AU2023222867B1

AU2023222867B1 - Formwork for structural columns

Info

Publication number: AU2023222867B1
Application number: AU2023222867A
Authority: AU
Inventors: Firas El Charkaoui
Original assignee: El Charkaoui Firas Badr Mr
Current assignee: El Charkaoui Firas Badr Mr
Priority date: 2023-08-29
Filing date: 2023-08-29
Publication date: 2025-02-27
Anticipated expiration: 2043-08-29

Abstract

A column formwork assembly including: a pair of sheathing panels arranged opposite each other to define a mould cavity; at least one elongated, steel support member located on the outwardly facing surface of at least one of the sheathing panels; and a tie member passing through the mould cavity between the opposite sheathing panels, wherein fasteners passing through the opposite sheathing panels and the support members located behind the sheathing panels engage opposite ends of the tie member thereby tying together the sheathing panels on opposite sides of the mould cavity.

Description

FORMWORK FOR STRUCTURAL COLUMNS TECHNICAL FIELD

[001] The present invention relates to formwork for use in concrete construction. The invention relates more particularly to prefabricated formwork for use in the construction of reinforced concrete columns, however, it is to be appreciated that the invention may have broader application as formwork for other concrete structures.

BACKGROUND

[002] Formwork is used in the construction of buildings and other structures to provide a temporary or permanent mould into which concrete or other similar materials may be poured to construct walls, slabs, beams, columns, footings and the like. It is a structure made to keep concrete in position until it cures and thereby gains strength and shape. Formwork may be employed off-site or on site for either precast or cast-in-place methods.

[003] Shuttering is a type of formwork which comprises a vertical temporary structure which is used to form a vertical mould for concrete structures such as columns and walls. Shuttering is usually made of timber or plywood, however, sometimes other materials such as steel sheeting or plastic moulds are used for irregular shaped or curved structures.

[004] Shuttering formwork requires support, which is known as bracing. This refers to stabilisers, poles or other kinds of material that will keep the formwork or shuttering in place while the concrete dries or cures.

[005] Formwork for concrete columns are subject to relatively high lateral forces because of their small cross section, large heights and relatively high rates of concrete placement. Thus It is necessary to provide tight joints and strong tie support to the formwork. As the sizes of concrete column increases, the stiffness of the formwork must be increased by either increasing the thickness of sheathing or vertical stiffeners must be added to prevent sheathing deflection.

[006] Column formwork typically consists of sheathing around the column periphery, timber framing and bearers to provide structural support for the sheathing. Tie rods extending through the mould cavity and through the sheathing and timber bearers are fixed with threaded nuts or bolts behind the timber bearers. In addition, tie rods can also be fixed to the ends of opposite timber bearers which act as yokes to tie opposite sheathing together.

[007] Steel reinforcement is placed inside the mould cavity and concrete is placed into the cavity and allowed to dry or cure. Once cured, the formwork is stripped to reveal the cured concrete column. In some cases, stripped formwork can be reused. In other cases, the formwork or shuttering will remain in place.

[008] A problem with existing methods for constructing formwork for columns is that they require a substantial amount of timber for use as framing and bearers supporting the sheathing. Some of the timber can be reused but a substantial amount cannot and must be disposed of.

[009] Another problem with existing methods for constructing formwork for columns is that once the timber structure supporting the sheathing is constructed, subsequent inspection of the underlying steel reinforcement is rendered difficult or impossible without dismantling a substantial portion of the entire formwork.

[0010] Accordingly, a need exists for a method and apparatus for constructing formwork for columns that reduces the requirement for timber or non-reusable materials. A need exists for a method and apparatus for constructing formwork for columns that enables relative ease of inspection of steel reinforcement inside the mould.

[0011] Any discussion of background art throughout the specification should in no way be considered as an admission that any of the documents or other material referred to was published, known or forms part of the common general knowledge.

