IE44000B1

IE44000B1 - Improvements in and relating to reinforcement units for reinforced concrete constructions

Info

Publication number: IE44000B1
Application number: IE271076A
Authority: IE
Original assignee: Treillis & Panneaux Soudes
Priority date: 1976-02-25
Filing date: 1976-12-10
Publication date: 1981-07-15
Also published as: DE7703618U1; IE44000L; GB1551430A; FR2342383A1; LU76351A1; BE851039A

Description

The present invention relates to reinforcement units for reinforcing concrete.

Composite reinforcement units are often employed for this purpose comprising main longitudinal bars and transverse bars forming closed loops. These reinforcement units have an elongated shape the cross section of which corresponds to that of the closed loops and may be of a triangular, square, rectangular or some other shape. Such reinforcement units are employed in particular for the construction of beams, columns or posts, lintels, longitudinal girders and for constructing piers.

According to a first known process, these reinforcement units are constructed on the site by tying together the main longitudinal bars and the transverse bars. This .5 process is very costly, since it requires a considerable amount of labour and time.

This is why a second more industrial process has come to be employed comprising preparing panels comprising three or four longitudinal bars and as many transverse bars as there are loops required in the reinforcement unit, the transverse bars being welded to the longitudinal bars.

This panel ia then bent in such a manner as to obtain the desired shape with a triangular or rectangular section. However, this process, although cheaper, has serious draw> backs. Thus when the bending operation is carried out some welds may break and this reduces the strength of the reinforcement unit. Moreover, the finished reinforcement - 3 44000 units are very large and consequently do not lend themselves to transportation. Again therefore there are a number of features which increase the cost of the units. Finally, in other existing reinforcement units it is necessary to add, on the site, additional longitudinal bars which substantially increases the time for placing the reinforcement units in position.

An object of the present invention is to provide a reinforcement unit which overcomes these drawbacks and which in particular may be of low cost, lends itself to transportation, even over long distances, and is particularly simple and efficient to place in position.

To this end, according to this invention, a reinforcement unit for reinforcing concrete comprises two substantially parallel longitudinal bars and a plurality of transverse bars each welded to each of the longitudinal bars, each transverse bar being of substantially L or V shape with two limbs and having a straight portion inclined to each limb at the corner of the L or V, one of the longitudinal bars being welded to the straight portion of each transverse bar and the other longitudinal bar being welded to each transverse bar adjacent the end of one of the limbs of the L or V.

According to other preferred features of the invention:the end of at least one of the limbs of each L or ν'shaped bar is bent inwardly to enhance anchorage of the bar, in use, in the concrete; the said end is bent inwardly to form an angle of substantially 45° to the remainder of the limb.

An example of a reinforcement unit in accordance with the invention will now be described with reference to the - 4 accompanying drawings, in which: Fig. 1 is a cross-sectional view of the reinforcement unit according to the invention; Fig. 2 is a view of two reinforcement units of the type shown in Fig. 1 assembled in the position of use, and Fig. 3 is a diagrammatic partial view illustrating the process of manufacture of the unit shown in Figs. 1 and 2.

Fig. 1 shows a reinforcement unit A constituted by two longitudinal straight bars 10a, 10b having the same diameter as each other. The bars may be of the type designated by the French standards FeE 40 or FeE 50 which are weldable, and transverse bars 11 welded to said longitudinal bars. The transverse bars are each bent in the shape of an L or a V, of which shape the corner has a flat portion 12 and one of the limbs 13 is bent inwardly of the L to form an anchoring portion 14 which lies at substantially 45° to the rest of the limb. The other limb 15 of the L is rectilinear. One of the longitudinal bars, 10a. is disposed in the region of the flat portion 12 and the other bar, 10b, is disposed very close to the end of the rectilinear limb 15 of the transverse bar.

Preferably, both the width of the flat portion 12 and tha distance between the bar 10b and the end of the adjacent limb of the transverse bar are equal to about 10mm, the bent rectilinear portion of the anchoring portion 14 having a length of the order of about 25mm, and, in the three regions 16, 17, 18 the radii of the bending of the bar are preferably at least equal to twice the diameter of the bar.

