Formwork connector for precast void former grout connections and void former system

Abstract

Formwork connector for precast void former grout connections in precast concrete elements, comprising an elongate body having a first end and a second end, the body providing a continuous grout receiving passage formed between the first and second ends of the body; and a chamfered face disposed towards the second end of the formwork connector having an opening providing a grout entry point. Also claimed is a void former system for precast concrete elements, comprising an elongate tubular void former having a first end and a second end; a void former holder, one end of which is fixable to a formwork face and the other opposite end being receivable coaxially within the internal diameter of the first end of the tubular void former; an end cap and spigot being coaxially receivable within the internal diameter of the second end of the tubular void former; a flexible grout tube having a first end and a second end, the first end being coaxially connectable to the end cap and spigot; and a chamfered formwork connector being coaxially connected to the opposite second end of the flexible grout tube and fixable to a formwork face using a formwork connector holder.

Description

Technical Field Of The Invention This invention relates to a formwork connector for precast void former grout connections and to a void former system. In particular, this invention relates to a formwork connector which, as part of a void former system, does not restrict grout application routes and flows. In use, this invention ensures a robust and reliable structural connection between precast concrete elements enabling faster, safer and more efficient assemblies. Background The use of offsite manufacturing for concrete construction elements is increasing in the United Kingdom and elsewhere. This trend has driven the development of new construction methodologies, particularly in the field of primary structural connections between precast concrete elements. One of the technologies applicable to such structural connections necessitates the use of spiral void formers. This method of connection is illustrated schematically in Figure 1 where precast building elements 10, 10', 10" are stacked one on top of the other. As shown, a male extension bar 12 made from reinforcement steel projects from building element 10 and engages in a preformed circular cross-sectional void 14 in the adjoining precast element 10'. This void 14 is created with the use of a spiral void former 16, which is a widely available item supplied by numerous manufacturers and which comprises a spiral metallic tube, typically, but not exclusively, 80mm in diameter. Although not shown in Figure 1. the spiral void former 16 is necessarily coupled to a grout forming channel, as described in further detail in relation to Figure 2. During assembly of the precast building elements 10, 10', 10", the voids 14 are filled using a high-strength cementitious grout which provides structural integrity in such modular construction projects. Though such structural connections of this type are relatively simple and cost-effective, they suffer from a number of drawbacks as such conventional filling methods rely on a horizontal inlet which does not allow free grout flow and can restrict the release of air as grout is poured into the void former 16, any restrictions to flow or entrapped air can lead to inadequate connections or voids in the connections. In certain instances water can collect in void formers 16 leading to future corrosion issues. Figure 2 shows a traditional arrangement of formwork 18 that is used to form such a precast element 10, 10', 10" as is described in Figure 1. The skilled person will understand that the term form work 18 is the mould into which concrete is poured to create the desired shape of the element 10, 10', 10". It can be made of wood, steel and / or other prefabricated forms depending on the requirements. Reinforcing steel bars 20 (rebar) are placed within the formwork 18 to provide structural strength to the concrete element 10, 10', 10". Figure 2 also shows a plurality of steel spiral void formers 16 disposed in the formwork 18. The spiral void formers 16 have at one open end a void former holder 22 which, in this illustrative example, is fixed to one face of the steel or timber formwork 18. At the opposite open end of the void former 16, a plastic bung with a straight spigot 24 is connected to a lesser-diameter flexible tube 26, this tube 26 is then connected to a straight bung 28 which is in turn connected to the formwork face 18 by a fixing plate 30. As can be clearly seen, this creates a 90° bend in the filling tube 26 presenting a horizontal opening in the cast concrete face. This 90° bend leads to the inherent problems of this method outlined above in terms of suboptimal grout flow, air entrapment and potential corrosion issues. Figure 2 is illustrative of a typical arrangement used throughout the UK and the Republic of Ireland, and the skilled person will understand that the finished precast element 10, 10', 10" will be rotated to vertical on completion. Arrows 32 points to vertical direction of finished wall. There are also formwork accessory products available on the market which consist of a fixed grout filling tube that connects directly to the metal void former, but these still present several notable challenges. Firstly, the larger diameter of the grout filling tube demands a higher usage of grout. This not only increases material costs but also raises concerns regarding environmental impact. Moreover, the extensive grout usage often results in a larger area of patching on the finished concrete element 10, 10', 10", leading both to increased labour and time for reinstatement. It is an object of the present invention to