AU9705198A - Reinforcing elements - Google Patents

Description

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION STANDARD PATENT Applicant(s): BHP STEEL (RP) PTY LTD A.C.N. 000 148 289 Invention Title: REINFORCING ELEMENTS The following statement is a full description of this invention, including the best method of performing it known to me/us: 2 REINFORCING ELEMENTS This invention relates generally to reinforcing elements and methods of fabricating reinforcing elements. The invention relates particular, but not exclusively, to methods of fabricating steel reinforcing elements for concrete structures such as, for example, concrete beams, slabs, columns and footings.

Conventional concrete structures subjected to bending loads are reinforced with steel reinforcing elements. Concrete offers great resistance to compressive load, but lacks tensile strength. Steel reinforcing elements placed into reinforced concrete structures are designed to take all the tensile load placed on the structures and can be also used to provide additional compressive strength where unreinforced concrete would prove too bulky.

Generally the position and size of the elements within the concrete structure is dependent upon the anticipated tensile loading on the structure. For example, in a beam or slab suspended on its ends and subjected to downward loads therebetween the reinforcing elements are located towards the bottom of the structure so that the steel reinforcement takes the tensile load. In concrete slab constructions lying on the ground and loaded downwardly, the uniform ground reaction places the top portion of the slab in tension and the steel reinforcing elements are placed in the top portions of the concrete slab.

Reinforcing elements adapted to be embedded in concrete or other cementitious materials are generally made of steel rods, bars or mesh fabricated on site or prefabricated remote from the site. Mesh generally comprises a network of intersecting longitudinal and transverse reinforcing J:\Speci\300 399\300 349\32918.doc 11/12/98 3 members, for example, wires or rods, welded, tied or otherwise secured at the intersections to form a grid.

Prefabricated elements usually comprise prefabricated welded steel mesh of predetermined mesh wire thickness and mesh size. The mesh is generally electric welded with the longitudinal and transverse members fixed in position by an electric welding machine designed to space the members accurately and weld them together at the contact points.

Accurate spacing of the longitudinal and transverse members enhances the intrinsic reinforcing value of the mesh by facilitating placement of the steel at its predetermined design location. Additionally, each welded intersection develops a positive anchor in the concrete.

Mesh fabricators commonly furnish prefabricated welded mesh in flat sheets or rolls of standard length and width.

Standard rolls are 2.4 metres wide and 60 metres long.

Welded mesh that is too stiff to be rolled is provided as flat sheets. Typically sheets are 2.4 metres wide and 6 metres long and can weigh up to 150 Kg. Handling and transportation of sheets can be cumbersome and labour intensive, often requiring the services of several people to safely handle each sheet.

Bar fabricators commonly furnish concrete reinforcing bars which are either straight and cut to the proper length, or bent and/or curved in accordance with plans and specifications. Concrete reinforcing bars are usually deformed or plain round bars. Deformed bars are bars in which the surface is provided with ribs, protrusions or other deformations which inhibit longitudinal movement of the bars relative to the surrounding concrete. Surface deformations can be hot formed in the final roll pass in the steel mill by passing the bars between rolls having patterns cut into them or cold roll formed by the bar or J:\Speci\300 399\300 349\32918.doc 11/12/98 4 mesh fabricators. Plain round bars are usually used in low gauge mesh.

Steel mills commonly provide reinforcing bars in coils or straight lengths either cut to design length in the mill or in long lengths to be recut for fabrication by the bar or mesh fabricators.

Traditionally in the fabrication of reinforcing members, hot rolled bar provided to fabricators in coils is reduced and then coiled remote from the fabrication station before being transported to the fabrication station. This process is time consuming, wasteful of human and other resources and adds to overall production costs.

