EP0032105A1 - Pin and sleeve for the connection of constructional elements in civil engineering - Google Patents

Abstract

1. Mandrel and sleeve for the absorbtion and transmission of lateral forces in the connection together of building elements in constructional and civil engineering works such as roofing elements, flooring elements, ceilings, walls, buttresses, shoring walls or parts thereof with each other or with other building elements, for which purpose the sleeve is to be embedded and secured in the one building element and the mandrel in the other in such a way that the sleeve and/or the mandrel protrude from the surface of their respective building elements, and that the mandrel penetrates the sleeve, and that the sleeve and/or mandrel are furnished with a reinforcement embedding piece for the transmission of lateral forces to the surrounding building element, _c_h_a_r_a_c_t_e_r_i_s_e_d by the following features : a) the reinforcement embedding piece (12, 22, 32, 42, 15, 25, 35 and 45) exhibits a longtitudinal solid or hollow form with either a continuous smooth surface or surface furnished with protruding vanes or the form of vanes mounted singly on the mandrel and/or sleeve ; b) the reinforcement embedding piece (12, 22, 32, 42, 15, 25, 35 and 45) emcompasses the mandrel (14, 24, 34 and 44) and/or the sleeve (11, 21, 31 and 41) wholly or partly and embeds such within at least one portion of its own length ; c) the axial length of the reinforcement embedding piece (12, 22, 32, 42, 15, 25, 35 and 45) is less than that of the sleeve (11, 21, 31 and 41) and/or the mandrel (14, 24, 34 and 44) and is several times greater than the sectional diameter of the sleeve and/or mandrel ; d) the exterior surface area of the reinforcement embedding piece (12, 22, 32, 42, 15, 25, 35 and 45) is greater than that of the mandrel (14, 24, 34 and 44) and/or sleeve (11, 21, 31 and 41) encompassed by itself ; e) the reinforcement embedding piece (12, 22, 32, 42, 15, 25, 35 and 45) is mounted upon the mandrel (14, 24, 34 and 44) and/or sleeve (11, 21, 31 and 41) as an independant part in such a way that it extends thereon, in that section to be embedded in the building element, at least from the external end thereof inwards ; f) the reinforcement embedding piece is so shaped and attached that it is at least transversally to its length more flexibly resilient than the mandrel and/or sleeve themselves thus creating a flexible link with the building element and compensating in its longtitudinal plane the tensions set up by the lateral forces to be absorbed and transmitted.

Description

The invention relates to a mandrel and a sleeve for the absorption and transmission of transverse forces and the compensation of thrust in the longitudinal direction, for connecting structural and civil engineering components such as roof panels, floor panels, ceilings, walls, supports, retaining walls or parts thereof together or with other components, for which the sleeve in one of the components to be connected, the mandrel in the other is to be inserted and fastened in such a way that the mandrel and / or the sleeve protrudes from the component in question and the mandrel penetrates the sleeve. The application primarily concerns components made of concrete, but is not excluded for other components.

As is known, the mandrel and sleeve serve to fix components in their plane, for which they must be able to absorb considerable forces in the transverse direction, while on the other hand the mandrel in the sleeve must be freely movable and remain so that the components are under the influence can expand and contract at different temperatures. Therefore, the mandrel and sleeve must be corrosion-resistant be and remain over the long lifespan required by buildings, which is why they mostly consist of stainless steel, a precious material of high strength.

The surrounding concrete does not have nearly the same specific load-bearing capacity, which is why it has been forced to insert a disproportionate number of mandrels and sleeves in order to keep the concrete load in the boundary layer around the mandrels and sleeves within permissible limits. At the same time, however, this means inadequate use and waste of the precious, increasingly rare material from which the mandrels and sleeves are made, and waste of working time.

The invention has for its object to remedy this, and it is that the mandrel and / or the sleeve is provided on the outside in the region of the part to be admitted and at least near its outer end with a reinforcement which has a larger surface than that section of the mandrel or sleeve covered by the reinforcement.