provide a formwork connector for precast void former grout connections and a void former system which overcomes or reduces the drawbacks associated with known solutions of this type. It is a further object of the present invention to provide a void former system which does not constrict the grout application routes when in use, and provides a robust and reliable juncture between components in the grouting system. It is a further object of the present invention to provide a chamfered grout entry point in the cast element which provides a convenient application point that utilises gravity to improve grout flow and aid the expulsion of air from the connection voids. This enables the use of smaller diameter flexible grout tubes and reduced grout usage, offering a more efficient and cost-effective solution for concrete formwork. The void former system providing an associated array of formwork connectors providing precise and robust fixing points for both steel and timber formwork designs. Summary Of The Invention The present invention is described herein and in the claims. According to the present invention there is provided a formwork connector for precast void former grout connections in precast concrete elements, comprising: an elongate body having a first end and a second end, the body providing a continuous grout receiving passage formed between the first and second ends of the body; and a chamfered face disposed towards the second end of the form work connector having an opening providing a grout entry point. An advantage of the present invention is that the formwork connector does not constrict the grout application route and utilises gravity to improve grout flow and expel air from the connection voids which ensures robust structural connections between precast concrete elements for efficient assemblies. Preferably, the chamfered face forms an angle of around 30° from the long axis of the body. Further preferably, the formwork connector further comprises a knockout panel disposed in the chamfered face to increase the cross-sectional area of the grout entry point. In use, the knockout panel may be formed as a line of weakness around the perimeter of the chamfered face. Preferably, the knockout panel is largely discorectangular-shaped. In use, the formwork connector may further comprise an offset face located between the chamfered face and the first end of the body that is parallel to the chamfered face and which provides a lip in the cast concrete element for filling with grout. Further preferably, the formwork connector is made from a polymer selected from the group consisting of Polyurethane (PU), Polypropylene (PP), High-Density Polyethylene (HDPE), Low-Density Polyethylene (LDPE), Polyethylene Terephthalate (PET), Polyvinyl Chloride (PVC), Acrylonitrile Butadiene Styrene (ABS), or blends thereof. In use, the formwork connector may be manufactured using a technique selected from the group consisting of injection moulding, blow moulding, vacuum forming, rotational moulding, compression moulding, rim moulding, powder impression moulding, additive manufacturing, or 3D printing. Preferably, the opening providing a grout entry point being formed having a female thread. Also according to the present invention there is provided a void former system for precast concrete elements, comprising: an elongate tubular void former having a first end and a second end; a void former holder, one end of which is fixable to a formwork face and the other opposite end being receivable coaxially within the internal diameter of the first end of the tubular void former; an end cap and spigot being coaxially receivable within the internal diameter of the second end of the tubular void former; a flexible grout tube having a first end and a second end, the first end being coaxially connectable to the end cap and spigot; and a chamfered formwork connector being coaxially connected to the opposite second end of the flexible grout tube and fixable to a formwork face using a formwork connector holder. Preferably, the tubular void former is formed from is formed from steel spiral tubing having a diameter of between 40mm to 150mm. Further preferably, the spiral void former is supplied in lengths for subsequent on-site customisation. In use, the void former holder may comprise a radial collar for receiving the internal diameter of the first end of the tubular void former and a radial taper which tapers inwardly towards the collar. Preferably, the end cap and spigot includes a series of progressively larger annular flexible ribs to grip the second end of the tubular void former. Further preferably, the chamfered formwork connector includes a knockout panel disposed in the chamfered face to increase the cross-sectional area of the grout entry point. In use, the void former holder and / or formwork connector holder may include a permanent magnet material. Preferably, the chamfered face of the chamfered formwork connector forms an angle of around 30°. Further preferably, the void former housing, tubular void former, end cap and spigot, flexible grout tube, formwork connector and formwork connector holder can be assembled between formwork faces so that their internal passages are linked and form a continuous route for subsequently receiving a cementitious grout in the cast concrete element. In use, the void former system further comprises an angled connector positioned between the second end of the tubular void former and a first end of the flexible grout tube. Preferably, the angled connector provides an angle of around 30° between the first end and second ends thereof. Further preferably, the void former housing, end cap and spigot, angled connector, formwork connector, and / or formwork connector holding plate are formed from a polymer selected from the group consisting of Polyurethane (PU), Polypropylene (PP), High-Density Polyethylene (HDPE), Low-Density Polyethylene (LDPE), Polyethylene Terephthalate (PET), Polyvinyl Chloride (PVC), Acrylonitrile Butadiene Styrene (ABS), or blends thereof. In use, the void former housing, end cap and spigot, angled connector, formwork connector, and / or formwork connector holding plate may be manufactured using a technique selected from the group consisting of injection moulding, blow moulding, vacuum forming, rotational moulding, compression moulding, rim moulding, powder impression moulding, additive manufacturing, or 3D printing. Preferably, the tubular void former is formed from galvanised steel having a zinc coating with a thickness ranging from 50 to 60 grams per square meter. Further preferably, the flexible grout tube comprises a low-friction internal surface and jacket to prevent the propagation of flames in the event of fire. In use, the flexible grout tube may be formed from a corrugated plastic material. It is believed that a formwork connector for precast void former grout connections and a void former system in accordance with the present invention at least addresses the problems outlined above. It will be obvious to those skilled in the art that variations of the present invention are possible and it is intended that the present invention may be used other than as specifically described herein. Brief Description Of The Drawings The present invention will now be described by way of example only, and with reference to the accompanying drawings, in which: Figure 1 is a largely schematic exploded side perspective view showing the principle of precast structural connections using grout void formers as is known in the art; Figure 2 shows an illustrative example of an arrangement of formwork that is used to cast reinforced concrete elements and which shows a typical void former system that is known in the art; Figure 3 is a side plan view of an exploded void former system in accordance with the present invention; Figure 4 illustrates a side perspective view of an exploded void former system in accordance with the present invention; Figure 5 shows a side perspective view of a formwork connector for precast void former grout connections in accordance with the present invention; and Figure 6 is a cross sectional side plan view of an assembled void former system in accordance with the present invention which has been cast and orientated in a vertical wall panel. Detailed Description Of The Preferred Embodiments The present invention has adopted the approach of utilising a formwork connector for precast void former grout connections and to an improved void former system. Advantageously, the present invention provides a void former system which does not constrict the grout application routes when in use, and provides a robust and reliable juncture between components in the grouting system. Further advantageously, the present invention provides a chamfered grout entry point in the cast element which provides a convenient application point that utilises gravity to improve grout flow and aid the expulsion of air from the connection voids. This enables the use of smaller diameter flexible grout tubes and reduced grout usage, offering a more efficient and cost-effective solution for concrete formwork. The void former system providing an associated array of formwork connectors providing precise and robust fixing points for both steel and timber formwork designs. Referring now to the drawings, a void former system 100 in accordance with the present invention is illustrated in Figures 3 and 4. The void former system 100 comprises a galvanised spiral tubing void former 102, which, typically between 40mm to 150mm in diameter, and this acts as a void former within precast concrete elements, similar to that described above in relation to Figures 1 and 2. Typically, the spiral void former 102 is supplied in lengths (3m) for subsequent on-site customisation, or it can be provided as a cut-to-length tailored product for site-specific need. Whilst Figures 3 and 4 illustrate the use of a cylindrical spiral void former 102, this is in no way intended to be limiting or exhaustive, as the tubular void former 102 can instead have an oval cross section. The cut-to-size tubular void former 102 has a first end 104 that in use would be orientated towards the base of the finished precast element (not shown), and would receive the reinforcement steel (not shown) projecting from a neighbouring precast element (not shown) as described above in relation to Figure 1. The first end 104 of the tubular void former 102 is connectable to a void former holder 106 for fixing the spiral void former 102 to a formwork face 108. The spiral void former holder 106 is largely disc-shaped, having a radial collar 110 which having diameter which receives the internal diameter of the tubular void former 102 by an interference or friction fit, and the like. The void former holder 106 also has a radial taper 160 which tapers inwardly towards the collar 110. The spiral void former holder 106 can be magnetic for use with metallic formwork faces 108, or alternatively can be nailed-on or otherwise attached to a timber formwork face. The spiral void former holder 106 includes an axially-positioned threaded aperture 112 which allows easy removal of the holder 106 from the spiral void former 102 after the formwork 108 is removed. Often, on removal of the concrete elements from the formwork 108, the magnetic force is insufficient to maintain the bond between the spiral void former holder 106 and the formwork face 108, and instead the holder 106 remains inside the metal spiral void former 102. The thread 112 that runs centrally through holder 106 enables a corresponding threaded bar or tool (not shown) to be inserted, and which allows an operative to break the bond with the surrounding