Current practice in forming reinforced concrete structures is to emplace reinforcing elements at a predetermined height within a formwork cavity with the elements extending across a substantial area of the structure. The elements are generally emplaced and positioned either in the form of arrays of single bars or as a prefabricated welded mesh or grid. In the former case the single bars of a first array are laid longitudinally to extend parallel or near parallel to one another, are laterally spaced apart a predetermined distance and are supported on chairs. A second array of single bars is then laid transversely to overlap the first array, with the single bars of the second array being laterally spaced apart a predetermined distance and tied to the bars of the first array with wire or are otherwise fixed at the cross intersections to secure the bars in their correct position. This is a manual operation which relies entirely on the skill and experience of the individual steel fixer. Hence, a disadvantage of this process is that the accuracy of bar positioning is entirely at the discretion of the steel fixer. Another disadvantage J:\Spei\300 -399\300 349\2918.doc 11/12/98 5 of this process is that errors can occur, and are known to have occurred, in accurately identifying and selecting the specified bar or bars from a large batch of bundled bars which may be of similar but different gauge, length or configuration and positioning of the bar in its correct location and position in the structure. Additionally this process is labour intensive, inefficient because of time wasted in locating, identifying and assembling groups of bars, and prone to errors in bar selection and placement position. Tying of bars at intersections to maintain them in their correct location is also laborious and time consuming.

Prefabricated welded mesh sheets are typically laid with overlapping edge margins or laps on the sides and ends to achieve continuity. Steel reinforcement in this form provides an accurate positioning and spacing system for the bars or wires but it results in inefficiencies of steel utilisation because of the high degree of overlapping inherent in mesh placement. Also, because of the normal standard sheet size of mesh, there is a high degree of wastage associated with the need to cut sheets into smaller pieces in order to accommodate the size and shape of an area of a concrete slab, for example, which is to be reinforced. Also, because there are a limited number of wire/bar sizes and spacings available in mesh sheet form, the reinforcement design requirement cannot be easily optimised. The designer would normally have to use a higher density of steel reinforcement than ideal because he has to choose a mesh size or bar size and spacing which is equal to or greater than the minimum design requirement and thus it would normally be at a higher level than the minimum.

Nominal bar spacings increase in increments of 20 mm to mm which represents a difference of about 5% to 15% between bar spacings. Mesh densities vary between standard mesh J:\Speci\300 399\300 349\32918.doc 11/12/98 I 6 sizes by around 20%. Australian Standard 3600-1994 specifies the minimum requirements for reinforcing elements in concrete structures.

An object of the present invention is to address or alleviate one or more of the above identified deficiencies or problems of the prior art.

The invention provides a method of fabricating reinforcing members comprising the following steps in sequence: providing a hot rolled bar of predetermined crosssectional shape and area to a reduction station; reducing said predetermined cross-sectional area; straightening the bar; cutting the bar into elongate load bearing reinforcing members of predetermined lengths; and optionally bending the members into predetermined shape and configuration, without intermediate coiling and uncoiling prior to straightening.

Preferably the reducing step is performed by a stretching process to improve the mechanical properties of the bar.

The invention also provides a method of fabricating a reinforcing element comprising the steps of: providing a plurality of elongate load bearing reinforcing members of predetermined length and predetermined shape and configuration in a predetermined sequence; and connecting sequential adjacent members by means of a plurality of non-load bearing links.

Preferably connection of the adjacent members is effected by a length of adhesive tape which serves as one of the plurality of non-load bearing links. More preferably the J:\Speci\3OO 399\300 349\32918.doc 11/12/98 7 length of adhesive tape is one of a pair of opposed adhesive tapes each having an adhesive surface being adhered one to the other so as to provide one of the links.

Preferably the method of fabricating a reinforcing element comprises the further steps of bundling the element into an elongate close-packed sheaf and tagging the sheaf.

The invention also provides a method of fabricating a reinforcing element comprising a plurality of elongate load bearing reinforcing members having adjacent members connected by non-load bearing links, said method comprising the following steps in sequence: providing a hot rolled bar of predetermined crosssectional shape and area; reducing said predetermined cross-sectional area; optionally coiling the bar and uncoiling the bar; straightening the bar; cutting the bar into elongate load bearing reinforcing members of predetermined lengths; optionally bending the members into predetermined shape and configuration; and connecting sequentially provided adjacent members one to the other by means of a plurality of non-load bearing links to provide an element having a predetermined maximum lateral spacing between adjacent members when the element is laterally expanded.

