This invention relates to a module for forming a reinforced concrete structure and to a brace for constructing a formwork member of the module. Additionally, there is disclosed a method of constructing the formwork member of the module and a method of constructing a pre-tensioned formwork member.
When manufacturing construction modules, there is typically a large safety margin factored into each component, to safely support the structure. As a consequence, some of the additional material factored into the design becomes redundant after concrete or an alternative substrate is introduced into the formwork. Once the concrete is introduced and set, the additional material and accompanying weight penalty is maintained in the structure for life.
A limitation on the size of formwork panels further imposes weight and handling penalties on construction projects, in part due to the limitations on manufacturing of the constituent components, for example the grade, gauge, surface coatings and dimensions of steel products available.
The present invention was conceived with these shortcomings in mind.
In broad terms, the invention provides a formwork brace for interconnecting a formwork member and an internal reinforcement structure, comprising: a body configured to partially extend around the formwork member; and a plurality of connectors configured to couple together the body, the formwork member, and the internal reinforcement structure, so that in use the body ties together the formwork member and the internal reinforcement structure.
The module may further comprise a plurality of formwork braces at spaced intervals along the length of the module.
The formwork member may comprise a plurality of sections along the length of the module.
At least one of the plurality of formwork braces may be located at an intersection between successive sections. The at least one formwork brace may be located at an intersection between successive sections thereby overlapping a portion of each of the successive sections in substantially equal amounts.
The module may further comprise a plurality of the formwork braces at spaced intervals along the length of each section.
The formwork brace may comprise a body that partially extends around the formwork member and a plurality of connectors that couple together the body, the formwork member, and the reinforcement structure.
The body may comprise a base and a pair of upwardly extending legs.
The pair of legs may be substantially parallel and extend outwardly from opposing ends of the base.
The body may be configured to be U-shaped.
At least one of the connectors may be configured to extend across the formwork such that both a first and a second end of the connector is engaged in tension across the body.
At least one of the connectors may be configured to extend across the formwork such that both a first and a second end of the connector are engaged in tension across the body.
At least one of the connectors may be configured to couple the body to the internal reinforcement structure.
At least one of the connectors may be configured to extend from the body inwardly across the formwork to directly engage the internal reinforcement structure.
The formwork brace may further comprise an anchor, wherein the anchor is interleaved with the internal reinforcement structure and coupled to the body from an exterior of the formwork member. The anchor may be adjustably coupled to the body to position the formwork member relative to the internal reinforcement structure.
In some embodiments the body may be located on an exterior of the formwork. In other embodiments, the body may be located on an interior of the formwork.
In a further aspect, the invention provides a formwork brace for interconnecting a formwork member and an internal reinforcement structure, comprising: a body configured to partially extend around the formwork member; and a plurality of connectors configured to couple together the body, the formwork member, and the internal reinforcement structure, so that in use the body ties together the formwork member and the internal reinforcement structure.
In a further aspect, the invention provides a method of constructing a formwork for a settable substrate, comprising the steps of: positioning a plurality of formwork sections end-to-end such that an end portion of a first section abuts an end portion of a second section; locating a formwork brace to cradle overlapping ends of the first and second sections; inserting a reinforcement structure into a cavity formed by each of the two formwork sections; and engaging at least one connector between the formwork brace and the reinforcement structure through the first and second formwork sections .
The method may further comprise the step of tightening the connector from an exterior of the plurality of formwork sections to thereby locate the formwork sections relative to the reinforcement structure.
The method may further comprise the step of tightening the connector from an exterior of the plurality of formwork sections such that a clamping force is applied to the formwork by the formwork brace urging the first and second formwork sections together.
The method may further comprise the step of introducing a fluid concrete mixture into the cavity of the formwork sections in which the reinforcement structure is located.
The step of introducing the fluid concrete into the cavity may load the formwork, particularly the base of the formwork, thereby pulling the abutting ends of the first and second sections towards one another.
