CA3165303A1

CA3165303A1 - Connection element, method for manufacturing a connection element and related installation kit

Info

Publication number: CA3165303A1
Application number: CA3165303A
Authority: CA
Inventors: Andrea ZAMPA; Allen DUDINE; Enrico ZANELLO
Original assignee: Dudine Allen; Zampa Andrea; Zanello Enrico; Fibre Net Holding Srl
Current assignee: Fibre Net Holding Srl
Priority date: 2019-12-18
Filing date: 2020-12-17
Publication date: 2021-06-24
Also published as: US20230012652A1; CN114945726A; WO2021124192A1; EP4077829A1; IT201900024511A1

Abstract

A connection element (12) made of composite material comprises a bundle of fibres (13) and a binding agent, and comprises at least one preformed portion (14) and at least one free fibre portion (16, 18, 19). The at least one preformed portion (14) comprises a section of fibres (13) embedded in the binding agent to form a monolithic structure. At least part of the fibres (13) of the at least one free fibre portion (16, 18, 19) consists of virgin fibres (13).

Description

2 DESCRIPTION
"CONNECTION ELEMENT, METHOD FOR MANUFACTURING A
CONNECTION ELEMENT AND RELATED INSTALLATION KIT"
FIELD OF APPLICATION
[0001] The present invention relates to a connection element, a method for manufacturing a connection element and a related installation kit. In particular, the present invention relates to connection elements made of composite material to be used, for example, for consolidating or improving the safety of structures in the building industry and in the industry in general.
BACKGROUND ART
[0002] As known, there are many techniques for consolidating architectural structures or the safety thereof. In particular, there are techniques which use rigid meshes made of composite material made with fibres incorporated in a thermosetting resin.

[0003]In some applications, the meshes are embedded inside a mortar with binding agents, which may be of different types, and are used for consolidating existing structures (masonry, concrete, reinforced concrete, etc.) creating a reinforced plaster to be applied on the surfaces, or as slabs for manufacturing load bearing floor slabs.

[0004] The mesh, for example, may be blocked in position by means of the use of junction elements inserted in holes made in the masonry. The junction elements are generally made of metal or another material, and have an L-shape, in which the two sides are substantially perpendicular to each other. In use, once an anchoring resin has been distributed inside the hole, one side is inserted into the hole obtained in the masonry, while the other side is arranged parallel to the surface of the masonry. Mesh and junction elements are therefore embedded inside a mortar with binding agents which may be of different types.

[0005]If the mesh is positioned on both surfaces of a masonry, it is possible to block it in position, making a through hole so that the two meshes may be connected to each other with two junction elements: a first junction element inserted at one surface, and a second junction element inserted at the opposite surface.

[0006] As an alternative to the type of junction elements mentioned, junction elements made with preformed bars made of composite material comprising fibres and thermosetting resin are known.

[0007]The preformed bar made of composite material may be obtained by means of a forging method or by means of a pultrusion method. In both cases, the fibres are picked up and passed through a resin impregnation bath.

[0008]In the moulding process, the impregnated fibres are modelled directly on the die, where they are subjected to natural or artificial curing in suitable furnaces.

[0009]In the pultrusion process, at the exit of the area in which the impregnation occurs, the impregnated fibres pass through a die so as to give the manufactured item a specific cross section, compacting the fibres together.
The impregnated fibres are then passed inside a curing furnace which provides heat so that the resin may polymerize and therefore cure. These two steps may be carried out jointly in the production die.

[0010] Downstream of the plant, a so-called pulling device is there, which provides the impregnated fibres with the traction necessary to move through the stations mentioned above.

[0011] The method is therefore free from downtime, since the pulling device allows the manufactured item being processed to move between the various stations of the apparatus.

[0012] Downstream of the pulling device, an area may be arranged for the automated cutting of the pultruded bars.

[0013] Bars made of composite material offer many advantages. For example, with respect to bars made of metal, they are lighter and are not subject to oxidation.

