EP3004490B1 - Assembly and method for reinforcing support structures - Google Patents

Description

Technical area

The invention relates to the field of reinforcement of support structures, preferably by applying surface reinforcement, in particular the introduction of force into the surface reinforcement.

State of the art

Methods to increase the bearing capacity of existing support structures, typically reinforced concrete components, have been used for many years. Often this happens by means of superficially mounted additional reinforcement. For the most part, superficially bonded reinforcements made of fiber composite materials have prevailed. The effectiveness of this surface reinforcement is normally limited by the maximum transferable from the concrete to the reinforcement force.

Various methods for improving the transmission of force from the support structure to the surface reinforcement are known. A widely used method is to introduce fiber bundles into a bore in the support structure and to anchor them there and to spread out or fan out an end of the fiber bundle projecting beyond the surface and to stick it to the surface. Subsequently, a surface reinforcement can then be glued to the reinforced structural surface. Alternatively, the surface reinforcement may first be glued to the structural surface, so that when an anchor attached thereto from a fiber bundle, the protruding end of this is glued to the surface of the surface reinforcement. In the case of surface reinforcements with multiple layers, it is often recommended for better force transmission to spread the anchors between the fabric layers.

The effectiveness of this measure has been experimentally proven to be limited for various reasons.

On the one hand, the near-surface potential fracture surface of each anchor is broken at only one point (at the shank). The resistance of this potential fracture surface is thus increased only to a limited extent. On the other hand, the transmission of force from the fibers of the fiber bundle spread on the surface to the fibers of the fabric is not optimal. The very thin, formed by the fibers of the fiber bundle on the surface fiber composite material can be charged only in the pulling direction substantially. When loaded under pressure, the fiber composite material buckles, but when subjected to thrust and bending, only very small forces can be transmitted. Therefore, only the approximately in the pulling direction of the surface reinforcement fibers are fully effective. These make up only a small part of the fiber bundle cross-section and cover only a small part of the width of the surface reinforcement.

Another disadvantage of the known method is that the projecting beyond the surface end of the fiber bundle is spread on the surface itself and thus caused by projections, protruding deformations on the surface, which can disturb the appearance of a building on the one hand, but also technical Disadvantages can bring. For example, elevations in an otherwise flat surface can cause water, especially rainwater, or snow, but also dirt to accumulate on these elevations and the long-term effect US Pat. No. 6,324,805 B1 discloses an arrangement according to the preamble of claim 1.

Presentation of the invention

The object of the present invention is therefore to provide an arrangement and a method according to which an improvement in the introduction of force into a surface reinforcement is to be achieved.

Furthermore, it is the object of the present invention to improve the power transmission of fiber bundles, which are attached to a supporting structure, in particular in a surface or in a near-surface region.

Surprisingly, it has been found that by means of an arrangement according to claim 1 and a method according to claim 8, this object can be achieved.

The core of the invention is therefore an assembly comprising a support structure having a surface consisting of one or more surfaces, wherein extending from at least one surface of a bore in an inner region of the support structure, and this bore with an adhesive and with a portion of a via this bore protruding fiber bundle is filled, wherein the support structure is provided on the at least one surface, from which the bore extends in an inner region of the support structure, with a plurality of grooves extending from the bore in a region of at least one circular sector and the protruding part of the fiber bundle divided into fiber strands at least partially located in the grooves and is secured therein with the adhesive.

As a support structure here is an element or part of an element referred to which is exposed to forces. Typically, the support structure is a building or component of a building, such as a slab, ceiling, wall, pillar, rib, beam or the like. The support structure is typically made of concrete, especially reinforced concrete, but may also consist of bricks or other bricks, wood, steel or other materials and any combination of these materials. Typically, the buildings are civil engineering works, such as houses, bridges, tunnels, dams, sports facilities, etc.

The fiber bundle is a loose arrangement of substantially rectified individual fibers or filaments, in particular of carbon (carbon), glass, basalt, aramid, steel or other inorganic or organic materials. Preferably, the fibers are carbon fibers.

The thickness of the fiber bundle depends on the area of use and on the forces which are to be transmitted through the fiber bundle. If the fiber bundle consists of carbon fibers, this comprises, in particular, 1000 to 50,000 individual fibers, each themselves having a diameter in the range from 5 to 10 have μm. A typical fiber bundle preferably has a cross-sectional area of from 20 to 70 mm ² , in particular from 25 to 40 mm ² .

The attachment of the fiber bundle to the support structure is typically carried out by attaching, in a first step, at the desired location, a bore which serves to receive a portion of the fiber bundle. The bore can be created by any means, such means are well known to those skilled. The dimensions of the bore resulting from the strength and the length of the fiber bundle and this in turn of the requirements that are imposed on the inventive arrangement. Typically, a suitable bore has a diameter of 1 to 5 cm, in particular 1.5 to 3 cm and a depth of 5 to 30 cm, in particular from 7 to 20 cm.

