METHOD AND APPARATUS FOR CONSTRUCTION
Background of the Invention
The present invention relates to a method and apparatus for construction using pourable concrete material. In particular, the present invention relates to interchangeable and reusable lightweight formwork and scaffolding, and to a method and apparatus to set the re-useable lightweight formwork and scaffolding in position for the in-situ construction of vertical, horizontal and other shaped concrete structures. In use, the present invention includes a method to transfer the trapped hydraulic forces of in-situ cast concrete to assist alignment and positioning of the formwork in its true positions. The present invention also seeks to utilise the same lightweight formwork to enable reinforcing steel to be used to post-tension both vertical and horizontal and other shaped in-situ concrete structures.
Description of the Prior Art The reference to any prior art in this specification is not, and should not be taken as, an acknowledgement or any form of suggestion that that prior art forms part of the common general knowledge in Australia.
Constructing buildings, suspended slabs, walls, columns, beams or the like of in- situ concrete material, has inherent advantages over other construction methods and materials, such as pre-cast concrete, timber, brick and manufactured wall cladding, etc., including considerably higher strength, durability and integrity. Post tensioning in-situ reinforced concrete is used almost universally on large scale constructions, demonstrating its effectiveness as a requirement with concrete building materials.
Whilst in-situ concrete construction methods are extensively used for major construction work, it is rarely used for small scale constructions, particularly in country regions. At present, a large portion of the cost of in-situ concrete construction is due to formwork costs, wastage of formwork materials, and, costs of materials handling and scaffolding for multistorey exterior work. Traditional techniques of vertical and horizontal in-situ concrete construction which use formwork panels and support material are required
to be cut to shape on site or assembled with heavy lifting equipment and manually secured in their positions by skilled trades people. Traditionally, most formwork components are not interchangeable. It is also a costly procedure to post-tension the concrete structure and the waste of non-reusable materials after the concrete pour is often considerable.
Traditional techniques of scaffolding for above ground work platforms are free standing and are required to be erected by skilled trades people on solid foundations. When erected, the scaffolding frames are required to be braced or supported to reduce accident during high winds.
The Applicant has herebefore developed various improvements and modifications to the traditional methods to enable the complete in-situ concrete structure to be established and completed. For example, the Applicant's Australian Patent Nos. 647783 and 701224, and corresponding overseas Patents/Applications thereto, describe various methods of construction which have distinct differences and advantages over the traditional and/or prior art methods. The disclosures of the specifications of the previously mentioned Australian Patent, and their corresponding counterparts overseas, should be considered to be incorporated in their entirety herein by this reference thereto.
Whilst the methods and apparatus described in the Applicant's earlier Patents provide significant difference and advantages over the traditional known building methods and apparatus which use pourable concrete material, special purpose formwork and special purpose scaffolding has been developed to establish in-situ concrete as an economical alternative building method. The inventor has now developed a significantly improved method and apparatus for in-situ building structures for both manufacture of the equipment and construction, which has advantages over the previous described methods particularly for homes and buildings in country regions.
A major problem with in-situ concrete walls and slabs is the formation of shrinkage cracks which occur in slabs and walls. A further problem when casting in-situ concrete
walls is positioning the wall formwork and maintaining it in its true position both during assembly and during the concrete pour.
Another major problem of cast in-situ building is the large variety of trade skills and quantities of formwork and scaffolding equipment required when producing vertically cast in-situ slabs, concrete walls, and columns, etc., and the large quantities of different formwork and scaffolding equipment and coordination of trade skills required to produce the formwork for multi-story suspended in-situ concrete slabs, beams and walls, etc., in single or multi-story constructions.
Yet a further and significant problem of cast in-situ buildings is the costs and availability of formwork materials and equipment particularly the skills and availability of materials to successfully manufacture the formwork and scaffolding equipment in remote areas when shortages occur through unforeseen circumstances.
Summary of the Invention
The present invention seeks to address the afore-mentioned disadvantages of the prior art.
The present invention seeks to utilise the same lightweight formwork with it's interchangeable and completely reusable components to produce any one or combination of vertical, horizontal, and other shapes of in-situ concrete structures that may be connected together to provide a lighter and complete post-tensioned and insulated reinforced concrete structure with integrity and greater strength, reduced building materials that are difficult to compromise and formwork equipment wastage and construction workers reduced to one trade skill for the complete concrete structure.