[0014] The main limitation of the pultruded bars is that they may not be bent on site, for example in the case in which an anchorage is to be made through the masonry between two reinforcement plates.

[0015] The only way to obtain bent bars made of composite material is to produce them directly bent by means of forging, in a dedicated plant. However, the production of these elements, even if they are manufactured already bent, fails to ensure the dimensional and inclination flexibility which would instead be necessary.

[0016] To establish a connection between the two reinforcement areas, or simply to perform the function thereof as a connector, it is therefore necessary to use two distinct L-shaped elements, then joined by means of an overlapping of the chemical or mechanical type, at the portions thereof, inside and not crossing the structural element.

[0017] Furthermore, in the case of L-shaped connectors, precisely at the connecting portion between the two sides of the L, a decrease in resistance and stiffness is there, with respect to the straight section.

[0018] The prior art has attempted to solve this issue by proposing pultruded bars subjected to a processing by means of which the fibres at one end of the bar are freed from the already cured resin.

[0019] The end of the bar, after the pultrusion process, is subjected to a solvent bath and/or a pyrolysis at a temperature to eliminate the resinous matrix and keep the fibre dry.

[0020] The bars thus obtained may be inserted inside a hole made in the support to be reinforced or positioned where previously defined, while the end consisting of free 5 fibres (called, in the technical jargon, the unravelled end) is radially widened and glued to the desired surface with specific organic and/or inorganic adhesives or embedded in the mortar with which the surface of the support is coated. Thereby, the unravelled end ensures the mechanical continuity of the elements.

[0021] The procedure used to free the fibres from the resin, however, has some disadvantages.

[0022]In the first place, it is a further processing which must be carried out on the bar, and therefore affects the production costs and the time required for the production of the preformed connector.

[0023] Furthermore, the fibres which are freed from the cured resin have worse mechanical features with respect to the intact bar, but also with respect to the fibres before the impregnating step, since the invasiveness of the process modifies the structure of the fibre and the priming thereof, the lubrication and assembly thereof, substantially removing the gripping power of the free and dry end.
PRESENTATION OF THE INVENTION

[0024] Therefore, the need is felt to solve the drawbacks and limitations mentioned above with reference to the prior art.

[0025] Therefore, the need is felt to provide a connection element for the building industry and industry in general, which may be adapted to different conditions of use.

[0026] Furthermore, the need is felt for a connection element for the building industry which may be easily used for the junction through a through hole in the support to be consolidated by means of reinforcement plates on the surfaces thereof, or simply as a connection element with the ends to be embedded in two or more solids to be connected.

[0027] Furthermore, the need is felt for a connection element for the building industry which is simple and cost effective to manufacture with respect to preformed connectors of the known type.

[0028] Furthermore, the need is felt for a connection element which is easier to use with respect to the connectors of the prior art.

[0029] Such needs are at least partially met by a connection element according to claim 1, by a method for manufacturing a connection element according to claim 11, and by a related installation kit according to claim 14.

DESCRIPTION OF THE DRAWINGS

[0030] Further features and advantages of the present invention will be more comprehensible from the following description of preferred embodiments given by way of non-limiting examples, in which:

[0031] - Figure 1 diagrammatically shows a perspective view of a first embodiment of a connection element according to the present invention;

[0032] - Figure 2 diagrammatically shows a perspective view of an alternative embodiment of a connection element according to the present invention;

[0033] - Figure 3 diagrammatically shows a perspective view of a further alternative embodiment of a connection element according to the present invention;

[0034] - Figure 4 diagrammatically shows a possible use of a connection element according to the present invention;

[0035] - Figures 5-7 diagrammatically show perspective views of possible embodiments of a connection element according to the present invention;

[0036] - Figure 8 diagrammatically shows a possible alternative embodiment of a connection element according to the present invention;

[0037] - Figure 9 diagrammatically shows a possible alternative embodiment of a connection element according to the present invention;

[0038] - Figure 10 diagrammatically shows a possible alternative embodiment of a connection element according to the present invention;

[0039] - Figure 11 diagrammatically shows a perspective view of a component of a kit according to the present invention; and

[0040] - Figure 12 diagrammatically shows a sectional view of a component of a kit according to the present invention.

