Formwork assembly and method for preparing a cast reinforced concrete structure

Abstract

The present invention provides a formwork assembly and method for preparing a cast reinforced concrete structure that can be reused for multiple castings and which provides a highly reproducible final cast product.

Description

FORMWORK ASSEMBLY AND METHOD FOR PREPARING A CAST REINFORCED CONCRETE STRUCTUREFIELD OF THE INVENTION

[0001] The present invention pertains to the field of prefabricated buildings and in particular to reinforced concrete modular structures.BACKGROUND

[0002] WO 2018 / 174825A1 discloses a method for constructing a pre-fabricated pre-finished volumetric construction (PPVC) module for a building, the method comprising: (i) casting of concrete to form a body of the PPVC module, where the body of the PPVC module comprises one or more load-bearing columns and beams, and six walls including a roof that covers a top of the PPVC module; and (ii) substantially finishing an interior of the PPVC module before the PPVC module is transported to a site for assembly into a building.

[0003] US3568380 discloses a prefabricated building unit consisting of a prefabricated rectangular floor panel structure having prefabricated vertical load-bearing columns for attachment at each corner and at an intermediate region in the length of each side.

[0004] EP3498929A1 discloses a building module with a cuboid housing formed from a stackable, monolithic tubular body consisting of a concrete material, the four tubular walls of which form the floor, the ceiling and the side walls, wherein the door and the window are provided in the end walls.

[0005] This background information is provided to reveal information believed by the applicant to be of possible relevance to the present invention. No admission is necessarily intended, nor should be construed, that any of the preceding information constitutes prior art against the present invention.SUMMARY OF THE INVENTION

[0006] An object of the present invention is to provide a formwork assembly and method for preparing a cast reinforced concrete structure. In accordance with an aspect of the present invention, there is provided a formwork assembly for preparing a cast reinforced concrete structure comprising a horizontal slab having a quadrilateral shape, an upper surface and a lower surface, four corner columns, each corner column extending downwardly from a respective corner of the horizontal slab, perimeter beams extending between the corner columns and downwardly along the peripheral edges of the slab, the formwork assembly being convertible between a pour configuration and a release configuration, the assembly comprising: a first fixed longitudinal side formwork having a first end and a second end and having a longitudinal support surface extending along an inner surface; a first end formwork and a second end formwork, each end formwork having first and second ends and two support frames located on an inner surface of the respective end formworks, the support frames having an upper surface, wherein the first and second end formworks are each independently movable between the pour configuration and the release configuration; a second longitudinal side formwork comprising a central panel and first and second hinged panels each located at opposing ends of the central panel, and having a longitudinal support surface extending along an inner surface; a support system configured to fit within the space defined by the first and second longitudinal side formworks and first and second end formworks; and an internal formwork configured to rest on the support system, wherein the upper surface of the internal formwork defines the shape of the lower surface of the horizontal slab, wherein outer peripheral faces of the internal formwork define the inner faces of the perimeter beams. In the pour position, the first end of the fixed side formwork abuts the first end of the first end formwork; the second end of the fixed side formwork abuts the first end of the second end formwork; the second end of the first end formwork abuts the first hinged panel of the second longitudinal side formwork; and the second end of the second end formwork abuts the second hinged panel of the second longitudinal side formwork; and in the release configuration, the first and second hinged panels are moved into an open position; and each of said first and second end formworks is moved away from the first and second ends of the fixed side formwork, respectively.

[0007] In accordance with another aspect of the present invention, there is provided a method for preparing a cast reinforced concrete structure comprising a horizontal slab having aquadrilateral shape, an upper surface and a lower surface, four corner columns, each corner column extending downwardly from a respective corner of the horizontal slab, perimeter beams extending between the corner columns and downwardly along the peripheral edges of the slab, the method comprising the steps of: providing an assembled formwork assembly in accordance with the present invention, wherein the formwork assembly is in the pour configuration; providing four column cages, each said column cage being located at a respective corner of the formwork assembly; providing two longitudinal perimeter beam cages, each said longitudinal perimeter beam cage extending between respective column cages along the longitudinal edges of the formwork assembly; providing two end perimeter beam cages, each said end perimeter beam cage extending between respective column cages along the end edges of the formwork assembly; tying the column cages, the longitudinal perimeter beam cages and the end perimeter beam cages to form an assembled rebar core structure; pouring the concrete into the assembled formwork; and curing the poured concrete to form the cast reinforced concrete structure.BRIEF DESCRIPTION OF THE FIGURES

[0008] Fig. 1 illustrates a perspective view of a formwork assembly in accordance with an embodiment of the present invention, in the pour configuration.

