Modular reinforcement panel for the construction of a wall

Abstract

A modular reinforcement panel (100) for the construction of a wall, for example the wall of a tunnel, is described. The panel comprises first longitudinal bars (la) and second longitudinal bars (1b), which are arranged respectively on a first surface and a second surface which are parallel to each other. The panel also comprises transverse bars (2) arranged substantially perpendicular to the first and second longitudinal bars, each transverse bar being fixed to each one of the first and second longitudinal bars. The panel also comprises longitudinal stiffening members (3a, 3b), each one of which connects together a respective pair of first longitudinal bars or a respective pair of second longitudinal bars. The longitudinal bars, the transverse bars and the longitudinal stiffening members are made of composite material.

Description

[0001] MODULAR REINFORCEMENT PANEL FOR THE CONSTRUCTION OF A WALL

[0002] Technical field

[0003] The present invention relates to the civil engineering field. The present invention relates in particular to a modular reinforcement panel for the construction of a wall, for example the curved wall of a tunnel. The present invention also relates to a reinforcement for the construction of a wall comprising two or more modular panels.

[0004] Background art

[0005] In various civil engineering fields it is known to use reinforcements for the construction of infrastructures or parts thereof. For example, in the field of construction of tunnels (for example road, motorway, subway, railway or hydraulic tunnels) it is known to use curved reinforcements for the construction of the tunnel walls. The reinforcement is generally self-supporting and has mainly the function of providing structural support for the wall, preventing it from collapsing under the weight of the material (soil, rocks, etc.) which surrounds the tunnel. The reinforcement may also perform a function of supporting and ensuring adhesion of the other layers of the wall, for example in the case where it is internally lined with concrete using the shotcrete technique.

[0006] The reinforcement generally is installed during the construction of the tunnel. However, with time it may be subject to wear, such that it must be replaced. In any case, the installation of the reinforcement (both during the construction of the tunnel and during replacement of the reinforcement) is a complex and costly operation since the reinforcement is a heavy and bulky object which is difficult to move and position, in particular inside the tunnel itself.

[0007] EP 2 534 338 describes a steel reinforcement for tunnels. The reinforcement may be modular and the various modules may be joined together during installation.

[0008] Summary of the invention

[0009] The Applicant has noticed that the steel reinforcement described in EP 2 534 338 has a number of drawbacks.

[0010] In particular, in order to ensure the mechanical performance of the reinforcement described in EP 2 534 338 capable of withstanding the pressures which typically act on the walls in a tunnel, it is necessary for the steel bars which form the reinforcement to have a crosssection able to guarantee adequate rigidity thereof. Such a crosssection of the bars, considering the specific weight of the steel, results in relatively heavy modules which are therefore not very easy to move and position inside the tunnel. The individual modules could be made lighter by reducing the diameter of the steel bars, but this could result in a reinforcement with an inadequate mechanical performance.

[0011] Furthermore, the steel of the reinforcement described in EP 2 534 338 is subject to corrosion, for example due to the moisture and infiltration of water present in the ground surrounding the tunnel wall. This corrosion results in deterioration of the reinforcement and could therefore negatively affect the stability of the tunnel. In order to preserve the stability of the tunnel, it may therefore be required to replace the reinforcement, this being a complex and costly operation resulting in interruption of the tunnel traffic for a relatively long period of time.

[0012] In view of the above, it is an object of the present invention to provide a modular reinforcement panel for the construction of a wall (for example, but not exclusively, the curved wall of a tunnel) which solves the aforementioned problems.

[0013] In particular, it is an object of the present invention to provide a module reinforcement panel for the construction of a wall (for example, but not exclusively, the curved wall of a tunnel) which is light, which is able to provide a reinforcement with a mechanical performance able to withstand the pressures acting on the wall and which is resistant to the corrosion resulting from the moisture and infiltration of water and other agents which may be present during the installation of the reinforcement.

[0014] According to embodiments of the present invention, these and other objects are achieved by a modular reinforcement panel for the construction of a curved wall, comprising: a plurality of first longitudinal bars and a plurality of second longitudinal bars, arranged respectively on a first surface and a second surface distinct from and parallel to each other; a plurality of transverse bars arranged substantially perpendicular to the first and second longitudinal bars, wherein each transverse bar is fixed to each one of the first longitudinal bars and to each one of the second longitudinal bars; a plurality of first longitudinal stiffening members and a plurality of second longitudinal stiffening members, wherein each first longitudinal stiffening member connects together a respective pair of first longitudinal bars and each second longitudinal stiffening member connects together a respective pair of second longitudinal bars; the first and second longitudinal bars, the transverse bars, and the first and second longitudinal stiffening members are made of a composite material.

