AU2020100237A4 - Apparatus to create step level changes in concrete building slabs - Google Patents

Abstract

- 16 Shuttering apparatus for the creation of a step level change in a poured-in-situ parent concrete building slab includes shuttering supported upon and connected to at least one vertical strut. Said strut is supported from a baseplate or other supporting means fixed to 5 formwork for creation of the parent concrete slab. Said strut is made with a variety of cross-sectional shapes and are provided with a vertically-arranged series of apertures through which fastenings are inserted to fix said shuttering to said strut. Said shuttering is made with high beam strength and takes the form of solid, core-stock or laminated wood, a hollow beam made from wood or wood and metal sheet, a closed metal form 10 folded from sheet metal or extruded in a metal alloy material, or a partially open metal form made by folding from sheet metal or extruded in a metal alloy material. The said fastening can include power tool-insertable, self-tapping screws, ball-lock pins or locking fasteners having a head engaging said shuttering and cam or screw tightening means. Sheet 5of 6 If %P

Description

APPARATUS TO CREATE STEP LEVEL CHANGES IN CONCRETE BUILDING SLABS

This invention relates generally to methods of generating step level changes in poured-insitu concrete building slabs. In particular, it relates to methods and apparatus for creating such step level changes on large-scale building sites.

In the construction of concrete building slabs in multi-storey buildings and other structures, many situations exist in which step level changes are required. Such level changes are commonly repeated on multiple floors of a building of other structure and may extend, overall, to thousands of lineal metres. The generation of step level changes thus requires the performance of a large number of repetitive tasks. As the construction industry is one in which time and cost are imperatives continuously addressed, improved methods of performing all repetitive tasks are eagerly sought.

In the creation of step level changes in poured-in-situ concrete building slabs, it is common for wooden formwork to be employed. The creation of a step level change towards the edge of a concrete building slab is straightforward, with formwork being supported by struts fixed to external supports. Where a step level change is required with the body of a large concrete building slab, the formwork employed commonly takes the form of shutters of water-resistant, multi-ply, wooden material. Concrete is poured and finished to a higher level on one side of the shutter and to a lower level on the other. As recently poured concrete is substantially fluid, it may impose a considerable hydrostatic force upon the shuttering. In order to safely resist this, the shuttering must be strongly supported from the formwork for creation of a concrete slab. The shuttering is built by carpenters and temporarily supported in an improvised way using props and struts or other ad hoc supporting means. Installation of such shuttering may necessitate additional visits to a worksite by carpenters following building of formwork and setting of steel reinforcing bar for a concrete slab. As such, it imposes an additional work phase with attendant costs. Shuttering may be temporarily fixed to formwork for creation of a concrete slab, being removed after setting of the concrete of the higher level part of the

2O7526AUB_CS_19Feb2O2O.DOC

-2slab to permit pouring of the lower part of the slab. Alternatively, shutters may be supported on struts or props which are left embedded in the cured concrete slab.

Kim, in KR 20150071417, teaches the use of a concrete placement height measuring device and an installation jig of the device including fixing brackets arranged to be in contact with a pair of second steel reinforcements placed perpendicularly to first steel reinforcements placed horizontally for forming a slab of a building. Those skilled in the art will understand that shutters for creating a step level change in a concrete building slab might be fixed to the perpendicular steel reinforcements. Jung, in KR 101446124, teaches the use of a height-adjustable fixing tool including a main body, a base section formed below the main body for fixing to formwork, a supporting section formed vertically above the main body and an auxiliary body of predetermined height, the fixing tool supporting at its upper end a mould for creation of a waterproof step. Those skilled in the art will understand that shutters for creating a step level change in a concrete building slab might be fixed to the fixing tool. Kim, in KR 960004048, teaches the use of a marker indicating a base level for concrete pouring to keep the thickness of a concrete slab at a specified level for uniformity of floors of buildings, the marker comprising a main body having steps on the inner side, a plurality of wings formed at regular intervals around the body, the body having an opening for insertion of an end of reinforcing rods on a side and a hand grip, in use, the inserted rod end being placed on the step of the body to indicate the level. Those skilled in the art will understand that shutters for creating a step level change in a concrete building slab might be fixed to the marker. In the first two prior art examples cited, the basic supporting device is too complicated and would therefore be too expensive. Attachment means for fixing the shuttering to the supporting device would have to be provided, imposing an additional cost. In the case of the third example, while the basic supporting device is quite simple, special attachment means to be clamped to the supporting device and employed to fix the shuttering to the supporting device would have to be provided. This would be an additional cost.