Preferably the reducing step is performed by a stretching process to improve the mechanical properties of the bar.

Preferably connection of the adjacent members is effected by a length of adhesive tape which serves as one of the plurality of non-load bearing links. More preferably the length of adhesive tape is one of a pair of opposed J:\Speci\300 399\300 349\32918.doc 11/12/98 8 adhesive tapes each having an adhesive surface being adhered one to the other so as to provide one of the links.

Preferably the method of fabricating reinforcing elements comprises the further steps of bundling the element into an elongate close-packed sheaf and tagging the sheaf.

Alternatively the reducing step may, for example, comprise drawing or rolling.

Additionally the bar may be provided as long straight lengths or in coil form and may comprise plain rounds or deformed rounds.

The invention also provides a method of installing reinforcing elements comprising the steps of: providing a pair of sheafs of reinforcing elements each comprising a plurality of longitudinal reinforcing members adapted to bear loads and of transverse links extending between adjacent members and joining them together in a predetermined sequence wherein the transverse links are non-rigid; laterally expanding one of the pair of sheafs to present an array of the reinforcing members extending longitudinally; laterally expanding the other of the pair of sheafs to overlap said array and-to present another array of the reinforcing members extending transversely; and fastening the overlapped expanded arrays to one another at several reinforcing member intersections.

The invention provides a reinforcing element for reinforced concrete structures comprising a plurality of longitudinal reinforcing members adapted to bear loads and of transverse J:\Speci\300 399\300 349\32918.doc 11/12/98 -9links extending between adjacent members and joining them together in a predetermined sequence wherein the transverse links are non-rigid.

The invention also provides a reinforcing element comprising a plurality of elongate reinforcing members disposed side by side to form an array of transversely spaced apart longitudinally extending load bearing members wherein adjacent members are connected one to the other by means of a plurality of non-load bearing transverse links whereby adjacent members are held in a predetermined sequence.

Preferably the non-load bearing links each include a pair of opposed adhesive tapes each having an adhesive surface contacting one another with one of the reinforcing members sandwiched therebetween. More preferably the adhesive tape is commercially available in Australia such as a "cloth tape".

Preferably the members are steel rods or bars. The members may be substantially straight. In other embodiments, one or more of the members are bent to a predetermined shape and configuration.

It is preferred that the rods or bars have a nominal diameter in the range of 5 mm to 40 mm and more preferably in the range of 8 mm to 24 mm.

Preferably one or more of the members are provided with a deformed surface.

Preferably the links are sufficiently flexible to enable the members to be bundled together to form an elongate substantially close-packed sheaf.

J:\Speci\300 399\300 349\32918.doc 11/12/98 10 It is preferred that the links are sufficiently flexible to enable the spacing between adjacent members to be varied from a minimum spacing when the element is bundled, to a predetermined maximum spacing when the element is laterally expanded to space apart the reinforcing members. The predetermined maximum spacing generally being the length of the particular link. The minimum spacing generally being such that the members contact.

Preferably the maximum spacing between adjacent members is in the range of 50 mm to 750 mm and more preferably in the range of 150 mm to 400 mm.

Preferably the links enable the element to be laterally expanded to effect a substantially constant predetermined maximum spacing between spaced apart adjacent members so that the members are substantially parallel.

In other embodiments, the plurality of links between a pair of adjacent members are of sequentially different length to enable adjacent members of the laterally expanded element to be presented in non-parallel spaced apart relationship.

Preferably each link is provided with ends having releaseable clamping means adapted to receive and/or grip respective adjacent members.

More preferably the clamping means comprise deformable extensions having reinforcing member receiving openings adapted to be snap-fitted to its respective adjacent member.

The clamping means preferably provides good frictional engagement with the material of the reinforcing member.

J:\Speci\300 399\300 349\32918.doc 11/12/98 11 In other embodiments, each link may be provided with ends adapted to be fixedly mounted to its respective member.