[0015] In the continuation of the present description and in the claims, “reinforcement” is understood as meaning a self-supporting structure suitable for the construction of masonry work such as a wall.

[0016] Moreover, in the continuation of the present description and the claims, “modular reinforcement panel” is understood as meaning a panel able to be connected to other similar panels so as to form a reinforcement. Moreover, in the continuation of the present description and the claims, “composite material” is understood as meaning a material comprising at least two phases with different physical properties, in particular:

[0017] - a continuous and homogeneous phase (called “matrix”) which ensures the cohesion of the composite material; and

[0018] - a dispersed phase (called “reinforcement”) - enclosed within the matrix - which provides the composite material with rigidity and mechanical strength.

[0019] The matrix is preferably made of a thermosetting plastic material, such as an epoxy resin. The reinforcement preferably is of a fibrous nature and may comprise for example carbon or glass fibers. By way of a non-limiting example, the composite material may be glass fiber reinforced plastic (GFRP).

[0020] Advantageously, the composite material is much lighter than steel (its specific weight may be up to one quarter that of steel, depending on the specific composite material used). It therefore allows the construction of a particularly light modular panel, which may therefore be easily moved during installation thereof. This advantageously reduces the complexity, the duration and the cost of the reinforcement installation operations.

[0021] The composite material is moreover resistant to corrosion due to moisture or water infiltration. This advantageously ensures that the modular panel maintains its mechanical performance features for a long time. The stability of the wall is thus maintained for a long time without the need for replacement of the reinforcement, this being a complex and costly operation which, for example, in the case of a tunnel wall, requires interruption of the traffic in the tunnel for a relatively long period of time.

[0022] Moreover, the composite material in combination with the form of the modular panel, advantageously is able to ensure a mechanical performance suitable for the pressures typically acting on the wall of a tunnel.

[0023] In particular, a number of load tests were carried out on reinforcements comprising a plurality of modular panels according to embodiments of the present invention. The reinforcement was formed by curved panels and was intended for the construction of the curved wall of a tunnel. The load tests were carried out during an intermediate stage of construction of the curved wall, in particular during lining of the reinforcement with concrete by means of the shotcrete technique and without using systems for performing anchoring to the extrados layer of the reinforcement. During the load tests, any deformations of the reinforcement were measured in a plurality of positions distributed along the entire arc of the reinforcement. The results of the tests were positive, confirming the substantial absence of deformations along the entire reinforcement arc and, therefore, the substantial self-supporting capacity of the reinforcement.

[0024] The use of the composite material, on the other hand, advantageously results in the modular panel being particularly fire- resistant, thus ensuring the unimpaired condition of the reinforcement - and therefore of the wall - also in the event of a fire.

[0025] In particular, a number of fire-resistance tests were carried out on reinforcements comprising a plurality of modular panels according to embodiments of the present invention. In this case also, the reinforcement was formed by curved panels and was intended for the construction of the curved wall of a tunnel. The fire-resistance tests were carried out after the reinforcement was lined with concrete using the shotcrete technique. These results of these tests were also positive, highlighting the absence of explosive cracking or separation of the reinforcement from the concrete lining owing to the presence of a fire. According to a first aspect of the present invention, a modular reinforcement panel for the construction of a wall is provided, said panel comprising:

[0026] - a plurality of first longitudinal bars and a plurality of second longitudinal bars, the first longitudinal bars being arranged on a first surface and the second longitudinal bars being arranged on a second surface parallel to the first surface;

[0027] - a plurality of transverse bars arranged substantially perpendicular to the first longitudinal bars and to the second longitudinal bars, wherein each transverse bar is fixed to each one of the first longitudinal bars and to each one of the second longitudinal bars; and

[0028] - a plurality of first longitudinal stiffening members and a plurality of second longitudinal stiffening members, each first longitudinal stiffening member connecting together a respective pair of first longitudinal bars and each second longitudinal stiffening member connecting together a respective pair of second longitudinal bars, wherein the first and second longitudinal bars, the transverse bars and the first and second longitudinal stiffening members are made of composite material.

[0029] According to one embodiment, the first longitudinal bars and the second longitudinal bars are curved, and the first surface and the second surface are cylindrical surfaces. In this way, the panel is suitable for the construction of a curved wall, for example the wall of tunnel

[0030] Preferably, each one of the transverse bars has a wave-like form between the first surface and the second surface. Said wave-like form is preferably a triangular wave-like (or zig-zag) form.