[0041] Elements or parts in common to the embodiments described will be indicated hereafter using the same reference numerals.
DETAILED DESCRIPTION

[0042] Figure 1 shows a connection element according to the present invention, which is indicated with the generic reference 12.

[0043] The connection element 12 is made of composite material comprising a bundle of fibres 13 and a binding agent. The binding agent may be a resin or an inorganic matrix.

[0044]In this disclosure, the term matrix and the term binding agent will be used indifferently to indicate the same material.

[0045]In particular, the connection element 12 comprises at least one preformed portion 14 and at least one free fibre portion 16, 18.

[0046] The preformed portion 14 comprises a section of the bundle of fibres 13 embedded in the binding agent to form a monolithic structure.

[0047]In particular, the preformed portion 14, which in use may be inserted inside a hole in the support to be consolidated or in the solids to be connected, may have an external surface with sand or grit and binding agent fillings, or an external surface subjected to roughing by means of a mechanical processing, by removing material or by forging, in order to improve the performance of the connection.

[0048] The length of the preformed portion 14 may, for example, range from 10 mm to 20000 mm. In any case, the length of the preformed portion 14 may be adapted to specific needs.

[0049] Advantageously, the length of the preformed portion 14 may be decided on the basis of the thickness of the structural or non-structural element crossed and/or the distance of the elements to be connected in which it must be inserted.

[0050] The preformed portion 14 may have a substantially circular cross-section, as shown in the embodiments of Figures 1, 2, 3, 8-10.

[0051] According to a possible alternative embodiment, shown in Figure 5, the cross section of the preformed portion may be C-shaped.

[0052]In a possible alternative embodiment, shown in Figure 6, the preformed portion 14 may have an elongated 5 cross-section, even with or without the presence of a reinforcing rib 21, having a longitudinal or transverse development. In the embodiment shown in Figure 6, the reinforcing ribs 21 are two and arranged parallel.

[0053]In a further embodiment, the preformed portion may 10 have a substantially circular and hollow section, as shown in the example of Figure 7.

[0054] The cross section may, for example, be T-, L-, C-, double T-shaped, rectangular, square, cylindrical or according to specific design requirements.

[0055] Advantageously, in the case where the section of the preformed portion 14 is hollow, the internal volume of the preformed portion 14 may be filled to increase the resistance, or in general the performance, thereof. The internal volume may be filled, for example, with resins, mortars, organic or inorganic matrices or matrices of another type.

[0056] The external surface may be continuous, provided with holes or subjected to other surface treatments capable of improving the adhesion of the connection element.

[0057] The free fibre portion 16, 18 may be arranged at one or both ends of the bundle of fibres 13. Embodiments of this type are shown for example in Figures 1 and 2.

[0058] According to a possible embodiment, the free fibre portion may be arranged between two preformed portions 14. An embodiment of this type is shown in Figure 3.

[0059] In particular, the length of the free fibre portion 16, 18 may, for example, range from 10 mm and 20,000 mm.

[0060] In any case, the length of the free fibre portion may be adapted to specific needs.

[0061] At the free fibre portion 16, 18, 19, at least one part of the fibres 13 consists of virgin fibres.

[0062] In this disclosure, the term virgin fibres means fibres which, at a portion thereof, have not been embedded in the resin, mortar, organic matrix, inorganic matrix, or matrix of another type. In technical jargon, virgin fibres may also be defined as dry fibres.

[0063] In particular, virgin fibres are fibres which, in the free fibre portion 16, 18, 19 have not been embedded with resin, mortar, organic matrix, inorganic matrix or another matrix to make a monolithic or preformed structure.

[0064] In other words, the fibres 13 which form the connection element 12 have been impregnated at the preformed portion 14, while they have not been impregnated in the free fibre portion 16, 18, 19.

