Abstract:
In one aspect of the present invention there is provided an expansion joint strip support module  12  comprising an expansion joint strip locating portion  24  adapted to locate an expansion joint strip  20  and one or more support means  26  and  28  integral with and arranged to support the expansion joint strip locating portion. 
     In a further aspect of the present invention there is provided an expansion joint crack forming device comprising: an elongate base strip  14  being adapted to extend along a proposed expansion joint; and a crack forming projection  84  connected to the base strip  14  and designed to form a cavity in a concrete slab which is to be formed on top of the base strip  14 , the crack forming projection  84  being positioned to promote cracking of the concrete slab along the proposed expansion joint.

Description:
PRIORITY CLAIM 
       [0001]    This application is a national stage application of International Application No. PCT/AU2005//001218, filed on Aug. 12, 2005 which claims priority to, and the benefit of, Australian Provisional Application No. 2004904549, filed Aug. 13, 2004, the entire content of which is hereby incorporated by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to concrete expansion joints. More particularly, the present invention relates to a support assembly for an expansion joint strip and a method for installing an expansion joint strip in a concrete slab. 
       BACKGROUND OF THE INVENTION 
       [0003]    Concrete floors and paving typically comprise a number of concrete slabs. The concrete slabs are typically designed for movement relative to each other to avoid formation of cracks in the floor or paving which would otherwise form with thermal expansion and contraction of the concrete slab and movement of supporting foundations. Concrete slabs are typically separated from each other by concrete expansion joints which usually comprise a compressible expansion joint strip. Compressible expansion joint strips fill the gaps between concrete slabs while allowing movement toward and away from each other. 
         [0004]    Devices for positioning an expansion joint strip and formation of a corresponding expansion joint between concrete slabs are disclosed in U.S. Pat. No. 6,598,364 B1 and Danley Construction Products Pty Ltd and Connolly Key Joint Pty Ltd websites www.danley.com.au and www.connollykeyjoint.com respectively. The corresponding expansion joint forming devices are typically cumbersome and time consuming to erect. 
       SUMMARY OF THE INVENTION 
       [0005]    According to one aspect of the present invention there is provided a support assembly for an expansion joint strip, said assembly comprising: an elongate base strip including at least two laterally spaced locating walls; a plurality of discrete support modules each being detachably connected to the locating walls at longitudinally spaced positions along the base strip; and means for adjusting the height of the expansion joint strip relative to at least one of the support modules. 
         [0006]    Preferably the support assembly also comprises an expansion joint strip cover adapted to support the expansion join strip and being arranged to be supported by one or more of the support modules. More preferably each of the modules includes a U-shaped channel configured to cradle the expansion joint strip cover. 
         [0007]    Preferably the height adjustment means includes a pin being designed to locate at one of a plurality of different height positions relative to the corresponding support module. More preferably the pin is received in one of a plurality of locating holes in the support module, the strip cover being designed to rest on the pin to support the expansion joint strip at the required height. Even more preferably the pin is enlarged at one end for press-fit engagement with said one of the locating holes. 
         [0008]    Preferably the locating walls are each in the form of stiffening ribs designed to strengthen the base strip. 
         [0009]    Preferably the support modules include a pair of spaced support legs each being perforated to promote the flow of concrete and encasing of said modules. 
         [0010]    Preferably said locating walls include a pair of outer locating walls and a central locating wall. More preferably the base strip includes a groove or slot underlying the central wall and designed to allow lateral movement of the strip. 
         [0011]    Preferably the support assembly also comprises another base strip joined to said base strip at an expansion joint juncture. 
         [0012]    According to another aspect of the invention there is provided a method of installing an expansion joint strip in a concrete slab, said method comprising the steps of: providing an elongate base strip having at least two laterally spaced locating walls; providing a plurality of discrete support modules; fitting two or more of the support modules to the locating walls of the base strip at spaced longitudinal positions along the base strip; placing the expansion joint strip upon one or more of the modules and adjusting the height of said strip relative to at least one of said modules; and pouring concrete to at least partly bury the base strip, the support modules and the expansion joint strip. 
         [0013]    Additional features and advantages of the present invention are described in, and will be apparent from, the following Detailed Description of the Invention and the figures. 
     
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         [0014]    A preferred embodiment of the present invention will now be described, by way of example only, with reference to the following figures in which: 
           [0015]      FIG. 1  is a partially exploded perspective view of one example of an expansion joint strip support assembly of the present invention. 