In a still further aspect, the invention provides a method of constructing a pre-tensioned formwork, the method comprising the steps of: orienting a formwork brace as described herein about an exterior of a formwork section; locating an internal reinforcement structure within a cavity of the formwork section; and engaging at least one connector between the formwork brace and the internal reinforcement structure, wherein as the at least one connector is engaged with the internal reinforcement structure, a compressive force is applied around the exterior of the formwork section, urging the formwork section towards the internal reinforcement member.
The method may further comprise the steps of: engaging a supplementary connector between two portions of the formwork brace, so that the supplementary connector extends across the formwork section; and tensioning the supplementary connector to apply a clamping force across the formwork brace, so that the formwork member is compressed about the internal reinforcement structure and the formwork brace.
Various features, aspects, and advantages of the invention will become more apparent from the following description of embodiments of the invention, along with the accompanying drawings in which like numerals represent like components.
Embodiments of the invention are illustrated by way of example, and not by way of limitation, with reference to the accompanying drawings, of which:
The invention will now be described more fully hereinafter with reference to the accompanying drawings, in which various embodiments, although not the only possible embodiments, of the invention are shown. The invention may be embodied in many different forms and should not be construed as being limited to the embodiments described below.
With particular reference to
The cross-sectional profile of the body 2 can be configured to correspond to the profile of the formwork member 10 to fit snugly thereabout.
The internal reinforcement structure 20 is located within the formwork member 10, such that the formwork member 10 provides a mould for receiving a fluid concrete mix. The concrete, as a fluid mix, will penetrate the reinforcement structure 20 whilst being retained within the formwork member 10. As the fluid concrete mix cures, the reinforcement structure 20 and formwork member 10 become integrated into a composite construction module 1 which can be used in multiple construction applications (illustrated in
The brace 100 further comprises a connector illustrated in
The dimensions of the body 2 can be varied for use with different sizes of formwork 10. A series of apertures 8 is located along the length of the body 2 for receiving bolts 12, 21 and connectors 75, 4 after the body 2 has been formed into a desired configuration.
The arms 7 extend away from the base 6, such that two apertures 8 are equidistantly spaced along the base 6 and an aperture 8 is located towards a distal end of each arm 7. Each of the apertures 8 within the arms 7 are spaced at an equal distance from the base 6, such that these apertures 8 are aligned in the folded body 2.
The anchor 4 of the brace 100 is illustrated in
The central member 3 can be a flat, planar member. In this embodiment, the central member 3 is circular in cross-section having a diameter of about 32 mm. A cylindrical central member 3 will facilitate release of any air bubbles or alternative trapped gases that can form in a concrete solution prior to curing. This can reduce the inclusions and therefore weaknesses within the cured concrete.
The central member 3 comprises two holes 9 which are threaded to receive retaining bolts 12 therein. Additional holes 9 can be introduced to receive additional retaining bolts 12. The central member 3 is about 300 mm in length, and the two holes 9 are spaced about 150 mm apart from each other. The length of central member 3 and the spacing between the two holes 9 can be varied depending on the dimensions of the brace 100 and reinforcement 20, and to vary the loading into the anchor 4. In some embodiments of the anchor 4 a single hole 9 can be used to receive a single bolt 12.
Each hole 9 is drilled to receive an M12 bolt 12. It is contemplated that larger bolts 12 can be employed or smaller bolts 12 depending on the loads to be taken by the brace 100.
The pair of legs 5 can be configured to have a cylindrical form, but are illustrated in
The legs 5 can be bolted, welded, glued or otherwise adhered to the central member 3.
The legs 5 are not connected to the body 2 of the brace 100 and act as spacers against the base 6 of the brace 100 to ensure that the formwork 10 is correctly spaced relative to the reinforcement structure 20. The legs 5 thus resist against over-tightening of the bolts 12 and maintain an ideal spatial relationship between formwork 10 and reinforcement structure 20.
The anchor 4 is located within the reinforcement structure 20 and becomes interposed between longitudinal and transverse members of the reinforcement structure 20. As the reinforcement structure 20 is introduced to the formwork 10, the anchor 4 is pivotally adjusted to align the legs 5 towards the base 6 of the body 2, in anticipation of retaining bolts 12 to tighten and lock the anchor 4 in place between the reinforcement structure 20 and the body 2 of the brace 100.