In a further step, one or more grooves are made starting from the bore or from the point of entry of the bore into the surface of the support structure. The grooves can be created by any means, for example with an angle grinder.

The grooves are dimensioned so that they in their entirety, the fiber bundle, which can be divided into individual fiber strands in the event that multiple grooves are present, can accommodate.

The number and arrangement of the grooves is dependent on the application of the inventive arrangement.

After attaching the bore and the plurality of grooves, the fiber bundle is inserted into the bore and grooves and glued therein. For this purpose, an adhesive is first introduced into the bore and into the grooves.

Thereafter, the fiber bundle, which is preferably pre-impregnated with a resin, introduced into the bore so that a portion of the fiber bundle protrudes beyond the bore. In the course of attaching the inventive arrangement to a supporting structure protrudes beyond the bore portion of the fiber bundle usually also beyond the surface of the support structure out. However, the portion of the fiber bundle, which is in the assembled arrangement in multiple grooves, then does not protrude more beyond the surface of the support structure, whereby a uniform and smooth surface can be ensured.

This projecting portion of the fiber bundle is at least partially inserted into the adhesive groove or uniformly divided into a number of grooves corresponding number fiber strands and inserted into the grooves. According to the invention, the entire fiber bundle or all fiber strands are inserted into a plurality of grooves, so that the fiber bundle does not protrude beyond the surface of the support structure at any point. After inserting the fiber bundle in the grooves, the fiber bundle can be pressed in it. Adhesive material emerging from the wellbore or grooves is then removed or evenly distributed in the area of the surface affected by the assembly. Are there any cavities in the hole or in the grooves after inserting the fiber bundle, these can be filled with adhesive. The introduction of the fiber bundle into the bore takes place in particular with a needle-like object. On the fiber bundle, a clip, a cable tie or the like can be attached to which the needle-like object can be hooked for better guidance with the needle-like object.

The impregnation of the fiber bundle with a resin prior to insertion in the bore and grooves has the advantage that the wetting of the entire fiber bundle with resin, even in the inner region, can be achieved. To ensure optimum adhesion between the fiber bundle and the support structure, the resin for impregnating the fiber bundle in particular has the same chemical basis as the adhesive for fastening the fiber bundle in the bore and grooves. In particular, both the resin and the adhesive are epoxy resin compositions. It is possible that the adhesive and the resin are the same composition, with the viscosity of the resin typically being set slightly lower than that of the adhesive, which in turn serves to better wet the fibers.

Both the adhesive for fixing the fiber bundle in the bore and groove and the resin for the possible impregnation of the fiber bundle, a two-component epoxy resin composition is preferably used. Suitable epoxy resin compositions are, for example, under the trade names Sikadur ^® are commercially available from Sika Switzerland AG.

The bonding sites on the support structure are preferably clean, dry, free of dust and grease. Depending on the materials of which the support structure is made, suitable cleaning measures or pretreatments may be used.

The inventive arrangement can be attached to a support structure for different purposes. In particular, the arrangement itself serves as a reinforcement for the support structure and / or serves as an anchor or as an anchorage for a surface reinforcement attached to the support structure.

If the arrangement serves as an anchorage for a surface reinforcement attached to the support structure, then it has several grooves which extend from the bore along the surface. In this case, the number of grooves per bore is preferably 2 to 16, in particular 6 to 10.

The grooves are in particular circular and arranged at regular intervals around the bore. According to the invention, the grooves are arranged in a circular sector around the bore, wherein the circular sector preferably has a center angle of 60 to 360 °. As a rule, the arrangement of the grooves depends on the loading direction of the surface reinforcement, which is adhesively bonded to the supporting structure via the arrangement according to the invention as an anchor or anchoring. In particular, the grooves extend in this case in the pulling direction of the surface reinforcement.

In a further embodiment, the arrangement itself can serve to reinforce a supporting structure. In this case, in particular, several of the arrangements described are mounted at regular intervals on a support structure. Also in this case, the inventive arrangement as previously described on several grooves. In this case, the arrangement preferably has a second bore which extends into an inner region of the support structure, wherein the second bore may be located on the same or on another surface of the surface. At least one of the plurality of grooves extends from the entry of one, so he first, bore along the surface of the support structure towards the entry of the second bore, so the two holes are connected to each other in the surface region of the support structure via at least one groove. If the two holes are not on the same surface of the surface of the support structure, i. If, for example, one or more edges or corners lie between the surfaces, the at least one groove also extends over these edges or corners.