[0031] According to an advantageous embodiment, each one of the transverse bars forms a plurality of folds, each fold forming a recess inside which one of the first longitudinal bars or one of the second longitudinal bars is housed and fixed.

[0032] Optionally, each one of the first longitudinal bars and the second longitudinal bars is fixed inside the respective recess by means of binding.

[0033] Preferably, each longitudinal stiffening member of said first longitudinal stiffening members and second longitudinal stiffening members comprises a bar arranged substantially coplanar with the pair of first longitudinal bars or second longitudinal bars connected together by the longitudinal stiffening member, said bar having a wave-like form between the two longitudinal bars of said pair. Said wave-like form is preferably a triangular wave-like (or zig-zag) form.

[0034] Preferably, the composite material comprises a thermosetting plastic matrix.

[0035] More preferably, the composite material comprises glass fiber reinforced plastic.

[0036] Preferably, the panel also comprises a plurality of lateral stiffening members, each one of the lateral stiffening members connecting a first longitudinal bar and a second longitudinal bar and being arranged in a central portion of the first longitudinal bar and the second longitudinal bar.

[0037] According to a second aspect of the present invention, a reinforcement for the construction of a wall is provided, said reinforcement comprising at least two modular panels and at least one joint suitable for connecting together the at least two modular panels, wherein each one of the at least two modular panels is as described above.

[0038] According to an embodiment, the joint comprises two end pieces, each end piece being suitable for being fitted onto the end of one of the first longitudinal bars or second longitudinal bars of a respective modular panel, the joint also comprising a casing having two opposite open ends, each end being configured to receive a respective end piece.

[0039] According to an advantageous embodiment, each end piece has a substantially cylindrical shape, with a base having a hole for the insertion of the end of one of the first longitudinal bars or second longitudinal bars of the respective modular panel and a side wall having a conical internal surface such that the diameter of the cavity enclosed by it increases in the direction away from the base, each end piece further comprising a plurality of balls housed in said cavity and able to move along the conical internal surface and a respective plurality of springs configured to push the plurality of balls towards said base, wherein, when the plurality of balls is pressed against the base, they define a passage having a diameter smaller than the diameter of the end of the one of the first longitudinal bars or second longitudinal bars of the respective modular panel.

[0040] Advantageously, each end piece may also comprise a slide suitable for being housed in said cavity, the slide forming a plurality of guides suitable for guiding the movement of the plurality of balls along the conical internal surface.

[0041] Brief description of the drawings

[0042] Further features and details may be better understood from the following description, provided by way of a non-limiting example, to be read with reference to the attached drawings in which:

[0043] - Figure 1 shows a perspective view of a modular reinforcement panel according to an embodiment of the present invention;

[0044] - Figure 2 is a cross-sectional view of the panel according to Figure 1 ;

[0045] - Figure 3 is a front view of the panel according to Figure 1 ;

[0046] - Figure 4 is a top plan view of the panel according to Figure 1 ;

[0047] - Figure 5 is a perspective view of the panel according to Figure 1 , in which only some of its components are shown; - Figure 6 is a perspective view of a portion of the panel according to Figure 1 , in which only some of its components are shown;

[0048] - Figure 7 is a perspective view of a portion of a reinforcement for the construction of a curved wall of a tunnel, comprising a plurality of modular panels connected together and similar to the panel of Figure 1 ;

[0049] - Figure 8 is a front view of the reinforcement portion according to Figure 7;

[0050] - Figures 9a-9d show a joint for the connection of two modular panels and its parts, according to an embodiment of the present invention; and

[0051] - Figures 10a and 10b show another joint for the connection of two modular panels, according to another embodiment of the present invention.

[0052] Detailed description of embodiments

[0053] Figures 1-6 shows a modular reinforcement panel 100 according to an embodiment of the present invention.

[0054] The modular panel 100 preferably comprises a plurality of longitudinal bars. More specifically, the modular panel 100 preferably comprises a plurality of first longitudinal bars 1a and a plurality of second longitudinal bars 1 b. According to the embodiment described hereinbelow with reference to the drawings, the reinforcement panel 100 is curved since configured for the construction of a curved wall. In this case, the first longitudinal bars 1a and the second longitudinal bars 1 b are curved. This, however, is not limiting since, in the case of a reinforcement panel for the construction of a flat wall, the first longitudinal bars and the second longitudinal bars 1 b are straight.