One object of the present invention is to provide means of or an apparatus or a shuttering apparatus for generating step level changes in poured-in-situ concrete building slabs using apparatus able to be quickly and easily installed simultaneously with the construction of formwork for the creation of concrete slabs; this obviating the need for the use of carpenters in an additional work phase, thereby saving time and money.

2O7526AUB_CS_19Feb2O2O.DOC

-3Another optional object of the present invention is to provide a form of shuttering which is quickly, easily and height-adjustably fixed to supporting means and quickly and easily removed when no longer required.

All references, including any patents or patent applications cited in this specification are hereby incorporated by reference. No admission is made that any reference constitutes prior art. The discussion of the references states what their authors assert, and the applicants reserve the right to challenge the accuracy and pertinency of the cited documents. It will be clearly understood that, although a number of prior art publications may be referred to herein; this reference does not constitute an admission that any of these documents form part of the common general knowledge in the art, in New Zealand or in any other country.

According to the present invention, which is a shuttering apparatus for the creation of a step level change in a poured-in-situ concrete building slab which includes shuttering supported upon and connected to at least one or a plurality of vertical struts. Said strut or struts are supported from a baseplate or other supporting means fixed to formwork for creation of the parent concrete slab. Said strut or struts are made with a variety of crosssectional shapes and are provided with a vertically-arranged series of apertures through which fastenings are inserted to fix said shuttering to said struts. Said shuttering is made with high beam strength and takes the form of solid, core-stock or laminated wood, a hollow beam made from wood or wood and metal sheet, a closed metal form folded from sheet metal or extruded in a metal alloy material, or a partially open metal form made by folding from sheet metal or extruded in a metal alloy material. Said fastening take the form of power tool-insertable, self-tapping screws, ball-lock pins or locking fasteners having a head engaging said shuttering and cam or screw tightening means. For location purposes, pegs are optionally provided in said shuttering to engage said apertures in said struts.

To those skilled in the art to which the invention relates, many changes in construction and widely differing embodiments and application of the invention will suggest themselves without departing from the scope of the invention as defined in the appended claims. The disclosures and the descriptions herein are purely illustrative and are not intended to be limiting.

2O7526AUB_CS_19Feb2O2O.DOC

-4The various aspects of the present invention will be more readily understood by reference to the following description of preferred embodiments given in relation to the accompanying drawings which:

Figure 1 is a transverse cross-sectional view of an embodiment of the present invention;

Figure 2 is a fragmentary face view of the embodiment of Figure 1;

Figure 3 is a transverse cross-sectional view of a first embodiment of shuttering apparatus of the present invention;

Figure 4 is a transverse cross-sectional view of a second embodiment of shuttering apparatus of the present invention;

Figure 5 is a transverse cross-sectional view of a third embodiment of shuttering apparatus of the present invention;

Figure 6 is a transverse cross-sectional view of a fourth embodiment of shuttering apparatus of the present invention;

Figure 7 is a transverse cross-sectional view of a fifth embodiment of shuttering apparatus of the present invention;

Figure 8 is a transverse cross-sectional view of a first embodiment of the strut of the present invention;

Figure 9 is a transverse cross-sectional view of a second embodiment of the strut of the present invention;

Figure 10 is a transverse cross-sectional view of a third embodiment of the strut of the present invention;

Figure 11 is a transverse cross-sectional view of a fourth embodiment of the strut of the present invention;

Figure 12 is a transverse cross-sectional view of a fifth embodiment of the strut of the present invention;