SUMMARY OF THE INVENTION

[0012] In one aspect, the present invention provides a prefabricated column formwork assembly including: first and second of sheathing panels each having a first surface and an opposite second surface and being arranged opposite each other to define a mould cavity therebetween with the first surface facing an interior of the mould cavity and the opposite second surface facing outwardly from the mould cavity; at least one elongated, steel support member being located on the outwardly facing second surface of one of the sheathing panels; a tie member passing through the mould cavity between the opposite first and second sheathing panels; fasteners passing through the first and second sheathing panels and the support members located behind the first and second sheathing panels engaging opposite ends of the tie member thereby tying together the first and second sheathing panels on opposite sides of the mould cavity; and a first one of the support members being secured directly to the second surface of one of the first or the second sheathing panels, a second one of the support members being secured directly to the first one of the support members, and a third one of the support members being secured directly to the second surface of a third sheathing panel adjacent to the one of the first or the second sheathing panels, wherein the second support member is releasably secured directly to the first and/or the third support member for removing one or the other of the adjacent sheathing panels to reveal the reinforcement beneath for inspection and for replacing the removed sheathing panel after inspection.

[0013] Advantageously, embodiments of the invention provide for the construction of formwork for columns that requires substantially less timber, in particular by doing away with the need for timber for use as framing and bearers supporting the sheathing panels.

[0014] Embodiments of the invention are advantageous in that they provide for the prefabricated construction of formwork for columns off-site for delivery and installation on site in a form that permits subsequent inspection of the underlying steel reinforcement.

Support Member

[0015] In embodiments, the support member comprises a steel plate member.

[0016] Preferably, the steel plate member includes an opening extending therethrough to opposite sides thereof.

[0017] Preferably, at least one of the support members is secured to the second surfaces of an adjacent pair of the sheathing panels.

[0018] In preferred embodiment, a first one of the support members is secured directly to the second surface of the at least one of the sheathing panels and a second one of the support members is secured directly to the first one of the support members.

[0019] Preferably, the second one of the support members is secured directly to a third one of the support members which in turn is secured directly to the second surface of another one of the sheathing panels adjacent to the first one of the sheathing panels.

[0020] In preferred embodiments, a laterally spaced apart pair of the support members are secured to the second surfaces of the sheathing panels.

Side Plates

[0021] In embodiments, the prefabricated column formwork assembly includes a pair of side panels being arranged opposite each other and extending transversely between the pair of the sheathing panels thereby enclosing lateral sides of the mould cavity.

[0022] Preferably, the side panels each have a first surface facing the interior of the mould cavity and an opposite second surface facing outwardly from the mould cavity, wherein frame members overlie the outwardly facing second surfaces of the side panels.

[0023] In preferred embodiments, one or more fasteners pass through the sheathing panels and into the frame members to secure side edges of the pair sheathing panels to the frame members.

Tie

[0024] In embodiments, the tie member includes an intermediate bar and coils fixed to opposite ends of the intermediate bar.

[0025] Preferably, the fasteners include bolts adapted to engage the coils at the opposite ends of the intermediate bar, wherein the bolts directly engage the support members located behind the opposite sheathing panels.

[0026] Preferably, at least one of the fasteners are removable to allow at least one of the opposite sheathing panels and at least one of the support members located behind the at least one sheathing panel to be removed to enable access to the interior of the mould cavity.

Reinforcement

[0027] In embodiments of the prefabricated column formwork assembly, reinforcement is located within the mould cavity between the opposite sheathing panels.

[0028] Preferably, the mould cavity forms a column shaped mould extending in a longitudinal direction wherein the reinforcement includes steel bars extending in directions substantially parallel, perpendicular, or both, relative to the longitudinal direction of the mould cavity.