[0055] The first longitudinal bars 1a are arranged parallel to each other on a first surface Ca (shown in Figure 3). The second longitudinal bars 1 b are also arranged parallel to each other on a second surface Cb (also shown in Figure 3). The two surfaces Ca and Cb are distinct from each other and are substantially parallel to each other. Since in the embodiment described the first longitudinal bars 1a and second longitudinal bars 1 b are curved, the first surface Ca and the second surface Cb are cylindrical surfaces. This, however, is not limiting since, in the case of a reinforcement panel for the construction of a flat wall, the first surface Ca and the second surface Cb are flat surfaces.

[0056] The mutual distance H between the first surface Ca and the second surface Cb (substantially corresponding to the thickness of the modular panel 100) is preferably comprised between 150 mm and 300 mm, more preferably between 200 mm and 230 mm, for example 216 mm.

[0057] The first longitudinal bars 1a and the second longitudinal bars 1b preferably are mutually staggered in the transverse direction, namely in the direction substantially perpendicular to their longitudinal direction of extension.

[0058] The first longitudinal bars 1a and the second longitudinal bars 1b preferably have the same radius of curvature. The radius of curvature depends on the application of the reinforcement, which the panel 100 forms part of. For example, in the case of construction of a tunnel wall, the radius of curvature depends on the shape and the dimensions of the tunnel. For example, the radius of curvature of the bars 1a, 1 b may be comprised between 4 m and 6 m, for example 5 m.

[0059] The diameter of each bar 1a, 1 b is preferably comprised between 10 mm and 20 mm, more preferably between 15 mm and 17 mm, for example 16 mm.

[0060] The first longitudinal bars 1a and the second longitudinal bars 1b preferably have the same length. The length of the curved longitudinal bars 1a, 1 b preferably is comprised between 2 m and 3 m.

[0061] The number of first longitudinal bars 1a included within the panel 100 may be between 4 and 7 bars, for example 6 bars. The number of second longitudinal bars 1 b included in the panel 100 may be equal to the number of first longitudinal bars 1a, or may be one more or one less than the number thereof.

[0062] The mutual distance La between the first longitudinal bars 1a preferably is comprised between 200 mm and 400 mm, for example 300 mm. The mutual distance Lb between the second longitudinal bars 1b is preferably equal to the mutual distance La between the first longitudinal bars 1a.

[0063] The length of the modular panel 100 is substantially the same as the length of the longitudinal bars 1a, 1 b, while its width depends on the number of longitudinal bars 1a, 1 b and their mutual distance. The width of the modular panel 100 may be for example comprised between 1 m and 2 m. For example, in the case of six first longitudinal bars 1a positioned at a mutual distance La of 300 mm and six second longitudinal bars 1b also positioned at a mutual distance Lb of 300 mm, the width of the modular panel 100 is equal to about 2 m.

[0064] The modular panel 100 also comprises a plurality of transverse bars 2, which can be seen more clearly in Figure 5. The transverse bars 2 are arranged perpendicular to the longitudinal bars 1a, 1b. Each transverse bar is fixed to each one of the first longitudinal bars 1a and to each one of the second longitudinal bars 1 b, so as to connect them together. Fixing is preferably performed by means of binding.

[0065] Since the first longitudinal bars 1a and the second longitudinal bars 1b are staggered with respect to each other in the transverse direction and also lie on the two surfaces Ca and Cb located at a mutual distance H, in order to be able to connect them together each transverse bar 2 preferably has a wave-like form between the two cylindrical surfaces Ca and Cb. For example, according to the embodiment shown in the drawings, each bar 2 has a series of folds which create a triangular wave-like or zig-zag form between the two surfaces Ca and Cb. Each fold of each transverse bar 2 forms a recess, inside which a longitudinal bar 1a or 1 b is housed and fixed, as shown in Figure 2. In this way, advantageously, fractional forces acting on the modular panel 100 are avoided when fixing (for example, binding) together the transverse bar 2 and the longitudinal bars 1a or 1 b.

[0066] The diameter of each transverse bar 2 may be smaller than the diameter of the longitudinal bars 1a, 1 b. For example, the diameter of each transverse bar 2 may be comprised between 10 mm and 20 mm, more preferably between 13 mm and 15 mm, for example 14 mm.