Each end may, for example, be shrink-fitted to its respective member.

It is preferred that the link ends are constrained from sliding along its respective member.

More preferably, the link ends are constrained from both sliding along and sliding about its respective member.

The plurality of links between adjacent members may be spaced apart predetermined distances, or may be spaced apart at random.

Preferably in elements having three or more members in array, the plurality of links between each sequential adjacent member form a respective plurality of rows of substantially in-register links. More preferably the links of each row are integral. That is to say, the in-register links are in the form of a single continuous link traversing and mounted to each sequential adjacent member of the array.

Alternatively the transverse links are in the form of strings, ties or other flexible connectors made of, for example, twine, plastics or other flexible or pliable material.

The links are adapted not to function as load bearing members. That is to say, they are of insufficient mechanical strength to bear loads of the kind anticipated to be borne by the reinforcing members. Indeed they may be J:\Speci\300 -399\300 349\32918.doc 11/12/98 12 of sufficient mechanical strength only to bear loads encountered during transport and handling of the elements.

The invention also provides a reinforcing mesh comprising two reinforcing elemepts according to the invention wherein one of the two reinforcing elements is laterally expanded to space apart its reinforcing members to present an array of reinforcing members extending longitudinally and the other of the two reinforcing elements is laterally expanded to overlap the said one reinforcing element to present an array of its reinforcing members extending transversely.

Preferably the two overlapped expanded reinforcing elements are fastened to one another at a plurality of reinforcing member intersections. Fastening may, for example, be by means of wire ties. However, fastening may be by means of welding, clips or other bindings.

The invention also provides a kit adapted to reinforce concrete structures comprising one or more reinforcing elements according to the invention, a plurality of bar chairs, and fastening means adapted to fasten reinforcing members of one reinforcing element to those of the other.

In order that the invention may be more fully explained, some particular embodiments will be described in some detail with reference to the accompanying drawings in which: Figure 1 is a plan view of a first embodiment of an expanded reinforcing element according to the invention; Figure 2 is a plan view of a second embodiment of an expanded reinforcing element according to the invention; Figure 3 is a plan view of a third embodiment of an expanded reinforcing element according to the invention; J:\Speci\300 399\300 349\32918.doc 11/12/98 13 Figure 4 is a plan view of a fourth embodiment of an expanded reinforcing element according to the invention; Figure 5 is a perspective view of a preferred embodiment of a mesh according to the invention; Figure 6 is a schematic diagram of an apparatus for manufacturing an embodiment of an element, in accordance with a preferred embodiment of a method of the present invention; and Figure 7a is a schematic diagram of an apparatus for interconnecting adjacent reinforcing members with flexible ties; and Figure 7b is an enlarged elevational view of connection of a flexible tie to one of the reinforcing members.

Figure 1 illustrates a reinforcing element for reinforced concrete structures in accordance with one embodiment of the invention in a fully expanded condition comprising three longitudinal reinforcing members 1 in the form of round bars of 12 mm diameter made of reinforcing grade steel, being a material having a high yield point and three transverse links 2 extending between each set of adjacent bars 1 and joining them together in a predetermined sequence wherein the transverse links 2 are flexible ties in the form of a pair of opposed adhesive tapes each having an adhesive surface contacting one another with the reinforcing member 1 sandwiched therebetween. The adhesive tape has substantially lower yield point than that of the reinforcing members i. The reinforcing members 1 are formed of steel rod having a minimum yield strength in the range of 250 to 550 MPa. The three links 2 between each sequential adjacent member 1 form three respective rows of substantially in-register links 2 with the links of each row being integral. That is to say, the in-register links 2 J:\Speci\3OO 399\300 349\3291B.doc 11/12/98 14 are in the form of a single continuous link traversing and mounted to each sequential adjacent member 1 of the array.

The links 2 are connected to the members 1 by adhering the pair of opposed tapes to one another. Alternatively the links may be in the form of string made of twine in which case they are connected to the members by tying and knotting. Other links may be connected by means of welding or by use of a separate clip, clasp or binding.

