each bracket 30 has an anchoring portion 32 at its inner end and by which the bracket is fitted into the channel with a wedging action by pivoting the bracket 30. Outwardly of the anchoring portion 32, the main body 34 of the bracket extends outwardly and has a threaded aperture 36 for a jacking screw 38 and an aperture 40 for a temporary locating pin 42. 30

To install the joint, the brackets 30 with jacking screws 38 are assembled to the rails 12, 14 C-\NRPonbl\DCCVPI.W\M4*J?M_l OOC-27/i)X/?0|0 2010214742 31 Aug 2010 -6- of the joint at suitably spaced positions along the length of the rails (for example at spacings of approximately 0.5m) and the joint with brackets is positioned within the rebates 6, 8 of the two concrete sections. The jacking screws 38 within the brackets 30 support the joint from the base of the rebates and are adjusted to set the joint to slightly 5 above (l-2mm) the required finish floor level. Then, using the apertures 40 as guides, anchor holes are drilled into the base of the rebates 6, 8, and the temporary locating pins 42 are inserted through the apertures 40 in the brackets 30 into the corresponding holes which have been drilled into the rebates in order to temporarily locate and retain the joint relative to the rebates as further anchor holes are drilled in alignment with the apertures 40 in the 10 brackets 30 and locating pins 42 are inserted via the apertures 40 into these further holes. As shown in Figures 1 and 2, each locating pin 42 is of stepped diameter to provide a lower stem portion 42a which fits into the drilled hole in the rebate and enlarged upper stem portion 42b which extends through the aperture 40 in the bracket 30; when fitted into the drilled hole, the lower end of the upper stem portion 42b abuts against the surface of 15 the base of the rebate. With all of the locating pins 42 in position in the rebates 6, 8, the joint is removed by lifting off from the pins 42 which remain in position, and debris is removed from the rebates for example by brushing or blowing. It is to be noted that as the pins 42 remain in position during this stage, debris does not fill the anchor holes which have been drilled into the rebates. 20

With the joint still removed from the rebates and the pins 42 still in position in the anchor holes, bedding mortar or grout for the joint is applied to the rebates; due to the presence of the pins 42, the bedding material will not penetrate into the anchor holes. To facilitate the application of the bedding material, it is preferred to provide a special applicator trowel 25 with notches to allow easy application around the projecting pins 42. Preferably the trowel is also provided with smaller notches to ensure the appropriate width and depth of bedding material to provide proper support for the joint along its full length. The joint is then reinstalled into the rebates by location of its brackets 30 over the locating pins 42, upper stem portions 42b of the pins re-engaging in the apertures 40 of the brackets. When the 30 bedding material has partially cured, the pins 42 are removed through the brackets and are replaced by masonry anchors which extend through the apertures 40 in the brackets 30, and C\NRPonbt\DCC\PLWVm95S3J DOC2?/nX/2(llt) 2010214742 31 Aug 2010 -7- through the holes in the bedding material vacated by the pins and into the holes drilled into the base of the rebate. A suitable anchor for this purpose is an expansion anchor such as that sold under the registered trade mark "Dynabolt". The anchors are then lightly tightened in order to bed the joint into the bedding material and to bring the jacking screws 5 38 back into engagement with the base of the rebate. The jacking screws 38 and anchors are then simultaneously adjusted to bed the joint down to the final floor finish level to ensure that the bedding material is compressed under the joint to provide effective support for the joint along its entire length. After the bedding material has cured, the anchors are tightened to a required torque to firmly lock the joint in place and the rebates 6, 8 are then 10 backfilled with further mortar or grout to the finished floor level.

It will be understood from the above that the brackets 30 with the adjustable jacking screws 38 and temporary locating pins 42 enable an installation process which ensures that the finish joint is fully supported along its entire length by the bedding material and is 15 firmly locked in place to the concrete sections at the required height. It is considered that the installation effected in this manner will provide an extended service life over that achieved by joints installed using current techniques.

Although in the embodiment described above, the rails of the expansion joint are 20 interconnected by pivotal links which also carry the cover plate, in other embodiments this form of interconnection between the rails may be absent and instead the cover plate system may be formed by two parts each carried by a respective one of the two rails with the two parts co-operating to close the variable gap between the rails; for this purpose, the two cover plate parts may inter-fit in such a manner that they can displace horizontally and 25 vertically one relative to the other while still closing the gap. It is to be understood that what is important in the present invention is the installation system provided for the joint rather than the detailed construction of the joint itself and the installation system is adaptable for use with a wide variety of different expansion joints. 30 The installation system of the preferred embodiment of the invention also provides a rebate form to ensure that the rebates are cast accurately into the concrete sections to the required

C \NRPcmbl\|>CC\J'LWVM4yJ53_ I .DOC-27/IM/2WU 2010214742 31 Aug 2010 -8- size and shape. With reference to Figures 5 to 7, the form 50, which is reusable, is an extrusion of suitable metal, for example aluminium, or a robust plastic, and comprises a downwardly open outer channel 52 of a size to fit over and receive formwork 54 for the overall concrete section. The upper edge of the formwork 54 and with which the upper 5 surface of the overall cast decking section will be coincident is engaged by the upper wall 52a of the channel 52 (and which forms the base of the channel) so that the rebate form will be set at a predetermined height. A ledge 56 extending inwardly (in relation to the decking section) from the channel 52 has generally vertical and horizontal surfaces 56a, 56b to define the corresponding surfaces of the rebate when the section is cast. The ledge 10 56 is closed at its upper side to prevent ingress of concrete during casting. In the embodiment shown, the ledge is reinforced with internal webbing to ensure that the rebate form has the requisite strength and rigidity when supplied in long lengths. The particular configuration of the internal webbing shown is one of many alternative forms of internal reinforcement. The rebate form shown also has structure 58 above the upper surface of the 15 ledge 56 and which not only provides further strength and rigidity for the form, it also provides an upstanding section which facilitates removal of the form after casting of the section.