As concerns the dimension of the longitudinal bars and the transverse bars, it may be mentioned that the - 5 longitudinal bars have a length of preferably between 2 and 6 metres and a diameter which may be between 6 and 12mm, the transverse bars are 5 or 6mm in diameter, the spacing between the transverse bars may be between about 150 and 300mm, and may be, as desired, constant or variable, depending on the utilization.

Each transverse bar may have a size ranging, for example, from 10 x 10cm side dimension to 20 x 35cm side dimension. These dimensions have been given, of course, only by way of example.

In order to constitute reinforcement in a reinforced concrete construction, the reinforcement unit just described is assembled with an identical unit as shown in Fig. 2.

This assembly is very simply made by means of bindings 20 or a small number of welds. It can be seen that the two identical units fit one inside the other with precision and together constitute a rigid rectangular structure. In the present example, this reinforcement structure has a square section but it may of course have some other rectangular or similar section. The bent portions 14 extending toward the interior of the reinforcement structure ensure particularly effective anchorage of the transverse bars in the concrete and participate in the mutual location of the two reinforcement units, each bent end portion engaging a longitudinal bar lOa_, lob.

The advantages of such reinforcement units are the following: First, their process of manufacture may be simplified and easily industrialized. As shown in Fig. 3, this process comprises furnishing from a suitable machine (not shown) a series of parallel bars Ila. corresponding to the transverse bars 11 of the reinforcement shown in Fig. 1. These bars 4dooe - 6 are welded at given intervals to the bars which will constitute the longitudinal bars 10a., lob of the unit. As can be seen in Fig. 2, the distance between successive bars is so chosen as to permit the obtainment of the shape shown in Fig. 1 after cutting and bending.

This cutting is done, after welding the longitudinal bars to the transverse bars, along the dot-dash lines shown in Fig. 3. Thereafter, the cut panels, each comprising two bars 10a, 10b, and a suitable number of transverse bars, are bent in one or two operations so as to produce the shape shown in Fig. 1. Note that the positions of the bends with respect to the welds are such that there is no danger of the welds breaking during the bending operation.

Another important advantage resides in the fact that L5 the illustrated L- or V-shaped units may be transported very easily since they very easily fit one inside the other and thus afford a very small overall size, whereas the stacking of units having a closed triangular, square or rectangular section is extremely space-consuming and has !0 precluded up to the present time transporting such units over long distances.

The combination of two units having main bars of different sections but in which the transverse bars have tha same diameter, the same spacing and the same shape permits the construction of many combinations, in particular reinforcement for beams.

A reinforcement structure or cage having a square or rectangular section comprising, in each corner, a longitudinal reinforcement bar can be easily constructed.

The bars may be of the high-bond type.

Claims

1. CLAIMS:1. A reinforcement unit for reinforcing concrete, the unit comprising two substantially parallel longitudinal bars and a plurality of transverse bars each welded to each of the longitudinal bars, each transverse bar being of substantially L or V-shape with two limbs and having a straight portion inclined to each limb at the corner of the L or V, one of the longitudinal bars being welded to the straight portion of each transverse bar and the other longitudinal bar being welded to each transverse bar adjacent the end of one of the limbs of the L or V.

2. A reinforcement unit as claimed in claim 1, wherein the end of at least one of the limbs of each L or V-shaped bar is bent inwardly to enhance anchorage of the bar, in use, in the concrete.

3. A reinforcement unit as claimed in claim 2, in which the said end is bent inwardly to form an angle of substantially 45° to the remainder of the limb.

4. A reinforcement unit according to claim 1, substantially as hereinbefore described with reference to and as shown in Figure 1 of the accompanying drawings.

5. A reinforcement structure for reinforcing concrete constructions comprising two reinforcing units as claimed in any one of claims 1 to 4 assembled to form a structure which has a substantially square or other rectangular section having one longitudinal reinforcing bar at each corner.

6. A reinforcement structure according to claim 5, substantially as hereinbefore described with reference to and as shown in Figure 2 of the accompanying drawings.