[0065] In any case, as it will be obvious to those skilled in the art, such fibres may, for example, be processed or treated in line or during a subsequent step to obtain products or elements with shape and features based on the specific function thereof, such as, for example, the possibility of impregnating with matrices and/or gripping material with different properties.

[0066] In other words, the free fibre portion 16, 18, 19 may comprise or consist of virgin fibres.

[0067] According to a possible embodiment, advantageously, the free fibre portion 16, 18, 19 may be made with at least 90% of virgin fibres.

[0068] Figure 4 shows some examples of installation of connection elements 12 according to the present invention, in which the free fibre portion 16 is visible, the fibres 13 of which are arranged radially.

[0069] According to alternative embodiments, the fibres of the free fibre portion 16, 18, at the ends, may also be arranged in different manners, as it may be easily assumed by those skilled in the art.

[0070] According to a possible embodiment of the present invention, the free fibre portion may consist of virgin fibres.

[0071] The bundle of fibres 13 may comprise synthetic organic fibres, natural organic fibres, inorganic fibres, and/or metallic fibres. Advantageously, a connection element may comprise fibres of a different type.

[0072] The synthetic organic fibres may comprise, for example, aramid fibres, poly-para-phenyl benzobisoxazole (PBO), and/or polyester.

[0073] Natural organic fibres may comprise, for example:
cotton, hemp, flax, sisal, bamboo, wood, wool, silk, etc.

[0074] The inorganic fibres may comprise, for example:
glass, carbon, basalt, quartz, etc.

[0075] The metallic fibres may comprise, for example:
stainless steel, carbon steel, copper, brass, aluminum, titanium, etc.

[0076] According to a possible embodiment of the present invention, the bundle of fibres 13 may comprise fibres of different type.

[0077] According to a possible embodiment, the binding agent may be a resin.

[0078] As for the resin, this may be of the thermosetting type, of the thermoplastic type, it may use inorganic matrices and/or matrices of another type.

[0079]In the case of thermosetting resin, this may, for example, be of the vinyl-ester, polyester, bisphenol, acrylic type, etc.

[0080]In the case of thermoplastic resins, the resin may be selected from the group comprising PVA, PP, Pen, etc.

[0081]In the case of inorganic matrices, the matrix may be cement, quartz, lime, gypsum, etc.

[0082] According to a possible embodiment of the present invention, the connection element 12 may comprise a guide element 24 (shown in Figure 8) sliding within the preformed portion 14, so as to be adapted to be moved between an extracted position, protruding from the preformed portion 14 at the at least one free fibre portion 16, 18 and a retracted position in which it does not protrude or protrudes from the preformed portion 14 at the at least one free fibre portion 16, 18.

[0083] The guide element 24 may be made of rigid polymeric material. For example, the guide element 24 may be made of thermoplastic, thermosetting, metallic material, etc.

[0084] According to an alternative embodiment, the guide element 24 protrudes from the preformed portion 14 at the at least one free fibre portion 16, 18, but it does not slide inside the preformed portion 14.

[0085] The guide element 24 is used to optimize the unravelling of the at least one free fibre portion 16, 18 of the ends of the connection element 12.

[0086] According to a possible embodiment of the present invention, the free fibre portion may comprise a grouping element 26 in a position substantially distal with respect to the preformed portion 14.

[0087] The grouping element 26 is adapted to group the virgin fibres together, in one or more positions of the section distal with respect to the preformed portion 14.
5 In other words, between the grouping element 26 and the preformed portion 14 there is a section comprising or consisting of virgin fibres.

[0088] According to a possible embodiment of the present invention, the grouping element 26 may, for example, be a 10 resin, or a retention element such as, for example, a ring or a device for grouping the fibres made of plastic material, or of any material durable in time, tightened about the guide element 24.