[0009] Fig. 2 illustrates a perspective view of a formwork assembly in accordance with an embodiment of the present invention, in the release configuration with a raised core frame.

[0010] Fig. 3 illustrates a perspective view of a formwork assembly in accordance with an embodiment of the present invention, in the release configuration with a lowered core frame.

[0011] Fig. 4 illustrates a perspective view of a formwork assembly in accordance with an embodiment of the present invention, after release of the cast reinforced concrete structure.

[0012] Fig. 5 illustrates a side view of an end formwork suitable for use in a formwork assembly in accordance with an embodiment of the present invention.

[0013] Fig. 6A and 6B illustrate a side view of an end support frame suitable for use in a formwork assembly in accordance with an embodiment of the present invention, in extended and collapsed positions, respectively.

[0014] Fig. 7 illustrates a side view of a side formwork suitable for use in a formwork assembly in accordance with an embodiment of the present invention.

[0015] Fig. 8A and 8B illustrate a side view of a longitudinal support frame suitable for use in a formwork assembly in accordance with an embodiment of the present invention, in extended and collapsed positions, respectively.

[0016] Fig. 9 illustrates a perspective view of an internal formwork on a core frame suitable for use in a formwork assembly in accordance with an embodiment of the present invention, in the raised position.

[0017] Fig. 10 illustrates a perspective view of an internal formwork on a core frame suitable for use in a formwork assembly in accordance with an embodiment of the present invention, in the lowered position.

[0018] Fig. 11 illustrates a perspective view of a column cage suitable for use in a formwork assembly in accordance with an embodiment of the present invention.

[0019] Fig. 12 illustrates a perspective view of a cast reinforced concrete structure in accordance with an embodiment of the present invention.

[0020] Fig. 13 illustrates a perspective view of a formwork assembly in accordance with an alternative embodiment of the present invention, in the pour configuration.

[0021] Figs. 14 and 15 illustrate perspective views of column jacket components in open and closed configurations, respectively, in accordance with an alternative embodiment of the present invention.

[0022] Fig. 16 illustrates a perspective view of a formwork assembly in accordance with an alternative embodiment of the present invention, in the release configuration.

[0023] Fig. 17 illustrates a perspective view of a formwork assembly in accordance with an alternative embodiment of the present invention, in the pour configuration after a concrete structure has been cast.

[0024] Fig. 18 illustrates a perspective view of a formwork assembly in accordance with an alternative embodiment of the present invention, in the release configuration after a concrete structure has been cast.

[0025] Fig. 19 illustrates a perspective view of a formwork assembly in accordance with an alternative embodiment of the present invention, with the internal formwork in a lowered position after a concrete structure has been cast.

[0026] Figs. 20 and 21 illustrate perspective views of the connector components suitable for use in stacking respective cast reinforced concrete structures, in accordance with an embodiment of the present invention.

[0027] Fig. 22 illustrates a perspective view of the lifting components suitable for use in lifting cast reinforced concrete structures, in accordance with an embodiment of the present invention.

[0028] Fig. 23 illustrates a cross-sectional detail of the lifting components, in accordance with an embodiment of the present invention.

[0029] Figs. 24 and 25 illustrate the cross-sectional profiles of a horizontal slab of a cast reinforced concrete structure in accordance with an embodiment of the present invention.

[0030] Fig. 26 illustrates an alternative formwork assembly 300 in accordance with an embodiment of the present invention, in the pour configuration.

[0031] Fig. 27 illustrates an alternative formwork assembly 300 in accordance with an embodiment of the present invention, in a first release stage.

[0032] Fig. 28 illustrates an end formwork assembly 330 in an open, pouring configuration, in accordance with an embodiment of the present invention.

[0033] Fig. 29 illustrates an end formwork assembly 330 in a collapsed, release configuration, in accordance with an embodiment of the present invention.

[0034] Fig. 30 illustrates an alternative formwork assembly 300 in accordance with an embodiment of the present invention, in a second release stage.

[0035] Fig. 31 illustrates an alternative formwork assembly 300 in accordance with an embodiment of the present invention, in a third release stage.

[0036] Fig. 32 illustrates an alternative formwork assembly 300 in accordance with an embodiment of the present invention, in a fourth release stage.

[0037] Fig. 33 illustrates an alternative formwork assembly 300 in accordance with an embodiment of the present invention, in a fifth release stage.

[0038] Fig. 34 illustrates further alternative formwork assembly 400 in accordance with an embodiment of the present invention, in a pour configuration.

[0039] Fig. 35 illustrates further alternative formwork assembly 400 in accordance with an embodiment of the present invention, after a concrete structure has been cast.