Returning to
The tie-bar mounts 70 provide central apertures 11. The apertures 11 are threaded to receive M12 securing bolts 21. The apertures 11 provide a central, internal bore 13 that is tapped, wherein the bore 13 extends into each mount 70 about 33 mm in depth.
Once the tie-bar 75 is mounted to the brace 100, and the brace is positioned to surround a formwork member 10 and internal reinforcement structure, the tie bar 75 is tightened via each mount 70 to the body 2. This allows the tie-bar 75 to be tensioned drawing the brace 100 about the formwork 10 prior to the introduction of a concrete mix.
As the brace 100 is mounted on the exterior of the formwork member 10, the securing bolts 21 are tightened from the exterior of the formwork member 10 allowing the tie-bar 75 to be tensioned in situ, extending through the reinforcement structure 20. The tightened tie-bar 75 is connected to the open ends 7a of each of the arms 7, and thereby tensions the body 2 of the brace 100 applying a load across each of the arms 7, drawing the body 2 inwardly around the formwork member 10. Accordingly, tightening the bolts of the tie-bar 75 reduces the angle α.
As illustrated in
The tie-bar 75 is bowed in the centre by a few degrees to sit flat against the arms 7 of the body 2 on the exterior surface of the formwork. The profile of the formwork 10 is also splayed at a corresponding angle of approximately 3-5 degrees to facilitate nesting of the formwork 10 for transportation.
In some embodiments the tie-bar 75 can be made from a solid bar, eliminating the need to weld or otherwise couple a pair of end mounts 70 to a central beam 71. The ends of the solid tie-bar 75 are drilled and tapped to provide the required threaded bore 13 for receiving a pair of securing bolt 21 therein.
Each mount 70 is cylindrical in shape having a diameter of about 20 mm. A threaded spacer or steel socket can be used to form each mount 70.
The tie-bar 75 has a central beam 71 that spans the pair of mounts 70. The central beam 71 can be manufactured from steel and can be formed from concrete reinforcing bar (re-bar). The rebar beam 71 can be centrally located within the mounts 70. Alternatively, the rebar beam 71 can be offset within the mounts 70 to facilitate a welded connection therebetween.
The central beam 71 is located between the pair of end mounts 70, such that the tapped bores 13 of each mount are facing outwardly in preparation for receiving securing bolts 21 to couple the tie-bar 75 across the body 2.
As the mounts 70 are internally threaded, a securing bolt 21 can be inserted into the aperture 11 and threadingly engaged with the threaded bore 13 through the co-operating apertures 8 in the body 2. This allows the body 2 to be located around the formwork 10 and internal reinforcement structure 20 therein, such that the tie-bar 75 can then be located and secured about or through the reinforcement structure 20. This arrangement also facilitates the tightening (tensioning) of the tie-bar 75 from the exterior of the formwork 10, through the body 2 of the brace 100.
With particular reference to
The reinforcement structure 20 includes an upper portion 30 that is formed to extend across the width and along the length of the cavity 63, and at least one lower portion 40 that is formed to extend at least substantially along the length of a lower section of the cavity 63, whereby when the reinforcement member 20 is located in the cavity 63 and concrete fills the cavity 63, the lower portion 40 of the reinforcement member 20 and the concrete thereby define an elongate beam 80.
As the concrete surrounds the reinforcement member 20 from all sides, the formwork 10, the reinforcement 20 and the concrete become integrated into the finished module 1. The load applied to the module 1 in receiving pourable concrete is thus reacted by both the formwork 10 and the reinforcement 20. However, when the concrete has cured thereby forming a steel reinforced concrete, composite structure, a large proportion of the module's working load is supported by the reinforcement structure 20 and the concrete. In the finished module 1, the formwork 10 is not a primary structural member and is not configured to be a load bearing structure. As such, the primary purpose of the formwork 10 is to contain the pourable concrete and to provide a mould while the concrete cures. The formwork 10 can also provide advantages in extending the curing phase of the concrete, keeping the concrete moist within the formwork 10 and thereby increasing the finished strength of the cured concrete.