BRIEF DESCRIPTION OF THE FIGURES

[0029] The invention will now be described in more detail with reference to embodiments of the invention illustrated in the accompanying drawings, wherein:

[0030] Figure 1 isometric a perspective view of a column formwork assembly in accordance with an embodiment of the invention including sheathing panels surrounding a mould cavity containing reinforcement and concrete placed therein, the assembly including a plurality of elongated steel support members located on outwardly facing surfaces of the sheathing panels wherein the support members and the underlying sheathing panels are tied together on opposite sides of the mould cavity;

[0031] Figure 2 isometric a perspective view of the column formwork assembly of Figure 1 wherein one of the sheathing panels is removed to reveal the reinforcement beneath for inspection;

[0032] Figure 3 isometric an enlarged perspective view of a section of the column formwork assembly of Figure 1 wherein a portion of the concrete is removed to reveal the reinforcement and tie members comprising an intermediate bar and coils fixed to opposite ends of the intermediate bar;

[0033] Figure 4 illustrates an isometric view of the column formwork assembly of Figure 1 including elongated prop members fastened to the elongated steel support members to support the formwork assembly in an upright position;

[0034] Figure 5 illustrates an exploded isometric view of the column formwork assembly of Figure 1, without any reinforcement or concrete therein;

[0035] Figure 6 illustrates a top view of the column formwork assembly of Figure 1 without any reinforcement or concrete therein; and

[0036] Figure 7 illustrates a perspective view of a truck carrying a plurality of the of the column formwork assembly of Figure 1.

DETAILED DESCRIPTION

[0037] Referring to Figures 1 to 6, there is shown an embodiment of a column formwork assembly 10. The formwork assembly 10 includes a plurality of sheathing panels 20. Each sheathing panel 20 has a first surface 22, an opposite second surface 24. A pair of the sheathing panels 20 are arranged opposite each other to define a mould cavity 50 therebetween. The first surfaces

24 of the sheathing panels 20 face an interior 52 of a mould cavity 50 and the opposite second surfaces 24 of the sheathing panels 20 face outwardly from the mould cavity 50.

[0038] Elongated, steel support members 30 are located on the outwardly facing second surfaces 24 of the sheathing panels 20. Tie members 40 pass through the mould cavity 50 between the opposite sheathing panels 20. Fasteners 45 pass through the opposite sheathing panels 20 and the support members 30 located behind the sheathing panels 20. The fasteners 45 engage opposite ends of the tie members 40 thereby tying together the sheathing panels 20 on opposite sides of the mould cavity 50.

Sheathing

[0039] The first surface 22 and the opposite second surface 24 of each sheathing panel 20 is generally planar. The first and second surfaces 22, 24 are bounded by opposite side edges 21, 23 and opposite top and bottom edges 25, 27 extending between the side edges 21, 23. The sheathing panels 20 are preferably formed out of plywood or another like, rigid, material.

[0040] As illustrated in Figure 1, the formwork assembly 10 includes an adjacent pair of the sheathing panels 20 located one atop another. The bottom edge 27 of the upper sheathing panel 20 abuts the top edge 25 of the sheathing panel 20 below. The first surfaces 22 of the adjacent sheathing panels 20 are contiguous with each other and together define a planar front wall 51 of the mould cavity 50. Similarly, a planar rear wall 53 of the mould cavity 50 is defined by the contiguous first surfaces 22 of another adjacent pair of the sheathing panels 20 opposite the first adjacent pair of the sheathing panels 20.

Side Panels

[0041] The formwork assembly 10 includes a pair of side panels 60, 62 arranged opposite each other and extending transversely between the pair of the sheathing panels 20 thereby enclosing lateral sides of the mould cavity 50. The side panels 60, 62 each have a first surface 61 facing the interior of the mould cavity 50 and an opposite second surface 63 facing outwardly from the mould cavity 50. The first surfaces 61 of the opposite side panels 60, 62 together define planar, opposite side walls 54, 56 of the mould cavity 50.

[0042] Frame members 65 overlie the outwardly facing second surfaces 63 of the side panels 60, 62. The frame members 65 are elongated and have a width spanning the distance between the opposite pair of the sheathing panels 20. In an embodiment, the frame members 65 are comprised of timber. However, the frame members 65 may be comprised of another material.