[0040] Fig. 36 illustrates further alternative formwork assembly 400 in accordance with an embodiment of the present invention, in a release configuration.

[0041] Fig. 37 illustrates further alternative formwork assembly 400 in accordance with an embodiment of the present invention, in the process of removing the cast concrete structure.

[0042] Fig. 38 illustrates further alternative formwork assembly 400 in accordance with an embodiment of the present invention, in the configuration of Fig. 37, with cast concrete structure removed.

[0043] Fig. 39 illustrates a side view of formwork assembly 400 in accordance with an embodiment of the present invention.

[0044] Fig. 40 illustrates an end view of formwork assembly 400 in accordance with an embodiment of the present invention.DETAILED DESCRIPTION OF THE INVENTION

[0045] As used herein, the term “about” refers to a + / -10% variation from the nominal value. It is to be understood that such a variation is always included in a given value provided herein, whether or not it is specifically referred to.

[0046] 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.

[0047] The present invention provides a formwork assembly for preparing a cast reinforced concrete structure that can be reused for multiple castings and which provides a highly reproducible final cast product.

[0048] In a preferred embodiment, the concrete structure formed using the formwork assembly of the present invention comprises a horizontal slab having a quadrilateral shape, an upper surface and a lower surface, four corner columns, each corner column extending downwardly from a respective corner of the horizontal slab, and perimeter beams extending between the corner columns and downwardly along the peripheral edges of the slab. In a preferred embodiment, the formwork assembly is convertible between pour and release configurations.

[0049] The formwork assembly comprises a first and second longitudinal side formworks and first and second end formworks. In one embodiment, the first and second longitudinal side formworks each have a longitudinal support surface extending along an inner surface and the first and second end formworks each have an end support surface extending along an inner surface.

[0050] In one embodiment, the first longitudinal side formwork is a fixed longitudinal side formwork. In one embodiment, the second longitudinal side formwork is formed from a central panel and first and second hinged panels each located at opposing ends of the central panel.

[0051] The formwork assembly also comprises an internal formwork configured to rest on a support system. In a preferred embodiment, the upper surface of the internal formwork defines the shape of the lower surface of the horizontal slab, and the outer peripheral faces of the internal formwork define the inner faces of the perimeter beams.

[0052] In a preferred embodiment, the first and second end formworks are movable between the pour configuration and the release configuration. In one embodiment, the assembly further comprises a rail system configured to move the first and second end formworks between the pour and release configurations.

[0053] The first ends of the longitudinal side formworks abut the respective ends of the first end formwork, and the second ends of the side formworks abut the respective ends of the second end formwork in the pour configuration. In the release configuration, each of the first and second end formworks is moved away from the ends of the longitudinal side formworks, respectively.

[0054] In one embodiment, the formwork assembly further comprises a support system to support the internal formwork during the pouring process. The support system is configured to fit within the space defined by longitudinal fixed side formwork and end formworks.

[0055] In one embodiment, the support system comprises comprising a support framework that supports a support platform. In one embodiment, the support framework is mounted on a concrete base.

[0056] In an alternative embodiment, the support system comprises a support truss framework. In this embodiment, the support truss sits on a concrete base.

[0057] In further alternative embodiment, the support system comprises a formwork assembly comprises a core frame, wherein the core frame can be raised and lowered between the pour and release configurations.

[0058] In the alternative embodiment in which the support system is provided by a core frame, the core frame is moved out of the space defined by the longitudinal fixed side formwork and first and second end formwork. In this embodiment, a rail system is provided to move the core frame outside the space defined by the side formwork and first and second end formworks after the concrete structure has been cast. In one embodiment, the core frame is further configured to be lowered to release the cast concrete structure when in the release configuration.

[0059] In this embodiment, the formwork assembly comprises a movable longitudinal side formwork attached to the core frame. In one embodiment, each of the first and second end formworks further comprises a hinged formwork panel configured to abut the end of the movable longitudinal side formwork when in the pour configuration.

[0060] In one embodiment, each of the first and second end formworks comprises an end support frame located on the inner surface of the end formworks, wherein the upper surface of the end support frame forms the end support surface, and wherein end support frames are movable between a collapsed position and an extended position.

[0061] In one embodiment, the support frame is formed from two L-shaped support frames which are moveable between extended and collapsed positions.

[0062] In an alternative embodiment, the end support frame is formed of three components: two outer frames and an inner frame. The inner frame is slidably movable in an up / down direction, between a raised position and a lowered position. In one embodiment, when the inner frame has been lowered, the two outer frames are allowed to collapse / move in an inward direction, allowing the cast reinforced structure to be released.