Along the length of each trough segment 82 a plurality of braces 100 are equidistantly spaced.
With a plurality of braces 100 spaced and engaged along the length of the formwork 10, through to the reinforcement structure 20 therein, there is an opportunity to reduce the gauge or grade of the formwork 10 material. This can improve the overall material utilisation of each module 1 with little to no impact on the strength of the finished module 1. Further improvements in material utilisation will be enabled for embodiments of the module where each of the plurality of braces 100 are directly engaged with the stiffening plate 86, together forming an exoskeleton to the module. The exoskeleton of braces 100 and stiffening plate 86 allow localised and tailored stiffening of the formwork 10 in selective areas, thus facilitating a reduction in material thickness (gauge) or strength across the entire formwork 10.
Along the length of formwork 10 a joint seam 14 is illustrated in
As the module 1 increases in size (length and/or width) the weight distribution of the module 1 changes as does the manner in which loads on the module 1 are reacted. For example, if a module 1 is intended to take high loads in use, the amount of reinforcement in the reinforcement structure 20 can be increased; the grade of the steel used in the formwork member 10 can be increased, the amount of concrete and subsequently, the depth of the trough segments 82 can be increased etc. An engineer will consider each of the above options and the design criteria to assess which is the best solution for a given structure 110. A limitation on these design options is the sizing of sheet steel available for forming the formwork member 10. While the reinforcement structure 20 can be fabricated to any desired size, and the volume of concrete is essentially limitless, the manufacturing capabilities that limit sheet steel production cannot be so easily overcome.
To reduce the impact of this limitation on the module 1, the brace 100 provides a connection means for bringing together and cradling multiple trough segments 82 to form a single formwork member 10. By coupling multiple trough segments 82 together, the limitation imposed by sheet steel sizes can be minimised.
The braces 100 illustrated in
The tie-bar 75 described herein can be used to tension (i) across each trough segment 82 and at various positions along the length, and (ii) between abutting trough segments 82. This reduces the opportunity for any fluid concrete to seep between adjacent trough segments 82 prior to curing.
The intermediate connector 17 couples an outer side wall 18 of the trough segment 82 to an inner side wall 19 of the trough segment 82 and is not coupled through a brace 100. As such the intermediate connector 17 is tensioned (and is loading) across the trough segment 82 only. Where increased working load is required in the module 1, additional braces 100 can be used to couple the intermediate connectors 17, thereby increasing the working load of the module 1.
The module 1 is designed to use 40 MPa concrete, by way of example, which is readily available. This is also a suitable concrete for the formation of abutments with which to support the modules 1, in constructing the structure 110.
Illustrated in
The trough segments 82 are roll formed or pressed from galvanized steel to form a U-shaped section. Each trough segment 82 extends from about 1.2 m to approximately 3 m in length. Each 3 m trough typically weighs about 100 kg. The periphery of the U-section has two opposing horizontal flanges 83a, 83b. An outer flange 83a is configured to engage the side structure on an outer side of the module 1 and an inner flange 83b is configured to engage and support the stiffening plate 86. The depth of each trough segment 82 can be adjusted to provide additional strength and bending resistance depending on the desired span of the bridge and/or load capacity of the structure 110.
The stiffening plate 86 is mounted on opposing sides to the flanges 83b of the two rows of trough segments 82. The stiffening plate 86 can be welded, riveted, bolted or bonded to the troughs to form a W-section. Along a base 36 of each of the trough segments 82 are disposed a plurality of holes (not illustrated) for inserting retaining bolts 12 to be threadingly received by the central member 3 of the anchor 4. This arrangement facilitates the insertion of the reinforcement structure 20 into the trough sections 82, before the retaining bolts 12 are inserted into the anchor 4 to anchor the trough base 36 to the reinforcement structure 20. In this manner the reinforcement structure 20 adds to the stiffness of the formwork 10 before concrete is introduced to bond the two together.
The two end caps 84 are roll-formed or pressed to form a mounting flange 85. These end caps 84 are then welded, riveted, bolted or bonded to the trough segments 82 and stiffening plate 86 to complete the formwork 10. It is contemplated that additional rows of trough segments 82 can be used to construct the formwork 10, such that two, three, four or even five rows of trough segments are interconnected with stiffening plates 86, each configured to receive a portion of the reinforcement structure 20 and thereby create up to five elongate beams 80 across the module 1.
