[01 ] This invention relates to a method and apparatus for forming a penetration in a deck during construction of an edifice on a construction site and for inhibiting entry to the penetration, whether by a person, or substance intrusion, such as by water.

Background to the invention

[02] On construction sites, service penetrations are provided in construction decks, for enabling communication between upper and lower spaces separated by the decks. Communication channels may be by way of bin chutes, electrical (conduits), hydraulic (fire collars), mechanical (fire dampers) and surveyor's penetrations and the like. However, these create hazards for personnel on the engaged in construction related activities on the deck. For example, site personnel risk falling through a larger penetration, stepping into a smaller penetration, or being struck by an object falling through a penetration to a deck below. Significant damage and delays, as well as insurance claims arise in the event of water intrusion. Workplace laws increasingly require that penetrations giving rise to such risks must be suitably guarded.

[03] Known measures for protecting open penetrations include edge protection, such as installed handrails, and secure covers to prevent falls through them. Penetrations in concrete slabs may be additionally protected by providing cast-in mesh as a back-up to a top covering system. The mesh is generally of a small aperture, for example 50 x 50 mm mesh size or smaller and is made of material capable of withstanding the weight of potential imposed loads. For larger penetrations, provision for mesh may be made in the slab design specifications for selection of a mesh structure that will withstand potential loads, including those applied by personnel, equipment and material passing over or resting on it. However, the result is not an engineered and tested system and effectiveness varies. Deficiencies tend to include the following: The ply cover is not load rated; form ply has no slip resistance; the ply does not display a notice such as "penetration below", and does not display a maximum load rating.

[04] When holes are needed to be cut in the mesh for services to pass through, they should be cut to the profile of the service, so the mesh remains in the penetration and the load-carrying capacity of the mesh is not reduced below design specifications. However, once the mesh is cut, it loses its integrity.

[05] Using plywood covers alone is not a satisfactory risk control measure because of their susceptibility to creating various other hazards, for example, having the same appearance as other pieces of plywood that may be in the vicinity, their purpose therefore being disguised; being difficult to ascertain whether secured effectively; and, if a cover is unsecured, being difficult to resecure or even to notice that it has been unsecured. Also, after the first service is installed, repositioning of the cover generally requires significant modification. Material becomes waste and is not re-usable.

Objects of the invention

[06] It is an object of this invention to address at least some of the shortcomings of the prior art and, in doing so, to provide apparatus and a method of using it that will at least ameliorate the risks inherent in the employment of penetrations on construction sites.

[07] The preceding discussion of the background to the invention is intended to facilitate an understanding of the present invention. However, it should be appreciated that the discussion is not an acknowledgement or admission that any of the matter referred to was part of the common general knowledge in Australia or elsewhere as at the priority date of the present application.

[08] Further, and unless the context clearly requires otherwise, throughout the description and the claims, the words 'comprise', 'comprising', and the like are to be construed in an inclusive sense - meaning "including, but not being limited to", as opposed to an exclusive or exhaustive sense, meaning "including this and nothing else".

Summary of invention

[09] According to a first aspect of the invention, there is provided a penetration former comprising a rigid frame having an open upper end and an opposite open lower end, the frame defining an internal passage extending from said upper end to said lower end, the frame being adapted for receiving a weight- bearing barrier, which, when operatively located in relation to the frame, blocks the passage against entry.

[010] In a preferred form of the invention, the frame is adapted for fixing to a temporary deck, such as a ply deck, on a construction site.

[01 1 ] In a further preferred form of the invention, the barrier is securable to the frame when operatively located to block the passage. The barrier preferably comprises a rigid panel. A suitable material for the barrier is autoclaved, aerated concrete (AAC), for example as sold under the trade mark HEBEL and available in Australia from CSR Building Products, of 39 Delphi Road, North Ryde, NSW 21 13, Australia. It will however be appreciated that suitable alternatives may be used.

[012] The frame has an axial profile that may, without limitation, be generally rectangular, circular, triangular, pentagonal, hexagonal and the like, or may be of irregular shape, depending on applicable requirements or restrictions.

[013] The frame may be constructed of moulded plastics materials, alloys of metals or composites.

[014] In a preferred embodiment, the frame defines a retaining wall in first and second attachable parts. The wall is adapted to hold back flowable concrete when cast, from entering the internal passage. [015] In a further preferred embodiment, the first and second attachable parts comprise a plurality of separably connectable side sections and corner elements.

[016] The frame preferably further comprises a rim at the upper end and a ledge inward of the rim.

[017] In a preferred embodiment, the barrier is operatively eatable to rest on the rim.