           [0016]      FIG. 2  is an end elevational view of the expansion joint strip support assembly of  FIG. 1  in its assembled condition. 
           [0017]      FIG. 3   a  is a perspective view of a base strip from the assembly of  FIG. 1 . 
           [0018]      FIG. 3   b  is an end elevational view of the base strip of  FIG. 3   a.    
           [0019]      FIG. 4  is an end elevational view of the base strip of  FIG. 3   a  used to directly support a compressible expansion joint strip. 
           [0020]      FIG. 5  is a perspective view of an alternative example of an expansion joint strip support assembly of the present invention. 
           [0021]      FIG. 6   a  is a perspective view of an expansion joint strip support assembly similar to that of  FIG. 5 . 
           [0022]      FIG. 6   b  is an end elevational view of an alternative strip cover to that of  FIG. 6   a.    
           [0023]      FIG. 7  is an end elevational view of the expansion joint strip support assembly of  FIGS. 5 and 6  but without a concrete slab locating rod. 
           [0024]      FIG. 8  is an end elevational view similar to that of  FIG. 7  except that it includes the concrete slab locating rod of  FIGS. 5 and 6 . 
           [0025]      FIG. 9  is an end elevational view of the expansion joint strip support assembly of  FIG. 1  attached to another expansion joint strip support assembly. 
           [0026]      FIG. 10  is a perspective view of an expansion joint strip support assembly similar to that of  FIG. 9  attached via an alternative attachment bracket. 
           [0027]      FIG. 11  is a perspective view of another alternative example of an expansion joint strip support module of the present invention. 
           [0028]      FIG. 12  is a perspective view of 2 base strips of  FIG. 1  attached end to end. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0029]      FIG. 1 to 3   b  show an expansion joint strip support assembly of the present invention in the form of support assembly  10 . The support assembly  10  comprises an expansion joint strip support module in the form of support module  12 , a base strip  14  and an expansion joint strip cover in the form of strip cover  16 . The support module  12  attaches to the base strip  14  as shown in  FIGS. 1 and 2  which is described in detail below.  FIGS. 1 and 3   a  show only a portion of the entire length of the base strip  14 . The base strip  14  ranges from about 4 metres to about 6 metres in length. Support modules  12  are positioned along the length of the base strip  14  and attached to the base strip so that they are longitudinally spaced apart by about 400 mm. With support modules  12  spaced in this manner along the base strip  14  they are each able to support, as described below, a portion of an expansion strip in the form of a compressible expansion joint strip  20 . The expansion joint strip  20  is typically a tar based compressible expansion strip. With the expansion joint strip  20  supported as shown in  FIG. 2  it is supported for separation of concrete slabs  250  and  252  which are subsequently poured on either side of the compressible expansion joint strip  20 . The support module  12  is suitable for concrete slabs of any thickness. 
         [0030]    The support assembly  10  shown in  FIG. 2  is assembled first by placing the base strip  14  on the floor or ground which is to support the concrete slabs  250  and  252 . The floor may, for example, be elevated. The base strip  14  is positioned on the floor or ground so that it&#39;s aligned with the space between the proposed concrete slabs  250  and  252 . Other base strips  14  are also positioned on the floor or ground both parallel with and normally to other base strips to correspond with the predetermined arrangement of expansion joints. If the base strips are positioned on the ground they are usually attached via pegs, for example, pegs  15  (see  FIGS. 1 and 2 ) as shown in  FIG. 2 . Plastic sheet, (not shown) are then laid over the base strips and slits are cut in the plastic to enable locating walls of the base strip which are described below to pass up through the plastic sheets. The plastic sheets function to seal the floor or ground to prevent moisture seeping upwardly into the concrete slab. Once all of the base strips  14  relating to a specific surface area have been appropriately positioned, reinforcing mesh (not shown) is then positioned appropriately on top of the base strips  14 . For some applications the mesh is cut above the locating walls so that it is not exposed after concrete is poured but is entirely embedded in the concrete. The support modules  12  are then positioned above the base strip  14  to which they are to be attached so that they attach to the base strip  14  as shown in  FIGS. 1 and 2  by passage through holes of the mesh (not shown). The support modules  12  also function to attach the plastic sheets to the base strips  14 . 