[0063] In one embodiment, the longitudinal side formworks comprise a longitudinal support frame located on the inner surface of the side formwork, wherein the upper surface of the longitudinal support frame forms the longitudinal support surface. In this embodiment, the longitudinal support frame is movable between a collapsed position and an extended position. In one embodiment, the longitudinal support frame is formed of four components: two outer frames and two inner frames. The inner frames are slidably movable in an up / down direction, between a raised position and a lowered position. When the inner frames have been lowered, the two outer frames are allowed to collapse / move in an inward direction, allowing the cast reinforced structure to be released.

[0064] In accordance with the present invention, there is provided a method for preparing a cast reinforced concrete structure using the formwork assembly of the present invention. In one embodiment, the method comprises the steps of providing an assembled formwork assembly in the pour configuration, four column cages located at a respective corner of the formwork assembly, two longitudinal perimeter beam cages extending between respective column cages along the longitudinal edges of the formwork assembly, and two end perimeter beam cages extending between respective column cages along the end edges of the formwork assembly. Once the cages are in place, they are tied to form an assembled rebar core structure. After therebar core structure has been assembled, concrete is poured into the assembled formwork and the resulting concrete structure is allowed to cure to form the cast reinforced concrete structure.

[0065] In one embodiment, the formwork assembly is assembled by moving the first and second end formworks into position abutting the first and second ends of the longitudinal side formwork and bolting the end formworks to the respective ends of the side formwork.

[0066] In one embodiment, the support system and internal formwork are located in the space defined by the longitudinal side formworks and end formworks such that the internal formwork abuts the longitudinal support surface of the longitudinal side formwork and the upper surface of the support frames of the end formworks. In this manner, the upper surfaces of the support frames and support surfaces form the moulding surfaces that define the lower surfaces of the perimeter beams of the cast concrete structure.

[0067] In an alternative embodiment, the internal formwork comprises a horizontal flange extending around the bottom periphery of the internal formwork, wherein the flange of the internal formwork rests on the longitudinal support surface of the side formworks and the end support surfaces of the first and second end formworks, and the upper surface of the horizontal flange defines the bottom faces of the perimeter beams.

[0068] In the embodiment employing the core frame as support system, the core frame and internal formwork are moved into the space defined by the longitudinal fixed side formwork and first and second end formworks such that the internal formwork abuts the upper surface of the longitudinal support frame forms and the upper surface of the end support frame forms. In one embodiment, horizontal flange on the internal formwork rests on the upper surface of the longitudinal support frame forms and end support frame forms. Each of the hinged formwork panels is moved to the closed position to abut the respective ends of the movable longitudinal side formwork and the hinged formwork panels are bolted to the movable longitudinal side formwork.

[0069] After the cast reinforced concrete structure has completed the curing process, the formwork assembly is moved to the release configuration. In one embodiment, the formwork assembly is moved to the release configuration to facilitate removal of the cast reinforcedconcrete structure by: unbolting the first and second end formworks from the side formwork, and unbolting and opening the hinged formwork panel.

[0070] In one embodiment, after the formwork has been moved to the release configuration and the cast concrete structure has been released from the formwork, it is lifted up and out of the formwork using a crane or similar lifting mechanism.

[0071] In the embodiment employing a moveable core frame, the core frame is raised to lift the internal formwork off the upper surface of the longitudinal support frame forms and the upper surface of the end support frame forms to relieve pressure from the formworks. After the pressure on the formworks has been relieved, the longitudinal support frame forms and the end support frame forms are moved into their collapsed configuration. After the longitudinal and end support frame forms are in the collapsed configuration, the first and second end formworks are moved away from the cast reinforced concrete structure. In one embodiment, the formworks are moved on a rail system.

[0072] In one embodiment, the core frame and the internal formwork are moved out of the space defined by the longitudinal fixed side formwork and first and second end formworks. In one embodiment, the core frame is moved on a rail system.

[0073] In this embodiment, the core frame, the internal formwork and the movable longitudinal side formwork are then moved away from the cast reinforced concrete structure to release the cast reinforced concrete structure. Once the cast structure has been released, the core frame and the internal formwork are returned to the space defined by the longitudinal fixed side formwork and first and second end formworks.

[0074] The invention will now be described with reference to specific examples. It will be understood that the following examples are intended to describe embodiments of the invention and are not intended to limit the invention in any way.

[0075] Fig. 1 depicts formwork assembly 100 in the pour configuration. Formwork assembly 100 includes fixed longitudinal side formwork 20 and first and second end formworks 30A, 30B. As shown, in the pour configuration, one end of fixed side formwork 20 abuts the edge of first endformwork 30A, and the other end of fixed side formwork 20 abuts the edge of second end formwork 30B.