[0067] The transverse bars 2 are preferably arranged equally spaced along the arc defined by the longitudinal bars 1a, 1 b. The number of transverse bars 2 and their mutual distance D (shown in Figure 4) may be chosen so as to obtain the desired mechanical performance. For the same length of the longitudinal bars 1a, 1b, the greater the number of transverse bars 2 (and therefore the smaller their mutual distance), the greater will be the rigidity of the modular panel 100. For example, in the case where the modular panel 100 is used for the construction of a tunnel wall, with longitudinal bars 1a, 1 b having a length of 2 m, it is possible to envisage nine transverse bars 2 located at a mutual distance of about 220 mm.

[0068] The modular panel 100 also comprises a plurality of longitudinal stiffening members. In particular, the modular panel 100 preferably comprises a plurality of first longitudinal stiffening members 3a and a plurality of second longitudinal stiffening members 3b. As can be seen more clearly in Figure 6, each first longitudinal stiffening member 3a connects together a respective pair of first longitudinal bars 1a and, similarly, each second longitudinal stiffening member 3b connects together a respective pair of second longitudinal bars 1b.

[0069] Preferably, each first longitudinal stiffening member 3a is fixed to each one of the two first longitudinal bars 1a of the pair which it must connect at a plurality of points of the latter. Similarly, each second longitudinal stiffening member 3b is fixed to each one of the two second longitudinal bars 1 b of the pair which it must connect at a plurality of points of the latter.

[0070] In order to allow said connection at a plurality of points, according to an advantageous embodiment, each longitudinal stiffening member 3a, 3b is in the form of a bar which is arranged substantially coplanar with the longitudinal bars 1a, 1 b (therefore on the surface Ca, Cb) and which has a wave-like form between the two longitudinal bars 1a, 1 b of the pair which it must connect together. For example, according to the embodiment shown in the drawings, each longitudinal stiffening member 3a, 3b has a series of folds which create a triangular wave-like or zig-zag form between the two longitudinal bars 1a, 1 b of the pair to be connected. At each fold, the longitudinal stiffening member 3a, 3b is fixed to one of the two longitudinal bars 1a, 1 b of the pair to be connected, for example by means of binding.

[0071] The diameter of each longitudinal stiffening member 3a, 3b may be smaller than the diameter of the longitudinal bars 1a, 1 b and the diameter of the transverse bars 2. For example, the diameter of each longitudinal stiffening member 3a, 3b may be comprised between 6 mm and 10 mm, for example may be equal to about 8 mm.

[0072] According to an advantageous embodiment, the modular panel 100 also comprises a plurality of lateral stiffening members 4. Each lateral stiffening member 4 connects together one of the first longitudinal bars 1a and one of the second longitudinal bars 1 b. The lateral stiffening members 4 preferably are arranged in a central portion of the longitudinal bars 1a, 1 b.

[0073] According to the present invention, the longitudinal bars 1a, 1 b, the transverse bars 2 and the longitudinal stiffening members 3a, 3b (and also the lateral stiffening members 4, if present) are made of composite material. As mentioned above, “composite material” is understood as meaning a material comprising at least two phases with different physical properties, in particular:

[0074] - a continuous and homogeneous phase (called “matrix”) which ensures the cohesion of the composite material; and

[0075] - a dispersed phase (called “reinforcement”) - enclosed within the matrix.

[0076] The matrix of the composite material from which the various elements of the modular panel 100 are made preferably is a thermosetting plastic material, such as an epoxy resin. The reinforcement of the composite material preferably is of a fibrous nature and may comprise for example carbon or glass fibers. By way of a non-limiting example, the composite material from which the various elements of the modular panel 100 are made may be glass fiber reinforced plastic (GFRP).

[0077] The modular panel 100 offers various advantages.

[0078] Firstly, the composite material is much lighter than steel (its specific weight may be up to one quarter that of steel, depending on the specific composite material used). The modular panel 100 is therefore particularly light and may therefore be easily moved during installation thereof. This advantageously reduces the complexity, the duration and the cost of the operations for installation of the reinforcement which the panel 100 forms part of.

[0079] The composite material is moreover resistant to corrosion due to moisture or water infiltration. This advantageously ensures that the modular panel 100 (and therefore the entire reinforcement which it forms part of) is able to maintain its mechanical performance features for a long time. The stability of the wall is thus ensured for a long time without the need for replacement of the reinforcement, this being a complex and costly operation which, for example, in the case of a tunnel wall, requires interruption of the traffic in the tunnel for a relatively long period of time.

[0080] Moreover, the composite material in combination with the form of the modular panel 100 advantageously is able to ensure a mechanical performance suitable for the pressures typically acting on the wall of a tunnel.