Figure 2 illustrates another embodiment similar to that illustrated in Figure 1 except that the reinforcing element comprises five elongate substantially straight reinforcing members of different length, diameter and lateral spacing.

The reinforcing members are disposed side by side to form an array of transversely spaced apart longitudinally extending substantially parallel load bearing members 3, 4, 6 and 7 wherein adjacent members are connected one to the other by means of three sets of non-load bearing links 8a, 8b, and 8c. Adjacent members are thus held in a predetermined sequence.

In a single "bundle" of linked reinforcing members such as 3, 4, 5, 6 and 7 the members can be positioned at different spacings and the spacing can be set to a precise distance and thus provide the optimum density or intensity of reinforcement. This is calculated by the designer and allows for the most efficient design possible. This can be contrasted with current conventional steel fixing procedures where the bar spacing and size has to be maintained fairly constant to be practical since individual bars have to be identified from large bundles and then positioned manually one at a time. Normal bar spacings in conventional steel fixing are usually rounded of to the nearest 20 or 25mm. The system of this embodiment of the J:\Speci\300 399\300 349\32918.doc 11/12/98 15 invention provides a practical means of achieving an optimum reinforcing member arrangement and at the same time reduces the labour involved in conventional bar fixing. In addition, the- reinforcing members can be of different diameter and length, and the reinforcing members positioned in varying lateral positions relative to each other. The spacing of the flexible ties 8a, 8b, and 8c can also be varied to suit the reinforcing member configuration.

As described below, reinforcing mesh can be formed by overlapping a pair of reinforcing elements with the reinforcing members of each element extending perpendicular to each other. An advantage with the reinforcing element such as that illustrated in Figure 2 is that fewer ties are required at reinforcing member intersections to hold the steel in position during concrete placement. The flexible ties provide an inherent means of reinforcing member constraint.

Figure 3 illustrates another embodiment similar to that illustrated in Figure 1 except that the reinforcing element comprises three load bearing members 10, 11, 12 each being bent to a predetermined shape and configuration with links 13 of substantially similar length.

Figure 4 illustrates another embodiment similar to that illustrated in Figure 1 except that the plurality of links 14, 15, 16 between each pair of adjacent members 17 are of sequentially different length to enable adjacent members of the laterally expanded element to be presented in out of parallel spaced apart relationship.

Figure 5 illustrates a mesh according to the invention comprising two reinforcing elements 18, 19 wherein one 18 of the two reinforcing elements is laterally expanded to J:\Speci\300 399\300 349\32918.doc 11/12/98 16 space apart its reinforcing members to present an array of reinforcing members extending longitudinally and the other 19 of the two reinforcing elements is laterally expanded to overlap the said one reinforcing element 18 to present an array of its reinforcing members extending transversely.

The two overlapped expanded reinforcing elements 18, 19 are fastened to one another at several reinforcing member intersections by means of wire ties (not shown). The links 20 of the one element 18 are disposed to extend substantially along the length of the reinforcing members of the other element 19 with the links 20 of the other element 19 extending substantially along the length of the reinforcing members of the one element 18 to minimise the risk of damage during on site construction of the reinforced concrete structure.

In reinforced concrete structures, the links do not function as load bearing members. That is to say, they are of insufficient mechanical strength to bear loads of the kind expected to be borne by the reinforcing members.

Indeed they are of sufficient mechanical strength only to bear loads encountered during transport and handling of the elements.

The links are sufficiently flexible to enable the members to be bundled together to form an elongate substantially close-packed sheaf and sufficiently flexible(to enable the spacing between adjacent members to be varied from a minimum spacing when the element is bundled, to a predetermined maximum spacing when the element is laterally expanded to space apart the reinforcing members.

J:\Speci\3OO 399\300 349\32918.doc 11/12/98 17 A method of fabricating reinforcing members according to one embodiment of the invention comprises in sequence: providing a hot rolled bar of predetermined cross-sectional shape and area (with or without surface deformations) to a reduction station, reducing said predetermined crosssectional area by feeding the bar through a rolling mill or a stretching device, straightening the bar, cutting the bar into elongate load bearing reinforcing members of predetermined lengths and optionally bending one or more of the members into predetermined shape and configuration.