[0089] According to a possible embodiment of the present 15 invention, the grouping element 26 may slide with respect to the guide element 24. In this case, once the preformed portion 14 has been inserted inside the hole obtained in the masonry, the grouping element 26 is made to slide on the guide element 24 which is fixed, so that the virgin fibres are arranged in the desired regular or irregular shape on the surface of the support to be consolidated or to be made integral. The excess part of the guide element 24, protruding from the surface of the masonry, may be cut before or after the adhesive or the matrix has been distributed on the surface of the support to embed and fix the virgin fibres.

[0090] In accordance with a possible alternative embodiment, the grouping element 26 may slide with respect to the guide element following a predefined arrangement, for example, using a preformed portion 14 having a helical development.

[0091]In this case, once the preformed portion 14 has been inserted inside the masonry, the guide element is made to slide, dragging the grouping element 26 by means of the movement thereof.

[0092]In accordance with a possible embodiment, the grouping element 26 may also be rotated about the main axis.

[0093] According to a possible embodiment, a free fibre portion 19 may be arranged between two preformed portions 14. In other words, the preformed part may comprise at least two monolithic sections separated from each other by a section at least partially made with virgin fibres.
Advantageously, it is therefore possible to make the connection element 12 maintaining one or more intermediate dry portions, for example, by means of a pultrusion process interrupted by bath or by impregnation. In this specific case, the use may be extended to the creation of real brackets of elements to be consolidated, keeping the dry section in the positions in which the preformed sections may not be used.

[0094] According to a possible embodiment of the present invention, said virgin fibres may comprise impregnation points 30, adapted to improve the grip of the virgin fibres in the binding agent used to cover the surface of the masonry.

[0095] A method for making a connection element 12 made of composite material comprising fibres and a resin-based binding agent according to the present invention will be described below.

[0096] The method comprising the steps of:

[0097] - providing a bundle of fibres 13;

[0098] - impregnating the fibres 13 with a binding agent;

[0099] - passing the impregnated fibres 13 inside a die having a certain cross-section;

[00100] - curing the resin inside a curing furnace or the die itself; and

[00101] - cutting the connection element.

[00102] In particular, the step of impregnating the fibres 13 may occur by means of a binding agent such as a resin of the thermosetting or thermoplastic type, or an inorganic matrix.

[00103] In particular, the impregnation is carried out at sections of the bundle of fibres 13, while in some sections the fibres of the fibre bundle comprise or consist of virgin fibres.

[00104] According to a possible embodiment of the present invention, the cutting may occur at a section of the bundle of fibres 13 impregnated with resin, or at a section of the fibre bundle in which the fibres comprise or consist of virgin fibres.

[00105] According to a possible embodiment of the present invention, the method may comprise a step in which the element 24 is provided inside the fibre bundle.

[00106] According to a possible embodiment of the present invention, the method may comprise a step in which the grouping element 26 is provided.

[00107] The present invention also relates to an installation kit comprising an insertion funnel 40 adapted to facilitate the insertion of the connection element 12 inside a hole in a masonry. Advantageously, the insertion funnel may comprise a tubular portion 44 at one end of which a flaring 42 is provided.

[00108] Advantageously, the insertion funnel may also be used to guide the virgin fibres of the free fibre portion at the curving area on the surface of the masonry.

[00109] The advantages which may be achieved by a connection element according to the present invention are therefore apparent.

[00110] First, a single connection element has become available, which may be used to connect two plate-like resistant elements through a hole in a masonry. In this case, the ends of the connection element are both prepared with a free fibre portion.

[00111] The virgin fibres are therefore modelled and embedded in the resin or in the cement matrix, so as to create an effective anchorage and ensure a better yield of the tensile connection element.

[00112] Furthermore, in the case where the ends of the connection element are both provided with a free fibre portion, the need to join two L-shaped elements inside the masonry has been eliminated.

[00113] The connection element according to the present invention may be used, for example, as a connection system between reinforcement elements for the wall/resistant element which is required to increase the performance by means of a symmetrical or partially symmetrical reinforcement layout.

[00114] The connection element also acts as a tie rod or bracing, the dry terminals/free ends thereof being possibly made on site with any geometric shape, by means of pre-moulding in the factory or direct pre-application on site, with or without the application of a mat to facilitate the creation of a junction plate or finally by providing a light primer already in the production step to improve the application steps, with the elements to be braced and/or tied.