2O7526AUB_CS_19Feb2O2O.DOC

-5Figure 13 is a face view of a shaped aperture employed in the attachment embodiment of Figure 16;

Figure 14 is a transverse cross-sectional view of an alternative embodiment of the present invention;

Figure 15 is a side view of a first embodiment of attachment means employed to attach said shuttering to said strut;

Figure 16 is a side view of a second embodiment of attachment means employed to attach said shuttering to said strut;

Figure 17 is a side view of an alternative embodiment of the present invention incorporating multi-legged support means;

Figure 18 is a transverse cross-sectional view of the embodiment of Figure 17 through the base of said strut;

Figure 19 is a side view of an alternative embodiment of the present invention moulded in unitary form;

Figure 20 is a view from above of the embodiment of Figure 19;

Figure 21 is a fragmentary, transverse cross-sectional view of stiffening means of a first form of leg of the embodiment of Figure 19;

Figure 22 is a fragmentary, transverse cross-sectional view of a second form of leg of the embodiment of Figure 19.

No significance should be inferred from the fact that the figures are drawn to a variety of scales.

With reference to Figures 1 and 2, a shutter apparatus includes at least one strut 1 operatively supporting and connecting to shuttering 2. Strut 1 is welded or otherwise fixed to baseplate 3 which is fixed to formwork 4 for the creation of a poured-in-situ parent concrete building slab, the location of typical fastenings being depicted as 5. In the embodiment depicted, said strut takes the form of a hollow, closed section, for

2O7526AUB_CS_19Feb2O2O.DOC

-6example, of square or rectangular transverse cross-sectional shape. Where a residual void is acceptable in a concrete building slab, such struts of closed section may be employed. In the creation of a step level change in a concrete building slab, a line of said struts is fixed to said formwork at regular intervals, the spacing of said struts being dependent upon the rigidity of said struts, the depth of said concrete building slab, the height of said step level change and the stiffness of said shuttering. Shuttering 2 of a variety of configurations is fixed to said struts by suitable fastening means. The term, shuttering or shuttering apparatus, is used herein to denote temporary or permanent formwork employed to impound concrete for the purpose of creating a step level change in a poured-in-situ concrete building slab. In the embodiment depicted, said shuttering apparatus takes the form of a suitable plan of core-stock timber and said fastening means take the form of one or more wood screws at each said column. In the preferred embodiment, said wood screws are of a self-tapping type having a head adapted to be engaged by powered driving means. A vertical sequence of suitably-spaced apertures 11 is provided along the upper parts of said columns to accommodate said fastening means. In making the higher level part 8 of said concrete building slab, concrete is poured and finished to the upper edge of said shuttering and, in making the lower level part of said slab, concrete is poured and finished to the lower edge of said shuttering. In an alternative embodiment (not shown) in which the concrete of said higher level part of said slab is poured and finished to a level below the upper edge of said shuttering, reference markings are provided on said shuttering or on said struts to define the correct concrete level. When the concrete of said slab has cured, said shuttering is removed for cleaning and re-use and said struts are cut off flush with the upper surface of said lower level part of said slab.

In an alternative embodiment (depicted in broken line in Figure 1), shuttering 66 is fixed to the outer surface (facing the lower level part of the said concrete slab). In this embodiment, the whole of said strut remains embedded in said concrete building slab following curing of said concrete, following which, depending upon its nature, said shuttering may optionally be left in place or removed.

In another alternative embodiment, (depicted in broken line in Figure 2), shuttering 67 is optionally raked where a fall is provided across a concrete building slab.

2O7526AUB_CS_19Feb2O2O.DOC

-7In another alternative embodiment (not shown), where said shuttering or shutting apparatus is to be removed following curing of said concrete, the face of said shuttering abutted by said concrete of said step level change is ribbed, textured or otherwise modified, said shaping being transferred to said step level change. In this embodiment, a suitable release agent is optionally applied to said shuttering.

