Positioning member This invention relates to a positioning member intended to carry and position non-rigid reinforcement at the reinforcing of arches or like concrete structures. At the erection of arches, bottom slabs, carrying concrete slabs etc. are placed in a form, into which the intended reinforcement is laid. In order to keep the reinforcement in place during the concreting, the reinforcement bars must be secured so as to maintain their positions relative to one another. This is carried out in such a way, that the reinforcement bars are tied together with reinforcement bars or rods, which extend perpendicularly to the mutually parallel reinforcement bars. At reinforcement with only one layer of reinforcement bars it is sufficient to use only a few reinforcement bars extending perpendicularly to the layer of mutually parallel reinforcement bars for keeping the latter in place.
At two-way slab reinforcement an additional layer of mutually parallel reinforcement bars is spread on an underlying layer of mutually parallel reinforcement bars. At two-way slab reinforcement the majority of junctions between the reinforcement layers are tied together.
The positioning and tying of reinforcement bars are processes of great work intensity. It is, therefore, desired to be able to minimize or eliminate tying and positioning.
The present invention meets this desire completely. According to the invention, a positioning member is offered, which eliminates the work of both tying and positioning.
The present invention, thus,relates to a positioning member intended to carry and position reinforcement bars at the reinforcing of concrete structures. The member is characterized in that the positioning member consists of an oblong body with equally spaced grooves extending perpendicularly to the longitudinal direction of the member and each groove intended to carry a reinforcement bar.
The invention is described in greater detail in the following, with reference to the accompanying drawings showingby way of example some embodiments. In said drawings, Fig. 1 is a longitudinal section of a positioning member according to a first embodiment, Fig. 2 is a longitudinal section of a positioning member according to a second embodiment, Fig. 3 is a horizontal view of erected positioning members, Fig. 4 is a perspective view of a longitudinal section of a positioning member according to a third embodiment. In Figs. 1, 2 and 4 different positioning members according to the invention are shown, which are capable to carry and position reinforcement bars at the reinforcing of concrete structures. The positioning members 1,2,3,4 consist of an oblong body, which preferably is made of concrete, but also can be manufactured of a different material, for example plastic. The choice of material depends a.o. on the number of reinforcement bars and on the total weight of reinforcement bars to be carried by the members.
The members comprise equally spaced grooves 5, which extend perpendicularly to the longitudinal direction of the members and are intended each to carry one reinforcement member 6, so that the reinforcement bar maintains its place when concrete is being poured over the reinforcement.
According to one embodiment, the members 1,2,3,4 have downward directed projections 7,8,9, which constiture supports for the members. The projections 7,8,9 are located in a certain spaced relationship, in order suitably to enable the member to rest on the base.
In Fig. 1 a member 1 according to a first embodiment is shown. This embodiment primarily is intended for reinforcement when only one layer of mutually parallel reinforcement bars 6 is to be laid out and cast-in. The projections 7 are intended to rest on a base, for example a shuttering panel 10 or the like. A plurality of members 1 are placed so as to be in parallel with each other. Thereafter reinforcement bars 6 are laid into the grooves 5 in the members, whereafter the reinforcement is complete. Concrete is poured and envelopes members and reinforcement bars. Due to the projections
7, the concrete can flow freely beneath the members in the intermediate space 11 between the projections 7. In Figs. 1,2 and 4 only longitudinal sections of members are shown, because the length thereof is adjusted to the surface to be reinforced. The members 1-4 preferably are prefabricated in certain lengths, for example in 3 m lengths.
The reinforcement often is to be carried out as two-way slab reinforcement, i.e. two layers of reinforcement bars are laid out so, that the reinfordement bars in the upper layer are mutually in parallel and extend perpendicularly to the reinforcement bars in the lower layer. For this purpose, according to a preferred embodiment two different members are used, of which certain members comprise projections 7 with a height exceeding the height of the projections of the other members. In Figs. 1 and 2 dashed lines 12 indicate the bottom surface of the lower projections while the fully drawn lines show the bottom surface of the higher projections 7,8,9.
At two-way slab reinforcement, thus, members 1 with higher projections mutually in parallel are laid out, and members 1" with lower projections are laid out perpendicularly thereto, as shown by way of example in Fig. 3. Reinforcement bars are laid out on the members 1", which have lower projections, and thereafter on the members 1', which have higher projections.
The difference in height between the two different members corresponds to the diameter of the type of reinforcement bars, for which the members are to be used.
This implies, thus, that the two layers of reinforcement bars abut each other or, in any case, are located close to each other in the junction points between the reinforcement bars.
According to a second embodiment, the members 2,3 in addition to the downward directed projections 8, as described above, also comprise recesses 13 on the side opposite to the projections 8. A distance member 14 further is provided, the shape of which corresponds to that of the projections 8 and recesses 13, as shown in Fig. 2. The distance member 14 thereby is capable to co-operate with the recess 13 of an underlying member 3 and the projection 8 of an overlying
member 2 and thereby to position the members 2,3 in parallel with each other at different heights.
An arrangement of this type is used when two or more mutually parellel layers of reinforcement bars at different heights are to be laid out and cast-in.
The projections 8 on certain underlying members, of course, can be designed higher and, respectively, lower, as described above, whereby several layers of two-way slab reinforcement can be arranged.
The distance member 14 preferably is manufactured of the same material as the meirbers 2,3, but other materials can be imagined.
According to a third entoodiirient shown in Fig. 4, the members consist of two parallel oblong concrete bodies 15,16, in which a main reinforcement 17 extends. The bodies 15,16 are spaced from each other by means of an intermediate reinforcement 18 extending between the main reinforcement 17 in each of the bodies 15,16. The intermediate reinforcement is bare, which implies that the member 4 is a beam with a very high strength in relation to its weight. In each of the bodies 15,16 grooves 5 for carrying reinforcement bars 6 are provided. In a way corresponding to that described above, the projections 9 of the member 4 can be designed to have two different heights, thereby rendering it possible in a simple way to carry out two-way slab reinforcement in two layers. A reinforcement bar 6' in Fig. 4 indicates how a layer of reinforcement bars, which is carried by members with higher supports 9, adjoins the reinforcement bars 6, which are carried by the member 4 shown in Fig. 4.
The member 4 in Fig. 4, thus is utilized not only as positioning member, but also as a carrying beam. Its carrying capacity advantageously can be utilized a.o. at the formworkand casting of an arch, where the members in the form of beams are dimensioned so as to be capable to carry forms and concrete poured therein. Members 4 according to Fig. 4 preferably are arranged as indicated in Fig. 3.
It is obvious that positioning members according to the invention eliminate the positioning and tying of reinforcement bars relative one another according to conventional labour-intensive techniqu.e.
Further advantages are that the members 1-4 can be designed so as to be capable to entirely or partially carry the weight of forms and concrete at the casting of arches and the like.
The present invention, of course, can be varied in many ways. The projections and recesses, for example, can have another configuration. The form and size of the grooves 5 can be varied. Furthermore, the material, of which the members are manufactured, can be any suitable material, and the material to a certain extent can influence the most suitable configuration of the members. The invention, therefore, must not be regarded restricted to the embodiments set forth above, but can be varied within the scope defined in the attached claims.