Thanks to its larger surface area, the reinforcement distributes the force that occurs over a larger area in the concrete, so that its specific load becomes smaller, without having to choose a larger diameter for the mandrel and the sleeve itself, while the reinforcement is not the same need to exist costly material; it is concreted in and thus protected against corrosion, and there is no requirement for permanent lubricity as for mandrel and sleeve in the reinforcement. This makes it possible to achieve optimal material utilization for the concrete and for the mandrel and sleeve at the same time, i.e. Save material and labor costs. However, there are other reasons for this, and their consideration will, among other things, show that the reinforcement is only moderately stressed on the inside with respect to the mandrel or the sleeve, namely far less than it would be in its place to reach concrete.

If no reinforcement is provided, the load is not distributed evenly when the transverse force occurs over the recessed part of the mandrel and sleeve, but mostly on a relatively short section near the outer end of the recessed part, with a steep tip directly at the edge of the component in question. It is this steep peak that primarily stresses the concrete and has previously forced it to be dimensioned with very poor material utilization. The reinforcement according to the invention, which under these circumstances only needs to cover a relatively short section from the outer end of the recessed part, not only reduces the specific stress where most of the stress occurs, but also builds that steep stress peak from.

This is particularly the case because the reinforcement has a certain elasticity; minimal elastic changes in shape in the reinforcement are sufficient so that the load is largely evened out over its length both with respect to the mandrel or the sleeve and on the concrete side. Plastics have this elasticity without further ado, and the elasticity of reinforcements made of a metallic material can be increased by suitable shaping. The equalization of the load, in particular the reduction of that steep load peak, not only relieves the concrete and the mandrel or the sleeve, but this also benefits the reinforcement itself, so that the strength properties of the material to be used for the reinforcement are not particularly demanding have to be and some plastics suffice.

It can be seen from the above that the invention is based on much more than just the simple idea of reducing the specific load by increasing the surface; But experts have not even come up with this alone, although there has been a need for many years to remedy the above-mentioned lack of poor and uneven material utilization and the associated additional costs. It had long been recognized that simply increasing the diameter of the mandrel and sleeve would not remedy this deficiency, but would exacerbate it; the credit for having continued to think in this direction is only now coming to the inventor. The invention is also such that, after you have got to know it, you spontaneously tell yourself that you have to do it, and you should have always done it that way. It would be naive to conclude that this solution to the problem is "self-evident"; rather, this is an important indicator of a particularly good invention and a meritorious inventive achievement.

The invention also includes the possibility of providing the reinforcement only on the mandrel or only on the sleeve. This is considered when the two components in question consist of substances with very different strength properties; the reinforcement will then be arranged in the component with a lower specific load capacity of its material.

The reinforcement can be designed in various ways; it can be cylindrical or cubic on the outside or have the shape of ribs or a body with ribs, which can be designed to be particularly elastic, and completely or partially surround the portion of the mandrel or sleeve covered by it.

In applications in which particularly high loads are to be expected, it is advantageous if the reinforcement is in the shape of a truncated cone or a truncated pyramid, completely or partially surrounds the portion of the mandrel or sleeve covered by it, and the larger diameter at the outer end of the part of the inlet to be let in Has mandrel or the sleeve. There, the mentioned, steep load peak is reduced by the reinforcement, but even with good elasticity of the reinforcement, one still has to reckon with the fact that the load there is 20 to 25% greater if the diameter of the reinforcement is moderate and constant. The conical or truncated pyramid-shaped design has the advantage that the specific load is constant over the length of the reinforcement thanks to the larger surface at the location of the greatest load and there increased elasticity. It is remarkable and an advantage of the invention that the equalization of the specific load is not occurs only on the outside opposite the concrete, but at least approximately also on the inside between the reinforcement and the mandrel or the sleeve, thanks to the role of the reinforcement as an elastic intermediate member with increasing flexibility towards the outside in the case of a truncated cone or pyramid-shaped configuration. The clamping point of the mandrel or the sleeve, which is concentrated on the component edge without reinforcement, is distributed over a longer section by the reinforcement, and is used even more gently in the form of a truncated cone or pyramid.

It is now also obvious that, in the case of different load capacities of the components, a conical or truncated pyramid-shaped reinforcement can be provided on the one hand in the material of lower load capacity, and on the other hand a cylindrical or cubic reinforcement. Furthermore, it is readily apparent that a reinforcement, which has the shape of ribs or a body with ribs, can also be designed in such a way that it has a larger surface at one, outer end than at the other.