The reinforcement member 20 is constructed from the upper reinforcement 30 and the lower reinforcement 40.
The upper portion 30 is formed from a double layer of mesh, illustrated in
The lower reinforcement member 40 received within the trough segments 82 is comprised of a plurality of frames 41, 41′, 41″ that form a truss 42.
Each frame 41, 41′, 41″ comprises an upper longitudinal member 44a and a lower longitudinal member 72a and an intermediate member 46 that traverses back and forth between the pair of longitudinal members 44a, 72a.
The intermediate member 46 extends diagonally between the pair of longitudinal members 44a, 72a to structurally reinforce, and stiffen the frame 41. The intermediate member 46 is permanently engaged with the longitudinal members 44a, 72a at multiple connection points along the length of the frame 41. The engagement member 46 can be bolted, or welded to the longitudinal members 41. From a side view of the frame 41, the intermediate member 46 defines a sinusoidal waveform traveling along the length of the frame 41.
Each frame 41 is arranged in spaced relationship across the lower portion 40 of the reinforcement member 20.
The reinforcement structure 20 can be fully constructed and rigorously tested to structural and safety standards to be certified independently of the formwork member 10. The testing can be carried out away from the construction site, meaning that the reinforcement structure 20, once installed in the formwork member 10 need not be certified or tested further. The mixing and integrity of the concrete are the only variables to be managed at the installation site. This can be advantageous, where a structure 110 is to be constructed in a remote location that is hard to reach or in an area where architects and other qualified professionals are in short supply for certification purposes.
As each frame 41 is comprised of a pair of outer longitudinals 44a, 72a and an intermediate member 46, the strength of the frame 41 is not constant along its length.
To rectify this varying strength along the length of the frame 41, 41′, 41″ the intermediate member 46 of each frame is displaced relative to an adjacent frame 41, 41′, 41″. In this manner the strength of the overall truss 42 is more consistent.
The reinforcement structure 20 can be jigged for dimensional tolerance and control of the fabrication and assembly process. The finished reinforcement structure 20 will be tested and certified before being dispatched to the structural 110 installation sites.
As the concrete cures around the reinforcement structure 20 binding it to the formwork member 10, the anchor 4 and tie-bar 75 of each brace 100 become affixed within the module 1.
When fabricating the reinforcement structure 20 the trusses 42 and frames 41 can be positioned or temporarily affixed to a jig in order to set the dimensional tolerances of the overall reinforcement structure 20. It is further contemplated that the jig can be configured such that the finished reinforcement 20 is pre-tensioned as it is fabricated. When removed from the jig or fixture, the reinforcement structure 20 will remain pre-tensioned when placed in position within the formwork member 10. This will ultimately provide a pre-tensioned module 1 from which to construct a structure 110.
The reinforcement structure 20 can be transported to the structure 110 installation location in isolation or in combination with the formwork members 10. The two components (reinforcement 20 and formwork 10) are designed to cooperate with one another and as such, nest well for transportation when shipped from a single manufacturing source.
As described above, each module 1 provides a form of integrated truss 42 within each module 1. The formwork member 10 is light and transportable, thus reducing transport costs. Once in situ, the reinforcement member 20 is combined with the formwork member 10 and located therein. Once both the formwork member 10 and the reinforcement 20 are in position the connections to the brace 100 are secured; the retaining bolts 12 are driven through the base 36 of the trough segments 82 to connect with adjacent anchors 4 and thereby set the reinforcement structure 20 relative to the formwork 10, and the tie-bars 75 are threaded through the reinforcement structure 20 to tension the arms 7 of each brace 100. At this time, concrete in pourable form is added into the formwork tray 10 to surround the reinforcement structure 20 and complete the module 1. The concrete as it cures and sets, integrates the reinforcement structure 20 and the braces 100 into the formwork member 10, thereby strengthening the module 1.