In another alternative embodiment (not shown), where said shuttering is to be removed following curing of said concrete, said shuttering is made with a thickness increasing or decreasing from top to bottom, as appropriate, the face of said step level change thereby being made canted.

In another alternative embodiment, the face of said shuttering abutted by said concrete of said step level change is modified (as depicted in broken line as 68), thereby providing a radius, chamfer or other shaping at the base of said step level change.

In an alternative embodiment (depicted in Figure 1), one of more pegs 6 are pressed into bores 7 provided in said shuttering at the requisite lineal spacing, said pegs engaging apertures 11 in said struts. The diameter of said pegs is such as to make a light, sliding fit in said apertures. Said engagement of said pegs with said apertures assists in locating said shuttering on said struts during the fastening process and permits the use of a single said fastening at each said strut. Obviously, said pegs may be incorporated into said struts and engage complementary bores in said shuttering. In an alternative embodiment (not shown), said pegs are deleted and said shuttering is temporarily supported on said struts during insertion of said fastenings by means of rods inserted through apertures 11 into bores of a suitable diameter provided in said shuttering.

With reference to Figure 3, in a first alternative embodiment, said shuttering takes the form of a rectangular, wooden box section comprising rails 12 at top and bottom to which are bonded side panels 13, 14. In the preferred embodiment, said rails are of core-stock wood and said side panels are of waterproof, multi-ply wood material.

With reference to Figure 4, in a second alternative embodiment, said shuttering takes the form of a closed, rectangular form folded from a suitable sheet metal alloy material. In this embodiment, the line of abutment 15 of the ends of said sheet metal material is preferably orientated towards said struts.

2O7526AUB_CS_19Feb2O2O.DOC

-8With reference to Figure 5, in a third alternative embodiment, said shuttering takes the form of a closed rectangular form extruded from a suitable metal alloy material. In this embodiment, the panel of said shuttering taking the hydrostatic loading of the concrete of said higher level part of said concrete building slab, and thereby subject to a compression force, is optionally provided on its inner surface with one or more deep ribbings to improve its compression strength.

With reference to Figure 6, in a fourth alternative embodiment, said shuttering takes the form of a rectangular section substantially open on the side abutting said struts, apertures for the engagement of pegs 6 or for the accommodation of said fastening means being provided in returns 16.

With reference to Figure 7, in a fifth alternative embodiment, said shuttering takes the form of a rectangular box section comprising rails 12 at top and bottom to which are bonded side panels 17, 18. In the preferred embodiment, said rails are of core-stock wood, side panel 17 is of a sheet metal alloy material and side panel 18 is of core-stock wood or a thick, waterproof, multi-ply wood material. Side panel 18 is made thick enough to sustain the compression forces imposed by the hydrostatic loading of said concrete of said higher level part of said concrete building slab.

With reference to Figure 8, in a first embodiment, said struts are made in a square or rectangular, transverse cross-sectional shape comprising abutment panel 19 abutting said shuttering, parallel side panels 20 and inwardly-directed returns 21, said returns acting to improve the stiffness of said struts in bending.

With reference to Figure 9, in a second embodiment, said struts are made in an open section comprising abutment panel 19 on the edges of which are formed side panels 22 orientated at an angle of between 90 and 150 degrees to said abutment panel.

With reference to Figure 10, in a third embodiment, said struts are made in an open section comprising abutment panel 19 on the edges of which are formed side panels 23 orientated normal to said abutment panel, outwardly-directed returns 24 orientated parallel to said abutment panel being formed on the edges of said side panels.

2O7526AUB_CS_19Feb2O2O.DOC

-9With reference to Figure 11, in a forth embodiment, said struts are made in an open section comprising abutment panel 19 on the edges of which are formed side panels 25 orientated normal to said abutment panel, outwardly-directed returns 26 being formed on the edges of said side panels and disposed at an angle of between 90 and 150 degrees to said side panels.

With reference to Figure 12, in a fifth embodiment, said struts are made in an open section comprising abutment panel 19 on the edges of which are formed side panels 29 orientated normal to said abutment panel, outwardly-directed returns 27 parallel to said abutment panel being formed on the edges of said side panels, backwardly-directed returns 28 parallel to said side panels being formed on the edges of said outwardlydirected returns.