If the two bores are located on mutually opposite surfaces of a support structure, it is possible for the two bores in the extension of their respective boring axes to be connected to one another.

This is the case, for example, if the arrangement according to the invention is to be applied in the region of the end face of a wall which is free-standing at least on one side. In this case, the two holes can be made by drilling the wall in one place. In particular, a groove is then positioned to connect the entry location and exit location of the bore in the wall with each other across the face. The exit location of a hole in the wall represents the entry point of the second hole.

Even with such an application of the inventive arrangement, a surface reinforcement can be attached to the surface of the support structure.

Regardless of the nature of the arrangement according to the invention, the surface reinforcement is preferably arranged so that it extends in at least one groove on the surface of the support structure Section of the fiber bundle and the bore or the entry of the bore in the surface covering a whole and is glued over this entire area with the surface of the support structure.

In particular, lamellae or tissue come into consideration as surface reinforcement, which run along the surface of a support structure and are adhesively bonded thereto, in particular over the entire surface. In particular, unidirectionally fiber-reinforced plastic flat strip lamellae are suitable as lamellae. The fiber reinforcement is usually made by carbon fibers, but can also be done as in the fiber bundle, by glass, basalt or aramid. The plastic matrix used is in particular an epoxy resin matrix. Also suitably a plastic matrix may be based on polyurethane, vinyl ester, polyacrylate or other compositions having structural properties. Suitable fiber-reinforced plastic ribbon strips are, for example, under the trade name Sika ^® CarboDur ^® are commercially available from Sika Switzerland AG.
The fabric is preferably a, in particular unidirectional, carbon fiber fabric, which also may consist of glass, basalt or aramid fibers. In contrast to the fiber-reinforced plastic flat strip lamellae, the fabric is typically not already applied to the surface in a cured plastic matrix, but provided with a curable composition before or after attachment to the surface. The curable composition is in particular an epoxy resin composition, polyurethane or polyacrylate could also be used here.
As fabric is particularly suitable a carbon fiber fabric, as it is commercially available for example under the name SikaWrap® from Sika Switzerland AG.

Both as a plastic matrix for the fiber-reinforced plastic ribbon strips as well as for bonding these or the fabric to the support structure are preferably bicomponent Epoxy resin compositions used, as they are commercially available for example under the trade names Sikadur® from Sika Switzerland AG.

As already described above, it is possible that the fiber bundle extends in several grooves over edges and / or corners which connect different surfaces of the surface of the support structure with each other. If this is an edge, this edge preferably has a rounding in the interior of the groove. The radius of the rounding is in particular about 0.5 to 10 cm, in particular 1 to 5 cm.

By rounding the edge of the fiber bundle, which is inserted in the bore and groove, spared, resulting in fewer fiber breaks and improved power transmission is possible. Most preferably, regardless of the particular embodiment of the present invention, all edges of the support structure, over which a groove with fiber bundle is to extend, are rounded within the groove.

Furthermore, it is also possible that the transition from the bore into the groove has a rounding according to the preceding description.

The inventive arrangement and a method for their application are typically used in the reinforcement of existing support structures, for example, during renovation, repair or later attached to support structures seismic reinforcement. If the support structure is a reinforced concrete structure, reinforcement takes place, for example, where the steel reinforcement is inadequate or where it has been damaged by an unforeseen event.

• ▪ Erstellen mindestens einer Bohrung ausgehend von einer Fläche der Tragstruktur in einen inneren Bereich der Tragstruktur,
• ▪ Erstellen mehrerer Nuten ausgehend von der Bohrung in mindestens eine Richtung auf der Oberfläche der Tragstruktur, welche sich ausgehend von der Bohrung in einem Bereich von mindestens einem Kreissektor erstrecken,
• ▪ Einbringen eines Klebstoffs in die mindestens eine Bohrung,
• ▪ Einführen eines Faserbündels in die Bohrung, sodass ein Abschnitt des Faserbündels über die Bohrung hinausragt,
• ▪ Aufteilen des hinausragenden Teils des Faserbündels nach Fasersträngen,
• ▪ Mindestens teilweises Einlegen der Faserstränge in die mehrere Nuten,
• ▪ Befestigung der Faserstränge in den Nuten mittels Klebstoff.

An inventive method for reinforcing a support structure with a surface consisting of one or more surfaces, therefore comprises the steps:

• Creating at least one bore starting from a surface of the support structure in an inner region of the support structure,
• Creating a plurality of grooves starting from the bore in at least one direction on the surface of the support structure, which extend from the bore in a region of at least one circular sector,
• Introducing an adhesive into the at least one bore,
• Introducing a fiber bundle into the bore such that a portion of the fiber bundle protrudes beyond the bore,
• Dividing the protruding part of the fiber bundle into fiber strands,
• At least partially inserting the fiber strands into the plurality of grooves,
• ▪ Attaching the fiber strands in the grooves by means of adhesive.