The truss 42 of
Illustrated in
A ligature reinforcement 78 is wound around the truss 42 constraining the frames 41 from separating from one another under load. These ligatures 78 are peripheral to the truss 42 and are repeated at spaced intervals along the length of the truss 42.
The member 72a is of a greater cross section to that of both the ligature 78 and a central brace beam 76. The member 72a is between 30-50 mm in diameter. In contrast the ligature 78 and central brace beam 76 are between 10-20 mm in diameter. It is contemplated that these secondary supports are made from steel or similar high tensile material.
In
A cross-section through a trough segment 82 is illustrated in
When at rest on the ground, the anchor limits upward movement through 72b. When the reinforcing is supporting the weight of the formwork and/or concrete, the anchor supports the formwork by being caught by 72a. The anchor 4, and thus the formwork 20 is held up by the lower longitudinal members 72a against the underside of the central member 3 to set the gap between the base 36 of the trough segment 82 and the reinforcement structure 20.
In
The elongate, spiralling shank 59 of the ringtail bolt 54 allows the bolt to be twisted into engagement with the longitudinal member 72c. The ringtail bolt 54 can be threaded in between the members of the reinforcement structure 20 and twisted into engagement with a selected member. Once the shank 59 is encircling the desired member (72a, 72b, 72c) the threaded end 37 of the ringtail bolt 54 is coupled to the end 58b of the mount 58. A securing bolt 21 is inserted into the mount end 58a from an external side of the brace 100 and formwork member 10, and tightened to tension the ringtail bolt 54 tightening the brace 100 around the reinforcement structure 20 and formwork member 10.
The hook 55 is elongate and planar. The hook 55 provides a mounting hole 57 at an end proximate the brace 100, to receive and capture a securing bolt 21. At a distal end of the hook 55 is a circular aperture 56 for receiving a longitudinal reinforcement member 72c. The mounting hole 57 and the circular aperture 56 are located on planes substantially perpendicular to one another. The hook 55 acts as a spacer between the formwork 10 and the reinforcement structure 20, locating the two, prior to the introduction of concrete thereto.
An enlarged view of circle G from
The brace 100 can be used to support blocks (not illustrated) within the cavity 63, such that voids are formed in the concrete as it cures. These blocks can be made of light weight material for example, foam or plastic, such that the overall weight of the finished module 1 is reduced. The support blocks can be positioned at locations within the module where module strength is not affected by the reduction in localised concrete volume.
This facilitates transport of the modules 1 over great distances. The reinforcement 20 is protected by both the shipping container and the formwork members 10. Furthermore, the available resources for transporting shipping containers, whether by sea or by land, can be easily applied to the transportation of modules 1. Packing the modules 1 into a container facilitates transport and handling of the modules 1, resulting in significant transport cost savings and enabling the modules 1′ to have a global reach. After the modules 1 arrive at the construction location, the modules 1 are manoeuvred into their predetermined positions, ready to receive the wet concrete mix.
It is contemplated that each of the frames 41 can be sold in kit form, to provide for assembly in a secondary location, after manufacture. This provides flexibility and packaging advantages for shipping and transportation of the frames to a location where the reinforcement structure 20 is to be constructed.
It is further contemplated that each trough segment 82 and each brace 100 can also be sold and delivered in a kit form to allow local tradesmen and local manufacturing to construct these components. In this manner, local economies can benefit from being involved in the construction process, not only stimulating local industry but investing local people in the construction and final structure 110.
The tie-bar 75 is illustrated having a central beam 71 comprising rebar. The end mount 70 comprises a metal socket, to which the central beam 71 has been welded. The mount 70 further comprises a washer 74 disposed between the socket and the formwork 10 to more evenly spread the load onto the formwork 10.
Extending approximately centrally behind the washer is the joint 14 between the two adjacent trough segments 82. The joint 14 can be seen where the two adjacent trough segments 82 touch along their bases 36, however, a gap 87 is illustrated where the joint 14 reaches the upper flange 83 of the formwork 10. As the concrete mix is added to the formwork 10, the weight of the concrete mix is reacted through the bases 36 of the trough segments 82 of the formwork 10. This load is applied across the base of the module 1, which pulls the central trough segments 82 downwards, pulling together the gap 87 as the formwork 10 is filled. Once the concrete cures and the module 1 is completed, the gaps 87 between adjacent trough segments 82 have been closed, sealing the formwork member 10.