[018] In a further preferred embodiment, the lower end comprises a flange. The flange is eatable to rest on the temporary deck.

[019] The flange preferably includes holes suitable for receiving fastenings between the flange and deck. In a preferred embodiment, the flange extends inwardly, ingressing partially into the passage.

[020] In a preferred embodiment, the penetration former is adapted for removal from the deck after the slab has formed.

[021 ] In a further preferred form of the invention, the weight bearing barrier is replaced in penetration covering location after removal of the former from the deck. The former preferably further comprises a cover adapted for positioning over the barrier when thus operatively located. Preferably, the cover extends peripherally beyond the barrier.

[022] According to a second aspect of the invention there is provided a method of forming a blockable penetration in an edifice, the method comprising the steps of providing a temporary deck, placing a former comprising rigid frame on the deck, the frame defining a passage therethrough from an upper to an opposite lower end; providing a barrier to block the passage; disposing concrete on the temporary deck to surround the frame and allowing the concrete to set to form a concrete slab over the temporary deck. [023] In a preferred form of the invention, the method includes securing the former to the temporary deck. The temporary deck may comprise plywood.

[024] Further, according to the invention, the method includes the step of removing the temporary deck after the concrete slab has set, thereby to allow access to the framed passage.

[025] In a further preferred form of the invention, the method includes locating the barrier in passage-blocking orientation in the former.

[026] Still further, the method preferably comprises securing the barrier within the former.

[027] Preferably, the former comprises an inner ledge on which the barrier may rest when in operative orientation.

[028] In a preferred form of the invention, the method includes the step of removing the former after the concrete slab has set. The barrier may then be located in the penetration vacated by the former.

[029] Preferably, the method includes creating a seal between the barrier and the former. The seal is preferably created by applying a sealant, preferably fire rated, between barrier and former.

[030] In a preferred embodiment of the invention, the method includes removing the former after the concrete has set to form a slab. The former may then be reused in forming another penetration.

[031 ] The method preferably further includes the step of applying a cover over the barrier. The cover is preferably secured to the slab. The method further preferably includes interposing a gasket between slab and cover.

[032] According to a third aspect of the invention there is provided a penetration forming and blocking kit comprising a former and a barrier in panel form, the former comprising a frame adapted to receive and support the barrier in operative, blocking orientation. [033] In a preferred embodiment, the former comprises an upper wall part and a lower wall part, adapted to fit one within the other.

[034] Preferably, the frame comprises an inner ledge adapted to support the barrier.

[035] Further preferably, the wall parts comprise separate connectable corner elements and side sections.

[036] The sections and elements may be adapted to have a plain end and an opposite recessed end, the recessed end being adapted to connectably receive a plain end of an adjacent element or section.

[037] Still further preferably, the sections and elements are connectable to provide a continuous surface on the wall parts. The continuous surface of the upper wall part is preferably adapted to abut the continuous surface of the lower wall part.

[038] In a preferred form of the invention, the upper and lower parts are adapted for mutual connection. The upper and lower wall parts are adapted preferably by having engageable formations.

[039] The formations may include a rib which lies generally horizontal between said abutting continuous surfaces.

[040] The kit further may comprise sealant for applying between frame and barrier. Preferably, the sealant is fire rated.

[041 ] In a preferred embodiment, the kit includes fastenings for fastening the former to a supporting temporary deck, prior to casting of a concrete slab on the deck.

[042] In a further preferred form of the invention, the kit includes a cover, adapted for positioning over the barrier when operatively located. The kit may include fastenings for securing the barrier to a concrete slab in which a penetration is to be formed using the former. [043] In an embodiment, the kit further includes a gasket for interposition between the cover and said slab.

[044] The barrier is selected to be weight supporting in relation to worksite personnel and plant that may pass over or come to rest on it.

[045] In a further preferred form of the invention, the barrier comprises autoclaved aerated concrete.

[046] In a still further preferred form of the invention, the frame has open upper and lower ends connected by a passage. The passage is suitable for receiving services conduits to pass therethrough in use.

[047] Preferably, the passage has an axial profile that is generally rectangular.

[048] The barrier material is selected to be suitable for perforation, for forming apertures therethrough to receive service conduits.

Brief description of drawings

[049] In order that the invention may be readily understood, and put into practical effect, reference will now be made to the accompanying figures. Thus:

Figure 1 shows in schematic form a perspective view of a preferred embodiment of the penetration former of this invention.

Figure 2 is a schematic side cross-sectional diagram of the former of Figure 1 , taken along line A1 -A2 and shown in use in a concrete slab.

Figure 3 illustrates implementation of the method of the invention in a preferred embodiment in sub-diagrams (a) through (h), using the former of Figure 1 .