         [0031]    The position of an upper surface  136  of the compressible expansion joint strip  20  relative to the upper surface  104  of the base strip  14  is adjusted by passing a locating pin  138  through opposed holes  38  and  40  of the U-shaped channel  24  as shown in  FIG. 2 . The upper surface  136  of the compressible expansion joint strip  20  can be used as a guide for forming an upper surface of the concrete slabs  250  and  252 . The means of adjustment involving the opposed holes  38  and  40  and the locating pin  138  can therefore be used, for example, to correct for any unwanted variation in the floor or ground height or alternatively to produce a sloping upper surface  136  to allow for drainage. 
         [0032]    Features of the support module  12 , base strip  14  and strip cover  16  will be described in more detail before providing a more detailed description of assembly of the support assembly  10 . The support assembly  10  comprises an expansion joint strip locating portion in the form of a U-shaped channel  24  and support legs in the form of planar legs  26  and  28 . The U-shaped channel  24  comprises opposed side walls  32  and  34  and an adjoining base  36 . The U-shaped channel  24  also includes adjustment means in the form of opposed holes  38  and  40  formed in respective side walls  32  and  34 . 
         [0033]    The planar leg  26  comprises 3 adjoining planar leg portions in the form of adjoining leg portions  46 ,  48  and  50 . The adjoining planar leg  28  similarly comprises 3 adjoining planar leg portions in the form of adjoining leg portions  50  to  54  and  56 . Although not shown in  FIG. 1 , planar leg portions  26  and  28  are perforated as described below in relation to support module  142  (see  FIGS. 5 and 6   a ) for flow of concrete or other cementitious material into the space underneath the leg portions  26  and  28 . In the support module  12  the adjoining leg portions  50  and  56  are integrally formed with the base  36  of the U-shaped channel  24 . The other adjoining leg portions of the support module  12  are also integrally formed with the adjoining leg portions  50  and  56 . The side walls  32  and  34  of the U-shaped channel  24  are also integrally formed with the base  36  and the adjoining leg portions  50  and  56 . In one alternative embodiment of the support module  12  the base  36  is V-shaped so that its longitudinal axis is positioned below its upper longitudinal edges. In this alternative embodiment a corresponding strip cover is identical to strip cover  16  except that its base is also v-shaped. The support module  12  is manufactured by cutting a corresponding extrusion into 80 mm lengths. It will be appreciated by persons skilled in the relevant art that the support module  12  can be manufactured by other means and could for example be injection moulded or formed from separate components corresponding to the adjoining leg portions, base  36  and side walls  32  and  34 . 
         [0034]    The adjoining leg portions  46  and  52  comprise attachment means for attachment to the base strip  14 . The attachment means of the adjoining leg portions  46  and  52  is in the form of respective locating slots  60  and  62 . Each of the locating slots  60  and  62  comprises locating slot walls  64  and  66 , and  68  and  70  respectively. The walls  64 ,  66 ,  68  and  70  are resiliently deformable for attachment to the base strip  14 . Formed on the inner surface of walls  64  and  70  are engaging surfaces in the form of barbs  74 . The barbs  74  are designed for engagement with corresponding engaging features of the base strip  14  which are described below. 
         [0035]    The base strip  14  is also extruded and includes 2 outer locating walls in the form of outer locating walls  80  and  82  and a central locating wall in the form of central locating wall  84 . The outer and central locating walls are the attachment means of the base strip  14  for attachment to a support module such as support module  12 . The central locating wall may also function to elevate the reinforcing mesh which reduces or in some cases may replace the need for reinforcing mesh support cradles. 
         [0036]    Outer locating walls  80  and  82  include on their outer surfaces  86  and  88  respectively engaging surfaces corresponding to the engaging surfaces of the locating slots  60  and  62  in the form of barbs  90 . As can be seen from  FIGS. 1 and 2  the barbs  74  and  90  are designed to slide over each other as the outer locating walls  80  and  82  are forced into the corresponding respective locating slots  60  and  62 . Insertion of the locating walls into the slots results in the corresponding locating slot walls resiliently separating and then resiliently compressing against the locating walls when the respective barbs  74  and  90  are appropriately engaged in the position shown in  FIG. 2 . Relative orientation of the barbs  74  and  90  means that withdrawal of the outer locating walls  80  and  82  from the corresponding respective locating slots  60  and  62  is resisted by engagement of the respective barbs as shown in  FIG. 2 . 