The module 1 is standardised, pre-engineered and pre-certified, and as such can be mass-produced off-site. It can then be transported globally within a shipping container, and stored in a depot for rapid deployment to maintain efficient construction timelines, and for emergencies. The product is designed to use locally available resources such as lightweight cranes and easily-available concrete (N40 strength). The bridge 100 further provides a multitude of structural and logistical advantages. As the stacked formwork 10 and reinforcement 20 do not contain concrete during transport, they are light and relatively easy to manoeuvre when compared to standard precast concrete panels. The combined weight of a formwork 10 and reinforcement 20 can vary widely from 1000 kg to 10,000 kg (10 tonnes) depending on the size of the structure, the reinforcement and the configuration of the braces. A standard 12m span formwork 10 and reinforcement 20 will weigh ˜4200 kg, where an equivalent precast concrete panel weighs ˜26000 kg. This weight saving simplifies the distribution and installation requirements, and the associated costs, as all the required moving machinery (side-loader container trucks, etc.) is more readily available for handling lighter loads.
Concrete for the module 1 is added in a single pour, creating one homogeneous slab and eliminating longitudinal joins across the length and/or the width of the module 1. This has major structural advantages and increases confidence in the module durability and lifespan. For example, it eliminates longitudinal joins, particularly undesirable ‘dry joins’ which occur when filling in the gaps between precast panels with wet concrete; and the single large mass of concrete can better resist braking inertia, which is particularly important for large freight trucks.
In some embodiments, for example having spans of more than 13.7m, two pours of concrete may be used—the first pour covering the beams, then after the concrete reached a predetermined strength, the deck is poured. This advantage is more relevant to the structure 110, made of multiple modules 1, where the concrete is poured into all modules at the same time, creating a homogeneous slab (regardless of whether there are more than one concrete pour).
In this manner the module 1 construction maintains many of the benefits of precast construction with the additional advantages of off-site manufacturing, standardisation, quality control and time savings, while reducing the transportation and cost limitations inherent to the precast construction method. It also eliminates the possibility of fractural cracking of the concrete during transport, which is a serious risk for precast panels.
The module 1 use pre-certified designs, reducing the need for on-site engineers. Additionally, the reduction in on-site skills required makes it easier to source the required labour locally. This construction method is particularly attractive for remote areas, such as mines, where transporting precast slabs is not a viable or economical option, and there are limited skilled resources for in situ construction.
A support wing 45 disposed on an underside of the module 1 is illustrated in
The support wing 45 is employed in combination with a formwork extension 65 to increase the overhang of at least one side of the module 1. This may provide advantages in facilitating an increase in the usable width of the module 1 without the expense of a subsequent module 1. In some embodiments a formwork extension 65 can be located on opposing sides of the module 1 in combination with support wings 45 on opposing sides of the module 1 to provide a symmetrical overhang on opposing sides of the module 1.
The formwork extension 65 is an L-shaped member comprising two arms 65a and 65b. The first arm 65a is positioned substantially horizontally to effectively extend the outer flange 83a of the trough segment 82 outwardly away from the formwork 10. The second arm 65b is positioned substantially vertically to accommodate the predetermined depth of upper reinforcement 30 to be incorporated into the module 1. The formwork extension 65 may further comprise a lip 65c. The lip 65c extends along the perimeter of the formwork extension and is angled inwardly and downwardly into the cavity 63 of the module 1. In this manner, the lip 65c assists in restraining the pourable substrate while curing. Furthermore, the lip 65c is obscured from view when the pourable substrate cures in the module 1, and does not protrude outwardly therefrom. Various additional forms of formwork extension 65 can be used, depending on the desired side profile to the module 1. In some embodiments the formwork extension can extend sufficiently above a top surface 25 of the module 1, to provide a railing or side barrier (not illustrated) to the edges of the module.