[0081] The use of the composite material, on the other hand, advantageously results in the modular panel 100 being particularly fire-resistant, thus ensuring the unimpaired condition of the reinforcement - and therefore of the wall - also in the event of a fire.

[0082] Figures 7 and 8 show a reinforcement 100 for the construction of a tunnel comprising a plurality of modular panels 100 similar to that shown in Figures 1-6 and described above.

[0083] The reinforcement 1000 in particular comprises a plurality of modular panels 100 (seven modular panels 100, by way of a nonlimiting example) connected together in the longitudinal direction (i.e. , in the direction of extension of the longitudinal bars 1a, 1 b), so as to form an arc or ring of the reinforcement 1000. The reinforcement 1000 generally comprises a plurality of arcs or ring which are adjacent to each other in the direction of extension of the tunnel and each of which is formed by a respective plurality of modular panels 100 connected together in the longitudinal direction in a manner similar to that shown in Figures 7 and 8.

[0084] Following its installation (for example for the construction of the curved wall of a tunnel), the reinforcement arc or ring 1000 is self- supporting and therefore acts as a structural support for the wall itself, preventing it from collapsing under the weight of the material (soil, stones, etc.) which surrounds the tunnel. It may also be lined internally with other materials. For example, it may be lined with concrete using the shotcrete technique.

[0085] In each reinforcement arc or ring 1000, the modular panels 100 are preferably connected together by means of a plurality of joints 200. Each joint 200 in particular connects each curved longitudinal bar 1a (or 1b) of a modular panel with a respective curved longitudinal bar 1a (or 1 b) of another modular panel adjacent to it.

[0086] Figures 9a-9d show in detail a joint 200 according to an embodiment of the present invention. By way of example, the drawings show the joint 200 used for the connection of two longitudinal bars 1a of two adjacent modular panels 100. The description below in connection with the joint 200 and the connection of the bars 1 a is however also applicable to the bars 1 b.

[0087] The joint 200 shown in Figures 9a-9d comprises a pair of end pieces 201 , each of which is configured to be fitted onto the end of a respective longitudinal bar 1a.

[0088] The joint 200 also comprises a casing 202 with an elongated shape, having two open opposite ends suitable for each receiving a respective end piece 201 . The casing 202 and the end pieces 201 comprise fixing members which allow stable fixing of each end piece 201 - fitted onto the end of a respective longitudinal bar 1a - inside the casing 202 so as to fix together in a stable manner the ends of the two longitudinal bars 1a. These fixing members, for example, comprise a thread on the outer surface of each end piece 201 and a corresponding thread on the inner surface of the casing 202.

[0089] Each end piece 201 preferably has a substantially cylindrical shape, with two opposite base 203, 204 and a side wall 205. One of the two bases 203 has a hole 203a for insertion of the end of the longitudinal bar 1a, while the opposite base 204 acts as an end-of- travel stop for the end of the longitudinal bar 1a, once it has been inserted in the end piece 201 . Preferably, the outer surface of the side wall 205 has the aforementioned fixing members (preferably a thread 208, visible in Figure 9c) for fixing the end piece 201 inside the casing 202.

[0090] The base 204 is preferably a component which is separate from the side wall 205. The base 204 and side wall 205 preferably comprise mutual fixing members. These fixing members, for example, comprise a thread on the side surface of the base 204 and a corresponding thread (indicated by the reference number 209 in Figure 9c) on the inner surface of the side wall 205. Preferably, the base 203 and the side wall 205 are made of metal (for example steel), while the base 204 is made of plastic material.

[0091] In order to prevent the end of the longitudinal bar 1a from coming out of the end piece 201 , the side wall 205 of the end piece 201 preferably has a conical internal surface 205a, such that the diameter of the cavity enclosed by it increases in the direction away from the base 203.

[0092] A plurality of balls 206 are housed inside the cavity enclosed by the conical internal surface 205a and are kept pressed against the base 203 around the hole 203a by a respective plurality of springs 207, which are also housed inside the cavity and rest against the base 204. Preferably, the balls 206 are made of metal (for example steel). When the balls 206 are pressed against the base 203 around the hole 203a by the springs 207, they define a passage, which preferably has a diameter smaller than that of the end of the longitudinal bar 1a to be inserted. When, instead, the balls 206 are subject to a force opposite to that of the springs 207, they may move away from the base 203 and slide along the conical internal surface 205a towards the base 204, thus moving away from each other and therefore widening the aforementioned passage.