With reference to Figure 14, in an alternative embodiment, where the thickness of a concrete building slab necessitates the use of tall said struts or where struts of lesser stiffness are employed, said struts are braced by the incorporation of gusset 30 welded or otherwise fixed to said struts and to said base plates, said base plate being extended in length as required.

With reference to Figure 15, said shuttering incorporating panels of a sheet metal alloy material are attached to said struts by means of ball-lock units 32, the pins 34 of which pass through apertures 11 in abutment panels 19 of said struts and through complementary apertures in shuttering panels 31, releasing of release of plunger 33 causing lock balls 35 to be outwardly displaced, thereby locking the two said panels together. Said ball-lock units are grasped by handles 36 while inserting said pins through said apertures and while depressing said release plunger. Ring 37 passing through a suitable aperture in said handles is employed to attach a bridle to said ball-lock unit to secure it to a said strut. When the concrete of said building slab has cured, said ball-lock units are quickly and easily removed, allowing said shuttering to be removed for cleaning and re-use. Said struts are then cut off flush with the upper surface of said lower level part of said slab.

With reference to Figures 13 and 16, said shuttering incorporating panels of a sheet metal alloy material are attached to said struts by means of clamping-type locking units 42, the

2O7526AUB_CS_19Feb2O2O.DOC

- 10plungers 48 and shaped flanges 49 of which pass through shaped apertures 50 in abutment panels 19 of said struts and through complementary shaped apertures in shuttering panels 31. The diameter of said plunger and the size and shaping of said shaped flanges is such that said plunger and flanges are just able to pass through said shaped apertures. Said shaped apertures comprise circular opening 38 which has formed in it extended lobes 39. Rotation of said plunger about its longitudinal axis though an angle of 90 degrees using handle 47 causes said shaped flanges to be displaced through the arc depicted in broken line as 40, to the position depicted in broken line as 41. Rotation of cam 44 of a said locking unit on pivot 45 using handle 47, said pivot turning in the outer end 46 of said plunger, causes said cam to thrust against the outer end of locking unit 42, retracting said plunger and thereby urging said shaped flanges against said shuttering panel, thereby clamping said abutment panel and said shuttering panel in abutment between said shaped flanges and the inner end of said locking unit. Said clamping unit is held by handle 43 while inserting said plunger and said shaped flanges through said shaped apertures. A ring for attachment of a bridle of the type depicted as 37 in Figure 15 is optionally provided on handle 43. When the concrete of said building slab has cured, said locking units are quickly and easily removed, allowing said shuttering to be removed for cleaning and re-use. Said struts are then cut off flush with the upper surface of said lower level part of said slab. In the preferred embodiment, stops (not shown) are provided to limit rotational displacement of handle 43 to 90 degrees between said insertion and clamping positions. Also in the preferred embodiment, said handle is disposed vertically downwards in said clamping position.

With reference to Figures 17 and 18, strut 1 is fixed to the upper surface of multi-legged support 51. Said multi-legged support has three or more legs, the lower ends of which are fixed to formwork 4 for the creation of said parent concrete slab, typically fastening positions being depicted in broken line as 5. In the embodiment depicted, a length of threaded rod 52 is welded or otherwise fixed to the outer surface of abutment panel 19 at the lower end of said strut, a protruding part of said rod of suitable length being screwed and tightened into a threaded bore (not shown), provided in the upper part of said multilegged support. In this embodiment, extended lower ends 53 of the side parts of said strut are turned inwardly through 90 degrees to provide surfaces to better transfer to said multi-legged support forces applied to said strut by the hydraulic load applied to