[00115]
Furthermore, it may be used as a continuous or 5 discontinuous bracket or reinforcement in general, for structural or non-structural elements made of reinforced concrete, completing the construction steps in the factory (co-moulding or similar techniques) or on site.

[00116]
Furthermore, the particular production method 10 allows to manufacture a product which maintains the mechanical resistance and stiffness properties of the connection in the anchorage area of the elements to be connected unaltered.

[00117] In order to meet specific needs, those skilled 15 in the art will be able to make changes to the embodiments described above and/or replace the elements described with equivalent elements without departing from the scope of the appended claims.

Claims

1. Connection element (12) in composite material comprising a fibre bundle (13) and a binding agent, said connection element (12) comprising at least one preformed portion (14) and at least one free fibre portion (16, 18, 19);
said at least one preformed portion (14) comprising a section of said fibre bundle (13) embedded in said binding agent to form a monolithic structure;
characterised in that at least part of the fibres (13) of the at least one free fibre portion (16, 18, 19) consists of virgin fibres (13).

2. Connection element (12) according to claim 1, characterised in that said at least one free fibre portion (16, 18) is arranged at one or both ends of the fibre bundle (13).

3. Connection element (12) according to any one of the preceding claims, characterized in that said at least one free fibre portion (19) is arranged between two preformed portions (14).

4. Connection element (12) according to any one of the preceding claims, characterized in that said bundle of fibres (13) comprises synthetic organic fibres, natural organic fibres, inorganic fibres, and/or metallic fibres.

5.
Connection element (12) according to any one of the preceding claims, characterized in that said binding agent is a thermosetting or thermoplastic resin or an inorganic matrix.

6. Connection element (12) according to any one of the preceding claims, characterized in that it comprises a guide element (24) sliding within said preformed portion (14), so as to be adapted to be moved between an extracted position, protruding from said preformed portion (14) at said at least one free fibre portion (16, 18) and a retracted position in which it does not protrude or protrudes from said preformed portion (14) at said at least one free fibre portion (16, 18).

7. Connection element (12) according to any one of the claims 1-4, characterized in that it comprises a guide element (24) protruding from said preformed portion (14) at said least one free fibre portion (16, 18).

8. Connection element (12) according to any one of the preceding claims, characterised in that it comprises a grouping element (26) of said fibres (13) of said free fibre portion (16, 18), in a substantially distal position with respect to the preformed portion (14).

9. Connection element (12) according to the preceding claim, characterized in that said grouping element (26) is obtained with a binding agent or a retention element.

10. Connection element (12) according to the preceding claim, characterized in that said at least one preformed portion (14) is hollow, and the internal volume is filled with resin, mortar, inorganic matrices, organic matrices.

11. Method for making a connection element (12) out of composite material comprising fibres (13) and a binding agent, said procedure comprising the steps of:
- providing a fibre bundle (13);
- impregnating the fibres (13) with a binding agent;
- passing the fibres (13) inside a die having a certain cross-section;
- curing the resin inside a furnace or said die; and - cutting the connection element (12);
said method being characterised in that said impregnation step of the fibres (13) with a binding agent is carried out on sections of the fibre bundles (13), while in some sections the fibres of the fibre bundle (13) comprise or consist of virgin fibres.

12. Method for making a connection element (12) according to claim 11, characterised in that the cut is made at a section of the fibre bundle impregnated with resin.

13. Method for making a connection element (12) according to any one of the claims 11-12, characterised in that the cut is made at a section of the fibre bundle where the fibres comprise or consist of virgin fibres.

14. Installation kit of a connection element (12) comprising a connection element according to any one of the claims 1-10, and an insertion funnel (40) suitable to facilitate the insertion of the connection element (12) into a hole in a structural or non-structural element, and to facilitate the arrangement of the fibre bundle (13) as the free fibre portion (16, 18).