AU2010236065B2 - Edging For Concrete Slabs - Google Patents

Abstract

A formwork assembly 10 comprising edging strips 11 and 12 which have upper flanges 13 and 14 positioned to protect the edges of concrete slabs 15 and 16 respectively, the upper surface of the concrete being shown in Figure 5 at 17 and 18. The edging strips 11 and 12 have lower flanges 19 and 20 and respective webs 21 and 22 which are in abutment so the strips are in back to back relation with the flanges 11, 12, 19 and 20 extending transversely in opposite directions. Spaced headed rods 23 and 24 on opposite sides serve to retain the edging strips 11 and 12 in place and vertical fixing plates 25 are welded at spaced intervals to the strip 11 with each plate 25 have a pair of spaced nail holes so that the edging may be nailed to a timber form being plank 26. Dowel sleeves 27 are also nailed to the timber form. The fixing plate 25 has a horizontal plate formed as a bridging member 31 with a platform 32 extending between the strips. The plate 31 has a lobe 33 (and lobe 34) so that is welded to the strip 38 and the strip 39 will slide on the platform 32 as the strips separate. The timber form is stripped away and the right side slab is poured and after contraction the strips 38 and 39 separate and a filler 40 shown cross hatched is inserted to fill the gap with the filler seated on top of the platform 32.