Hitherto the hot rolled bar provided to a fabrication station in coil form after is reduced and coiled remote from the fabrication station and then transported to the fabrication station. The above described embodiment of the present invention eliminates the need to coil, transport and handle and then uncoil the reduced bar prior to straightening thereby reducing costs. To compensate for variations in production speeds of equipment in the line, an accumulator is provided.

A preferred method of fabricating a reinforcing element comprises the steps of: providing a plurality of elongate load bearing reinforcing members of predetermined length and predetermined shape and configuration in a predetermined sequence; and connecting sequential adjacent members by means of a plurality of non-load bearing links.

The reinforcing element can then be bundled into an elongate close-packed sheaf and tagged for identification, storage, transport and handling.

J:\Speci\300 399\300 349\32918.doc 11/12/98 18 A preferred method of fabricating reinforcing elements comprising a plurality of elongate load bearing reinforcing members having adjacent members connected by non load bearing links comprises the following steps in sequence: providing a hot rolled bar of predetermined crosssectional shape and area; reducing said predetermined cross-sectional area; optionally coiling the bar, uncoiling the bar and straightening the bar; cutting the bar into elongate load bearing reinforcing members of predetermined lengths; optionally bending the members into predetermined shape and configuration; and connecting sequentially provided adjacent members one to the other by means of a plurality of non-load bearing links to provide on element having a predetermined maximum lateral spacing between adjacent members when the element is laterally expanded.

The element is then bundled into an elongate close-packed sheaf and tagged for identification, storage, transport and handling.

The reducing step is performed by stretching. It has surprisingly been found that stretching provides reinforcing members of improved mechanical properties, for example, improved ductility over cold reduced members.

Alternatively the reducing step is performed by drawing or cold rolling. Cold reduction generally provides 20 to reduction in cross-sectional area of the bar whereas stretching of hot-rolled deformed bar provides 1% to 8% permanent elongation.

Reinforcing members can be processed from coils or straight lengths and generally comprise plain rounds or deformed rounds.

J:\Speci\300 399\300 349\32918.doc 11/12/98 19 Figure 6 is a schematic diagram of an apparatus for manufacturing a preferred embodiment of an element, in accordance with a preferred embodiment of a method of the present invention. With reference to Figure 6 a preferred embodiment of a method of fabricating an element according to the invention comprises providing bar 21, of 12 mm diameter low carbon steel, in continuous length from a coil to a fabrication station, in line straightening and cutting of the bar, at a straightening and cutting station 22, into reinforcing members of predetermined length 23, with members predetermined to have sections bent into predetermined shapes or configurations bent or otherwise shaped at a shaping station 24. Each shaped member 25 is then transferred sequentially to a spacing and linking station 30, where each member 25 is positioned so that it is spaced apart its predetermined maximum spacing from its next adjacent member 25. Three continuous ties 26 such as adhesive tape are connected at predetermined locations along the members 25. Typically the member spacing is 200 mm. It can readily bp appreciated that the present invention is not limited to this particular spacing. This process is repeated to provide a number of members 25, four members in the illustrated example, which are sequentially connected by the three continuous flexible ties 26 in this manner to form an element 27 that can be expanded to provide an array of longitudinal spaced apart members in a concrete structure. The element 27 is bundled into a close packed sheaf 28 for storage and handling. The sheaf or bundle 28 is then provided with an identification tag 31 which provides information regarding the element 27 and reference position of the element 27 in the concrete structure. The apparatus is controlled by a master controller 29.

J:\Speci\300 399\300 349\32918.doc 11/12/98 20 Various production techniques may be appropriate in connecting the continuous ties or adhesive tape between adjacent members i. In one embodiment as illustrated in Figure 7a the adhesive tape 34A or 38B is reeled from a pair of opposed rolls of tape 40A/40B and applied to adjacent members 1 which are together fed between a pair of pressure rollers 42A/42B. The tape 38A/38B extends transverse to the adjacent members 1 which are arranged parallel to one another. The reinforcing member 1 is sandwiched between opposing lengths of tape 38A/38B as depicted in the lower representation of Figure 7b.