         [0037]    The height of the outer locating walls  80  and  82  and the depth of the corresponding respective locating slots  60  and  62  is such that the locating walls are fully received within the corresponding locating slots before free ends  100  and  102  of the planar legs  26  and  28  (see  FIG. 2 ) contact an upper surface  104  of the base strip  14 . 
         [0038]    The base strip  14  includes outer regions in the form of recessed regions  110  and  112 . The recessed regions  110  and  112  have corresponding respective recessed surfaces  114  and  116  which are offset relative to the upper surface  104  of the base strip  14 . The base strip  14  also includes recess strips in the form of recess strips  120  and  122  which are formed in an underneath side of the base strip  14 . Finally, the base strip  14  includes a groove in the form of a V-shaped groove  106  (see  FIGS. 1 and 2 ) which is also formed in the underneath side of the base strip  14  and positioned directly beneath the central locating wall  84 . Referring to  FIG. 3   b , the V-shaped groove  106  in an alternative embodiment coincides with a deflection slot  108 . The V-shaped groove  106  and optional deflection slot  108  enable sides of the base strip  14  to deflect relative to each other in a plane which is substantially normal to a longitudinal axis of the base strip  14 . This ability to deflect enables the base strip  14  to accommodate movement in the ground or floor without affecting its integrity. The deflection slot  108  may extend the entire depth of the central locating wall  84 . 
         [0039]      FIG. 4  shows an alternative use of the base strip  14 . In this alternative use the base strip  14  directly supports an assembled compressible expansion joint strip  20  and corresponding strip cover  16  by attachment of the expansion joint strip and strip cover directly to the central locating wall  84 . In this alternative use of the base strip  14 , the base strip  14  functions as an expansion joint strip support module. The central locating wall  84  functions as an expansion joint strip locating projection of that module while the support means of the expansion joint strip support module comprises the plates  85  and  87  which the central locating wall  84  is integrally formed with and which are positioned on either side of the central locating wall. This alternative use of the base strip  14  is used to form reduced depth concrete slabs consisting of concrete slabs  320  and  322  positioned either side of an expansion joint strip  324 . 
         [0040]    The alternative use of the base strip  14  shown in  FIG. 4  can also be used to top an existing concrete slab. The base strip  14  is positioned on top of an existing concrete slab  330  and attached to that slab via screws  332 . Pouring concrete on top of the base strip  14  then results in formation of the slabs  320  and  322  and the corresponding expansion joint  324 . Expansion joints similar to expansion joint  324  positioned on top of the existing concrete slab  330  can be used, as described above, to level concrete slabs formed on top of the existing slab  330 . This process can also be used to improve the finished surface of a concrete slab. 
         [0041]    The alternative use of the base strip  14  shown in  FIG. 4  can also be used to form full depth expansion joints by using strip cover and compressible expansion joint strip assemblies described below in relation to the support assembly  140 . The strip cover  16  comprises a U-shaped channel  130  having opposed side walls  132  and an adjoining base  134 . The strip cover  130  is designed to cover the compressible expansion joint strip  20  as shown in  FIGS. 1 and 2 . With the strip cover  130  covering the compressible expansion joint strip  20  it can be placed into the U-shaped channel  24  for support by the support module  12 . Although the strip cover  16  is designed to increase the rigidity of the compressible expansion joint strip  20  which, as described below, makes it suitable for directly inserting an assembled strip cover and expansion joint strip into wet concrete, the strip cover  16  is also flexible in a plane which is aligned with the adjoining base  134 . The strip cover  16  can therefore be used for forming non linear expansion joints. 
         [0042]    An alternative expansion joint strip support assembly in the form of support assembly  140  is shown in  FIGS. 5 to 8 . The support assembly  140  includes a support module  142 , base strip  144  and strip cover  146 . The support module  142  differs from the support module  12  and is described in detail below. The base strip  144  is identical to the base strip  14  and its features are referenced using the reference numerals of base strip  14 . The strip cover  146  is the same as the strip cover  16  except that it is deeper for receipt of a deeper compressible expansion joint strip  148  (see  FIGS. 6   a ,  7  and  8 ). The strip cover  146  may also include holes (not shown) for receipt of locating rods  150 , as described below. 