The special purpose reusable and interchangeable lightweight formwork and special purpose scaffolding enables the production of a complete in-situ concrete structure produced by trained semi-skilled trades persons with wall insulation sheeting in position and other components insert moulded in selected positions in the structure to satisfy a
variety of safety and mandatory requirements and reduce the costs of following electrical, plumbing and specialist fit-out trade skills.
The vertically cast in-situ walls and slabs connected together, and post-tensioned to limit the formation of shrinkage cracks and reduce structural steel, the system opens up structural design possibilities for both architects and engineers to design new building structures utilising both strengths of the vertical in-situ walls and suspended concrete slabs locked together post-tensioned to provide complete and improved structural integrity at reduced maintenance costs for the entire life of the building.
The formwork system/scaffolding and components are lightweight to enable manual use. They are interchangeable and used for both vertical and horizontal in-situ concrete constructions, all components are reusable thus reducing materials handling and on site material requirements and costs for in-situ vertically cast concrete walls, columns and horizontal suspended concrete slabs and beams.
The present invention seeks to provide a complete method of construction and an apparatus or kit therefor, which has advantages or at least provides an alternative to the traditional and prior art methods of construction, using pourable concrete material to produce a complete cost effective building with certified concrete and certified structural steel placement for the complete building structure.
The present invention seeks to utilise the same light formwork to produce both vertical and horizontal in-situ concrete building structures which provide greater strength and reduced materials and reduced building costs. In-situ concrete structures enable engineers to introduce the most stringent building codes for safety at no extract costs. The invention introduces in-situ concrete as an alternative cost effective construction option, it opens up design possibilities for vertical and horizontal in-situ concrete structures. Both the slabs and walls are produced by the same trade skills and a formwork in a kit form with interchangeable components that enables different shapes and designs to be easily achieved.
In its broadest form, the present invention provides a method of construction of a vertical wall using pourable concrete material, said method including the steps of: positioning and securing opposed panels atop a concrete slab or other foundation; pouring concreter material, in a single pour, via an upper opening between said panels; allowing said concrete material to set; and, removing said panels.
In one broad form, the present invention provides a method of construction of a vertical wall using pourable concrete material, including the steps of: identifying and marking wall positions on an upper surface of a concrete slab or other foundation; placing reinforcing steel in position; securing base guide members to said foundation following said markings; vertically aligning internal corner formwork panels by abutment to said base guide members, and securing said internal corner formwork panels into position; positioning opposed formwork panels relative to said internal corner formwork panels; securing top portions of said internal corner formwork panels to said opposed formwork panels by attaching top locking pins; abutting corner formwork panels against said corner formwork panels, supporting said corner formply panels in position by spacers; progressively installing intermediate formwork panels and intermediate formply panels; pouring concrete material via an upper opening between said formply panels, and allowing said concrete material to set; removing all components.
Preferably, after said step of progressively installing said intermediate formwork panels and said intermediate formply panels, said method further includes the steps of:
installing strongback supports and associated straight-edged beams to provide additional strength during construction.
Also preferably, after said step of placing said reinforcing steel into position, said method further including the step of: installing post-tensioning reinforcing rods into position.
Also preferably, after said step of placing said reinforcing steel into position, said method further includes the step of: placing wall insulation into position.
Also preferably, in conjunction with said step of progressively installing intermediate formwork panels and intermediate formply panels, the method further includes the step of: installing blanking panels to allow for doors, windows, or other openings, in said vertical wall.
Also preferably, the method further includes the step of: installing locking pins between opposed strongback supports, said locking pins extending via conduit.
In a further broad form, the present invention provides a kit for in-situ construction of vertical wall atop a concrete slab or other foundation, said kit including: base guide members, corner formwork panels and corner formply panels, intermediate formwork panels and intermediate formply panels, spacers to maintain placement of formply panels, and, locking pins to maintain placement of said formwork panels.
Also preferably, said formwork panels and said formply panels include any one or combination of: plain panels to form a plain wall surface;
shaped opposed panels having blanking means to provide for windows, doors or the like in a wall surface; corner panels to provide for an inwards or outward corner walls or to allow for T- shaped a wall to join another wall; and, cross panels to allow for multiple walls to join together.