[0043] Fasteners 67 pass through the opposite sheathing panels 20 and into the frame members 65 to secure the side edges 21, 23 of the pair of opposite sheathing panels 20 to the frame members 65. Any suitable fasteners 67 such as screws or bolts can be used to secure the sheathing panels 20 to the frame members 65.

Support Member

[0044] The support members 30 are comprised of one or more steel plate members 32. Each steel plate member 32 is comprised of a length of plate steel that is preferably 12mm thick and has a first surface 31 and an opposite second surface 33. The first and second surfaces 31, 33 are bounded by opposite side edges 35, 37 and opposite top and bottom edges 36, 38 extending between the side edges 35, 37. Each steel plate member 32 is elongated and has a length dimension substantially greater that its width dimension.

[0045] Each one of the steel plate members 32 includes one or more openings 34 extending therethrough to the opposite first and second surfaces 31, 33 thereof. In use, the first surface 31 of one of the steel plate members 32 is placed face to face with the second surface 24 of at least one of the sheathing panels 20 and is secured thereto.

[0046] Some of the steel plate members 32 are secured to the second surfaces 24 of an adjacent pair of the sheathing panels 20. In this instance, the top edge 25 of one of the sheathing panels 20 abuts with the bottom edge 27 of an adjacent sheathing panel 20 and the steel plate member 32 is fastened to both adjacent sheathing panels 20 and spans a junction between the sheathing panels 20 defined by the abutting top and bottom edges 25, 27 thereof.

[0047] As illustrated in Figures 1 to 5, a series of the steel plate members 32 are secured in a line to the second surfaces 24 of an adjacent pair of the sheathing panels 20. A second series of the steel plate members 32 are secured in a second line to the second surfaces 24 of the sheathing panels 20 laterally spaced apart from the first series of the steel plate members 32. The result is a pair of laterally spaced apart support members 30, each defined by a series of the steel plate members 32 secured in a line to the second surfaces 24 of the sheathing panels 20. The support members 30 serve as reinforcement for the sheathing panels 20 to increase the stiffness of the sheathing to prevent sheathing deflection. The pair of laterally spaced apart support members 30 also serve as a means for providing tight joints along the junction between the adjacent sheathing panels 20 defined by the abutting top and bottom edges 25, 27 thereof.

[0048] In an embodiment, a first one of the support members 30 is secured directly to the second surface 24 of one of the sheathing panels 20 and a second one of the support members 30 is secured directly to the first one of the support members 30. As illustrated in Figures 1 to 5, one of the steel plate members 32 is secured directly to the second surface 24 of one of the sheathing panels 20 and a second one of the steel plate members 32 overlays and is secured directly to the first one of the steel plate members 32. The second overlaying one of the steel plate members 32 then overlays and is secured to a third one of the steel plate members 32 which is secured to a second, adjacent one of the sheathing panels 20.

Tie

[0049] Referring to Figures 3, 5 and 6, the assembly 10 includes a number of the tie members 40 which are adapted to tie together the sheathing panels 20 on opposite sides of the mould cavity 50.

[0050] Each tie member 40 includes an intermediate bar 42 and coils 44 fixed to opposite ends of the intermediate bar 42. The coils 44 each include an internal cavity 49. As illustrated in Figure 3, 5 and 6, the tie members 40 are arranged within the mould cavity 50, perpendicularly to the sheathing panels 20 so as to span the width of the mould cavity 50 therebetween. The internal cavities 49 within the coils 44 at the opposite ends of each tie member 40 are located in alignment with openings 26 within the sheathing panels 20. The openings 26 within the sheathing panels 20 extend through to the opposite first and second surfaces 22, 24 thereof.