According to the preceding description of the arrangement according to the invention, the method may comprise further steps.

In particular, the fiber bundle is impregnated with a resin prior to insertion into the bore and insertion into the grooves.

If a surface reinforcement is provided on the support structure, the method further comprises a step of attaching a surface reinforcement to the surface of the support structure, wherein a surface reinforcement, in particular a lamella or a fabric, is affixed over the portion of the fiber bundle which has been adhesively secured in the groove is glued and at least in the region of the portion of the fiber bundle, which was fixed in the groove by means of adhesive with the surface of the structure.

Brief description of the drawings

Reference to the drawings embodiments of the invention will be explained in more detail. The FIGS. 1B, 3B, 5A-7B show a non-inventive embodiment of the arrangement. The same elements are provided in the various figures with the same reference numerals. Of course, the invention is not limited to the illustrated and described embodiments.

• Figuren 1 A bis 2C: Tragstrukturen mit Bohrungen und Nuten und darin eingeklebten Faserbündeln bzw. Fasersträngen;
• Figuren 3A bis 4B: Tragstrukturen mit Bohrungen und Nuten und darin eingeklebten Faserbündeln bzw. Fasersträngen sowie Oberflächenbewehrung;
• Figuren 5A bis 6F: Ausführungsformen von Tragstrukturen mit Bohrungen und Nuten und darin eingeklebten Faserbündeln bzw. Fasersträngen;
• Figuren 7A und 7B: Detailansichten von Tragstrukturen mit abgerundeten Kanten innerhalb der Nut.

Show it:

• Figures 1 A to 2C : Supporting structures with bores and grooves and fiber bundles or fiber strands glued therein;
• FIGS. 3A to 4B : Supporting structures with bores and grooves and fiber bundles or fiber strands glued therein and surface reinforcement;
• FIGS. 5A to 6F Embodiments of support structures with holes and grooves and fiber bundles or fiber strands glued therein;
• FIGS. 7A and 7B : Detail views of support structures with rounded edges inside the groove.

In the figures, only the elements essential for the immediate understanding of the invention are shown.

Ways to carry out the invention

• Figure 1 A shows a section through a support structure 1 having a surface consisting of a plurality of surfaces 2a, 2b, 2c, wherein from the surface 2a, a bore 3 extends in an inner region of the support structure. This bore is filled with an adhesive 12 and with a portion of a projecting beyond this bore fiber bundle 4. The support structure 1, is provided on the surface 2a with a groove 5, which extends from the bore 3 and from the entry point of the bore in the Area extends in one direction on the surface. The projecting beyond the bore part of the fiber bundle 4 is located in the groove 5 and is fixed therein with adhesive 12.
• FIG. 1B shows a non-inventive plan view of the in Figure 1A shown arrangement, wherein a single groove 5 extends from the bore 3 in a direction on the surface. Furthermore, the entire protruding part of the fiber bundle is in the groove and is fixed therein with adhesive 12.
• Figure 1C also shows a plan view of the in Figure 1 A shown arrangement, wherein in this embodiment, a plurality of grooves 5 extend from the bore 3 in different directions on the surface. The protruding part of the fiber bundle 4 is divided into fiber strands, which fiber strands preferably have about the same thickness, and the fiber strands are in the grooves and are secured therein with adhesive 12.
• FIGS. 2A and 2B shows essentially an analogous embodiment, as shown in the FIGS. 1A and 1C is shown, wherein the plurality of grooves 5 extend radially from the bore 3 to the surface of the support structure 1.

Regardless of the embodiments described above, the portion of the fiber bundle, which is located in the bore, in particular one of the two loose ends of the fiber bundle. The other loose end of the fiber bundle represents that part of the fiber bundle, which projects beyond the bore or which is located in the grooves and fixed there.

In another, less preferred embodiment, it is also possible to fold over a fiber bundle, in particular in the region of its center or its geometric center of gravity, and thus to overlay the two loose ends of the fiber bundle. Thereafter, the fiber bundle, preferably with the folded end is then inserted into the bore and the two loose ends are inserted into the groove or divided into a plurality of grooves.

In both cases, in each case the portion of the fiber bundle, which is located in the bore, in particular approximately the same length as that which projects beyond the bore.