Preferably, said formwork panels are locked together horizontally by "C" clamps to contain wall and concrete forces. The opposing wall panels are locked together with one or more locking pins extending between said opposed panel and strong back members to retain the equal forces of the liquid concrete against the said panel members in position.
In a further broad form, the present invention provides a method of construction of a horizontal slab and/or beam, including the steps of: positioning a plurality of support frames atop a substrate surface in spaced-apart relationship, each said support frame including a H-frame, each lower end of which is supported on a base support means, and each upper end of which supports a U-head; the slab formwork apparatus rests atop the said support frames. Placing one or more straight edge members atop said support frame 1U' heads. The lightweight formwork frames are placed atop the straight edge member and the formply is placed atop the formwork frame. The formply is positioned to form the slab base and beam base. the lightweight formwork corners are used to connect the beam formply lower sides, to the beam base formwork apparatus. The support sides of the beam formply is connected to the slab base formply. pouring settable concreter material within said formwork members in a continuous pour and allowing said settable material to set; and, removing said formwork members and said support frames for reuse.
Preferably, said method is carried out using similar components to the components used in the method of construction of the vertical walls as herein described.
In a further broad form, the present invention utilises the strong back to support
scaffolding for the concrete pore.
The scaffolding apparatus, e.g. planks, kick boards and handrails, are attached to a strong back secured on the face of the concrete wall structure to provide an external platform for work above. A vertical strong back member is attached to the concrete wall with one or more locking pins through the top end of the strong back member and the concrete wall.
The vertical strong back member has horizontal holes placed at various points below the strong back top attaching pin. The work platform support arm is locked to the strong back member through the horizontal holes at a preselected height position. The lower portion of the work platform support arm rests on the vertical strong back member to assist hold the platform in a horizontal position.
m a further broad form, the present invention also provides simplified equipment manufacturing details and commercially available materials to enable general trades people to successfully manufacture the formwork equipment in existing steel fabrication workshops throughout Australia.
hi a further broad form, the present invention provides a building or other construction formed by the method as hereinbefore described.
hi yet a further broad form, the present invention provides a method for post- tensioned in-situ concrete buildings, suspended concrete slabs, columns, beams, walls, or the like formed by using the kit as hereinbefore described.
Brief Description of the Drawings
The present invention will become more fully understood from the following detailed description of a preferred but non-limiting embodiment thereof, described in connection with the accompanying drawings, wherein:
Fig. 1 illustrates a cross-sectional view of the various components of a kit apparatus
for constructing a vertical wall in accordance with the present invention;
Fig. 2 illustrates a various steps in the method of vertical wall construction, in accordance with the present invention, Fig. 2(a) showing a preliminary step in the layout of the initial components, Fig. 2(b) showing the positioning of the corner formwork panels, Fig. 2(c) showing the installation of the top locking pin, Fig. 2(d) showing the positioning of the formply, and, Fig. 2(e) showing the progressive installation of the intermediate panels;
Fig. 3, in Fig. 3(a) illustrates a cross-sectional view of a formwork panel apparatus used in the method of construction of a vertical wall in accordance with the present invention, Fig. 3(b) illustrates a front view of a support panel, Fig. 3(c) illustrates a front view of a support panel with support inserts, and Fig. 3(d) illustrates the support inserts installed on the support panel shown in Fig. 3(c);
Fig. 4 illustrates various components used in constructing a horizontal slab or beam in accordance with the present invention, Fig. 4(a) showing a perspective view of the basic components in position, Fig. 4(b) detailing the base support component, Fig. 4(c) detailing the 'H' frame component, Fig. 4(d) detailing the 'U' head component, Fig. 4(e) detailing the formwork frame component, Fig. 4(f) detailing the formply component, and, Fig. 4(g) showing how one side of the beam or slab components are lowered for stripping during disassembly of the components; Fig. 5 illustrates a view of the various scaffolding components used to provide scaffolding;
Fig. 6 illustrates the post-tensioning rods, end sleeves and nuts for stressing the steel rods after the liquid concrete has begun to set; and,
Figure 7 illustrates a cross-sectional view of the various components of the kit, with concrete poured, also showing the use of a brace for extra support.