[0051] The openings 26 within the sheathing panels 20 and the openings 34 through the steel plate members 32 allow the fasteners 45 to pass through the opposite sheathing panels 20 and the support members 30 located behind the sheathing panels 20. The fasteners 45 enter the internal cavities 49 within the coils 44 to thereby engage opposite ends of the tie members 40 and thereby tie together the sheathing panels 20 on opposite sides of the mould cavity 50.

[0052] The fasteners 45 includes a shank 46 which is configured to enter and engage the internal cavities 49 within the coils 44 and a head 47 which engages the second surface 33 of the steel plate member 32 around the opening 34 through which the shank 46 is inserted. In an embodiment, the shank 46 is threaded and is configured to engage a complementary thread within the internal cavities 49 within the coils 44. In another embodiment, the shank 46 is expanding and is configured to enter and expand within the internal cavities 49 within the coils 44 and thereby secure the fastener 45 to one of the opposite ends of the tie members 40.

[0053] As illustrated in Figure 2, at least some of the fasteners 45 are removable to allow at least one of the opposite sheathing panels 20 to be removed to enable access to the interior 52 of the mould cavity 50. In relation to the sheathing panel 20 that is to be removed, all of the fasteners 45 that are securing the sheathing panel 20 to any one the tie members 40, and any of the fasteners 67 that are securing the lateral sides of the sheathing panel 20 to the frame members 65, must be removed. Once the fasteners 45, 67 are removed, the sheathing panel

20 can be removed to enable access to the interior 52 of the mould cavity 50. Once the sheathing panel 20 is removed, inspection of steel reinforcement inside the mould cavity 50 is rendered possible.

Reinforcement

[0054] Referring to Figures 1 to 4, the assembly 10 preferably includes reinforcement 80 located within the mould cavity 50 between the opposite sheathing panels 20. The mould cavity 50 is defined by the contiguous first surfaces 22 of opposite pairs of the sheathing panels 20, which define the front and rear walls 51, 53, and by the opposite side panels 60, 62, which define side walls 54 to the mould cavity 50. The walls 51, 53, 54 generally form a column shaped mould cavity 50 extending in a longitudinal (i.e. vertical) direction. The reinforcement 80 includes steel bars 82 extending in directions substantially parallel, perpendicular, or both, relative to the longitudinal direction of the mould cavity 50. As illustrated in Figures 1 to 4, vertical steel reinforcement bars 82 are arranged parallel to the front and rear walls 51, 53 of the mould cavity 50.

[0055] In embodiments, the vertical steel reinforcement bars 82 may be supplemented with horizontal steel reinforcement bars (not shown) that are tied to the vertical bars 82.

Prefabricated

[0056] The column formwork assembly 10 of the invention is adapted to be fabricated off-site and delivered and installed on-site. Referring to Figure 7, a plurality of the column formwork assemblies 10 are fabricated off-site in accordance with the above and are loaded onto a truck 100 for delivery to site. The trust is configured to carry a plurality of the column formwork assemblies 10 complete with reinforcement 80 within the mould cavities 50.

[0057] Once on site, one or more of the column formwork assemblies 10 can be removed from the truck 100 using a crane and positioned in the location where the column is to be constructed. After the assemblies 10 are located in position, one or more of the sheathing panels 20 is removable in the manner described above to permit inspection of the underlying steel reinforcement 80 by a structural engineer.

[0058] Figure 4 illustrates an embodiment including elongated prop members 70 fastened to the elongated steel support members 30 to support the formwork assembly 10 in an upright position. One end of the prop members 70 are fastened to the elongated steel support members 30 at a height above the floor surface level and the other end of the prop members 70 are fixed to the floor surface a distance apart from the bottom of the formwork assembly 10.

[0059] After inspection is completed, the sheathing panels 20 are replaced and concrete is placed into the cavity 50 and allowed to dry or cure. Once cured, the assembly 10 is disassembled by first removing the fasteners 45, 67 and removing the support members 30 and frame members 65 and stripping away the sheathing panels 20 and side panels 60, 62 to reveal the cured concrete column.