The upper plate 45a of the wing 45 is located adjacent to the outer flange 83a of the trough segment 82 such that the upper plate 45a is substantially parallel and contiguous with at least a portion of the first arm 65a of the formwork extension 65. The upper plate 45a and the first arm 65a can be adhered to one another via chemical bonding agents or alternatively can be welded, riveted, or bolted (as shown in
The lower plate 45b of the support wing 45 extends downwardly towards the base 36 of the trough segment 82 and forms a hypotenuse with the outer side wall 18 of the trough segment 82 and the first arm 65a of the formwork extension 65, thereby distributing load from the top surface 25 of the module 1 downwardly into the trough segments 82 and the internal reinforcement structure 20 therein.
The support wing 45 is contemplated to have a thickness of about 5 mm; however, this can be varied up or down depending on the extension dimensions and the load carrying requirements of the extended module 1. Each plate of the support wing 45 is about 50 mm in length; however, these plates can be reduced or extended to support the desired overhang to the module 1.
The support wing 45 is configured to not extend all the way to the base 36 of the trough segment 82 or to extend all the way to the second arm 65b of the formwork extensions 65. By stopping the support wing 45 short of the extremities of the module 1 by about 50 mm, the support wing does not affect the aesthetics of the module 1 or provide unnecessary snagging protrusions around the perimeter of the module 1.
In some embodiments the second arm 65b of the formwork extension 65 is configured to support an intermediate connector 17 therethrough to connect the formwork extension 65 to the upper reinforcement 30 of the reinforcement structure 20. A plurality of intermediate connectors 17 can be used around the upper reinforcement 30 and can be tightened to pre-tension the top surface 25 of the module 1 prior to the introduction of concrete or alternative pourable substrate into the cavity 63 of the module 1.
In a second aspect of the invention, a formwork brace 100′ is configured integrally by a pair of overlapping ends of two adjacent troughs 82, 82′ as illustrated in
A second opposing end of the trough 82 has a crimped end 89, where the material of the trough 82 is folded over on itself to form a double material thickness at the second end of the trough 82. The crimped end 89 has a width of about 75 mm-100 mm.
When the two segments 82 are brought together, the flanged end 88′ of one segment 82′ receives the crimped end 89 of the adjacent segment 82. Three-ply of material is then overlapped, one-ply from the flanged end 88′ and two-ply from the crimped end 89, forming an integrated brace 100′ between the two, overlapping segment 82, 82′ having a material thickness of three times the base material of the segments 82, 82′.
Also illustrated in
The person skilled in the art will appreciate that the size of module 1, span of the module 1 and function of the module 1 will dictate the strength required in the finished module 1. As such, the ability to increase the strength of the brace 100′ by incorporating additional thicknesses of material will allow for more tailored, and localised reinforcement to the module 1. The tailoring of material only where needed, as opposed to increasing the gauge of the material throughout all the segments 82, 82′, should provide overall mass savings and improved material utilisation for the finished module 1.
Each of the segments 82, 82′ can be formed in 3-metre-long sections. Alternatively, each of the segments 82, 82′ can be formed in 2 metres, or 1 metre sections, making them easier to form, easier to handle, easier to transport and removing manufacturing limitations from the size of the tooling required to form each section. This can open up new manufacturing opportunities and further modularise the production of each module 1.
Also illustrated in
It will be appreciated by persons skilled in the art that numerous variations and modifications may be made to the above-described embodiments, without departing from the scope of the following claims. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although any methods and materials similar or equivalent to those described herein can also be used in the practice or testing of the present invention, a limited number of the exemplary methods and materials are described herein.
It is to be understood that, if any prior art publication is referred to herein, such reference does not constitute an admission that the publication forms a part of the common general knowledge in the art, in Australia or any other country.
In the claims which follow and in the preceding description of the invention, except where the context requires otherwise due to express language or necessary implication, the word “comprise” or variations such as “comprises” or “comprising” is used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention.
Number | Date | Country | Kind |
---|---|---|---|
2018200667 | Jan 2018 | AU | national |
Filing Document | Filing Date | Country | Kind |
---|---|---|---|
PCT/AU2019/050063 | 1/29/2019 | WO | 00 |