[0076] Formwork assembly 100 also includes core frame 50 configured to fit within the space defined by longitudinal fixed side formwork 20 and end formworks 30A, 30B. Formwork assembly 100 also includes internal formwork 60 configured to rest on core frame 50. As shown in Fig. 1, the upper surface of internal formwork 60 defines the shape of the lower surface of the horizontal slab of the concrete cast structure (not shown), and the outer peripheral faces of internal formwork 60 define the inner faces of the perimeter beams of the concrete cast structure. Internal formwork 60 also includes movable ends 62 at each end which are configured to collapse to facilitate release of the concrete structure (not shown).

[0077] Formwork assembly 100 also includes movable longitudinal side formwork 55 attached to core frame 50. Each of end formworks 30A, 30B further includes hinged formwork panels 40 configured to abut the end of movable longitudinal side formwork 55 when in the pour configuration, as shown in Fig. 1.

[0078] Formwork assembly 100 also includes core frame 50 which is provided to support internal formwork 60, which can be raised and lowered between pour and release configurations.

[0079] Figs. 2 to 4 depict assembly formwork 100 in different stages of a release configuration. In the first stage shown in Fig. 2, hinged formwork panels 40 have been opened by hinging away from contact with end of movable longitudinal side formwork 55, each of end formworks 30A, 30B have been moved away from the fixed side formwork 20, and core frame 50 with cast concrete structure 10 have been moved out of the space defined by longitudinal fixed side formwork 20 and first and second end formworks 30A, 30B.

[0080] In the second stage shown in Fig. 3, movable longitudinal side formwork 55 has been hinged away from contact with the side of cast concrete structure 10, and core frame 50 has been lowered away from contact with the bottom of cast concrete structure 10.

[0081] In the third stage shown in Fig. 4, core frame 50 and internal formwork 60 are returned to the space defined by fixed side formwork 20 and first and second end formworks 30A, 30B, and cast concrete structure 10 has been released and is ready for transport.

[0082] Figs. 2 to 4 also show the structural details on the inner faces of fixed longitudinal side formwork 20 and end formworks 30A, 30B. Side formwork 20 has longitudinal support surface 22 extending along its inner surface, and first and second end formworks 30A, 30B each have end support surfaces 32 extending along their respective inner surfaces.

[0083] Also shown in Figs. 1 to 4, rail system 80 is provided to move core frame 50 into and out of the space defined by fixed side formwork 20 and first and second end formworks 30A, 30B after concrete structure 10 has been cast. Also shown is end rail system 70, which is provided to move first and second end formworks 30A, 30B away from fixed side formwork 20 between the pour and release configurations.

[0084] As shown in Fig. 1 , internal formwork 60 comprises horizontal flange which extends around the bottom periphery of internal formwork 60. Flange 60 is configured to rest on longitudinal support surface 22 of fixed side formwork 20 and end support surfaces 32 of first and second end formworks 30A, 30B. The upper surface of horizontal flange 65 defines the bottom faces of the perimeter beams.

[0085] Fig. 5 depicts end formwork 30A, suitable for use on the formwork assembly, including end support frame 34. Fig. 6A and 6B depict end support frame 34 which is located on an end formwork (not shown), in extended and collapsed positions, respectively. End support frame 34 is formed of three components, two outer end frames 35 and inner end frame 36. Inner frame 36 is slidably movable in an up / down direction, between a raised position (shown in Fig. 6A) and a lowered position (shown in Fig. 6B). When inner frame 36 has been lowered, the two outer end frames 35 are allowed to collapse / move in an inward direction, allowing the cast reinforced structure to be released.

[0086] Fig. 7 depicts side formwork 20 suitable for use on the formwork assembly, including two outer longitudinal frames 25 and two inner longitudinal frames 26. Fig. 8A and 8B depict longitudinal support frame 24, which located on a side formwork (not shown), in extended andcollapsed positions, respectively. Longitudinal support frame 24 is formed of four components, two outer longitudinal frames 25 and two inner longitudinal frames 26. Inner longitudinal frames 26 are slidably movable in an up / down direction, between a raised position (shown in Fig. 8A) and a lowered position (shown in Fig. 8B). When the inner longitudinal frames have been lowered, the two outer longitudinal frames are allowed to collapse / move in an inward direction, allowing the cast reinforced structure to be released.

[0087] Fig. 9 depicts internal formwork 60 on core frame 50 in the raised position, and Fig. 10 depicts internal formwork 60 on core frame 50 in the lowered position. Also shown are wheels 52, which are provided to move core frame 50 on rail system 80.