concrete and retrieve the magnetic void former holder 106 from the first end 104 of the tubular void former 102. The opposite second end 114 of the cut-to-size tubular void former 102 receives an end cap 116 which seals the open second end 114 of the void former 102. The end cap 116 is provided as a generally open cylindrical shape having a flange 118 which seals off the second end 114 of the void former 102. The end cap 116 includes a series of progressively wider flexible ribs 120 which grip the open second end 114 of the void former 102. Opposite to this is a spigot 122 which serves as the linkage between the spiral void former 102 and flexible grout tube 124. Figures 3 and 4 also show that an optional angled connector 126 that can be positioned between the second end 114 of the void former 102 and a first end 128 of the flexible grout tube 124. The angled connector 126 having a first end 130 that has an internal diameter that receives the outer diameter of the spigot 122 by an interference or friction fit. The opposite second end 132 of the angled connector 126 has an internal diameter that receives the outer diameter of a first end 128 of the flexible grout tube 124 by an interference or friction fit. The skilled person will understand that this fit could be ordinarily achieved by the use of engineered tolerances between the diameters of the moulded products, or by way of internal radially-placed tapered fins (not shown) within the opening 132 of the angled spigot 126. Equally, should the void former system 100 be used without the optional angled connector 126, and the first end 128 of the flexible grout tube 124 received directly within the spigot 122, the skilled person will understand that such a precision fit could be ordinarily achieved by the use of engineered tolerances between the diameters of the moulded products, or by way of internal radially-placed tapered fins (not shown) within the spigot 122. The optional angled connector 126 preferably forms a 30° offset angle. The angled connector 126 is optional since the grout tube 124 is itself flexible, provided by a series of corrugations, but the advantages of using the angled connector 126 are that it further reduces any lateral strain on the flexible grout tube 124, as perhaps best shown in Figure 6 which shows the assembled void former system 100. The opposite second end 134 of the flexible grout tube 124 is received inside a first end 138 of a chamfered formwork connector 136 by an interference or friction fit, and through an opposite 30° chamfered face 140 onto either a magnetic fixing plate 142 or a nailed-on plastic fixing plate to accommodate for either a metal or timber formwork face 144. Again, the skilled person will understand that the precision fit between the second end 134 of the flexible grout tube 124 inside the first end 138 of a chamfered formwork connector 136 could be ordinarily achieved by the use of engineered tolerances between the diameters of the moulded products, or by way of internal radially-placed tapered fins (not shown) within the first end 138 of the form work connector 136. Figures 3 and 4 show that the fixing plate 142 is largely disc-shaped, having an annular mating face 148 which projects from a radial taper 146 which tapers inwardly towards the mating face 148, and onto which the chamfered face 140 of the formwork connector 136 is seated in use, as best described in relation to Figure 5. Projecting from the centre of the annular mating face 148 is a screw thread 150 which engages with an aperture 152 disposed in the chamfered face 140 which is proximal to a second end 162 of the formwork connector 136. In a preferred embodiment, the screw thread 150 being M42 to mate with the 42mm diameter aperture 152 in the chamfered face 140. The length of the screw thread 150 is only around 10mm long, so that it does not strike the far edge of the 30° form work connector 136 when engaged. The circular hole 152 for pouring grout features a tapered edge 168 forming a section of female thread, ensuring alignment parallel to the line of draw. This tapered edge 168 engages with the thread 150 of the fixing plate 142, resembling the threading action of a nut onto a bolt. These male 150 and female 168 screw threads also aids removal of the fixing plate 142 as they self-extract as they are rotated. In this way, the skilled person will understand that the void former housing 106, tubular void former 102, end cap 116, optional angled connector 126, flexible grout tube 124, formwork connector 136 and fixing plate 142 can be assembled between formwork faces 108, 144 so that their internal passages are linked and form a continuous route for subsequently receiving a cementitious grout in the cast building element. Figure 5 shows further detail of the chamfered formwork connector 136 for precast void former grout connections of the present invention. The formwork connector 136 is a shaped as a generally closed-ended cylinder having an open first end 138 which receives and retains the outer diameter of the second end 134 of the flexible grout tube 124 by an interference or friction fit, as described above. A chamfered face 140 is disposed in the second end 162 of the formwork connector 136 and which forms an acute angle (and denoted as angle a in Figure 3) of around 30° in the preferred embodiment of the invention. The chamfered face 140 provides a convenient entry point to administer grouting compounds in the cast building element that does not inhibit flow and allows expelled air to escape more readily, improving grout flow and reducing the likelihood of voids in the completed connection. The formwork connector 136 also comprises a largely discorectangle-shaped knockout panel 154 disposed in the chamfered face 140 which can increase the cross-sectional area of the grout entry point 152 to