2O7526AUB_CS_19Feb2O2O.DOC

- 11 shuttering 2 by higher level part 8 of said concrete slab. In an alternative embodiment (not shown), said length of threaded rod is welded or otherwise fixed to the inner surface of said abutment panel at the lower end of said strut. In another alternative embodiment (not shown), extended lower ends 53 of said strut are deleted and a square, rectangular or circular plate is welded or otherwise fixed to the lower end of said strut, said plate being fixed to the upper part of said multi-legged support by a threaded stud fixed to the lower surface of said plate being screwed and tightened into said threaded bore, or by multiple screws passing through suitable apertures in said plate into said multi-legged support. In another alternative embodiment (not shown), the lower end of said strut is fixed to the upper surface of said multi-legged support by welding, bonding or other fixing method. In another alternative embodiment (not shown), said strut is fixed to the upper surface of said multi-legged support by an extending part of a tapered spigot of suitable length welded or otherwise fixed to the lower end of said strut wedgingly entering a complementary tapered recess provided in the upper part of said multi-legged support. In another alternative embodiment (not shown), said strut is fixed to the upper surface of said multi-legged support by a tapered spigot of suitable length fixed to the upper part of said multi-legged support wedgingly entering a complementary tapered sleeve welded or otherwise fixed to the lower part of said strut. In another alternative embodiment (not shown), said strut is fixed to the upper surface of said multi-legged support by a threaded stud of suitable length fixed to the upper part of said multi-legged support passing through a suitable aperture in said plate welded or otherwise fixed to the lower end of said strut, a nut being screwed and tightened onto said threaded stud.

With additional reference to Figure 19, 20, 21 and 22, in an alternative embodiment, shuttering 2 is fixed to the upper ends of a plurality of struts 1 in the manner previously described, said struts being moulded in a suitable polymer material in a unitary form with two or more supporting legs 54, 55. In the preferred embodiment, in order to sustain the compression loading imposed upon legs 54 by the tendency to bend said struts of the hydrostatic force of wet concrete during pouring of said higher level part of said concrete building slab, legs 54 are duplicated and separated by an angle of between 60 and 90 degrees, said legs comprising panel 61 stiffened along the outer edge by the Y-shaped, transverse cross-sectional shape depicted in Figure 21. Said stiffening is fixed to the lateral surfaces of said strut and to attachment panel 60 formed transversely within said

2O7526AUB_CS_19Feb2O2O.DOC

- 12strut and having a shallow, inverted-V, transverse cross-sectional shape. The lower, outer ends of said legs are formed into feet 56 which are fixed to formwork 4 for the creation of said parent concrete slab by suitable fastenings (typical locations indicated in broken line as 5) passing through apertures 57. The inner edges of webs 61 are fixed to outer edges 65 of said struts. The upwardly-directed panels 63 of said Y-shaped transverse crosssectional shape prevent the trapping of air during pouring of said concrete. In the preferred embodiment, for the same purpose, a suitable aperture is made in attachment panel 60. In order to sustain the tensile loading imposed upon legs 55 by the tendency to bend said struts of the hydrostatic force of wet concrete during pouring of said higher level part of said concrete building slab, legs 55 are made in the form of panel 62 with stiffening beading 64 provided along the outer edge. Legs 55 are fixed medially to abutment panel 19 of said struts. The lower, outer ends of legs 55 are formed into feet 58 which are fixed to formwork 4 for the creation of said parent concrete slab by suitable fastenings (typical locations indicated in broken line as 5) passing through apertures 59. In the preferred embodiment, the thickness of panels 61, 62 is made in the range 3.0 to 10 millimetres, with one or other of said panels made thinner or thicker. In the preferred embodiment, panels 61, 62 act to positively locate the lower parts of said struts. Said strut and supporting leg arrangement moulded in unitary form is adapted to be made using a multi-piece injection-moulding die. In alternative embodiments (not shown), the stiffening of legs 54 as depicted in Figure 21 takes any suitable cross-sectional shape, including solid forms, such as square with flat surfaces orientated obliquely, inverted triangular, round or partly-round and T-shaped. In another alternative embodiment (not shown), suitable apertures are provided in panels 61, 62 to ensure better embedding in said concrete slab. In other alternative embodiments (not shown), said struts have other transverse cross-sectional shapes. In other alternative embodiments (not shown), panels 61, 62 are made thin with localized stiffening in the form of ribbing, additional thickness or the like. Obviously, all said legs may be made identical or similar.