[0088] Fig. 11 depicts a perspective view of column cage 90, including column cages 90, coupler locators 92, couplers 94, located at the end of column cages, and bottom connectors 96. Column cages 90 are installed in the corners of formwork assembly 100 and are tied to the beam cages (not shown) prior to pouring of concrete.

[0089] Fig. 12 illustrates a perspective view of final cast reinforced concrete structure 10 prepared using formwork assembly 100. Shown are coupler locators 92 located at each corner of the upper face of the horizontal slab, as well as bottom connectors 96 located at the bottom of each column.

[0090] Figs. 13 and 16 to 19 illustrate an alternative formwork assembly 200 for use in preparing a cast concrete structure. Figs. 13 and 17 depict the assembly in the pour configuration and Figs. 16, 18 and 19 depict the assembly in the release configuration (Fig. 16).

[0091] These drawings show bottom frame 250 formed from four horizontally oriented beams connected at respective ends to form a right-angled quadrilateral shape. The formwork assembly also includes a perimeter frame formed from four horizontally oriented perimeter beam jackets 230 connected at respective ends. The inner faces of the perimeter frame define the outer peripheral faces of the horizontal slab. Formwork assembly 200 also includes four vertically oriented column jackets 290, each column jacket being attached at the bottom end to a respective corner of bottom frame 250, and at the top end to a respective corner of the perimeter frame.

[0092] Formwork assembly 200 also includes internal formwork 260 configured to fit within the perimeter frame. The upper surface of the internal formwork defines the shape of the lower surface of the horizontal slab, including transversal beams that extend across, and the outer peripheral faces of the internal formwork define the inner faces of the perimeter beams; and a slab supporting frame configured to support the internal formwork.

[0093] Figs. 14 and 15 illustrate perspective views of column jacket components in open and closed configurations, respectively, in accordance with an alternative embodiment of the present invention.

[0094] Figs. 17, 18 and 19 depict formwork assembly 200 after a concrete structure 210 has been cast. Fig. 19 further shows formwork assembly 200, with the internal formwork in a lowered position, ready for removal of the cured concrete structure 210.

[0095] Figs. 20 and 21 illustrate perspective views of the connector components suitable for use in connecting stacked cast reinforced concrete structures. Shown is upper connector 96a, which is configured to engage lower connector 96b by sliding engagement of corresponding slots on each connector. This configuration provides rigid and stable connectivity between respective concrete structures, as shown in Fig. 21.

[0096] Fig. 22 depicts a cast concrete structure having lift connectors 85, installed around the peripheral edge of the upper surface of the concrete structure to provide attachment points suitable for lifting cast structures using, for example, a crane or other suitable lifting means. Fig. 23 illustrates a cross-sectional detail of lift connector 85, including attachment loop 88, coil rod 86, coil and nut washer 87, and plate 87.

[0097] Figs. 24 and 25 illustrate the cross-sectional profiles of a horizontal slab of a cast reinforced concrete structure, showing the angled inner surfaces of the perimeter beams 18, as well as the angled surfaces of the transversal beams 17. These angled surfaces facilitate release from the internal formwork.

[0098] Figs. 26 to 34 illustrate an alternative formwork assembly 300 for use in preparing a cast concrete structure.

[0099] Fig. 26 illustrates formwork assembly 300 in the pour configuration. Formwork assembly 300 Includes fixed longitudinal side formwork 320 and first and second end formworks 330A, 330B. As shown, in the pour configuration, one end of fixed side formwork 320 abuts the edge of first end formwork 330A, and the other end of fixed side formwork 320 abuts the edge of second end formwork 330B.

[0100] Formwork assembly 300 also includes support truss framework 350 configured to fit within the space defined by longitudinal fixed side formwork 320 and end formworks 330A, 330B. Formwork assembly 300 also includes internal formwork 360 configured to rest on support truss framework 350 resting on concrete platform 351. As shown in Fig. 26, the upper surface of internal formwork 360 defines the shape of the lower surface of the horizontal slab of the concrete cast structure (not shown), and the outer peripheral faces of internal formwork 360 define the inner faces of the perimeter beams of the concrete cast structure. Internal formwork 360 also includes movable ends 362 at each end which are configured to collapse to facilitate release of the concrete structure (not shown). Also shown in Fig. 26 are rails 370, which facilitate movement of end formworks 330A, 330B into the release configuration.

[0101] Formwork assembly 300 also includes movable longitudinal side formwork 355, which further includes hinged formwork panels 340 configured to abut the end of end formworks 330A, 330B when in the pour configuration. Also shown in Fig. 26 are column jackets 390 which form the mould for the columns of the resulting concrete structure (not shown).