Detailed Description of a Preferred Embodiments
Throughout the drawings, like numerals will be used to identify similar features, except where expressly otherwise indicated.
m reading the specification, it is assumed that the reader is well aware of standard
building techniques. It is also assumed that the reader has read and understood the specification of the Applicant's Australian Patent Nos. 647783 and 701224, or foreign equivalents thereto, the disclosures of which should be considered to be incorporated entirely herein by this reference thereto.
It should also be clearly understood that, whilst various system components, methods of construction, etc., are described herein to produce a composite building method and apparatus, the separate components and separate methods of construction can be utilised separately. Therefore, it should be clearly understood that the invention is not limited to the composite system and method as hereinafter described, but also, to the separate components and methods.
Vertical wall construction
Figures 1, 2, 3 and 6 show the various components of the kit or apparatus for constructing vertical walls in accordance with the present invention.
In essence, the walls are constructed by pouring settable concrete material via the upper opening 20 between the various components 1, allowing the concrete material to set, and, thereafter, removing the components 1.
The components 1, include guide members 2, which may be secured to a substrate surface 3, such as a concrete slab, formply members 4 and 5, which act to retain the concrete material, support frames 13 and 14 which are standardised sizes and which support the formply members 4 and 5, strong back frames 15 and their associated straight edge members 16 which are also of standardised sizes and which provide support to the assembly, and, locking pins 9 which contain the forces of the required concrete and retain the various components in position.
In order to construct vertical walls atop a concrete slab foundation, the following steps may typically be followed:
1. Identify and mark the wall positions on the surface of the concrete slab 3, including the positions of any door or window openings. Such markings are shown in Fig. 2 by reference numeral 17.
2. Place the wall reinforcing steel 7 in position as per engineers details, as also shown in Fig. 2.
3. Optionally insert any post tensioning reinforcing rods in position (see Fig. 6).
4. Optionally place any wall insulation into position.
5. Fix base guide members 2 to the concrete slab 3, or other substrate surface, following the markings 17. The guide members 2 will ensure correct positioning of the formply members 4 and 5 and of the other components. The guide members 2 may be affixed to the concrete slab 3 by using concrete bolts, which may be later removed.
6. Vertically align the internal corner formwork panels 18 (see Fig. 2(b)) into position, abutting the base guide members 2, and securing them into position by bolting to the concrete or other substrate surface 3.
7. Attach top locking pins 7 to secure the external and internal opposing corner formwork panels into their vertically correct position (see Fig. 2(c)).
8. Install corner formply panels 4 and 5 (see Fig. 2(d)). These are maintained in position by abutting against the corner formwork panels, and by being supported by spacers 6 (which are secured to the reinforcing steel 7).
9. Progressively install the intermediate formwork panels 13 and intermediate formply panels 4 and 5 into position (see Fig. 2(e)), whilst optionally installing any door, window or other opening framework, inlets, and any electrical, plumbing or other services conduits, pipes, wires or the like. Figures 3(a) and 3(b) show side and front views of a basic formwork panel 13, whilst Fig. 3(c) shows a formwork panel 13 having additional formply supports, by inserting a support insert 14.
10. Install strong back supports 15 and their associated straight-edge beams to provide additionally strength to the components 1 during construction of the wall. This is done by horizontally positioning the straight-edge beams 15 on outwardly extending brackets provided on the formwork panels 13. The strongback supports
are then locked in their positions by a plurality of spaced-apart locking pins 9 which are spanned between the opposing strongbacks, being fed through conduits 11 and secured by locking pin bolts and nuts.
11. Once all the framework sandwich is positioned, it is adjusted to the correct wall cavity width by the locking pins and nuts and is securely tightened. The concrete is then poured via upper opening 20.