Figure 2C shows an embodiment of the invention in which a central portion of the fiber bundle is located in the bore. The support structure 1 shown here has a surface consisting of a plurality of surfaces 2a, 2b, 2c, etc., and a first bore 3a, which extends from the surface 2a in the inner region of the support structure. The second bore 3b extends from the surface 2b in the inner region of the support structure. The surface 2b is facing away from the surface 2a and the two bores 3a and 3b are arranged so that they are connected to each other in the extension of their respective drilling axes. Of course, the two holes can be created in the case shown by the fact that the support structure is pierced by a surface and thus the second bore represents the exit point of the first bore. The holes 3a and 3b are filled with an adhesive 12 and with a portion of a fiber bundle 4. In particular, in this Embodiment, a fiber bundle arranged in the bore, that its central portion is located in the bore and that its loose ends each project beyond the surface of the support structure. Of the bores 3 a and 3 b, in each case a plurality of grooves 5 extend in different directions on the surface, for example in the manner in which FIG. 2B is shown. The protruding parts of the fiber bundle 4 are divided into fiber strands and the fiber strands are in the grooves and are fixed therein with adhesive.

In the FIGS. 3A (Cross-section) and 3B (top view) is a non-inventive embodiment of the arrangement is shown. In this case, a surface 2a of the surface of a support structure 1 has a plurality of bores 3, which run in the inner region of the support structure 1, and in each case a single groove 5 per bore, which extends along the surface (see also FIG. 1 B) , The holes 3 and the grooves 5 are offset from each other, however, mounted in their entirety linear to the surface. Over the grooves 5 with the sections of the fiber bundles 4, a lamella 6 is attached as a surface reinforcement, said lamella is bonded at least in this area with the surface of the support structure. In particular, such a lamella is glued over the entire surface of the surface of the support structure. Arrangements as they are in the FIGS. 3A and 3B are shown, especially in the area of the end sections, for example. In the last 0.5 to 1 meters, the lamellae and serve the improved power transmission between the support structure and lamella, so surface reinforcement.

FIG. 3C shows a plan view of an inventive arrangement, which is essentially that of Figure 1C corresponds, wherein above the grooves 5, which go out of the bore 3 and are provided with fiber strands of the fiber bundle 4 and with adhesive, a fabric 7 is attached as a surface reinforcement. Such a fabric is preferably glued over its entire surface with the surface of the support structure. The bonding of the over the region of the fiber bundle glued into the grooves leads to improved power transmission between the support structure and tissue, so surface reinforcement.

An embodiment of the inventive arrangement, as shown in the Figures 1C and 3C is shown in the Figure 3D shown. In this case, the bore 3, which runs in the inner region of the support structure, at a joint between two flat elements of a support structure, for example. At a junction between two walls or between the wall and bottom plate. Also in this case, a surface reinforcement in the form of a fabric 7 is attached above the anchor area.

Another embodiment of the invention is in FIG. 3E shown. The support structure 1 shown here has a surface consisting of a plurality of surfaces 2a, 2b, 2c and a first bore 3a, which extends from the surface 2a in the inner region of the support structure. The second bore 3b extends from the surface 2b in the inner region of the support structure. The surface 2b is facing away from the surface 2a and the two bores 3a and 3b are arranged so that they are connected to each other in the extension of their respective drilling axes. Of course, the two holes can be created in the case shown by the fact that the support structure is pierced by a surface and thus the second bore represents the exit point of the first bore. The holes 3a and 3b are filled with an adhesive (not shown) and with a portion of a fiber bundle 4. In particular, in this embodiment, a fiber bundle is disposed in the bore such that its central portion is in the bore and that its loose ends project beyond the surface of the support structure, respectively. From the bores 3 a and 3 b, a plurality of grooves 5 each extend in different directions on the surface. The protruding parts of the fiber bundle 4 are divided into fiber strands and the fiber strands are in the grooves and are fixed therein with adhesive. About the arrangements described a fabric 7 is mounted, which extends over the end face of the support structure and is bonded in the region of the grooves extending from the point of entry of the bore 3a to that of bore 3b with the support structure.

An embodiment of the present invention, in which also two holes are present, which are connected to each other in the extension of their drilling axes is in the Figures 3F (Cross section) and 3G (top view). Here, a T-shaped support structure with a surface comprising a plurality of surfaces 2a, 2b, etc. at the junction between their two flat elements, two holes 3a and 3b, which connect the surfaces 2a and 2b together. The fiber bundle 4 is disposed in the bore such that its central portion is in the bore and that its loose ends project beyond the surface of the support structure, respectively. From the holes each have a plurality of grooves 5 in different directions on the surface. The protruding parts of the fiber bundle 4 are divided into fiber strands and the fiber strands are in the grooves and are fixed therein with adhesive.