Among the plastics from which the reinforcement can be made, synthetic resin with or without filler and a cement-based mortar with or without plastic additive should be mentioned. The synthetic resin can include is an epoxy resin, e.g. Bisphenol-A-epichlorohydrin with a tertiary amine as hardener, which requires higher temperatures for hardening, but to shorten the hardening time it is also recommended to use it with epoxy resins that can harden at room temperature. Quartz sand is usually used as the filler, and in the case of particularly high strength requirements, acicular aluminum oxide can also be used. There are also suitable thermoplastics that meet high demands on mechanical properties and aging resistance, but unfortunately they are still relatively expensive. The development in this area is in flux, so that an even larger selection of suitable plastics can be expected in the future. The plastic reinforcement can be assembled in any way, e.g. be glued on, the mandrel and the sleeve can also be encapsulated.

Furthermore, the reinforcement can also consist of a metallic material and then be welded, soldered, riveted, screwed or glued on; there are no concerns regarding the strength of the connection even in the latter case, and With this type of fastening, a high degree of heating of the mandrel and sleeve material and thus the risk of a deterioration in its structure are avoided and an afterglow correcting this is saved.

Since the transverse load on the mandrel and the sleeve is generally greatest at the outer end of the recessed part and then decreases sharply further back, there would be no purpose in inserting the mandrel and sleeve disproportionately deep and making them correspondingly long; the load would then no longer be distributed over a greater length, and there would be an unnecessary expenditure of expensive material. Experiments under the most varied conditions have shown that the length of the part of the mandrel and sleeve to be let in is optimally dimensioned when it is approximately equal to seven times the mandrel diameter. The optimal length of the reinforcement cannot simply be stated in relation to the mandrel diameter, because the diameter, the shape and the material properties of the reinforcement also play a role here; with usual mandrel diameters, an optimal length of 7 to 1D cm results, which is not critical for the rest.

On the reinforcement of the mandrel or on the sleeve, a fastening plate can be attached to the outer end of the part to be let in, which is also called "nail plate" in the construction field. In this context, it seems appropriate to go into the installation of the mandrel and the sleeve, especially since their design is thereby determined; for this it is assumed that the sleeves to be let in at the edge in a first component each carry a fastening plate and that the corresponding mandrels are to be let in in a second, adjacent component. The formwork of the first component is produced, the sleeves are nailed to the intended positions with their fastening plates from the inside against the formwork, if necessary the reinforcement and then the concrete mortar are inserted and removes the formwork after it has set. Then you insert the corresponding mandrels into the concreted-in sleeves, create joint insulation and formwork for the second component, if necessary bring in the reinforcement and then the 8-tone mortar and remove the formwork after it has set. If the second component is joined by another component to be connected with mandrels and sleeves, the sleeves provided are attached to the adjacent formwork side of the second component as described above, and the installation process continues accordingly.

How many mandrels and sleeves to install or at what intervals they should be arranged, to decide this based on the load and the gap play, is up to the structural engineer. On the other hand, the rule can be given here that the concrete layer thickness around the mandrel or sleeve should be at least four times as large as the mandrel diameter. If this value has to be fallen short of, it is advisable to install a support reinforcement to distribute the concrete stress over a larger section.

So that cement milk and other foreign bodies cannot penetrate, it is expedient if the outer opening of the sleeve or the fastening plate has a cover which can be easily removed after installation, e.g. a glued-on film, and when the sleeve bore is closed at the other end.

The mandrel and the bore of the sleeve usually have a circular cross section, but this can also be selected differently, e.g. square, rectangular, polygonal or oval; the outer shape of the sleeve is irrelevant in this connection, and the rest will depend on what rod and tube material is available.

The mandrel can also be designed as a tubular hollow body. With the same outside diameter, the permissible shear and bending stress is smaller, but the maximum stress occurring at the clamping point is also smaller thanks to the effect of the reinforcement. You can even make a tubular mandrel relatively thin-walled when you start facial stress wants to save material; on the other hand, it is often possible to accept a somewhat larger diameter under high loads. A tube has than solid material of the same cross section the advantage of a larger modulus and smaller surface pressure in the vice _- reproduced body, and the latter also affects the shear strength like these also depend largely on the cross section. Shearing is initiated by exceeding the permissible surface pressure [specific load] and consequently plastic deformation on the surface of the object as soon as the yield point is exceeded there; so it happens that a pipe has a greater shear strength than a solid rod of the same cross-section and material.

