AU675905B1 - Reinforcement bar - Google Patents

Description

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AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT 0 *00 Name of Applicants: Actual Inventor: Address for Service: HALS VANDER POORTEN LEE ROBERT

MEIKLEJOHN

HALS VANDER POORTEN CULLEN CO., Patent Trade Mark Attorneys, 240 Queen Street, Brisbane, Qld. 4000, Australia.

REINFORCEMENT BAR Invention Title: 0 0 00 The following statement is a full description of this invention, including the best method of performing it known to us.

REINFORCEMENT BAR The present invention relates to a reinforcement bar for reinforcing concrete structures.

It is often necessary to provide reinforcement for concrete structures so as to compensate for the relatively low tensile strength of concrete. Such reinforcement may be provided by continuous steel bars, mesh or fibres such as glass fibres. In some applications, steel bars are assembled into a grid shaped reinforcement layout prior to pouring of the concrete.

The strength of the bars and the dimensions of the reinforcement grid are important in determining the strength of the final structure and are generally subject to strict guidelines. Important features of the :o 15 reinforcement grid are the number of bars and the spacings between them. These grids are assembled manually and the bars are placed according to measurements made by the steel fixer. This is tedious Sand time consuming and subject to the accuracy of the 20 steel fixer.

In other applications, the reinforcement layout has fitments or supports for holding the bars in position before and during concrete pouring. The placement of fitments or supports is also important and requires 25 measurements to be made by a steel fixer.

The completed reinforcement layout must be properly checked prior to pouring of the concrete.

SoChecking is conducted by manually measuring the spacings between bars and any supports or fitments. This is also a time consuming procedure and leads to an increase in construction costs.

It is an ol-ject of the present invention to provide a reinforcement bar and method of constructing a reinforcement layout which may alleviate at least some of the above disadvantages and/or to provide the public with a useful choice.

According to a first embodiment of the present invention, there is provided a reinforcement bar for a reinforcement layout having a plurality of bars spaced at a desired distance relative to each other or to retaining or support means, wherein said bar has markings occurring at a predetermined spaced distance along the length of said bar, said predetermined distance being proportional to said desired distance such that said desired distance can be visually determined without measurements being taken.

According to a second embodiment of the present invention, there is provided a method of constructing a reinforcement layout having a plurality of bars spaced at a desired distance relative to each other or to retaining or support means, the method including assembling the layout by placing a plurality of bars according to any 15 one of claims 1 to 5 at positions relative to each other or to the retaining or support means, the bars being placed such that the distance between the bars or the retaining or support means is proportional to the predetermined spac.ed distance between the markings on the V v I c Ik- 20 bars and can be determined without measurements being taken.

The reinforcement bar of the present invention is typically a rolled steel bar. The bar has markings occurring at predetermined spaced distances along the S 25 length of the bar. The markings may take any form which is visible to a steel fixer. Preferably, the markings S•are clearly visible when the bar is viewed from any direction. The markings may be introduced by known means during rolling of the bar.

Generally, reinforcement bars are ,vided with helical ribs along their length. This allows for a greater purchase with the concrete. The markings may also be indicated by a small break in the continuity of the ribs. Alternatively the markings may be indicated by ribs having a reverse orientation, pitch or width. The markings may also comprise indentations and/or projections on the bar.

The reinforcement layout is generally assembled by known methods. A typical reinforcement layout is in the form of a grid having a first set of spaced parallel bars positioned transverse to a second set of spaced parallel bars. Generally, the bars intersect or cross over at right angles. In some applications, the bars may intersect at other angles. The markings on the bars of the present invention are used to visually identify and check the desired spacings between the bars. The reinforcement layout is constructed such that intersection points are proportional to the markings on the respective bars. In this way, it is easy to check whether the bars are positioned correctly by observing the alignment of the bars with the markings. Adjustments may accordingly be made without requiring further 15 measurements.