In the Figures 3H and 3I is a possible application of the in the Figures 3F and 3G shown arrangement. In the support structure 1, this is a concrete slab 10, which has a plurality of reinforcing ribs 11, ie T-shaped sections. The reinforcing ribs 11 had in the region of their joints with the concrete slab 10 holes 3, which are designed so that in each case two holes in the extension of their drilling axes are interconnected. Starting from the point of entry of the respective borehole 3, a plurality of grooves extend along the surface of the concrete slab. Similar to the embodiments described above, boreholes and grooves are filled with fiber bundles or fiber strands of the fiber bundle and adhesive. Over the surfaces of the concrete slab, which are located between the reinforcing ribs 11, a surface reinforcement in the form of a fabric 7 is attached. This fabric is glued in particular all over the surface with the underlying surface.

In the FIGS. 4A (Cross-section) and 4B (top view) is shown a further embodiment of the invention, in which arrangements, as for example in the FIGS. 2A and 2B are shown are attached to a support structure 1 at regular intervals. The arrangements can be mounted on a surface of the surface of the support structure or on multiple surfaces. Above the arrangements, furthermore, a fabric 7 is glued to the surface of the support structure, at least with the arrangements, but in particular over its full area. The fabric can run continuously over corners and edges in the surface of the support structure.

FIG. 5A shows a section through a non-inventive embodiment of a support structure 1 having a surface consisting of a plurality of surfaces 2a, 2b, 2c, etc. and a first bore 3a, which extends from the surface 2a in the inner region of the support structure. The second bore 3b extends from the surface 2b in the inner region of the support structure. The surface 2b faces away from the surface 2a. From the one bore 3a, a groove 5 extends along the surface of the support structure towards the entry point of the other bore in the support structure. The groove, which thus connects the two inlet holes of the holes with each other, runs in particular on the shortest path between the two holes. Depending on the requirements on the reinforcement of the support structure, however, it is also conceivable that the groove assumes a different course between the bores, for example to ensure the most uniform possible distribution of force. In the groove 5, a fiber bundle 4, which opens with its loose ends in the two holes 3a and 3b. Both in the holes and in the groove is adhesive 12 for fixing the fiber bundle.
A similar embodiment not according to the invention as in FIG. 5A is also in FIG. 5B represented here, wherein here the fiber bundle surrounds a reinforcing rib 11 of a structure 1.

FIG. 6A shows a section through a further non-inventive embodiment of the invention, which is a modification of the embodiment FIG. 5A equivalent. In contrast to this, the embodiment in FIG FIG. 6A two holes 3a, 3b in different, mutually remote surfaces 2a, 2b of the surface of the support structure, wherein the two holes 3a and 3b are arranged so that they are connected to each other in the extension of their respective drilling axes. The entry holes of the two Boreholes 3a and 3b are as in FIG. 5A connected to each other via a groove 5. Both the holes 3a, 3b and the groove 5 contain an adhesive 12 and a fiber bundle 4. The fiber bundle is in particular arranged so that its two ends overlap. This overlap may be in the hole or anywhere in the groove. The length of the overlapping region of the fiber bundle is in particular chosen so that a possible seamless power transmission is ensured and is about 5 to 50 cm. Depending on the requirements of the support structure, it is also possible to wrap the fiber bundle several times around the support structure.

In general, and in particular also with respect to the embodiments of the invention, as described in the FIGS. 5A and 5B as well as in the FIGS. 6A to 6D are shown, those embodiments are preferred in which the two bores 3a and 3b are arranged so that they are connected to each other in the extension of their respective drilling axes and the fiber bundle is arranged so that its two ends overlap at least. As a result, the fiber bundle forms a closed loop, whereby the transmission of the thrust force between the two ends of the fiber bundle, that is contact-critical within the same material takes place. Compared to embodiments in which the ends of the fiber bundle are used in separate holes and the transmission of the thrust thus between the support structure and the fiber bundle, so verbund critical, takes place, the preferred embodiments allow a higher efficiency of reinforcement and a much better utilization of the fiber bundle.

The Figures 6B and 6C show modifications of the embodiment not according to the invention, as in FIG. 6A is described. Shown here are arrangements according to the invention, as they can be used for example to reinforce a rectangular column as part of a support structure. FIG. 6C shows that it is also possible that the fiber bundle 4 is repeatedly passed through a bore, but to run in two different grooves from the entry of the first bore to that of the second bore. On the other hand, the embodiment can FIG. 6C also be created by the projecting beyond the bore part of the fiber bundle is divided into two fiber strands, which then extend in different grooves.

FIG. 6D shows a non-inventive modification of the embodiment, as shown in FIG. 5B is shown, in which case the fiber bundle 4 completely surrounds the reinforcing rib 11.