• Fig. 1 und 2 Hülse und Dorn einer ersten Ausführungsform in Ansicht,
• Fig. 3 und 4 Hülse und Dorn einer zweiten Ausführungsform in Ansicht,
• Fig. 5 den Gegenstand von Fig. 1 in perspektivischer Darstellung,
• Fig. 6 den Gegenstand von Fig. 2 in perspektivischer Darstellung,
• Fig. 7 und 8 Hülse und Dorn einer dritten Ausführungsform in Ansicht,
• Fig. 9 und 1D Hülse und Dorn einer vierten Ausführungsform im Schnitt,
• Fig. 11 den Gegenstand von Fig. 10 in perspektivischer Darstellung,
• Fig. 12 den Gegenstand von Fig. 8 in perspektivischer Darstellung.

The accompanying drawings illustrate the subject matter of the invention with the aid of some exemplary embodiments selected, namely

• 1 and 2 sleeve and mandrel of a first embodiment in view,
• 3 and 4 sleeve and mandrel of a second embodiment in view,
• 5 shows the object of FIG. 1 in a perspective view,
• 6 shows the object of FIG. 2 in a perspective view,
• 7 and 8 sleeve and mandrel of a third embodiment in view,
• 9 and 1D sleeve and mandrel of a fourth embodiment in section,
• 11 is a perspective view of the subject of FIG. 10,
• Fig. 12 shows the subject of Fig. 8 in perspective.

Figures 1 to 4 and 7 to 10 have in common that a component edge K is indicated; this clarifies how far the object shown is to be let into the component.

1 and 2, a sleeve 11 with a reinforcement 12 and a fastening plate 13 and a mandrel 14 with a reinforcement 15 fitting into the sleeve 11 can be seen. The reinforcements 12 and 15 are frustoconical on the outside, therefore in accordance with the instructions given above for high loads or in components made of not very strong material and particularly suitable consisting of an epoxy resin with quartz sand filling, with which the parts therein are cast, and which can then also take over the mounting of the mounting plate 13, which would otherwise be connected to the sleeve 11 in a known manner.

For better illustration, the subject of Figure 1 in Figure 5, that of Figure 2 and Figure 6 is perspective shown; 5 shows four holes in the mounting plate 13 through which the mounting plate is nailed when installed in the casing of the component.

3 and 4 show a second embodiment with a sleeve 21 with a reinforcement 22 and a fastening plate 23 and a mandrel 24 which fits into the sleeve with a reinforcement 25. The only remarkable difference compared to FIGS. 1 and 2 is that the reinforcements 22 and 25 are cylindrical on the outside in this case. Figures 3 and 4 would not look different if the cross-section of the reinforcements 22 and 25 were limited on the outside square or rectangular, and this would also represent an expedient embodiment of the subject matter of the invention.

7 and B show a third embodiment with a sleeve 31 with a reinforcement 32 and a fastening plate 33 and a mandrel 34 which fits into the sleeve 31 with a reinforcement 35. In this case, the reinforcements 32 and 35 made of plastic or metal have the shape a body with ribs, which becomes clear from Fig.12, which represents the subject of Fig.B in perspective. Finned tubes are commercially available; from this, for example, reinforcements 32 and 35 can be produced by simply parting off and then e.g. stick on.

A comparison between FIGS. 1 to 4 suggests that the body can also be designed with ribs in such a way that it itself has a larger diameter at the outer end and / or further unload its ribs there, in order to thereby even out the load and a to achieve higher resilience. Relatively thin ribs increase the overall elasticity of the body with ribs, which is easy to use, especially when made of metal; in this case he can e.g. be a cast or injection molded part.

9 and 10 show in section a fourth embodiment with a sleeve 41 with a reinforcement 42 and a mandrel 44 fitting in the sleeve 41 with a reinforcement 45, which carries a fastening plate 43. The reinforcements 42 and 45 are hollow bodies in this case, which is the section position clearly shows; 11 also illustrates the object of FIG. 10 in a perspective representation.