Description

P/00/011 Regulation 3.2 AUSTRALIA Patents Act 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT Name of Applicant: Underwood Companies Holdings Pty Ltd Actual Inventor(s): Daniel Charles Underwood, Australian citizen Address for Service: INTELLEPRO Patent & Trade Mark Attorneys Level 5 320 Adelaide Street BRISBANE, QLD, 4000 (GPO Box 1339, BRISBANE, 4001) Invention Title: Edging For Concrete Slabs Details of Associated Provisional Australian Patent Application No 2009905330 Application(s) No(s): filed 28 October 2009 The following statement is a full description of this invention, including the best method of performing it known to me: 1 H:\azmlnenvovn\NRPonb\DCC\AZM\469214 ILdoc-4/12/2013 Edging for Concrete Slabs TECHNICAL FIELD THIS INVENTION relates to improvements in and in relation to edging and metal edging 5 for concrete slabs. BACKGROUND Applicant has for the first time recognised problems that were not previously recognised in relation to concrete joints employing edging of the type using prefabricated 10 parallel metal strips or bars to form the joint. The strips or bars are held together for transport and installation purposes using some kind of frangible connection so that when in-situ the strips or bars, as the case may be, can separate as the concrete contracts. In this way the strips remains in intimate protective engagement with the concrete so that each strip serves to protect the adjacent edge of the concrete at the joint. 15 Applicant's specification is directed to a number of improvements and these are set out below both independently and in combination. Applicant reserves the right to divide the application and/or claim the improvements in combination subject to the outcome of any official search and examination. In the present specification a reference to "metal" is non-limiting as other material 20 may be used but generally these materials will be effective in protecting the edge of the concrete and could include particular plastics or other materials that might be sufficiently robust. OUTLINE 25 In one aspect there is provided edging for concrete slabs at a joint, the edging comprising a first edging strip and a second edging strip, the strips being set in back to back relationship with upper edges of the strips being in alignment and extending in opposite transverse directions, the edging further comprising spaced vertical fixing means extending from the strips and being rigid with one of said strips, the fixing means being 30 adapted to secure the edging to formwork located below the edging, wherein the first edging strip has a longitudinally extending web and an upper flange and the second edging strip has a longitudinally extending web and a further upper flange mating the flange of the 2 H:.m\1me.,,rwovn\NRPonblDCC\AZM\469214 I- I.doc4/12/2013 first edging strip. The edging may have a lower horizontal flange adapted to locate the edging on top of a form with the fixing means preferably comprising a plate secured to the side of the form in offset relation. In this case the lower flange and the plate are typically set at 90 5 degrees and a nail or screw or other fitting is driven or screwed through the fixing plates into the form. The form may be timber and below the edging in use dowel sleeves may be secured to the timber form. After one slab is poured the timber form is stripped away leaving the metal edging in place and then another slab is poured. When the slabs contract the strips separate with the slabs. It is preferable to have each strip equipped with 10 projecting bolts or other suitable transverse projecting means that project into the slabs to aid retention of the strips and prevent separation of the strips from the concrete. Typically, the edging strips are held together by frangible fasteners. Typically the frangible fasteners comprise spaced apart rivets with plastics washers so the rivets pass through the edging strips and are expanded within the washers so that the rivets shear off 15 when the concrete contacts and the strips separate. In another embodiment, there is provided edging for concrete at a joint, the edging comprising back-to-back edging strips adapted as lost formwork in concrete and being adapted to separate upon contraction of the concrete to form a gap between the strips, each edging strip having an upper edge, a bridging member extending across the strips and 20 being secured to at least one of the edging strips so that upon separation of the edging strips in-situ, the bridging member extends at least part way across the gap below the upper edge. Typically, the bridging member slides underneath the other edging strip. Preferably the bridging member is plate welded or otherwise secured to an underside of one of the strips so that it projects under the other strip. 25 In one preferred embodiment the bridging member is a trapezium shaped plate. Preferably the bridging member is one of a plurality of spaced bridging members located along the length of the strips. In a preferred aspect, a gap between strips in a concrete metal edging comprising separable strips is fillable by a filling strip insertable in the gap after the strips have 30 separated, the gap so formed having a bottom and a top, the top being adjacent an upper edge of the edging, the edging having a filling strip support located in the gap at so that the filling strip is located substantially contiguous with the upper edge of the edging when 3 H:\nz.mkinvoven\NRPorbhDCC\AZM\469214 1_ Idoc-4112/2013 located in the gap and supported by the support. Typically the support is a bridging member as described above. The filling strip may be a mastic paste or a preformed strip in metal or hard plastics or any suitable filler may be employed. In another aspect, the present invention provides a form work assembly, 5 comprising edging according to any of the embodiments described above, and a form secured to the edging of the fixing means. BRIEF DESCRIPTION OF THE DRAWINGS In order that the present improvements may be more readily understood and put 10 into practical effect reference will now be made to the accompanying drawings which illustrate preferred embodiments of the invention and wherein: Figure 1 is a plan view of a formwork assembly according to the present invention; Figure 2 is a side view of the formwork assembly of Figure 1; 15 Figures 3 and 4 are opposite ends of the assembly illustrated in Figures 1 and 2; Figure 5 is an end view of the formwork assembly of Figures 1 to 4; Figures 6 to 9 illustrate part of the formwork assembly of Figures 1 to 5 illustrating in particular a shear rivet arrangement which holds the edging strips together while the concrete is being poured; 20 Figure 10A -10C are respective top, front and side views of a combined fixing plate and bridging member which may be welded to one of the strips to provide the dual function of securing to a timber form and also supporting a gap filler; Figure 11 illustrates the combined fixing plate and bridging member in section; and 25 Figure 12 is a view similar to figure 11 but showing the strips separated and filler in place in the gap between the strips and supported on the bridging member. METHOD OF PERFORMANCE 30 Referring to the drawings and initially to Figures 1 to 5 there is illustrated a formwork assembly 10 comprising edging strips 11 and 12 which have upper flanges 13 and 14 positioned to protect the edges of concrete slabs 15 and 16 respectively, the upper 4 KazmAlniCwoVCvenNKPoribI\DLUALM\45f91141 d C-4/IIZU13 surface of the concrete being shown in Figure 5 at 17 and 18. The edging strips 11 and 12 have lower flanges 19 and 20 and respective webs 21 and 22 which are in abutment so the strips are in back to back relation with the flanges 11, 12, 19 and 20 extending transversely in opposite directions. 5 Spaced headed rods 23 and 24 on opposite sides serve to retain the edging strips 11 and 12 in place and vertical fixing plates 25 are welded at spaced intervals to the strip 11 with each plate 25 have a pair of spaced nail holes so that the edging may be nailed to a timber form being plank 26. Dowel sleeves 27 are also nailed to the timber form. Strips 11 and 12 and the headed rods 23 and 24 and the dowel sleeves 27 are lost 10 in the concrete slab 15 and the timber plank 26 is stripped from the slab 15 before the slab 16 is poured. After the plank 26 is stripped dowels are inserted into the sleeves 27 before the slab 16 is poured. It will be appreciated that in the region of contact with the form of the flange 20 and the plates 25 there is a right angle between the flange 20 and the plate 25 and this 15 serves to easily locate and secure the strip in proper position 5 H Ln,. tn\onsoso NRPortblDCC\AZMl\46J2141[ doc-4/12/21I13 relative to the plank 26. Of course the plank 26 ideally is selected to be straight so that the proper depth and positioning of the edging strip can be achieved. Since the first slab to be poured is the slab 15 and the flange 25 is on the same side of the timber plank 26 the 5 tendency of either of the edging strips 11 and 12 5 to roll to the right in terms of Figure 5 will be reduced by this arrangement of fixing of the strip to the plank 26 in offset. Once the slab 16 has been poured and the concrete expands and contracts, rivets 28 are designed to shear so that the plates 11 and 12 may separate. Thus the strips 11 and 12 have spaced holes 29 for the purpose of taking the rivets illustrated in Figure 8 and the 10 rivet is retained in place by being passed through a nylon washer 30 and the rivet is selected so that it shears when the concrete contracts. The strips 11 and 12 separate and a gap is formed between then. Now one improvement set out above is the implementation of a platform for a filler to go in this gap. While a single long platform could be provided it is preferable to 15 locate short horizontal plates at spaced interval along one of the strips. In the preferred embodiment these are centred on the headed rods 23 and 24 so there is one for each rod. Figures 10A-10C show a typical bridging member 31 comprising a steel plate with a platform 32 comprising an elongate section of the plate having lobes 33 and 34 at each end. These lobes are welded to the underside of one of the strips 11 or 12 with the 20 other strip located on top of the platform. It is convenient to form a fixing plate 35 which functions the same as the fixing plate 25 of the earlier example. It will be appreciated that the fixing plate and the bridging member need not be made in a single unit but this works better for ease of manufacture and assembly. The platform 32 has tapered corners 36 and 37 to aid release from the concrete. 25 Figure 11 shows a combined fixing plate and bridging member 31 in place. The lobe 33 (and lobe 34) is welded to the strip 38 and the strip 39 will slide on the platform 32 as the strips separate. This is shown in Figure 12; only the left side slab has been poured in Figure 11. The timber form is stripped away and the right side slab is poured and after contraction the strips 38 and 39 separate and a filler 40 shown cross hatched is inserted to 30 fill the gap with the filler seated on top of the platform 32. As mentioned above the combined fixing plates and bridging members are secured on at each rod. Whilst the above has been given by way of illustrative example many variations 6 Mm.m12mmcmwaVei-ro!Iviw - - n . U4_........ - - -- J and modifications will be apparent to those skilled in the art without departing from the broad ambit and scope of the claims. Throughout this specification and claims which follow, unless the context requires otherwise, the word "comprise", and variations such as "comprises" or "comprising", will 5 be understood to imply the inclusion of a stated integer or group of integers or steps but not the exclusion of any other integer or group of integers. 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 admission or any form of suggestion that that prior publication (or 10 information derived from it) or known matter forms part of the common general knowledge in the field of endeavour to which this specification relates. 7