FIG. 6E shows a non-inventive side view of a support structure, which in the Figures 6A, 6B and 6C illustrated variants of the arrangement comprises. Depending on the requirements, the different variants can be combined with each other, or several identical arrangements are continuously attached to a support structure.

FIG. 6G shows a non-inventive support structure 1 comprising a bottom plate 10 and a wall created thereon, the wall is provided in its lower portion with a plurality of arrangements, which from those FIG. 6A correspond. Optionally, a fabric for additional reinforcement of the support structure can be attached via these arrangements (not shown here).

FIG. 6F shows a cylindrical column comprising a plurality of arrangements.

FIG. 7A shows a detailed view of a section of a non-inventive support structure 1 having a surface consisting of a plurality of surfaces 2a, 2b, 2c, wherein from a surface 2a of a bore 3 extends into an inner region of the support structure. The support structure 1 is provided on the surface 2a, from which the bore extends into an inner region of the support structure, with a groove 5 which extends from the bore in a direction on the surface.

The groove 5 extends over each edge 8, which connects the two surfaces 2 a and 2 c, and 2 c and 2 b of the surface of the structure together, and this one edge 8 has in the interior of the groove 5 a rounding 9.

FIG. 7B shows a section through a portion of a non-inventive support structure 1, which has two holes 3a, 3c in different, mutually remote surfaces 2a, 2c of the surface of the support structure, wherein the two holes 3a and 3c are arranged so that they in the extension their respective drilling axes are interconnected. The inlet holes of the two holes 3a and 3b are connected to each other via a groove 5. Within the groove 5, the edges 8 each have a rounding 9. Again, the respective transitions from the bore into the groove may have a rounding according to the above description.

Examples

In the following, exemplary embodiments are listed which are intended to explain the described invention in more detail. Of course, the invention is not limited to these described embodiments.

specimen

Concrete cubes with an edge length of 20 cm were produced as test specimens, using concrete from the same batch for all cubes. The concrete cubes were stored for 28 days at 23 ° C and 50% relative humidity. The concrete cubes were sanded off on one side to remove cement slurry. In the middle of the treated area, a hole with a diameter of 20 mm and a depth of 100 mm was attached. Two concrete cubes were left without drilling. Starting from the hole, eight grooves with an angle grinder were placed on the concrete cubes evenly around the hole. The grooves were 5 mm wide and 5 mm deep and extended over a length of 8 cm. The angle between the grooves was 45 ° each. With four concrete cubes, only five grooves each were mounted semicircularly. The edges at the transition from the bore into the grooves has been slightly rounded. Two grooves did not have grooves. Subsequently, the concrete cubes were repeatedly cleaned on the machined surface and inside the hole with compressed air and a brush and thus largely freed of dust.

Sikadur®-330, commercially available from Sika Schweiz AG, with a mean layer thickness of about 1 mm was applied to the machined surface of the concrete cubes without drilling. For the concrete cubes with holes, the hole was filled from bottom to top and the grooves filled with Sikadur®-330. It was ensured that no air was trapped in the hole.

A fiber bundle with a length of 20 cm and a fiber cross-sectional area of about 25 mm ² was completely impregnated using a brush with Sikadur® 300 from Sika Schweiz AG. Subsequently, a cable tie was attached to a loose end of the impregnated fiber bundle and tightened and cut to length. With the help of a knitting needle, which was hooked to the cable tie, the fiber bundle was inserted all the way into the hole. The protruding end of the fiber bundle was divided into fiber strands, the number of fiber strands having to correspond to those of the previously mounted grooves, and inserted into the grooves. In the concrete cubes without grooves, the protruding end of the fiber bundle was fanned out evenly and spread on the machined surface of the concrete cube.

At the machined surface of the concrete cube was now evenly distributed over the grooves with the fiber bundle Sikadur®-330, so that the entire machined surface was covered with sufficient adhesive.

A fabric provided with SikaWrap® 300 C NW (width 20 cm, length 180 cm) was laminated in the area of the last 20 cm of its loose ends by means of a paint roller with Sikadur®-300. A laminated loose end was placed on the machined surface of the concrete cube and pressed there with a paint roller. Sikadur®-330 was applied over the attached tissue using a dental trowel. The fabric was looped over and the other loose and laminated end was placed on the same spot of the concrete cube so that the two ends of the fabric came to lie one above the other. Again, the fabric was pressed with the paint roller. With a spatula of the width of the concrete cube, excess adhesive was removed from the specimen.

The test specimens thus produced were left for 7 days at 23 ° C and 50% relative humidity, so that the adhesive could cure.

In the same way, specimens were also made with fiber bundles of glass fibers with a fiber cross-sectional area of about 25 mm ² .