bring further improvements in terms of grout flow and air expulsion. The minimal surface impact simplifies any patching processes on the finished face that may be required. As best shown in Figure 5, the formwork connector 136 also includes a step 156 and an offset face 164 which provides a lip or ledge, generally indicated by numeral 166 in Figure 6, in the cast building element for filling with grout. The lip or ledge 166 ensures that the form work connector 136 is a suitably stepped-back from the concrete surface to prevent spalling of the concrete. Figure 6 shows an assembled void former system 100 in accordance with the present invention which has been cast and orientated in a vertical wall panel. The outline of the wall panel being shown by the numeral 158. The skilled person will appreciate that once the formwork 108, 144 is removed the magnetic or plastic fixing plate 142 would be visible on the concrete surface. This is then removed by unthreading to reveal the open pouring face 140 of the 30° chamfered form face connector 136. Once the wall panels are installed in their temporary works state, the installer has two options: 1) They can pour grout straight into opening 152 to form the grouted connection. 2) The exposed face has a narrow band that closely follows the perimeter of the exposed knockout panel 154, allowing the cast material to be cut or knocked away to increase the opening area. Figure 6 shows the void former system 100 installed in a vertical wall panel 158 and the improved gradient that grout will flow down in the initial stages. It is also believed that this configuration will also allow trapped air to escape as there will not be the build-up of grout that otherwise occurs because of the 90° bend in the grout filling tube 26 of the traditional system. In a preferred embodiment, the void former housing 106, end cap 116, angled connector 126, formwork connector 136 and / or formwork connector holding plate 142 is formed from a polymer such as Polyurethane (PU). Alternatively, the housing 12 and parts thereof can be formed from a polymer such as Polypropylene (PP), High-Density Polyethylene (HDPE), Low-Density Polyethylene (LDPE), Polyethylene Terephthalate (PET), Polyvinyl Chloride (PVC) or Acrylonitrile Butadiene Styrene (ABS) or blends thereof. Equally, the skilled person will appreciate that the void former housing 106, end cap 116, angled connector 126, formwork connector 136 and / or form work connector holding plate 142 can be formed from any number of synthetic plastics, such as a thermoplastic or thermoset material. The above list is no way intended to be limiting or exhaustive. The void former housing 106, end cap 116, angled connector 126, form work connector 136 and / or formwork connector holding plate 142 may also be formed from a biobased polymer or a bioplastics material obtained from renewable biomass sources, such as, but not limited to, any of the following: vegetable fats and oils, corn starch, straw, woodchips, sawdust, recycled food waste and the like. The void former housing 106, end cap 116, angled connector 126, form work connector 136 and / or formwork connector holding plate 142 can be manufactured using techniques such as injection moulding, blow moulding, vacuum forming, rotational moulding, compression moulding, rim moulding, powder impression moulding or any other form of plastics or rubber manufacture, as additive manufacturing or 3D printing. In a preferred embodiment, the flexible grout tube 124 is formed from a high-speed, medium-duty corrugated plastic. It features a low-friction inner surface and jacket that in the event of fire prevents the propagation of flames. The void former holder 106 and / or formwork connector holding plate 142 can alternatively include a permanent magnet material. The void former 102 is formed from galvanised steel having a zinc coating with a thickness ranging from 50 to 60 grams per square meter. Therefore, a formwork connector 136 for precast void former grout connections and a void former system 100 is provided which provides the advantages outlined above. When used in this specification and claims, the terms “comprises” and “comprising” and variations thereof mean that the specified features, steps or integers are included. The terms are not to be interpreted to exclude the presence of other features, steps or components. The singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “includes” and / or “including” when used herein, specify the presence of stated features, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups thereof. The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, separately, or in any combination of such features, can be utilised for realising the invention in diverse forms thereof. The invention is not intended to be limited to the details of the embodiments described herein, which are described by way of example only. It will be understood that features described in relation to any particular embodiment can be featured in combination with 5 other embodiments. It is contemplated by the inventor that various substitutions, alterations and modifications may be made to the invention without departing from the spirit and scope of the invention as defined by the claims. Examples of these include the following: 10 The skilled person will understand that whilst the angle the chamfered face 140 on the chamfered formwork connector 136 in the preferred embodiment is around 30° this is in no way intended to be limiting. Improved grout flows and the expulsion of air from the connection voids will also occur when the chamfer angle is around 45° or less. The 15 skilled person will also appreciate that the optional angled connector 126, when used, would ideally utilise an angle which is complementary to the chamfered face 140 on the chamfered formwork connector 136.