Alternatively as indicated in the upper representation of Figure 7b a single length of adhesive tape 44A or 44B extends between adjacent members 1 and each of the reinforcing members 1 is sandwiched between lapping end portions of adjacent lengths of said tape 44A and 44B In use, each sheaf or bundle is expanded to provide one layer of reinforcement. Typically two layers of reinforcement in the form of two overlapping expanded elements extending in mutually perpendicular directions, are used to provide a mesh according to the invention.

Mesh according to the present invention may facilitate engineered or design solution to reinforcing concrete structures as opposed to the conventional standard mesh solution. That is to say, it enables the use of an engineered mesh with its inherent economies of material.

Reinforcing elements according to the present invention additionally may facilitate supply, handling and emplacement of reinforcing bars, may ameliorate human and economic resources involving labour in placing reinforcing bars and in tying reinforcing bars at bar intersections and J:\Speci\300 399\300 349\32918.doc 11/12/98 21 may ameliorate problems of correctly identifying bars by grouping bars in small bundles in which adjacent bars are interconnected with flexible ties; may reduce the wastage of steel reinforcement by eliminating off-cuts and minimising laps, may enhance the efficiency of steel reinforcement design and use in concrete structures by reducing waste and the inherent need for over-design common in the art, may reduce placement/fixing labour and ameliorate conventional error prone methods.

Many modifications may be made to the preferred embodiments of the present invention described without departing from the spirit and scope of the present invention.

In the claims which follow and in the preceding summary of the invention, except where the context requires otherwise due to express language or necessary implication, the word "comprising" is used in the sense of "including", that is the features specified may be associated with further features in various embodiments of the invention.

J:\Speci\300 399\300 349\32918.doc 11/12/98

Claims (22)