[0093] In order to guide the movement of the balls 206 along the conical internal surface 205a, according to an advantageous embodiment, the end piece 201 comprises a slide 210 which is suitable for being housed inside the cavity defined by the conical internal surface 205a and which defines a plurality of guides 210a. The guides 210a preferably follow the conicity of the conical internal surface 205a and are arranged in positions which are substantially angularly equally spaced. Each guide 210a preferably houses a respective ball 206 and a respective spring 207. The slide 210 is also provided with a hole 210b for the passage of the end of the longitudinal bar 1 a. When the slide 210 is housed inside the cavity defined by the conical internal surface 205a, the hole 210b is substantially aligned with the hole 203a. Preferably, the slide 210 is made of plastic material.

[0094] In order to connect together the ends of two longitudinal bars 1a of two adjacent modular panels 100, each end piece 201 is fitted onto the end of a respective bar 1 a. When the end piece 201 is fitted onto the end of the respective bar 1 a, the latter passes through the hole 203a of the base 203 and starts to press against the balls 206 since, as described above, the latter define a passage with a diameter smaller than the diameter of the bar 1 a itself. When the end of the longitudinal bar 1 a is pushed against the balls 206 counteracting the force exerted by the springs 207, the balls 206 start to move towards the base 204 following the conicity of the conical internal surface 205a and therefore moving away from each other gradually. The sliding movement of the balls 206 towards the base 204 continues until they move away from each other sufficiently to allow the insertion of the end of the longitudinal bar 1 a, which may therefore go beyond the balls and slide in the longitudinal direction towards the base 204.

[0095] If one tried to pull the longitudinal bar 1 a out of the end piece 201 , the balls 206 would lock it in position. In order to assist the extraction of the end of the longitudinal bar 1 a, the balls 206 would in fact have to move again towards the base 203, a movement however which they cannot perform since, in positions closer to the base 203, the cavity defined by the conical internal surface 205a has a diameter which is not sufficient to allow the housing both of the balls 206 and of the end of the longitudinal bar 1a.

[0096] The end pieces 201 are then screwed into the casing 202. The balls 206 allow each end piece 201 to rotate about the end of the respective bar 1a during the screw tightening operation.

[0097] Figures 10a and 10b show in detail a joint 200’ according to another embodiment of the present invention. By way of example, the drawings show the joint 200’ used for the connection of two longitudinal bars 1a of two adjacent modular panels 100. The description below in connection with the joint 200’ and the connection of the bars 1 a is also applicable to the bars 1 b.

[0098] The joint 200’ shown in Figures 10a and 10b comprises a pair of end pieces 20T, each of which is configured to be fitted onto the end of a respective longitudinal bar 1a.

[0099] Each end piece 20T comprises a blind cylindrical sleeve 202’ suitable for housing the end of a respective bar 1a and a plate-like element 203’ provided with a hole 204’. The sleeve 202’ and platelike element 203’ are integral with each other and preferably made of metal (for example steel). The two plate-like elements 203’ of the two end pieces 20T preferably have centering elements. For example, according to one embodiment, the upper surface of the plate-like element 203’ of one of the two end pieces 20T has grooves (indicated by the reference number 205’ in Figure 10b), while the bottom surface of the plate-like element 203’ of the other end piece 20T has protrusions (not shown in the drawings) corresponding to the grooves 205’. The grooves and the corresponding protrusions are for example arranged radially around the hole 204’.

[0100] In order to connect together the ends of two longitudinal bars 1a of two adjacent modular panels 100, each end piece 201’ (i.e., its sleeve 202) is fitted onto the end of a respective bar 1 a. Once the end of each bar 1a has been inserted in the respective sleeve 202’, the latter is pressed onto the bar 1a by means of a mechanical press so as to fasten it thereto and prevent it from becoming accidentally detached during the installation operations. The two end pieces 20T are then moved towards each other and their plate-like elements 203’ are arranged on top of each other so that their holes 204’ are aligned. The centering members advantageously facilitate this operation. Then the two end pieces 20T are connected together by inserting a pin 206’ inside the holes 204’ and fixing it (for example by means of a nut 207’). The two bars 1a are thus connected together.

