The present invention relates to a joining element for construction, especially for transferring loads between modules, preferably prefabricated and made of reinforced concrete, provided with a material which when used under certain conditions allows flexible, reliable, lasting and easily installed joints to be made and which, when said prefabricated modules are stacked, contributes towards making buildings of considerable height.
Known in the art are modular prefabricated concrete elements for dwellings.
Such elements are generally conceived for arranging contiguously and stacked in order finally to form buildings several storeys high.
For structural and constructional reasons it is necessary to provide vertical and horizontal joints between contiguous elements in the vertical and horizontal directions, respectively.
One common solution is to use rigid joining elements, generally made of steel, so as to form rigid joints between contiguous elements.
The rigid nature of such joints nevertheless leads to inflexible structures with limitations vis-à-vis seismic forces. Such forces are related with the dimensions of the buildings obtained by stacking of prefabricated modules.
One solution to this limitation lies in the utilisation in these joining elements of some material with elastic characteristics that lend the building a degree of flexibility that allows it to absorb vibrations and reduce the maximum tensions created due to horizontal forces. This solution further achieves a new characteristic, that of isolating from transmission of vibrations of an acoustic nature.
One example of such a material is neoprene, which does indeed present suitable elasticity characteristics from the mechanical point of view.
This solution nevertheless presents a number of disadvantages, namely:
Examples of this are described in the document EP 1700964 A2.
It is therefore clear that the construction sector, and especially the specific sector of building based on prefabricated elements for construction, lacks a joining element that overcomes the aforesaid disadvantages.
To that end, the present invention proposes a joining element that overcomes the problems of the state of the art and that presents other characteristics and advantages that will be set out below.
The flexible joining element for constructions for placement between contiguous parts of said construction in order to transmit vertical or horizontal loads is characterised in that it includes at least one body made of braided and pressed steel strands, preferably stainless or galvanised, which supports the vertical or horizontal loads transmitted between adjoining modules, with said braided and pressed steel strands characterised by a deformation-tension curve that has a zone of shallower slope and a zone of steeper slope, with said body using in relation to said curve the zone of steeper slope.
This material, at present used as an anti-vibration support for heavy machines, has characteristics that make it particularly suited to the construction sector, and especially to buildings constructed with prefabricated modules, and even more especially to reinforced-concrete buildings. These characteristics are set out below.
It has deformation-tension behaviour that is very well-suited for adjustment during the stacking process and for supporting high loads, both static and dynamic. This material is characterised by a tension-deformation diagram (tension σ on the y-axis and deformation δ on the x-axes), as illustrated in
The aforesaid division of the tension-deformation diagram can be obtained approximately by dividing it into two zones that are situated both sides of the deformation corresponding to the intersection of the x-axes with the tangent to the curve for high tensions and deformations.
Owing the widespread use of this material in the industrial machinery sector, its response under all working conditions is very well known, and particularly its response in static situations and when subjected to vibrations. In the case of constructions with a large number of storeys resulting from the stacking of modules, especially prefabricated modules, simulation of the structural response is essential in order to achieve optimum dimensions, without which it is impossible to reach great building heights. Such simulation and the resulting prediction from the viewpoint of dynamic loads, and particularly those originating from earthquakes, is only possible when the response of the materials considered in the simulation is known very well, as in the case of pressed braided steel.
Preferably, the above-mentioned body has an outline delimited by two coaxial cylinders and two planes perpendicular to the axis of said cylinders. Already known in its application in machines, this shape is optimum in that it permits radial expansion of the material in both directions, and thus can work under compression with high loads. For this purpose the body can be placed on a circular steel base provided with a perimetral rim for housing said body. This base is placed on the upper surface of a module and the body fits into it in such a way that said joining element is centred in the position that has been determined.
Advantageously, the joining element of the invention comprises two coaxial cylindrical pieces of different diameter, forming between them a volume in which is housed at least one, though preferably four or six of said bodies, with the innermost piece being designed to receive a positioning element whose lower part is fitted into a first lower module and whose outermost part is for inserting into the module immediately above it, so that said body transmits the lateral forces between said pieces and therefore between said first lower module and said second module immediately above it.
A positioning joining element is therefore obtained that can transmit horizontal stresses in any direction. Indeed, for the positioning to be correct a positioning appendage, which is usually a solid oblong-shaped element embedded into the lower element, has to be inserted with precision into an opening in the element immediately above it. This precision implies a joint between two upper and lower elements that can transmit forces but not vibrations.
More advantageously, the joining element of the invention includes at least one, though preferably four or more preferably still six of said bodies placed between the aforesaid cylinders and by the fact that they are equi-spaced angularly. With the structure described, such vibrations are absorbed by the braided steel material. More particularly, the four or six bodies allow for there to be always one working under compression and absorbing the forces/stresses or vibrations.
Preferably, the pieces each have covers on one of their ends, with said covers having at least one orifice, in such a way that said cylindrical pieces can be attached to each other by at least one fastening screw, which allows the prefabricated element to be manufactured together with the larger-diameter piece and the rest of the element to be fitted later. Similarly, with such a configuration if any of the braided steel bodies has to be replaced then the joining element can be dismantled easily.
Preferably, the joining element of the invention includes two bent plates each provided with an orifice, each one for attachment to adjoining modules, and said orifices facing opposite each other in order to house a joining screw and a plurality of washers, and is characterised in that said at least one body is placed between at least two of said washers, and mounted in such a way that said body can transmit the horizontal loads between said adjoining modules.
Advantageously, the orifices of said plates have slack play of approximately 1 cm when said screw is inserted, thereby allowing a height and depth movement that allows construction defects to be taken up.
Finally, the joining element of the invention includes two of said bodies placed between two pairs of washers, with at least one of them being between said two plates and the other by the other side of the plates in relation to the preceding one, so that the element can transmit forces in the longitudinal direction of said screw in both directions.
For a better understanding of what has been set out some drawings are enclosed which, schematically and solely by way of non-restrictive example, show three practical cases of embodiment.
There follows a description of three preferred embodiments of the invention, corresponding to:
1. a joining element for transmitting forces that are mainly vertical and between two adjoining modules in a vertical direction.
2. a positioning joining element that can transmit forces in any horizontal direction between two adjoining modules in the vertical direction.
3. a joining element for transmitting lateral (horizontal) forces between two adjoining modules in a horizontal direction.
As shown in
As shown in
With this structure, the innermost piece 9 is designed to receive a positioning element 12, as shown in
In this second embodiment, the above-mentioned pieces each include covers 15 and 16 with at least one orifice 17 on one of their ends, such that said cylindrical pieces can be attached to each other by one or more fastening screws, as shown in
According to another embodiment, the joining element 1″ of the invention is of the type that includes two bent plates 18 and 19 each provided with at least one orifice, and each one for attachment to as many adjoining modules 20, 21, with said orifices facing opposite each other in order to take an attachment screw 22 and a plurality of washers 23, as shown in
In order to be able to transmit forces in the longitudinal direction of said screw in both directions, the joining element can include two of said bodies placed between two pairs of washers, with at least one of them 2a situated between said two plates, and the other 2b on the other side of one of the plates in relation to the preceding one.
Accordingly, in a building formed of prefabricated elements, the simultaneous use of the three forms of preferred embodiment of the invention allows a flexible and predictable structural response to be achieved with the calculation, such that buildings many storeys high can be assembled with structural solidity.
Number | Date | Country | Kind |
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P200801311 | Apr 2008 | ES | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/IB09/51748 | 4/29/2009 | WO | 00 | 10/28/2010 |