Figure 4 illustrates the invention when provided in kit form, according to a further embodiment.

Figure 5 is a fully exploded view of the wall parts of the kit of Figure 4. Figure 6 is a side section of the wall parts of Figure 4 when fitted together as shown in Figure 7, the section being taken along line X-Y in Figure 7(c).

Figure 7 is a partially assembled view of the parts of Figure 5.

Detailed description of the invention

[050] A penetration frame according to the invention is illustrated in Figure 1 , and generally denoted by the number 1 0. The frame comprises a wall 12 having an upper end 14 and an opposite lower end 16. The wall defines and surrounds a passage 18 extending between said opposite ends as shown with assistance from directional arrow 18. It is through this passage that service conduits will be installed to pass. By way of example only, the passage has lateral dimensions of 600mmx 600mm. From end to end, it is about 200mm high.

[051 ] In this embodiment, the former is moulded from aluminium, but may be made of other metals, plastics and even of wood. Suitable plastics include (by way of non-limiting example) acrylonitrile butadiene styrene (ABS) and polypropylene.

[052] The upper end 14 of frame 12 comprises a recess 20 having an inner ledge 22, adapting the frame wall to support, within the passage, a barrier (shown in Figure 2) for preventing access to and through the passage. At lower end 16 there is a similar ledge 24 defined by an internally extending flange. This provides an under-surface 26 which rests in abutment with the upper surface of a temporary plywood deck 30 (see Figure 2), through which the penetration will provide access. Apertures are formed in ledge 24 for receiving fixing crews (not shown) for securely fastening the lip and hence the frame to the deck on which it rests.

[053] In Figure 2, the former of Figure 1 is shown in side cross section taken along line A1 -A2 of Figure 1 . The former is surrounded by a concrete slab 40. Ledge 24 has screw holes centred at locators 32 for facilitating temporary fixing to the underlying plywood deck 30. Similarly, ledge 22 receives fixing screws at the positions marked 34 on opposite sides of frame 12. [054] Blocking passage 18 is a barrier panel 36, fashioned of aerated concrete (or any alternative suitable weight-bearing material). The barrier is located to rest on ledge 22. Above barrier 18 there is placed a cover plate 38 made of a hardened plastics compound such as ABS. Between cover 38 and slab 40 there is a sealing gasket ring 42 of nitrile rubber or similar.

[055] A process of forming a penetration according to the invention will now be described with reference to Figure 3, which illustrates a preferred embodiment of the method of this invention in illustrations (a) through (h). Like numbers from Figures 1 and 2 will be used to denote like features.

[056] In this embodiment, beginning at Figure 3(a), a temporary deck 30 is provided in the form of a raised sheet of plywood, generally horizontally disposed and suitably secured to a supporting structure according to methods practiced in the art. The frame 12 of Figure 1 is placed on the upper surface 32 of deck 30, at a preordained position where services are designated to pass through the deck.

[057] The frame is fixed at lower end 14 to deck 30, using fastenings conventional in the art, for example, wood screws 36 passing through suitable holes drilled in the lower lip of the frame. Passage 18 is therefore closed off at bottom end 16.

[058] Deck 30 may be fashioned from materials other than plywood, but plywood is commonly used in the construction industry in this and other temporary and more permanent applications, not only for cost considerations, but also because of its inherent mechanical properties.

[059] In Figure 3(b), a barrier 40, made by way of example from a panel of HEBEL autoclaved, aerated concrete, is inserted into recess 20 at upper end 14 and allowed to rest on upper supporting lip 22, effectively blocking entry to passage 18.

[060] Referring to Figure 3(c), a slab 42 of concrete is poured on to deck 30 to surround frame 12, to the level of upper end 14. Frame 12 serves as a retaining wall that preserves the integrity of passage 18 as a communications means between the spaces to be separated by the concrete, when set.

[061 ] The concrete is allowed to set with an edge 44 being trowelled around the perimeter of upper end 14. The HEBEL barrier is then removed as shown with the aid of directional arrow D in Figure 3(d), before former frame 10 too is unscrewed from temporary deck 30 and lifted out, as suggested by vertical upward arrows V, leaving behind a penetration 50 within slab 42. The penetration is barred by plywood deck 30. Former 10 can be reused again when required for forming a further penetration.

[062] With reference to Figure 3(e), the HEBEL autoclaved, aerated concrete barrier is then replaced on a concrete ledge 44, which has been left below the location of removed upper ledge 22 of frame wall 12 by the set concrete. The barrier is sealed in place using a suitable fire-rated sealant 48 conventional in the industry.