12. After the concrete is set, typically after 24-48 hours, remove all the framework components for re-use.
That is, a guide member 2, which is similar in size to the formwork straight edge supports, is initially positioned and secured on top of a foundation means, such as a concrete slab flooring 3. This guide member 2 is carefully marked out and positioned to ensure that one side of the formwork thereabouts is correctly positioned. Once the guide member 2 is positioned and secured to the foundation 3, a formwork panel apparatus is positioned thereto. Both base guide members may be fixed to the substrate surface to adjust the wall thickness and positions. As seen in Fig. 1, the formwork panel apparatus includes a pair of opposing formply members 4 and 5 which are progressively attached to the formwork panel members and maintained in a spaced apart relationship by spacers 6. In a preferred form, one opposing panel member is not fixed to the substrate surface 3, but rather, it remains floating. Once the formwork panel apparatus is provided into position and supported with external bracing, pourable settable concrete material may be supplied through a top opening 20, in a continuous pour between the opposing formply members 4 and 5, and allowed to set. The rising forces of the vertically cast liquid concrete are trapped between the opposing panel members 4 and 5. The forces are equally transferred from the opposing panels to the straight edge and strong back supports. The strong back supports transfer the forces to the extent of the top and bottom locking pins that space the opposing strong backs at a set distance apart. The trapped forces of the liquid concrete are evenly applied to the opposing panel members, the opposing lightweight panel members self-align to the fixed guide member to the extent of the top and bottom locking pins. After the liquid concrete has been placed and before it sets, the fixed vertical position of the wall can be adjusted if necessary with the adjustable wall braces 18 (see Figure 7) that
support the formwork against wind loads during assembly. Once set, the various foraiwork supports and the panel apparatus components, including the guide member 2, may be removed leaving a completed visible concrete construction produced in accordance with the present invention.
It will be appreciated by persons skilled in the art that formwork panels and formply of a variety of shapes and sizes may be used. For example, plain panels may be used to form a plain wall surface, shaped panels to produce different shapes and having blanking means therein may be used to construct windows, doors or other openings in a wall surface, corner panels may be used to provide either inward or outward corners or T- wall junction on a building, to allow for various walls to join one another, cross-panels may be provided to allow for multiple walls to join together, etc., to enable a complete building wall structure to be poured and permanently locked together in one continuous concrete pour.
It will be appreciated by persons skilled in the art that various "standard" panels may be provided in a kit form, or, panels may be custom made to suit particular custom shaped constructions and be interchangeable with or attachable to the standard panels.
It will also be understood by persons skilled in the art that it is often desirable to insert mould post-tensioning rods, reinforcing steel and wall insulation and other components within such a concrete structure. Post-tensioning and reinforcing steel and insulation may likewise be provided within the foraiwork panel apparatus of the present invention prior to pouring the settable concrete material. The post-tensioning rods, reinforcing and insulation material and other components may be supplied and a detailed certified steel inspection carried out at any convenient time during the method of construction, preferably before, or during, positioning of the formply and formwork panel apparatus. Appropriate spacers, and sleeves, preferably formed of plastics or like material which is not prone to temperature transfer or rust, may be supplied to support and isolate the reinforcing and insulation material within the formwork panel apparatus.
The vertical cast concrete walls may also be formed to a selected width to provide a cavity for water storage.
In order to provide access to the post-tension rod ends, after the concrete pour, a block-out is necessary at the end of the post-tensioning rod to enable a stressing nut and washer and to be assembled and tensioned after the concrete has begun to set, Fig. 6.
In order to support the formwork panel apparatus in a correct vertical position an adjustable wind brace is fixed to a base support and near the top of one opposing panel, a top support locking pin and wall spacer arrangement 10 (Fig. 3) is fixed in position and adjusted to space and hold the top of the opposing formwork panels in position during assembly and disassembly.
A variety of support means may then be provided including straight edges (Fig. 1) which are similar in size to the base fixed guide member 2 (Fig. 1). The straight edge supports 16 are placed horizontally at predetermined spaces to support the formwork panels and ply sheeting of Fig. 1. A locking pin arrangement 9 and 9a may, for example, be produced by providing a suitable conduit material 11 supported by and extending it through the formwork panels 4 and 5 to space the predetermined distance between the opposing strong backs 15, as showing Fig. 1. A threaded rod with certified strength may be supplied through the conduit 11 and bolt 12 may be threaded on one or each end thereof to secure the locking pin into position.