In each case, two identical specimens of each type were produced. The results of the measurements represent the mean of the measurements on the two identical test specimens.

measurement method

The tensile shear strength of different test specimens was measured according to ISO 527-4 / EN 2561 with a measuring speed of 2 mm / min at 23 ° C and a relative humidity of 50%.

The tensile shear strength of the bond was tested by placing the loop formed by the SikaWrap-300C NW fabric around a steel pipe connected to the moving frame of the testing machine.

The concrete cube was connected to the fixed frame of the testing machine via an applied steel crossbar and threaded rods. <U> results </ u> drilling Grooves (number) Material fiber bundles Maximum load (kN) Mean value (kN) No None - 36.1 37.1 40.3 34.9 Yes None carbon fiber 47.6 44.6 39.0 47.2 Yes None glass fiber 54.9 52.6 50.6 52.2 Yes 8th carbon fiber 61.9 64.3 66.8 64.3 Yes 8th glass fiber 70.9 63.8 56.8 63.7

LIST OF REFERENCE NUMBERS

1

supporting structure

2

Areas (2a, 2b, 2c)

3

Bore (3a, 3b, 3c)

4

Fiber bundles or fiber strands

5

groove

6

lamella

7

tissue

8th

edge

9

rounding off

10

concrete slab

11

reinforcing rib

12

adhesive

Claims (10)

1. An arrangement comprising a supporting structure (1) with a surface consisting of one or more faces (2a, 2b, 2c), wherein a bore (3) runs from at least one face into an inner region of the supporting structure, and said bore is filled with an adhesive (12) and with a portion of a fiber bundle (4) projecting beyond said bore, characterized in that, on the at least one face (2a) from which the bore runs into an inner region of the supporting structure, the supporting structure (1) is provided with a plurality of grooves (5) which extend from the bore (3) in a region of at least one circular sector, and the projecting part of the fiber bundle (4), divided up according to fiber strands, is at least partially located in the grooves (5) and is fastened therein with adhesive (12).
2. The arrangement as claimed in claim 1, characterized in that the number of grooves which emerge from the bore is 2 to 16.
3. The arrangement as claimed in either of the preceding claims, characterized in that the circular sector has a center point angle of 60 to 360°.
4. The arrangement as claimed in claim 1, characterized in that a second bore (3b) runs from the at least one face (2a) or from another face (2b, 2c) of the surface of the supporting structure into an inner region of the supporting structure, and the at least one groove (5) runs from the inlet location of the one bore (3a) along the surface of the supporting structure toward the inlet location of the second bore (3b), and in that the projecting part of the fiber bundle (4) at least partially runs in the at least one groove (5) and leads into the second bore (3b) and is fastened therein with adhesive (12).
5. The arrangement as claimed in claim 4, characterized in that the second bore runs from another face of the surface of the supporting structure into an inner region of the supporting structure, which face faces away from the at least one face from which the bore runs into an inner region of the supporting structure, and in that the two bores are connected to each other in the extension of the respective bore axes thereof.
6. The arrangement as claimed in one of the preceding claims, characterized in that the groove runs over at least one edge which connects two faces of the surface of the supporting framework to each other, and said at least one edge has a rounded portion in the interior of the groove.
7. The arrangement as claimed in one of the preceding claims, characterized in that the surface of the supporting structure is at least partially connected to at least one surface reinforcement, in particular to a lamella and/or to at least one woven fabric, wherein the surface reinforcement is adhesively bonded to the surface of the supporting framework at least in the region of that part of the fiber bundle which has been fastened in the groove by means of adhesive.
8. A method for reinforcing a supporting structure with a surface consisting of one or more faces, comprising the following steps:

   ▪ providing at least one bore from a face of the supporting structure into an inner region of the supporting structure,

   ▪ providing a plurality of grooves from the bore in at least one direction on the surface of the supporting structure, which grooves extend from the bore in a region of at least one circular sector,

   ▪ placing an adhesive into the at least one bore,

   ▪ introducing a fiber bundle into the bore such that a part of the fiber bundle projects beyond the bore,

   ▪ dividing up the projecting part of the fiber bundle according to fiber strands,

   ▪ at least partially inserting the fiber strands into the plurality of grooves,

   ▪ fastening the fiber strands in the grooves by means of adhesive.
9. The method as claimed in claim 8, characterized in that the fiber bundle is impregnated with a resin before being introduced into the bore and inserted into the at least one groove.
10. The method as claimed in either of claims 8 and 9, characterized in that a surface reinforcement, in particular a lamella or a woven fabric, is attached over that portion of the fiber bundle which has been fastened in the groove by means of adhesive and is adhesively bonded to the surface of the supporting framework at least in the region of that part of the fiber bundle which has been fastened in the groove by means of adhesive.

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