Claims

1. A formwork connector for precast void former grout connections in precast concrete elements, comprising:an elongate body having a first end and a second end, the body providing a continuous grout receiving passage formed between the first and second ends of the body; anda chamfered face disposed towards the second end of the form work connector having an opening providing a grout entry point.

2. The formwork connector as claimed in claim 2, wherein the chamfered face forms an angle of around 30° from the long axis of the body.

3. The formwork connector as claimed in claims 2 or 3, further comprises a knockout panel disposed in the chamfered face to increase the cross-sectional area of the grout entry point.

4. The formwork connector as claimed in claim 3, wherein the knockout panel being formed as a line of weakness around the perimeter of the chamfered face.

5. The form work connector as claimed in claims 3 or 4, wherein the knockout panelis largely discorectangular-shaped.

6. The formwork connector as claimed in any of the preceding claims, further comprising an offset face located between the chamfered face and the first end of the body that is parallel to the chamfered face and which provides a lip in the cast concrete element for filling with grout.

7. The formwork connector as claimed in any of the preceding claims, wherein the formwork connector is made from a polymer selected from the group consisting of Polyurethane (PU), Polypropylene (PP), High-Density Polyethylene (HOPE), Low-Density Polyethylene (LDPE), Polyethylene Terephthalate (PET), Polyvinyl Chloride (PVC), Acrylonitrile Butadiene Styrene (ABS), or blends thereof.