It will be appreciated that once the liquid concrete material begins to rise in the cavity between the opposing lightweight formwork panels 4 and 5, the pressure of the liquid concrete will force the panels apart One of the panels will be forced against the fixed guide member 2 and the opposing panel, which is floating, will pull the strong back
15 against the fixed guide member 2. The fixed guide member 2 will be firmly clamped between the formwork panel apparatus 4 and the strong back 15. The opposing lightweight formwork panel apparatus is locked into position by the equal forces of the liquid concrete being applied to each formwork panel apparatus 3 and the locking pins 9
and 9a. The fixed guide member 2 selects the position of the wall as the concrete forces are applied to the opposing lightweight panels in a continuous concrete pour.
The straight edges 16 are clamped firmly between the strong backs 15 and the formwork panel and formply apparatus 4 and 5. The equal forces of the concrete then forces the ply sheeting against the selected profile of the external supports 4, 5, 16 and 15 and the wall positions selected by the fixed base members. The strength of the lightweight formwork to contain the forces of the liquid concrete relies upon the certified strength of the locking pins and strong backs.
The forces of the liquid concrete applied to the opposing lightweight formwork panels apparatus 3 in one continuous concrete pour aligns the formply and opposing lightweight formwork panels to the full extent the locking pin will allow and self aligns to the selected position of the fixed base member and fixed corner panel which was first secured to identify the true position of the concrete wall. The vertical correctness if necessary can be adjusted by the adjustable wind braces during the concrete pour.
It will be appreciated that once the concrete material is set, the locking pin bolts may be removed, the locking pin may be extracted from the conduit, and the conduit may be removed or the ends clipped such that they do not protrude and the block-outs removed to enable early stressing of the post-tensioning rods, Fig. 6.
The top locking assembly may also be supplied above the proposed concrete wall at the top extremity of the formply sheeting, such as shown in Fig. 1 and illustrated by the numeral 9a.
Also shown in Fig. 3 are various support panels which may be used to support the form ply joints that are supported by the form panel 5 by placing them in an abutting manner on the opposed side of the formply to that in which the concrete is supplied. The support panel 13 and 14 may optionally be included for additional support. Details of the insert panels attached to the support panel are shown in Fig. 3(c), whilst details of the form
ply sheeting and sheet ply joints to reduce a joint step are illustrated separately in Fig. 3(d).
It will therefore be appreciated that the above description describes a method of construction and a kit for construction using pourable concrete material, for in-situ casting of vertical walls.
Horizontal beam/slab construction
Using the same kit components as hereinbefore described with reference to casting a vertical wall, a horizontal slab or beam may also be cast in-situ, this also being within the ambit of the present invention.
Fig. 4 illustrates the various components and how a horizontal slab or beam may be cast in accordance with the present invention. Whilst Figs. 4(b) to 4(f) illustrate some of the core components used in the construction of the horizontally cast slab or beam, Fig. 4(a) illustrates how they are assembled together, and, Fig. 4(g) illustrates how they are disassembled.
Once the slab or beam positions are selected, a plurality of base supports 50 are spaced out over a substrate surface. TT frame members 51 are then installed atop the base supports 50, and, 'U' head 52 are installed atop the 'H' frames 51. Either or both of each base support 50 and 'U' head 51 may be adjusted to the desired height, as required.
Atop the 'U' heads 52, RHS straight edges are used a support base 54. The support base may be of any desired position, depending whether a beam or a slab is to be formed, and may be constructed using the formwork panel components used in constructing the vertical walls.
The standard procedure in-situ casting of a suspended concrete slab is as follows: 1. select the suspended slab and beam positions; 2. support the under slab beams base on a typical wall or column blanking end placed horizontally at right angles on the typical RHS straight edge adjusted the straight
edge and frame to the correct height with adjustable U head supports; Note: the horizontal formwork may also be formed with a wall frame and two standard external wall corner brackets placed horizontally each side of the formwork panel to support the beam base and side frames and formply. 3. assemble the beam reinforcing steel in position on the support base;
4. secure the side panels of the beams to the under slab heights to the beam with typical 1C clamps and lock the opposing side panels together with a wall locking pin;
5. using typical H frame supports to form the suspended slab rest the RHS straight edge supports horizontally on the H frame U heads;
6. rest the formwork frames horizontally at right angles upon the RHS straight edge supports;
7. place the formply in position upon the horizontal formwork support frames and placing the formply on the top edge of the beam side panels to ensure a clean joint in the exposed concrete slab to beam joint;
8. place the slab edge formply behind the protruding wall starter bars from the wall below to form a slab edge rebate for the external concrete wall above to extend over the slab edge;
9. assemble the slab reinforcing steel and post-tensioning rods in position with end block-outs and plastic sleeves to enable post-tensioning to take place.