Other types of reinforcement layouts which may be prepared by the method of the present invention have a single set of parallel bars and there are no intersection S"points. Such reinforcement layouts are used to reinforce concrete girders and the like. The parallel bars define the outer dimensions of the girders or the like. The baL: may be held in position relative to each other by S"means of steel wire fitments which typically encircle the reinforcement layout at predetermined spacings along the bars. The fitments may be attached to the bars with tiewire. In the method of the present invention the fitments are placed at positions relative to the markings .on the bars such that no measurement is necessary.

Another type of fitment used for a reinforcement layout of this type is in the form of a continuous helical wire which surrounds a set of bars. In this case the pitch of the helix is proportional to the markings on the bar.

Reinforcement grids which are used to reinforce horizontal slabs may have supports which hold the grid above the ground. The supports are typically placed at a desired distance apart. In the method of the present invention the supports are placed at positions

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proportional to the markings such that no measurement is necessary.

It is not necessary that each marking coincides with an intersection point between bars or between the retaining or support means. This means that for example, the bars may intersect at every second, third or fourth marking. Alternatively the intersection points may coincide with half, third or quarter spacings between the markings. It is preferred that a number of markings occur between intersection points or between the retaining or support means. This allows for bars having the same spacings between markings to be used for different types of reinforcement layouts. Such bars may also be used for reinforcement layouts in which different spacings within the same layout may be required. Also, when the distance between the markings is known, the distance between the intersection points or retaining or support means may simply be obtained by counting the Snumber of intermediate markings. No measurement is 20 necessary. A preferred distance between markings is cm.

It is not essential that every bar of the reinfJorcement layout is a bar according to the present invention, although this is preferred. Any combination of marked and unmarked bars may be used, providing the correct spacings are observed. For example, an unmarked S• bar may be placed between two parallel marked bars.

Once the reinforcement layout has been assembled, there is no need to physically measure the spacings between the bars or between any retaining or support means. This can be done visually using the markings on the bars as described above.

By way of example only, the invention will be described with reference to the following Figures in which: Figures 1A and lB illustrate side views rotated through 900 of a bar according to the prior art.

Figures 2A and 2B illustrate side views rotated through 900 of a bar according to a preferred embodiment of the present invention; Figures 3 and 4 illustrate further preferred embodiments of a bar of the present invention.

Figure 5 illustrates a reinforcement layout assembled by a preferred method fo the present invention.

Figure 6 illustrates a reinforcement layout assembled by a further preferred method of the present invention.

Figure 7 illustrates a reinforcement layout assembled by a further preferred method of the present invention.

Figure 8 illustrates a reinforcement layout assembled by a further preferred method of the present invention.

Figure 9 illustrates a reinforcement layout assembled by a further preferred method of the present invention.

""Figures 1A and lB illustrate a prior art bar 1.

20 The bar 1 has uniformly spaced helical ribs 2.

Figures 2A and 2B illustrate a preferred bar 3 of the present invention. The bar has helical ribs 4.

At uniform distances along the bar, there are breaks 6, 7 in the continuity of the ribs. Pairs of circular projections 8, 9, 10 are located on the bar at each of these breaks. Each pair of circular markings are S"positioned such that each circle is located on opposing "sides of the bar.

Figures 3A, B C and Figures 4, A, B C and D illustrate bars having different types of markings.

Figures 3A, B, C and Figure 4C illustrate bars having symbols 11 located in breaks 12 in the helical ribs 13.

In Figure 4A the marking is indicated only by a break 14 in the ribs. Figure 4B illustrates a bar having a marking 15 indicated by a raised line about the diameter of the bar and Figure 4D illustrates a bar in which the markings are indicated by a change in the direction of the helical ribs.

Figure 5 illustrates a corner 20 of a reinforcement layout in which two sets of bars 21, 22 meet and overlap. The extent of overlap is indicated by alignment of the markings 23 of the first set of bars 21 with markings 24 on the second set of bars 22. A detail of the respective markings is illustrated in Figure The first set of bars 21 are bent at an angle of about 450. The distance between the ends 25 of the bars and the bend 26 can be simply obtained by counting the number of markings. No measurement is required.

Figure 6 illustrates a reinforcement layout 31 constructed according to the method of the present invention. The layout has a first set 32 of bars and a second set 33 of bars transverse to the first set.