It will be noted from Figure 6 that the upper surface 56c of the ledge 56 is coplanar with 20 the upper edge of the formwork 54 when the upper edge of the formwork is engaged by the base 52a of the channel 52. This is significant because the upper edge of the formwork normally provides a reference for screeding the surface of the concrete during casting. With the rebate form in position along that formwork, the upper surface 56c of ledge 56 now fulfils that reference function during screeding. 25

Although in the embodiment shown in Figures 5 to 7 the underside 56b of the ledge 56 extends horizontally whereby the base of the rebate will also be horizontal, the ledge can be configured as shown in Figure 8 whereby its underside 56b inclines downwardly in a direction away from the fixing channel 52 by a few degrees whereby the base of the rebate 30 thereby formed will incline downwardly towards its inner edge at the junction with its vertical side to assist retention of the bedding material when under pressure during curing. 2010214742 31 Aug 2010 C:\NRPenbM>COf>LVWOI4«53_I.DOC-27fl»K/icM«l -9-

Altematively or in addition, the underside 56b of the ledge may be ribbed to provide keying grooves extending along the base of the rebate to ensure a strong keyed connection with the bedding material. 5 In a modification as shown in Figure 9, the outer edge of the ledge 56 of the form is extended beyond the upper surface 56a of the ledge to provide a lip 56d. The upper edge of the lip 56d provides the datum edge to which the concrete is accurately trowelled or screeded and enables any residue of concrete on the upper surface 56c to be easily removed. In this version, the upper edge of the lip 56d is co-planar with the base of the 10 channel 52 and thus with the upper edge of the formwork 54.

Although as particularly described the joint is mounted within rebates formed at the edges of the concrete sections and that is likely to be the usual form of installation, nevertheless as indicated at the outset when the concrete sections are to carry a thick floor covering, for 15 example thick tiles applied to a thick mortar base, there may be sufficient depth present within the tiles and mortar base to allow for fitting of the expansion joint without the need to "recess" the joint into rebates. In that case the joint will be mounted directly to the upper surfaces of the concrete sections by means of the installation system as previously described. 20

The embodiments have been described by way of example only and modifications are possible within the scope of the invention.

Claims

THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:

1. An expansion joint for installation at adjacent edges of concrete sections, the joint having an installation system comprising adjustable jacking screws co-operable with the concrete sections to set the joint at a desired height relative to the sections, and locators for temporarily locating the joint in position for installation of anchors for fastening the rails to the concrete sections, wherein the temporary locators are in the form of removable pins which, when anchor holes have been drilled into the concrete sections, engage within the holes and locate the joint.
2. An expansion joint according to claim 1 having substantially parallel rails mounted to the respective concrete sections and the installation system is associated with the rails.
3. An expansion joint for installation at adjacent edges of concrete sections, the joint comprising opposed substantially parallel rails mounted for substantially parallel contraction and expansion movement upon contraction or expansion of the space between the two concrete sections, and a cover plate system spanning a gap between the two rails, and an installation system associated with the rails for installing the joint, the installation system comprising adjustable jacking screws co-operable with the concrete sections to set the joint at a desired height relative to the sections, and locators for temporarily locating the joint in position for installation of anchors for fastening the rails to the concrete sections, wherein the temporary locators are in the form of removable pins which, when anchor holes have been drilled into the concrete sections, engage within the holes and locate the joint.
4. An expansion joint according to any one of the preceding claims, wherein the jacking screws are carried by brackets spaced along the rails of the joint, the brackets also having apertures for receiving upper parts of the locating pins, the apertures facilitating drilling location for the anchor holes and then location of the joint when lower parts of the pins are temporarily engaged within the anchor holes and upper parts of the pins are within the apertures in the brackets.
5. An expansion joint according to claim 4, wherein the brackets are formed separately from the rails and are then clipped to the rails.
6. A method of installing an expansion joint as defined in any one of claims 1 to 5, comprising setting the joint to a required height relative the concrete sections by means of the jacking screws, drilling anchor holes into the concrete sections with the anchor holes being located in predetermined positions relative to the joint, inserting locating pins into the holes and, with the locating pins remaining within the anchor holes and the joint removed, applying bedding mortar or other bedding material for the joint, fitting the joint back onto the concrete sections with correct location being ensured by co-operation between the joint and the locating pins, removing the pins and inserting anchors into the anchor holes thereby vacated via the voids thereby formed in the bedding material and tightening the anchors to lock the joint into the position previously determined by the cooperation between the pins and the joint.
7. A method according to claim 6, wherein the jacking screws are adjusted to provide final height adjustment of the joint relative to the concrete sections prior to curing of the bedding material.
8. A method according to claim 6 or claim 7, wherein prior to curing of the bedding material the anchors are tightened to an extent sufficient to provide preliminary anchorage of the joint and to compress the bedding material, with final tightening to a prescribed anchoring torque occurring after curing.
9. A method according to any one of claims 6 to 8, wherein the expansion joint is installed within rebates at adjacent edges of the concrete sections and the anchor holes are drilled into the base of the rebates.