Abutting ends of lengths of said hollow shuttering are joined using double-ended, plugtype joiners, the ends of which are frictionally captured in the cavities of the two said ends. Where necessary, the open ends of said hollow shuttering are closed with moulded polymer plugs pressed into them.

2O7526AUB_CS_19Feb2O2O.DOC

- 13 This application should be taken to encompass any feasible combination of any one or more of the features described herein with any one or more other features described herein.

Any reference in the foregoing to the fixing of one part or component to another part or component by ‘other fixing method’ or to be ‘otherwise fixed’, should be taken to include but not be limited to fixing by means of gas welding, arc welding of various types, stud welding, spot welding, bonding with a chemically settable adhesive, bonding with a hotmelt adhesive, bolting, screws, nuts, rivets, clamps, clips, hooks, hook-and-loop attachment systems, catches, and patent retaining devices.

It will also be understood that where a product, method or process as herein described or claimed and that is sold incomplete, as individual components, or as a “kit of Parts”, that such exploitation will fall within the ambit of the invention.

These and other features and characteristics of the present invention, as well as the method of operation and functions of the related elements of structures and the combination of parts and economics of manufacture, will become more apparent upon consideration of the following description with reference to the accompanying drawings, all of which form part of this specification, wherein like reference numerals designate corresponding parts in the various figures.

It is acknowledged that the term ‘comprise’ may, under varying jurisdictions, be attributed with either an exclusive or an inclusive meaning. For the purpose of this specification, and unless otherwise noted, the term ‘comprise’ shall have an inclusive meaning - i.e. that it will be taken to mean an inclusion of not only the listed components it directly references, but also other non-specified components or elements. This rationale will also be used when the term ‘comprised’ or 'comprising' is used in relation to one or more steps in a method or process.

For purposes of the description hereinafter, the terms “upper”, “lower”, “right”, “left”, “vertical”, “horizontal”, “top”, “bottom”, “lateral”, “longitudinal”, “side”, “front”, “rear”

2O7526AUB_CS_19Feb2O2O.DOC

- 142020100237 19 Feb 2020 and derivatives thereof shall relate to the invention as it is oriented in the drawing figures. However it is to be understood that the invention may assume various alternative variations, except where expressly specified to the contrary. It is also to be understood that the specific devices illustrated in the attached drawings, and described in the 5 following specification are simply exemplary embodiments of the invention. Hence specific dimensions and other physical characteristics related to the embodiments disclosed herein are not to be considered as limiting.

Claims (5)

1. Claims:

   1. A concrete formwork support strut for use in supporting shuttering for the production of level changes in poured-in-situ concrete building slabs, the support strut being configured such that it can be left in place when the poured-in-situ concrete building slab is poured; the support strut having a baseplate and a column member; the base member comprising a metal plate having fastener holes configured to allow the baseplate to be fastened to a formwork structure for creating a poured-in-situ concrete building slab when in use, and the column member comprising a formed metal section having a lower part and an upper part; the lower part of the column member being welded to the baseplate and the column member extending in a substantially vertical direction from the baseplate, and the column member having a series of vertically-arranged apertures through which fasteners can be installed to fasten shuttering to the support strut when in use.
2. 2. A concrete formwork support strut as claimed in claim 1, wherein the column member comprises a formed metal section having side panels that are oriented at an angle to an abutment panel.
3. 3. A concrete formwork support strut as claimed in claim 1, wherein the side panels of the column member are oriented at an angle of between ninety and one hundred and fifty degrees to the abutment panel of the column member.
4. 4. A concrete formwork support strut as claimed in claim 1, wherein the base member comprises a substantially flat metal plate.
5. 5. A concrete formwork that includes provisions to produce level changes in pouredin-situ concrete building slabs, wherein the concrete formwork includes a plurality of support struts as claimed in claim 1 that are used to support shuttering material.