Circular markings 34 on the first set of bars are clearly visible from the direction of view. The second set 33 of bars are positioned such that the circular markings are pointing at about 900 away from the angle of view.

The reinforcement layout has been constructed 20 so that circular markings 34 of the first set of bars mark the intersections 35 with the second set.

*Intersections occur at every third marking. Thus, in order to check that the transverse bars are located at the desired spacing, it is necessary only to visually 25 check that the intersections coincide with every third

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~marking. It is also not necessary to make any 0 measurements to ascertain the distances between the bars.

S* For example, if the markings are 10cm apart then it can be easily calculated that the bars are 30cm apart.

Figure 7 illustrates a reinforcement layout 41 similar to that illustrated in Figure 6. Support chairs 42 are placed at positions corresponding to markings 43 on the bars. A detail of the markings 43 and chair 42 is illustrated in Figure 7A.

Figure 8 illustrates a reinforcement layout 51 which may be used to provide reinforcement for a girder or beam having a rectangular cross section. The reinforcement layout has a number of parallel bars 52

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which define the shape of the girder. Steel retaining wires 53 are placed around the bars and are fixed to the bars by tie wire. The bars are thereby fixed in positions relative to each other. The wire 53 is fixed to the bars at locations corresponding to the markings 54 on the bars 52. It is not necessary to measure the distance between the retaining wires.

Figure 9 illustrates a reinforcement layout 61 used to provide reinforcement for a concrete beam of circular cross-section. Parallel bars 62 are placed at positions such that they define a cylindrical space. A helical wire 63 retains the bars 62 in position. The pitch of the helix corresponds to markings 64 on the bars 62.

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Claims (11)

1. A reinforcement bar for a reinforcement layout having a plurality of bars spaced at a desired distance relative to each other or to retaining or support means, wherein said bar has markings occurring at a predetermined spaced distance along the length of said bar, said predetermined distance being proportional to said desired distance such that said desired distance can be visually determined without measurements being taken.

2. A bar according to claim 1 wherein said bar is a rolled steel bar.

3. A bar according to claim 1 or claim 2 wherein said markings comprise indentations and/or raised portions on said bar.

4. A bar according to any one of claims 1 to 3 wherein said predetermined spaced distance is A reinforcement bar substantially as hereinbefore described with reference to Figures 2, 3 or 4.

6. A reinforcement layout including one or more bars according to any one of claims 1 to

7. A reinforcement layout, substantially as hereinbefore described with reference to any one of Figures 5 to 8.

8. A method of constructing a reinforcement layout having a plurality of bars spaced at a desired distance relative to each other or to retaining or support means, the method including assembling the layout by placing a plurality of bars according to any one of claims 1 to at positions relative to each other or to the retaining or support means, the bars being placed such that the distance between the bars or the retaining or support means is proportional to the predetermined spaced distance between the markings on the bars and can be V LSV----L1 determned without measurements being taken.

9. A method according to claim 8 wherein said reinforcement layout has a plurality of intersecting bars and each intersection coincides with a marking. A method according to claim 8 wherein said reinforcement layout is in the form of a grid.

11. A method according to claim 8 wherein said reinforcement layout has retaining means for retaining said bars and said retaining means coincides with at least one marking.

12. A method according to any one of claims 8 to 11 wherein said reinforcement layout has means for supporting said bars and said support means is located at a position proportional to said markings.

13. A reinforcement layout constructed according to the method of any one of claims 8 to 12. DATED this 23rd day of October 1996 Hals Vander POORTEN and Lee Robert MEIKLEJOHN By their Patent Attorneys CULLEN CO. 4 ABSTRACT The present invention relates to a reinforcement bar for use in a formwork having a plurality of bars spaced at a desired distance relative to each other or to retaining or support means, wherein said bar has markings occurring at a predetermined spaced distance along the length of said bar, such that said desired distance can be visually deturmined without measurements being taken. The present invention also relates to a method of constructing a formwork using the bars of the present invention whereby the formwork may be constructed without any measurements being taken. eo6 ft f *t ff*f