[0102] Figs. 27 and 30 to 33 depict assembly formwork 300 in different stages of the release process. Fig. 27 depicts assembly formwork 300 with cast concrete structure 310 in the first release stage, in which column jackets 390 have been removed. In the second stage shown in Fig. 30 (without showing concrete structure for clarity), movable ends 362 of internal formwork 360 are shown in the collapsed position, which facilitates release of the horizontal slab from contact with internal formwork 360.

[0103] In the third stage shown in Fig. 31, each of end formworks 330A, 330B have been moved away from the fixed side formwork 320 and hinged end formworks 340. Column jackets 390 have also been removed. Concrete structure 310 has been raised off bottom connectors 396, which have been provided to ensure proper positioning of the base of thecolumns. Also shown on end formwork 330A are end support L-frames 334. Details of end support frames 334 in extended and collapsed positions, respectively are provided in Figs. 28 and 29. When end support frames 334 are in the collapsed position, loss of contact between cast concrete structure 310 (not shown) allows concrete structure 310 to be released.

[0104] In the fourth stage shown in Fig. 32, hinged end formworks 340 have been hinged away from contact with cast concrete structure 310. Fig. 33 shows the fifth stage, with hinged longitudinal formwork panel 355 folded down under the horizontal slab in the release configuration allowing concrete structure 310 to be removed.

[0105] Figs. 34 to 40 illustrate an alternative formwork assembly 400 for use in preparing a cast concrete structure.

[0106] Fig. 34 illustrates formwork assembly 400 in the pour configuration. Formwork assembly 400 Includes fixed longitudinal side formwork 420 and first and second end formworks 430A, 430B. As shown, in the pour configuration, one end of fixed side formwork 420 abuts the edge of first end formwork 430A, and the other end of fixed side formwork 420 abuts the edge of second end formwork 430B.

[0107] Formwork assembly 400 also includes support framework 450, resting on and connected to concrete base 451, and support platform 452, supported by support framework 450. Support framework 450 and platform 452 are configured to fit within the space defined by longitudinal fixed side formwork 420 and end formworks 430A, 430B. Formwork assembly 400 also includes internal formwork 460 configured to rest on support platform 452. As shown in Figs. 34 and 36, the upper surface of internal formwork 460 defines the shape of the lower surface of the horizontal slab of the concrete cast structure (not shown), and the outer peripheral faces of internal formwork 460 define the inner faces of the perimeter beams of the concrete cast structure.

[0108] As shown in Fig. 34 to 39, end formwork 430B has on its internal face two end support L-frames 434 (corresponding L-frames are also present on end formwork 430A, but are not shown). End support frames 434 are moveable between extended and collapsed positions (as shown in Figs. 28 and 29), such that when end support frames 434 are in the collapsedposition, loss of contact with the cast concrete structure allows concrete structure 310 to be released.

[0109] Shown in Fig. 34 to 39 are rails 470, which facilitate movement of end formworks 430A, 430B between the release and pour configurations.

[0110] As shown in Figs. 34 to 38, formwork assembly 400 also includes longitudinal side formwork 455, which further includes hinged formwork panels 440 configured to abut the end of end formworks 430A, 430B when in the pour configuration. Also shown in Figs. 34 to 39, column jackets 490 and 491 are provided to form two sides of the mould for the columns of the resulting concrete structure.

[0111] Figs. 34 to 38 depict assembly formwork 400 in different stages of the process. Fig. 34 depicts assembly formwork 400 prior to casting, and Fig. 35 depicts assembly formwork 400 after concrete structure 410 has been cast. Fig. 37 depicts assembly formwork 400 in the release configuration after cast concrete structure 410 been removed.

[0112] In the configuration shown in Fig. 37, each of end formworks 430A, 430B have been moved away from the fixed side formwork 420 and hinged end formworks 440. Concrete structure 410 has been raised off connectors 497, which have been provided to ensure proper positioning of the base of the columns. Fig 38 shows the configuration of Fig. 37, with concrete structure 410 removed for clarity.

[0113] It is obvious that the foregoing embodiments of the invention are examples and can be varied in many ways. Such present or future variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.