[0060] The steel plate members 32 that comprise the support members 30 can be recovered and reused. Furthermore, in some instances, the sheathing panels 20 and side panels 60, 62 can be recovered and reused whereas in other cases, the sheathing panels 20 and/or side panels 60, 62 will remain in place.

[0061] Embodiments of the invention are advantageous in that they provide for the construction of formwork for columns that requires substantially less timber, in particular by doing away with the need for timber for use as framing and bearers supporting the sheathing panels 20.

[0062] Embodiments of the invention are advantageous in that they provide for the construction of formwork for columns, in particular construction of formwork off-site and delivery and installation on site, that permits subsequent inspection of the underlying steel reinforcement.

[0063] While various embodiments of the invention have been set forth above, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. Thus, it is intended that the present invention cover such modifications and variations as fall within the scope of the appended claims and their equivalents.

Claims

Claims: 1. A prefabricated column formwork assembly including: a. first and second sheathing panels each having a first surface and an opposite second surface and being arranged opposite each other to define a mould cavity therebetween with the first surface facing an interior of the mould cavity and the opposite second surface facing outwardly from the mould cavity; b. at least one elongated, steel support member being located on the outwardly facing second surface of one of the sheathing panels; c. a tie member passing through the mould cavity between the opposite first and second sheathing panels; d. fasteners passing through the first and second sheathing panels and the support members located behind the first and second sheathing panels engaging opposite ends of the tie member thereby tying together the first and second sheathing panels on opposite sides of the mould cavity; and e. a first one of the support members being secured directly to the second surface of one of the first or the second sheathing panels, a second one of the support members being secured directly to the first one of the support members, and a third one of the support members being secured directly to the second surface of a third sheathing panel adjacent to the one of the first or the second sheathing panels, wherein the second support member is releasably secured directly to the first and/or the third support member for removing one or the other of the adjacent sheathing panels to reveal the reinforcement beneath for inspection and for replacing the removed sheathing panel after inspection.
2. The prefabricated column formwork assembly of claim 1, wherein the support member comprises a steel plate member.
3. The prefabricated column formwork assembly of claim 1, wherein the steel plate member includes an opening extending therethrough to opposite sides thereof.
4. The prefabricated column formwork assembly of claim 1, wherein a laterally spaced apart pair of the support members are secured to the second surfaces of the sheathing panels.
5. The prefabricated column formwork assembly of claim 1, including a pair of side panels being arranged opposite each other and extending transversely between the pair of the sheathing panels thereby enclosing lateral sides of the mould cavity.
6. The prefabricated column formwork assembly of claim 5, wherein the side panels each have a first surface facing the interior of the mould cavity and an opposite second surface facing outwardly from the mould cavity, wherein frame members overlie the outwardly facing second surfaces of the side panels.
7. The prefabricated column formwork assembly of claim 6, wherein one or more fasteners pass through the sheathing panels and into the frame members to secure side edges of the pair sheathing panels to the frame members.
8. The prefabricated column formwork assembly of claim 1, wherein the tie member includes an intermediate bar and coils fixed to opposite ends of the intermediate bar.
9. The prefabricated column formwork assembly of claim 8, wherein the fasteners include bolts adapted to engage the coils at the opposite ends of the intermediate bar, wherein the bolts directly engage the support members located behind the opposite sheathing panels.
10. The prefabricated column formwork assembly of claim 1, wherein at least one of the fasteners are removable to allow at least one of the opposite sheathing panels and at least one of the support members located behind the at least one sheathing panel to be removed to enable access to the interior of the mould cavity.
11. The prefabricated column formwork assembly of claim 1, wherein reinforcement is located within the mould cavity between the opposite sheathing panels.
12. The prefabricated column formwork assembly of claim 10, wherein the mould cavity forms a column shaped mould extending in a longitudinal direction wherein the reinforcement includes steel bars extending in directions substantially parallel, perpendicular, or both, relative to the longitudinal direction of the mould cavity.