         [0043]    The support assembly  140  also includes a concrete slab locating rod  150  (see  FIGS. 5 ,  6   a  and  8 ). The locating rod  150  also forms part of the support assembly  10  and the description relating to the locating rod  150  in relation to its use with the support assembly  140  also applies to use of the locating rod  150  with the support assembly  10 . 
         [0044]    The support module  142  is formed as described above in relation to the support module  12  by cutting 80 mm lengths from a correspondingly shaped extrusion. The support module  12  includes a planar leg  160  which is essentially identical to the planar leg  26  of the support module  12 . The planar leg  160  includes intersecting leg portions  162 ,  164  and  166 . The intersecting leg portion  162  includes a locating slot  170  formed between locating slot walls  172  and  174 . Barbs  176  are formed on an inner surface of the locating slot wall  172  as described above in relation to the support module  12 . 
         [0045]    The support module  142  includes an expansion joint strip locating portion in the form of U-shaped channel  180 . The U-shaped channel  180  includes side walls  182  and  184  and an adjoining base  186 . The side wall  182  extends from the base  186  upwardly beyond the intersecting leg portion  166 . An upper end of the extension of the side wall  182  is in the form of a strip cover locating projection  190 . 
         [0046]    The support module  142  also includes attachment means in the form of a locating slot  192  formed between a locating slot wall  194  and an outer surface of the side wall  182  and its corresponding upward extension. Formed on the inner surface of the locating slot  192  are engaging surfaces in the form of barbs  196 . The locating slot  192  is designed for engagement with the central locating wall  84  of the base strip  144  as described in relation to the locating slot  170 . 
         [0047]    The side wall  182  and its corresponding upward extension which connects to the intersecting leg portion  166 , as well as the base  186  of the U-shaped channel  180  also functions as a second support leg of the support module  142 . 
         [0048]    In addition to being a different height than the strip cover  16  of the support assembly  10 , the strip cover  146  includes an axial flange  200 . The axial flange  200  attaches to an outer surface of a side wall  202  of the strip cover  146 . The axial flange  200  provides a module locating slot  204  for receipt of the strip cover locating projection  190  of the support module  142 . The axial flange  200  prevents the strip cover  146  and corresponding compressible expansion joint strip  148  from tilting away from the strip cover locating projection  190 . The axial flange  200  also stiffens the strip cover  146  to prevent distortion, particularly in a plane which is parallel with the base  186  of the U-shaped channel  180 . The axial flange  200  also increases torsional stiffness of the strip cover  146  about its longitudinal axis. 
         [0049]    An alternative strip cover  147  is shown in  FIG. 6   b . This alternative strip cover is designed to locate an expansion joint strip in the form of compressible expansion joint strip  149  which is typically known to people skilled in the relevant art as a “metal cracker strip”. Compressible expansion joint strip  149  includes a metal strip  152  and a compressible strip  154 . 
         [0050]    The strip cover  16  of the support assembly  10  and the strip covers  146  and  147  of the support assembly  140  can be used independently of the corresponding support modules  12  and  142  and base strips  14  and  144  to form an expansion joint. The strip covers  16 ,  146  and  147  sufficiently increase the rigidity of the corresponding respective compressible expansion joint strips  20 , and  148  and  149  to enable the assembled strip covers and compressible expansion joint strips to be inserted into wet concrete. Advantages provided by remaining components of the support assemblies  10  and  140  as described throughout the specification may be considered unnecessary for a particular application. If so, this alternative use of the assembled strip covers and compressible expansion joint strips enables expansion joints to be formed more easily and cost effectively. 
         [0051]    The locating rod  150  includes a locating sleeve  206  and a corresponding rod  208 . As can be seen from  FIG. 8  an end  210  of the locating rod  208  is positioned close to a blind end  212  of the locating sleeve  206 . Referring to  FIGS. 5 and 6   a  the locating sleeve  206  has lower and upper walls  214  and  216 . The distance between inner surfaces of these lower and upper walls is less than the separation of internal surfaces of the walls which join the lower and upper walls  214  and  216 . Referring to  FIG. 8 , the locating sleeve  206  limits upward and downward movement of the round locating rod  208  but allows some movement in a lateral direction. 