Claims

We claim:

1. A formwork assembly for preparing a cast reinforced concrete structure comprising a horizontal slab having a quadrilateral shape, an upper surface and a lower surface, four corner columns, each corner column extending downwardly from a respective corner of the horizontal slab, perimeter beams extending between the corner columns and downwardly along the peripheral edges of the slab, the formwork assembly being convertible between a pour configuration and a release configuration, the assembly comprising: a first fixed longitudinal side formwork having a first end and a second end and having a longitudinal support surface extending along an inner surface; a first end formwork and a second end formwork, each end formwork having first and second ends and two support frames located on an inner surface of the respective end formworks, the support frames having an upper surface, wherein the first and second end formworks are each independently movable between the pour configuration and the release configuration; a second longitudinal side formwork comprising a central panel and first and second hinged panels each located at opposing ends of the central panel, and having a longitudinal support surface extending along an inner surface; a support system configured to fit within the space defined by the first and second longitudinal side formworks and first and second end formworks; and an internal formwork configured to rest on the support system, wherein the upper surface of the internal formwork defines the shape of the lower surface of the horizontal slab, wherein outer peripheral faces of the internal formwork define the inner faces of the perimeter beams; wherein in the pour position, the first end of the fixed side formwork abuts the first end of the first end formwork; the second end of the fixed side formwork abuts the first end of the second end formwork; the second end of the first end formwork abuts the first hinged panel of the second longitudinal side formwork; and the second end of the second end formwork abuts the second hinged panel of the second longitudinal side formwork; andwherein in the release configuration, the first and second hinged panels are moved into an open position; and each of said first and second end formworks is moved away from the first and second ends of the fixed side formwork, respectively.

2. The assembly of claim 1, wherein the cast reinforced concrete structure further comprises one or more transverse beams located on the lower surface of the horizontal slab and extending in a transverse direction between opposing perimeter beams, and the internal formwork further defines the shape of the plurality of transverse beams.

3. The assembly of claim 1 or 2, wherein the two support frames on the first and second end formworks are moveable between extended and collapsed positions, wherein the support frames are in the extended position in the pour configuration and are in the collapsed position in the release configuration.

4. The assembly of claim 3, wherein the support frames on the first and second end formworks are formed from two L-shaped frames, wherein the two L-frames are moveable between the extended and collapsed positions.

5. The assembly of any one of claims 1 to 4, wherein the support system is mounted on a concrete base.

6. The assembly of claim 5, wherein the support system comprises a support platform on a support framework connected to the concrete base.

7. The assembly of claim 5, wherein the support system comprises a support truss framework connected to the concrete base.

8. The assembly of any one of claims 1 to 4, wherein the support system comprises a core frame, wherein the core frame is configured to be lowered when in the release configuration to release the cast concrete structure.

9. The assembly of claim 8, wherein the core frame is moveable out of the space defined by the longitudinal fixed side formwork and first and second end formwork.

10. The assembly of any one of claims 1 to 9, further comprising a rail system configured to move the first and second end formworks between the pour configuration and the release configuration.

11. The assembly of any one of claims 1 to 10, further comprising a rebar cage assembly comprising four perimeter beam cages, four column cages and a slab cage.

12. A method for preparing a cast reinforced concrete structure comprising a horizontal slab having a quadrilateral shape, an upper surface and a lower surface, four corner columns, each corner column extending downwardly from a respective corner of the horizontal slab, perimeter beams extending between the corner columns and downwardly along the peripheral edges of the slab, the method comprising the steps of: providing an assembled formwork assembly as defined in any one of claims 1 to 8, wherein the formwork assembly is in the pour configuration; providing four column cages, each said column cage being located at a respective corner of the formwork assembly; providing two longitudinal perimeter beam cages, each said longitudinal perimeter beam cage extending between respective column cages along the longitudinal edges of the formwork assembly; providing two end perimeter beam cages, each said end perimeter beam cage extending between respective column cages along the end edges of the formwork assembly; tying the column cages, the longitudinal perimeter beam cages and the end perimeter beam cages to form an assembled rebar core structure; pouring the concrete into the assembled formwork; and curing the poured concrete to form the cast reinforced concrete structure.

13. The method of claim 12, wherein the formwork assembly is assembled by: moving the first end formwork into position abutting the first end of the longitudinal side formwork and bolting the first end formwork to the first end of the side formwork;moving the second end formwork into position abutting the second end of the longitudinal side formwork and bolting the second end formwork to the second end of the side formwork; placing the support system and internal formwork in the space defined by the longitudinal fixed side formwork and first and second end formworks such that the internal formwork abuts the longitudinal support surface of the longitudinal side formwork and the upper surface of the support frames of the end formworks; moving the second longitudinal side formwork into position abutting the second ends of the first and second end formworks, and closing each of the hinged formwork panels to abut the respective ends of the end formworks and bolting .

14. The method of claim 12, further comprising the step of removing the formwork assembly from the cast reinforced concrete structure. 1

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