If in the previous embodiments protruding mandrels and flush sleeves were provided relative to the respective component edge K, the reverse is true for the embodiment according to FIGS. S and 10: there the sleeve protrudes opposite the respective component edge K and the mandrel is flush with it. This means that a gap of annular cross section must remain free around the mandrel 44 to a certain depth so that the sleeve 41 can slide there over the mandrel 44. In the embodiment according to FIG. 10, the reinforcement 45 is simultaneously used to keep this gap free by being open at the outer end. The truncated cone shape of the reinforcement 45 serves in this case not only to even out the load and increase the load capacity as before with the designs according to FIGS. 1 and 2, but also also to stiffen the reinforcement 45, which is advantageous because it is only attached at one end to the mandrel 44, the rest is self-supporting. This is not the case with the reinforcement 42, which is why, for the sake of simplicity, it can also be carried out with a constant diameter over its length, as shown there and if the load there permits. In the case of a thin-walled design, the reinforcements 42 and 45 are preferably made of metal, together with the fastening plate 43, in one piece or composed of several parts, depending on the respective suitability, and e.g. glued.

If, as shown, the mandrel or the sleeve can be allowed to protrude from the respective component edge K, it is obvious that the mandrel and the sleeve can also be protruded. This can lead to several advantages. Thus, compared to the embodiment according to FIGS. S and 1D, the annular gap around the mandrel 44 does not have to be as deep and the reinforcement 45 only has to be cantilevered over a shorter length; Furthermore, this relocates the center of gravity of the transverse forces occurring between the mandrel and the sleeve precisely to the joint between the two components in question, so that the transverse forces act on the mandrel and sleeve with the same lever arm. Details of such an embodiment are evident from the figures shown.

Claims (10)

1. Mandrel and sleeve for absorbing and transmitting transverse forces and compensating thrust in the longitudinal direction, for connecting structural or civil engineering components such as roof panels, floor panels, ceilings, walls, supports, retaining walls or parts thereof with one another or with other components , for which the sleeve in one of the components to be connected, the mandrel in the other is to be inserted and fastened in such a way that the mandrel and / or the sleeve protrudes from the component in question and the mandrel penetrates the sleeve,
characterized ,
that the mandrel [14, 24, 34, 44] and / or the sleeve [11, 21, 31, 41] on the outside in the area of the part to be let in and at least near its outer end with a reinforcement [12, 22, 32, 42, 15, 25, 35, 45] is provided, which has a larger surface area than the section of the mandrel or sleeve covered by the reinforcement. 2. mandrel and sleeve according to claim 1, characterized in that the reinforcement [22, 25, 32, 35, 42] is cylindrical or cubic on the outside or has the shape of ribs or a body with ribs and the portion covered by it completely or partially surrounds. 3. mandrel and sleeve according to claim 1, characterized in that 1 the reinforcement [12, 15, 45] outside is frustoconical or frustum-shaped, completely or partially surrounds the portion covered by it and has the larger diameter at the outer end of the part to be let in. 4. mandrel and sleeve according to one of claims 1 to 3, characterized in that the reinforcement [12, 22, 32, 15, 25, 35] consists of a synthetic resin with or without filler or from a cement-based mortar with or without plastic and mounted, or that the mandrel [14, 24, 34] or the sleeve [11, 21, 31] is encapsulated with it. 5. mandrel and sleeve according to one of claims 1 to 3, characterized in that the reinforcement [32, 42, 35, 45] consists of a metallic material and is welded, soldered, riveted, screwed or glued. 6. mandrel and sleeve according to claim 1, characterized in that its part to be let has a length which is approximately equal to seven times the mandrel diameter, and that the reinforcement [12, 22, 32, 42, 15, 25, 35, 45] is about 7 to 10 cm long. 7. mandrel and sleeve according to claim 1, characterized in that on the reinforcement [45] of the mandrel [44] or on the sleeve [11, 21, 31] at the outer end of the part to be let in a fastening plate [13, 23, 33, 43] is appropriate. 8. mandrel and sleeve according to claim 1, characterized in that the outer opening of the sleeve [11, 21, 31, 41] or the mounting plate [13, 23, 33, 43] has a cover, which prevents the penetration of cement milk and other foreign bodies and is easy to remove after installation, and that the sleeve bore is closed at the opposite end. 9. mandrel and sleeve according to claim 1, characterized in that the mandrel [14, 24, 34, 44] and the bore of the sleeve [11, 21, 31, 41] has a circular, square, rectangular, polygonal or oval cross section . 10. mandrel and sleeve according to claim 1, characterized in that the mandrel [14, 24, 34, 44] is designed as a tubular hollow body.

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