Claims (11)

1. Edging for concrete slabs at a joint, the edging comprising a first edging strip and 5 a second edging strip, the strips being set in back to back relationship with upper edges of the strips being in alignment and extending in opposite transverse directions, the edging further comprising spaced vertical fixing means extending from the strips and being rigid with one of said strips, the fixing means being adapted to secure the edging to formwork located below the edging, wherein the first edging strip has a longitudinally extending web 10 and an upper flange and the second edging strip has a longitudinally extending web and a further upper flange mating the flange of the first edging strip.

2. Edging according to claim 1, wherein the first edging strip and/or the second edging strip has a lower horizontal flange adapted to locate the edging on top of a form, 15 and the fixing means comprises a plate securable to the side of a form in offset relation.

3. Edging according to claim 2 wherein the fixing means comprises spaced apart plates set at 90 degrees to the flange. 20 4. Edging according to any one of the preceding claims wherein each strip is equipped with spaced projecting bolts or other suitable transverse projecting means that project into the slabs to aid retention of the strips and prevent separation of the strips from the concrete, each fixing means being spaced and located adjacent each projecting means. 25 5. Edging according to any one of the preceding claims wherein the strips are held together by frangible fasteners, the frangible fasteners comprise spaced apart rivets with plastics washers so the rivets pass through the edging strips and are expanded within the washers so that the rivets shear off when the concrete contacts and the strips separate. 30 6. Edging according to any one of the preceding claims, wherein the first and second strips are adapted as lost formwork in concrete and being adapted to separate upon contraction of the concrete to form a gap between the strips, a bridging member extending 8 H:\Wm\lnlcnvoven\NRPortbl\DCC\AZM\4692141 .doc-II1214 )1u across the strips and being secured to at least one of the edging strips so that upon separation of the edging strips in-situ, the bridging member extends at least part way across the gap. 5 7. Edging according to claim 6, wherein the bridging member is adapted to slide underneath the other edging strip.

8. Edging according to claim 6 or claim 7, wherein the bridging member is a plate welded or otherwise secured to an underside of one of the strips so that it projects under 10 the other strip.

9. Edging according to any one of claims 6 to 8, wherein the bridging member is a trapezium shaped plate. 15 10. Edging according to any one of claims 6 to 9, wherein the bridging member is one of a plurality of spaced bridging members located along the length of the strips.

11. Edging according to any one of claims 6 to 10, wherein the gap has a bottom and a top, the top being adjacent an upper edge of the edging, the edging having a filling strip 20 support located in the gap, and a filling strip located substantially contiguous with the upper edge of the edging when located in the gap and supported by the support.

12. Edging according to claim 13, wherein the support is provided by the bridging member or members extending beneath the strips. 25

13. Edging according to any one of claims 6 to 12, wherein the or each bridging member has two plates set substantially at 90 degrees, one plate being set in use horizontally and the other plate projecting downward. 30 14. A form work assembly, comprising edging according to any one of claims I to 13, and a form secured to the edging by the fixing means. 9 H:\anInICnwOVCMNK rOn0WM t MOVti 14 i_.O--4Ll IJ

15. A form work assembly according to claim 14, comprising dowel sleeves secured to the form.

16. Edging for concrete slabs at a joint, substantially as hereinbefore described with 5 reference to the drawings and/or Examples.

17. A form work assembly, substantially as hereinbefore described with reference to the drawings and/or Examples. 10