Claims

CLAIMS1. Modular reinforcement panel (100) for the construction of a wall, comprising:- a plurality of first longitudinal bars (1a) and a plurality of second longitudinal bars (1 b), the first longitudinal bars (1a) being arranged on a first surface (Ca) and the second longitudinal bars (1b) being arranged on a second surface (Cb) parallel to the first surface (Ca);- a plurality of transverse bars (2) arranged substantially perpendicular to the first longitudinal bars (1a) and to the second longitudinal bars (1 b), wherein each transverse bar (2) is fixed to each one of the first longitudinal bars (1a) and to each one of the second longitudinal bars (1 b); and- a plurality of first longitudinal stiffening members (3a) and a plurality of second longitudinal stiffening members (3b), each first longitudinal stiffening member (3a) connecting together a respective pair of first longitudinal bars (1a) and each second longitudinal stiffening member (3b) connecting together a respective pair of second longitudinal bars (1b), wherein the first and second longitudinal bars (1a, 1 b), the transverse bars (2), and the first and second longitudinal stiffening members (3a, 3b) are made of a composite material.

2. Modular reinforcement panel (100) according to claim 1 , wherein the first longitudinal bars (1a) and the second longitudinal bars (1 b) are curved, and wherein the first surface (Ca) and the second surface (Cb) are cylindrical surfaces.

3. Modular reinforcement panel (100) according to claim 1 or 2, wherein each one of the transverse bars (2) has a wave-like form between the first surface (Ca) and the second surface (Cb).

4. Modular reinforcement panel (100) according to claim 3, wherein said wave-like form of said each one of the transverse bars (2) isa triangular wave-like form.

5. Modular reinforcement panel (100) according to any one of the preceding claims, wherein each one of the transverse bars (2) forms a plurality of folds, each fold forming a recess inside which one of the first longitudinal bars (1a) or one of the second longitudinal bars (1 b) is housed and fixed.

6. Modular reinforcement panel (100) according to claim 4, wherein each one of the first longitudinal bars (1a) and the second longitudinal bars (1 b) is fixed inside the respective recess by means of binding.

7. Modular reinforcement panel (100) according to any one of the preceding claims, wherein each longitudinal stiffening member of said first longitudinal stiffening members (3a) and second longitudinal stiffening members (3b) comprises a bar arranged substantially coplanar with the pair of first longitudinal bars (1a) or second longitudinal bars (1 b) connected together by the longitudinal stiffening member, said bar having a wave-like form between the two longitudinal bars of said pair.

8. Modular reinforcement panel (100) according to claim 7, wherein said wave-like form of said bar is a triangular wave-like form.

9. Modular reinforcement panel (100) according to any one of the preceding claims, wherein the composite material comprises a thermosetting plastic matrix.

10. Modular reinforcement panel (100) according to claim 9, wherein the composite material comprises glass fiber reinforced plastic.

11. Modular reinforcement panel (100) according to any one of the preceding claims, also comprising a plurality of lateral stiffening members (4), each one of said lateral stiffening members (4) connecting a first longitudinal bar (1a) and a second longitudinal bar (1b) and being arranged in a central portion of the first longitudinal bar (1a) and the second longitudinal bar (1 b).

12. Reinforcement (1000) for the construction of a wall, comprising at least two modular panels (100) and at least one joint (200) suitable for connecting together the at least two modular panels (100), wherein each one of the at least two modular panels (100) is according to any one of the preceding claims.

13. Reinforcement (1000) according to claim 12, wherein the joint (200) comprises two end pieces (201 ), each end piece (201 ) being suitable for being fitted onto the end of one of the first longitudinal bars (1a) or second longitudinal bars (1 b) of a respective modular panel (100), the joint (200) also comprising a casing (202) having two opposite open ends, each end being configured to receive a respective end piece (201 ).

14. Reinforcement (1000) according to claim 13, wherein each end piece (201 ) has a substantially cylindrical shape, with a base (203) having a hole (203a) for the insertion of the end of the one of the first longitudinal bars (1a) or second longitudinal bars (1 b) of the respective modular panel (100) and a side wall (205) having a conical internal surface (205a) such that the diameter of the cavity enclosed by it increases in the direction away from the base (203), each end piece (201 ) further comprising a plurality of balls (206) housed in said cavity and able to move along the conical internal surface (205a) and a respective plurality of springs (207) configured to push said plurality of balls (206) towards said base (203), wherein, when said plurality of balls (206) is pressed against said base (203), they define a passage having a diameter smaller than the diameter of said end of the one of the first longitudinal bars (1a) or second longitudinal bars (1b) of the respective modular panel (100).

15. Reinforcement (1000) according to claim 14, wherein each endpiece (201 ) also comprises a slide (210) suitable for being housed in said cavity, the slide (210) forming a plurality of guides (210a) suitable for guiding the movement of said plurality of balls (206) along the conical internal surface (205a).

Images