8. The formwork connector as claimed in any of the preceding claims, wherein the formwork connector is manufactured using a technique selected from the group consisting of injection moulding, blow moulding, vacuum forming, rotational moulding, compression moulding, rim moulding, powder impression moulding, additive manufacturing, or 3D printing.

9. The formwork connector as claimed in any of the preceding claims, wherein the opening providing a grout entry point being formed having a female thread.

10. A void former system for precast concrete elements, comprising:an elongate tubular void former having a first end and a second end;a void former holder, one end of which is fixable to a formwork face and the other opposite end being receivable coaxially within the internal diameter of the first end of the tubular void former;an end cap and spigot being coaxially receivable within the internal diameter of the second end of the tubular void former;a flexible grout tube having a first end and a second end, the first end being coaxially connectable to the end cap and spigot; anda chamfered formwork connector being coaxially connected to the opposite second end of the flexible grout tube and fixable to a formwork face using a formwork connector holder.

11. The void former system as claimed in claim 10, wherein the tubular void former is formed from is formed from steel spiral tubing having a diameter of between 40mm to 150mm.

12. The void former system as claimed in claims 10 or 11, wherein the spiral void former is supplied in lengths for subsequent on-site customisation.

13. The void former system as claimed in claim 10, wherein the void former holder comprises a radial collar for receiving the internal diameter of the first end of the tubular void former and a radial taper which tapers inwardly towards the collar.

14. The void former system as claimed in claim 10, wherein the end cap and spigot includes a series of progressively larger annular flexible ribs to grip the second end of the tubular void former.

15. The void former system as claimed in claim 10, wherein the chamfered form work connector includes a knockout panel disposed in the chamfered face to increase the cross-sectional area of the grout entry point.

16. The void former system as claimed in claim 10, wherein the void former holder and / or formwork connector holder includes a permanent magnet material.

17. The void former system as claimed in claim 10, wherein the chamfered face of the chamfered formwork connector forms an angle of around 30°.

18. The void former system as claimed in any of the preceding claims, wherein the void former housing, tubular void former, end cap and spigot, flexible grout tube, formwork connector and formwork connector holder can be assembled between formwork faces so that their internal passages are linked and form a continuous route for subsequently receiving a cementitious grout in the cast concrete element.

19. The void former system as claimed in claim 10, further comprising an angled connector positioned between the second end of the tubular void former and a first end of the flexible grout tube.

20. The void former system as claimed in claim 19, wherein the angled connector provides an angle of around 30° between the first end and second ends thereof.

21. The void former system as claimed in any of the preceding claims, wherein the void former housing, end cap and spigot, angled connector, formwork connector, and / or formwork connector holding plate are formed from a polymer selected from the group consisting of Polyurethane (PU), Polypropylene (PP), High-Density Polyethylene (HDPE), Low-Density Polyethylene (LDPE), Polyethylene Terephthalate (PET), Polyvinyl Chloride (PVC), Acrylonitrile Butadiene Styrene (ABS), or blends thereof.

22. The void former system as claimed in any of the preceding claims, wherein the void former housing, end cap and spigot, angled connector, formwork connector, and / or formwork connector holding plate are manufactured using a technique selected from the group consisting of injection moulding, blow moulding, vacuum forming, rotational5 moulding, compression moulding, rim moulding, powder impression moulding, additive manufacturing, or 3D printing.

23. The void former system as claimed in claims 10 or 11, wherein the tubular void former is formed from galvanised steel having a zinc coating with a thickness ranging 10 from 50 to 60 grams per square meter.

24. The void former system as claimed in claim 10, wherein the flexible grout tube comprises a low-friction internal surface and jacket to prevent the propagation of flames in the event of fire.1525. The void former system as claimed in claims 10 or 24, wherein the flexible grout tube is formed from a corrugated plastic material.

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