         [0052]    The locating sleeve  206  includes a locating rod locator  220  for attachment of the locating rod  206  to the base strip  144 . The locating rod locator  220  is integrally formed with the locating sleeve  206  and includes at an end remote from the locating sleeve a locating slot  222  which is described in the relation to the locating slot  170 . The locating slot  222  is designed for removable attachment to the locating slot wall  172  as described above in relation to the location slot  170  and locating slot wall  172 . 
         [0053]    For some applications the strip cover  146  does not include holes in its walls but is marked for formation of holes through its walls and also through the compressible expansion joint strip  148  located between the strip cover side walls. These holes (not shown) are designed for passage through the strip cover  146  and corresponding compressible expansion joint strip  148  of the locating rod  150 . The holes in the strip cover and compressible expansion joint strip are usually more easily formed prior to assembly of the strip cover and support module  142  using an appropriate tool. 
         [0054]    The support module  142  is attached to the base strip  144  as described above in relation to the support assembly  10 . The strip cover  146  or alternative strip cover  147  and associated respective compressible expansion joint strip  148  or  149  is then fitted into the U-shaped channel  180  so that the strip cover locating projection  190  slides upwardly through the module locating slot  204 . With the strip cover  146  and support module  142  assembled as shown in  FIGS. 5 to 8  walls of the strip cover  16  are clamped together via a clip  340  as shown in  FIG. 6   a . The clip  340  prevents walls of the strip cover  146  separating if concrete being poured on one side of an expansion joint flows on top of the expansion joint strip. A similar clip (not shown) can be designed for use with the alternative strip cover  147 . 
         [0055]    The locating rod  150  is inserted through holes in the strip cover and expansion joint strip  148  and then attached to the base strip  144  as shown in  FIGS. 5 ,  6   a  and  8 . To prevent removal of the compressible expansion joint strip  148  it can be screwed to the corresponding strip cover  146  and the strip cover locating projection  190  by screws  260  (see  FIG. 8 ). 
         [0056]    Referring to  FIGS. 5 and 6   a  the intersecting leg portions  164  and  166  have perforations in the form of round holes  230  and  232  and square and rectangular holes  234  and  236 . These holes ensure that concrete or other cementitious material flows into the space underneath the intersecting leg portions  164  and  166  as it is poured onto the base strip  144  and against side wall  202  of the cover strip  146  to form slab  240  (see  FIGS. 7 and 8 ) which abuts the side wall  202 . 
         [0057]    After concrete is poured on both sides of the compressible expansion joint strip  148  it sets around the locating sleeve  206  and locating rod  208 . After the concrete slabs  240  and  242  set they will move relative to each other in response to changes in temperature and movement of the supporting floor or ground. Movement of the concrete slabs normally of the compressible expansion joint strip  148  is accommodated by compression and expansion of that strip and axial movement of the locating rod  208  within the locating sleeve  206 . Movement of the slabs  240  and  242  in a direction aligned with a longitudinal axis of the base strip  144  lies is accommodated by lateral movement of the locating rod  208  within the locating sleeve  206 . 
         [0058]    As can be seen in  FIGS. 7 and 8  the compressible expansion joint strip  148  extends the entire depth of concrete slabs  240  and  242 . This is in contrast to the compressible expansion joint strip  20  of the support assembly  10  (see  FIG. 2 ) which only extends partway into the depth of concrete slabs  250  and  252 . The concrete slabs  250  and  252  join beneath the base  36  of the U-shaped channel  24  and above the central locating wall  84 . Contrastingly, the concrete slabs  240  and  242  of the support assembly  140  are completely separated by the corresponding compressible expansion joint strip  148 . The central locating wall  84  of the support assembly  10  (see  FIG. 2 ) functions as a crack propagator to facilitate formation of a crack above the central locating wall  84  in the event that slabs  250  and  252  move. The central locating wall  84  therefore functions to limit the likelihood of cracks occurring within slabs  250  and  252 . 
         [0059]    Termites typically pass from the ground into a building via its walls by passing upwardly through expansion joints of corresponding concrete slabs. The base strips  14  and  144  of  FIGS. 1 and 5  prevent this from occurring by sealing the expansion joint from the corresponding supporting floor or ground. 