Various modifications may be made to the method and apparatus for horizontally casting concrete, as per the modifications and variations herein described with reference to vertical casted concrete.
It will therefore be appreciated that the presently invention provides significant advantages over the construction techniques previously known. The components of the present invention lend themselves to being produced in kit form, and sold or licensed for use and re-use on alternative building sites. This consequently reduces skilled labour costs and material costs and wastage. It will be appreciated that various components may be fabricated from a variety of materials, including, but not limited to, any one or combination
of steel, rods, tubes sheet metal, or rigid plastics or timber. The building constructed in accordance with the present invention has various advantages over timber, plaster, bricks and other materials and former known concrete constructions methods.
Fig. 5 illustrates the assembly of a special purpose scaffolding apparatus, incorporated with the present invention. The scaffolding is attached to the strong back support 31 of a concrete wall 30, and including an outwardly extending platform support 33 and hand rail support 32. Platform support braces 34 and 36 assist in supporting the platform 33, which may be attached via one of a plurality of connection points 40 via assembly pin 30. For securement, a locking pin 37 and locking pin nut and washer 38 are used. Work platform and kickboards 41 provide a working surface. The assembly procedure is as follows:
1. secure the strong back 31 support firmly to the reinforced concrete wall 30;
2. assemble the platform support arm to a preselected height position 40 in the strong back with the assembly pin;
3. place the work platform and kickboards 41 in position; and,
4. place the hand rails in their supports 42 and lock in position.
The formwork frames and scaffolding and components are manufactured from commercially available steel tubes and angles. The locking pins are commercially available with certified strength to ensure the trapped liquid concrete does not escape.
These materials, for the strong backs and straight edges, usually have certified quality and strength and lightweight properties. The locking pins and nuts are commercially available with certified strength to ensure the trapped hydraulic forces of the liquid concrete does not escape.
The manufacturing processes has been simplified by purchasing the readily available materials, the strong back and straight edge RHS tube can be cut to selected lengths. The lightweight frame tubes are welded together for ease of materials handling and transport, and purchasing a quantity of form ply sheeting to form the profile and shape
of the concrete surfaces. The certified locking pins are readily available along with other small items used during assembly.
The horizontal forces of the liquid concrete are locked in a formwork sandwich between the opposing formwork apparatus. The formwork apparatus consists of loose form ply sheets cut to required size and shape to contain the liquid concrete. The form ply sheeting is supported by the frames and horizontal RHS straight edge. The horizontal RHS straight edge the panel frames and formply is sandwiched between liquid concrete and the vertical RHS strong backs. This simple sandwich of the opposing lightweight formwork apparatus are locked together at a predetermined distance apart by steel locking pins and nuts of specified strength to contain the forces of the vertical cast in-situ concrete.
The hydraulic forces of the liquid concrete are equally applied to each opposing formwork sandwich with the consequential effect that the strength and profile of the sandwich RHS formwork and formply apparatus forms a controlled surface finish of the vertically cast concrete material, the formwork under the forces of the vertical liquid concrete are self aligned to the base horizontal RHS which is attached to the base concrete slab and a top locking pin.
Referring to Fig. 2 illustrates the wall position lines 17 marked on the floor. The base guide member 2 fixed to the floor slab 3 reinforcing steel 7 fixed in position in the wall cavity. The special plastic wall spacers 6 attached to the reinforcing steel to hold both the wall insulation and reinforcing steel in position and the opposing formwork panels apart prior to and during the concrete pour.
Referring to Figure 6 illustrates the post-tensioning rods, end sleeves and nuts for stressing the steel rods after the liquid concrete has begun to set.
It will be understood that various additional features such as insulative materials, provision for piping and wiring, etc., may be easily supplied prior to pouring the concrete material and moulded firmly in position to reduce the work of following trades.
Various modifications and additions may be made to the building method and apparatus as hereinbefore described. AU such variations and modifications should be considered to fall within the spirit and scope of the invention as broadly hereinbefore described.