[063] In Figure 2(f), a rubber gasket 52 is inserted between HEBEL autoclaved, aerated concrete barrier 40 and the surrounding concrete of the recess wall 54. A cover plate 56 of a hard plastics compound is placed over the barrier and is fixed to the underlying concrete slab using concrete bolts 58. Suitable plastics include without limitation high density polyethylene, polypropylene, polyvinylchloride, acrylonitrile butyl styrene (ABS) and the like.

[064] Thereafter, as depicted in Figure 3(g), the original temporary ply deck 30 is stripped away, exposing the underside 60 of the concrete deck, and revealing penetration 50 from below.

[065] Thereafter, as shown in Figure 3(h), top cover 56 is removed and apertures 64 are formed in the barrier plate and upper cover plate by methods such as drilling. Service conduits 66 can then be inserted to extend through the passageway and connect the spaces above and below the concrete deck. A fire rated sealant 68 is applied around the circumferential periphery of barrier 40 to seal any gaps between barrier 40 and concrete deck 42. Filler and additional sealant is applied to the cavities 62 vacated by bolts 58. Alternatively, instead of forming apertures in the barrier plate for receiving service conduits, the conduits are installed and a sealant is applied around them within passage 18 to seal the passage against entry of foreign objects or substances.

[066] A penetration former assembly, generally denoted by the number 100 is illustrated in assembled form in Figure 4(a) and in exploded view in in kit form in Figure 4(b). The embodiment in this figure is the preferred for production of the invention as a kit, but not intended to be considered as limiting of the scope of the concept underlying the invention.

[067] In Figure 4(a), the former assembly is shown with a portion of a concrete slab 140 formed to surround it. For convenience, the slab is shown with finite edges and sides. However, in most applications of the invention, the slab will be of far greater area than the assembly. The slab may be of any thickness, according to the dictates building codes and structure designers, such as engineers and architects. All that can be seen of the former assembly in this view is a cover-plate 138 and fastening screws 134. However, in Figure 4(b), an exploded view is provided, in which it can be seen that slab 140 has a penetration defining a passage through it, reaching a supporting plywood board 130, prepared for the forming thereon of a concrete deck defined by said slab.

[068] Although former assembly 100, as shown in Figure 4(b) suggests that it is fitted into the penetration, the assembly is partially pre-assembled and the concrete slab then cast around it, in a manner much as described with reference to Figure 3. The former assembly is preferably provided in kit form for on-site assembly when required. This way it can be provided as a flat pack for space saving during transportation and storage. Indeed, individual components of the kit are available individually in different sizes for enabling the user to assemble a former assembly in a size of choice, for example, to match the thickness of the deck required in the construction concerned.

[069] The former assembly has an outer frame comprising a retaining wall 1 12 having an upper end 1 14 and an opposite lower end 1 16. The wall defines and surrounds a passage 1 18 extending between said opposite ends, for service conduits to pass therethrough, at least temporarily, or in the final structure.

[070] In this embodiment, the former assembly wall 1 12 is in two parts, 1 10 and 1 12 of moulded aluminium. Part 1 12 has an inwardly extending ledge 124 defined by a flange, which surrounds the passage opening at its lower end 1 16. This provides an under-surface 126 which rests in abutment with the upper surface of the temporary plywood deck 130. Apertures are formed in ledge 24 for receiving fixing screws 106 for securely fastening the lip and hence the frame to the deck on which it rests.

[071 ] The upper end 1 14 of passage 1 18 is defined by the upper rim 108 of part 1 10 when the wall parts are placed on the waiting deck former 130. The length of passage 1 18 and the maximum depth to which concrete may be cast around the wall assembly is determined by the height of parts 1 10 and 1 12 and by the distance of insertion of part 1 12 into 1 10, so that upper wall part 1 10 fits snugly around part 1 12 in a friction fit arrangement, complemented by engagement formations comprising horizontally directed interfacial ribs and grooves 214 on the opposed abutting surfaces. These are marked in Figure 6. The distance of insertion is adjustable using ridges on part 1 10 and spaced parallel grooves on part 1 12 for mechanical inter-engagement, which enables them to retain the relative elevation at which they are set. Optionally, contact adhesive may be applied to the contact surfaces prior to insertion. This may be used as a means of attachment instead of the ribs and grooves, or in addition. Mechanical fastening means such as staples or screws may also be employed as alternatives, as may clips and other known devices.