         [0060]    Support assemblies  10  and  140  can be joined to corresponding support assemblies which, for example, extend normally of those support assemblies for intersection of corresponding expansion joints. One example of intersecting support assemblies is shown in  FIG. 9  in relation to support assembly  10 . A support assembly ie  10 ′ appears on the left of the support assembly  10 . A compressible expansion joint strip  20 ′ of the support assembly  10 ′ extends normally of the compressible expansion joint strip  20  of the support assembly  10 . Referring to  FIGS. 1 and 9 , material from an underneath surface of end region  270  of the base strip  14 ′ is removed to enable the end region  270  to sit on top of recessed surface  114  of the base strip  14 . Material is removed or checked out from the end region  270  so that an end  276  of the base strip  14 ′ either abuts or is positioned close to an abutting surface  278  of the base strip  14 . 
         [0061]    With the support assemblies  10  and  10 ′ positioned as shown in  FIG. 9  the corresponding base strips  14  and  14 ′ are attached relative to each other using a base strip locator in the form of base strip locator  280 . The base strip locator  280  includes a locating slot  282  and another locator in the form of base strip locating lug  284 . The locating slot  282  has the features described in relation to locating slots  60  and  62  and is designed for attachment to the outer locating wall  80  as described above in relation to the locating slot  60  and outer locating wall  80 . The locating lug  284  is designed to sit above the upper surface  104  of the base strip  14 ′ and locate the end region  270  of the base strip  14 ′ between the locating lug  284  and the recessed surface  114  of the base strip  14 . The strip covers  16  and  16 ′ of the respective support assemblies  10  and  10 ′ are attached via an angled bracket  290 . 
         [0062]    The base strip locator  280  may, for example, in place of the base strip locating lug  284  include another locating slot (not shown) identical to the locating slot  282  but designed for attachment to outer locating walls  80 ′ or  82 ′ of the base strip  14 ′. 
         [0063]      FIG. 10  corresponds to  FIG. 9  and includes angled brackets  350  and  352  in place of the angled bracket  290 .  FIG. 10  also shows that part of the outer locating wall  80  of the base strip  14  has been removed to provide an unobstructed region adjacent the central locating wall  84 ′ of the base strip  14 ′ which extends through to the central locating wall  84  of the base strip  14 . 
         [0064]      FIG. 11  shows a support module  300  which is effectively identical to the support modules  12  and  12 ′ except that it includes intersecting U-shaped channels  302  and  304 . The support module  300  therefore provides alternative means to that described in relation to  FIGS. 9 and 10  to join compressible expansion joint strips that extend normally of each other. Intersecting base strips are joined as described above in relation to base strips  14  and  14 ′ of  FIGS. 9 and 10 . The compressible expansion joint strip (not shown) which is received within the U-shaped channel  304  would normally extend continuously through the intersection with the U-shaped channel  302  and compressible expansion joint strips of channel  302  would normally abut the continuous expansion joint strip. 
         [0065]    Support assemblies  10  and  140  can also be joined to corresponding support assemblies which are aligned with those support assemblies for end to end connection of corresponding expansion joints. End to end connection of base strips  14  is shown in  FIG. 12 . This end to end connection includes an end to end base strip coupling  360 . The base strip coupling  360  includes barbs  362  which are designed for removable attachment to locating walls  80 ,  82  and  84  of the base strip  14  as described above in relation to the support assemblies  10  and  140 . 
         [0066]    Support assemblies  10  and  140  of these embodiments of the present invention provide a number of advantages: 
         [0067]    (a) quick and easy assembly involving placement of freestanding integrally formed support modules  12  and  142 . 
         [0068]    (b) sealing of an expansion joint from underneath abutting concrete slabs to prevent termites or moisture passing upwardly through the expansion joint; and 
         [0069]    (c) quick, easy and discrete adjustment of upper surfaces of the compressible expansion joint strips  20  and  148 . 
         [0070]    All publications mentioned in this specification are herein incorporated by reference. Any discussion of documents, acts, materials, devices, articles or the like which has been included in the present specification is solely for the purpose of providing a context for the present invention. It is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present invention as it existed anywhere before the priority date of each claim of this application. 
         [0071]    It will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the invention as shown in the specific embodiments without departing from the spirit or scope of the invention as broadly described. For example, an inverted T-shaped support leg may replace the planar legs  26  and  28  of the support assembly  10 , in which case, the base strip  14  would not include the central locating wall  84 . This alternative support leg could, for example, attach to the adjoining base  36  of the U-shaped channel  24 . The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive. 
         [0072]    It should be understood that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of the present invention and without diminishing its intended advantages. It is therefore intended that such changes and modifications be covered by the appended claims.