1. 2. A method of fabricating reinforcing members as defined in claim 1 wherein the reduction step involves stretching of the bar to improve its mechanical properties.
2. 3. A method of fabricating a reinforcing element comprising the steps of: providing a plurality of elongate load bearing reinforcing members of predetermined length and predetermined shape and configuration in a predetermined sequence; and connecting sequential adjacent members by means of a plurality of non-load bearing links.
3. 4. A method of fabricating a reinforcing element as defined in claim 3 further comprising the steps of bundling the element into an elongate close-packed sheaf. A method of fabricating a reinforcing element comprising a plurality of elongate load bearing reinforcing members having adjacent members connected by non-load J:\Speci\300 399\300 349\32918.doc 11/12/98 23 bearing links, said method comprising the following steps in sequence: providing a hot rolled bar of predetermined cross- sectional shape and area; reducing said predetermined cross-sectional area; straightening the bar; and cutting the bar into elongate load bearing reinforcing members of predetermined lengths; connecting sequentially provided adjacent members one to the other by means of a plurality of non-load bearing links to provide an element having a predetermined maximum lateral spacing between adjacent members when the element is laterally expanded.
4. 6. A method of fabricating a reinforcing element as defined in claim 5 wherein the reduction step involves stretching of the bar to improve its mechanical properties.
5. 7. A method of fabricating a reinforcing element as defined in any one of claims 3 to 5 wherein the reducing step comprises drawing or rolling of the bar.
6. 8. A method of fabricating a reinforcing element as defined in any one of claims 3 to 7 wherein connection of the adjacent members is effected by a length of adhesive tape which serves as one of the plurality of non-load bearing links.
7. 9. A method of fabricating a reinforcing element as defined in claim 8 wherein the length of adhesive tape is one of a pair of adhesive tapes each having an adhesive surface adhered one to the other. J:\Speci\300 399\300 349\32918.doc 11/12/98 I 24 A method of fabricating a reinforcing element as defined in any one of claims 5 to 9 further comprising the step of coiling and uncoiling the bar following reduction of the hot rolled bar.
8. 11. A method of fabricating a reinforcing element as defined in any one of claims 5 to 10 additionally comprising the step of bending the cut members into predetermined shape and configuration.
9. 12. A method of fabricating a reinforcing element as defined in any one of claims 5 to 11 further comprising the step of bundling the element into an elongate close-packed sheaf.
10. 13. A method of installing reinforcing elements comprising the steps of: providing a pair of sheafs of reinforcing elements each comprising a plurality of longitudinal reinforcing members adapted to bear loads and of transverse links extending between adjacent members and joining them together in a predetermined sequence wherein the transverse links are non-rigid; laterally expanding one of the pair of sheafs to present an array of the reinforcing members extending longitudinally; laterally expanding the other of the pair of sheafs to overlap said array and to present another array of the reinforcing members extending transversely; and fastening the overlapped expanded arrays to one another at several reinforcing member intersections.
11. 14. A reinforcing element for reinforced concrete structures comprising a plurality of longitudinal reinforcing members adapted to bear loads and of transverse J:\S~eci\300 399\300 349\32918.doc 11/12/98 25 links extending between adjacent members and joining them together in a predetermined sequence wherein the transverse links are non-rigid.
12. 15. A reinforcing element comprising a plurality of elongate reinforcing members disposed side by side to form an array of transversely spaced apart longitudinally extending load bearing members wherein adjacent members are connected one to the other by means of a plurality of non- load bearing transverse links whereby adjacent members are held in a predetermined sequence.
13. 16. A reinforcing element as defined in claim 14 or wherein the members are steel rods or bars.
14. 17. A reinforcing element as defined in any one of claims 14 to 16 wherein the links are sufficiently flexible to enable the members to be bundled together to form an elongate substantially close-packed sheaf.
15. 18. A reinforcing element as defined in claim 17 wherein the links are sufficiently flexible to enable the spacing between adjacent members to be varied from a minimum spacing when the element is bundled, to a predetermined maximum spacing when the element is laterally expanded to space apart the reinforcing members.
16. 19. A reinforcing element as defined in any one of claims 14 to 18 wherein each link is provided with ends having releaseable clamping means adapted to receive and/or grip respective adjacent members. A reinforcing element as defined in claim 19 wherein the clamping means comprise deformable extensions having J:\Speci\300 399\300 349\32918.doc 11/12/98 26 reinforcing member receiving openings adapted to be snap- fitted to its respective adjacent member.
17. 21. A reinforcing element as defined in any one of claims 14 to 18 wherein each link is be provided with ends adapted to be fixedly mounted to its respective member.
18. 22. A reinforcing element as defined in any one of claims 14 to 18 wherein the transverse links are in the form of adhesive tape.
19. 23. A reinforcing element as defined in any one of claims 14 to 21 wherein the transverse links are in the form of strings, ties or other flexible connectors constructed of twine, plastics or other flexible or pliable material.
20. 24. A reinforcing mesh comprising two reinforcing elements according to any one of claims 14 to 23 wherein one of the two reinforcing elements is laterally expanded to space apart its reinforcing members to present an array of reinforcing members extending longitudinally and the other of the two reinforcing elements is laterally expanded to overlap the said one reinforcing element to present an array of its reinforcing members extending transversely. A reinforcing mesh as defined in claim 24 wherein the two overlapped expanded reinforcing elements are fastened to one another at a plurality of reinforcing member intersections.
21. 26. A method of fabricating a reinforcing element or reinforcing member substantially as hereinbefore described with reference to the accompanying drawings. J:\Speci\300 399\300 349\32918.doc 11/12/98 27
22. 27. A reinforcing element, reinforcing member, or reinforcing mesh substantially as hereinbefore described with reference to the accompanying drawings. Dated this 11th day of December 1998 BHP STEEL (RP) PTY LTD By their Patent Attorneys GRIFFITH HACK Fellows Institute of Patent Attorneys of Australia J:\Speci\300 399\300 349\32918.doc 11/12/98