[072] Located a distance below the upper rim 108 of wall part 1 10 is an upper end recess 120 having an inner ledge 122, adapting the wall portion to support, within passage 1 18, a barrier 136 for preventing access to and through the passage. The barrier may be an aerated concrete plate, a metal alloy plate, a composite plate, or of similar weight-bearing construction. [073] Wall portions 1 10 and 1 12 may be supplied in a further broken-down form, as illustrated in Figure 5. Each portion is made up of separable and connectable corner elements 172, 174 and straight wall sections 176, 178. In the case of upper, outer portion 1 10, the portions 172 and 176 are stepped, having a horizontal step 182 separating upper 184 and lower 186 vertical wall portions of straight section 176. Correspondingly, corner element 172 has a step 188 that is alignable to be substantially co-planar with step 182 when sections 176 and corners 172 are operatively connected.

[074] Means for connecting sections 176 to corners 172 are shown in Figure 5(b). Each section and corner element has a plain end and an opposite end adapted to receive the plain end of the adjacent corner or section, as the case requires. The adapted end is labelled 190 and the plain end 200.

[075] Each adapted end 190 has a discontinuity 192 in the form of an offset 202 that outwardly offsets the main planar surfaces of the relevant part, namely step surface 182 and wall surfaces 184 or 186, to a smaller offset surface 194. The outward offset 194 is shown in a detail callout in Figure 5(b). Edge 198 of corner element 172 is slid into abutment with the discontinuity 192, so that the outer surface 204 at the opposing end of corner element 172 is brought into abutment with inner, recessed surface 194 of section 176. Adhesive is applied to abutting surfaces 194 and 204 and allowed to set. This arrangement results in the joined parts presenting a flush fitting substantially continuous inner surface for wall part 1 10. The horizontal surfaces 182 join to form continuous ledge 122 in recess 120, as depicted in the separate and fitted configurations of Figure 7.

[076] The lower frame part 1 12 is similarly constructed from separate pieces: Side sections 178 and corner elements 174. Each has a plain end 206 and an opposite, adapted end 208, adapted for fitting against the plain end of the adjacent piece. The adapted end has an offset surface 210, the offset being to the inner side of inner surface 212 of the pieces 174 and 178.

[077] The callout ring B in Figure 7 (a) relates to the illustration in Figure 5(b). Similarly, callout ring c in Figure 7(b) relates to Figure 5(c). [078] In Figure 7(c) the separate assemblies of wall parts 1 10 and 1 12 are fitted together, the smooth, continuous outer surface of part 1 12 fitting into the passage defined within part 1 12, as described above. Braces 220 are inserted transversely into part 1 12, resting against and supported by ledge 124. The braces are guided and retained against lateral movement by pairs of parallel ribs 218, vertically moulded on inner vertical surface 212 to define slots into which the braces slide until arrested by flange ledge 124.

[079] The use of the braces is optional, largely depending on the manner of fixing of the components of wall parts 1 10 and 1 12 and the choice and structural rigidity of the material of their manufacture, remembering that the frame of assembly 100 is required to hold back flowable unset concrete.

[080] Referring again to the partially exploded components diagram of Figure 4(b), a first set of braces 220 is shown ready for insertion into wall part 1 10 as described above, as suggested by the broken lined arrow D. A second set of braces 222 is shown ready for being disposed transverse to the first set. The use of the second set is also optional. The second set has a set of aligned notches (not shown) for guiding their installation on to the first set. The notches are formed in the lower surfaces 224 so that when the two sets are fitted, they define a reinforcing grid between the sides of wall portion 1 10. Weight-bearing plate 136 is placed over the reinforcing grid (where present) and rests on ledge 122, which is formed from the surfaces 182 of the corner and side sections of wall part 1 10. Fastening means such as screws 230 are used to secure the plate to the ledge. The concrete slab is then poured and allowed to set.

[081 ] As described above with reference to Figure 3(d) and (e), when the concrete slab has set, the weight bearing cover is removed, followed by the remainder of the former assembly, leaving the unlined penetration, still covered from below by the temporary plywood deck. The weight-bearing barrier is then replaced, this time on the ledge formed in the concrete slab to coincide with the ledge previously defined by surface 122 in recess 120. [082] A sealing gasket 232 is placed around the barrier plate and cover plate 138 is placed thereover and secured by mounting screws 134 into the slab.

[083] As described in Figure 3(g), the base plywood cover on which the slab is poured is removed to reveal passage 1 18. Plates 138 and 136 are removed when service conduits are ready for installation as described with reference to Figure 3(h).

[084] These embodiments merely illustrate specific, non-limiting examples of the method, kit and apparatus of the invention providing for the formation of a communications passage between spaces separated by a concrete deck. With the insight gained from this disclosure, the person skilled in the art is well placed to discern further embodiments by means of which to put the claimed invention into practice.