EP3676463A1

EP3676463A1 - Building structure and use of a reinforcing mesh

Info

Publication number: EP3676463A1
Application number: EP18762486.1A
Authority: EP
Inventors: Jacques Porcheret; Laurence Pollet; Freddy MACREZ
Original assignee: Porcher Industries SA
Current assignee: Porcher Industries SA
Priority date: 2017-08-28
Filing date: 2018-08-28
Publication date: 2020-07-08
Also published as: WO2019043013A1; FR3070409B1; FR3070409A1

Abstract

Building structure comprising a carcass reinforced by a reinforcing mesh (5), the mesh (5) comprising longitudinal wires (18, 19) and transverse wires (17) forming intersections (20), the longitudinal wires (18, 19) and the transverse wires (17) being connected at their intersections (20), at least some of the longitudinal wires (18, 19) being carbon wires (18), and at least some of the wires (17, 18, 19) of the reinforcing mesh (5) being retaining wires (17, 19) made of a material which is different from that of the carbon wires (18), the building structure being a masonry structure, the carcass comprising at least two blocks of adjacent bodies, and a layer of masonry binder for connecting the two blocks of adjacent bodies, the reinforcing mesh being embedded in the layer of masonry binder.

Description

Construction work and use of a reinforcement grid

The present invention relates to a construction work and use of a reinforcement grid.

The invention relates to the general field of means for making masonry structures, that is to say constructions by assembling a plurality of elementary blocks, most of which can be described as blocks (such as rubble stones, blocks of stone, bricks, concrete blocks and / or aggregates or blocks of cellular concrete), with a masonry binder (eg glue, mortar, cement or glue-mortar). Masonry also concerns structures in which several layers of mortar-bonded material are stacked, such as for certain rammed earth constructions.

For certain applications, especially in seismic zones or for masonry materials of modest mechanical strength, it is known to provide a chaining of the masonry, that is to say to include reinforcements to the masonry work to increase its resistance.

Most of the time, the elements to form the chaining are in the form of a rigid assembly of welded metal rods, comparable to a concrete iron, or in the form of logs, for the case of rammed earth.

Some chaining, elongated two-dimensional form, are designed to be arranged horizontally between two successive horizontal rows of masonry blocks, in the length direction, while being embedded in the mortar binding the two rows of blocks together, or two layers of successive materials. Depending on the application, there is a horizontal chaining for example near openings of the structure such as doors or windows, or every two rows. For the construction of a building, the horizontal chaining is arranged to form a horizontal closed loop to surround the building.

For some applications, it is also possible to provide vertical links, whose three-dimensional structure recalls that of chaining used as reinforcing bars. Generally, the vertical masonry line crosses several successive rows of masonry blocks, through through openings of the latter, the vertical chaining being then embedded in the mortar. Vertical chaining is usually intended to reinforce a wall angle of the structure.

However, the rigid chaining elements are difficult to store, to transport, while being difficult to use and not very versatile, because of the size, weight and difficulty in cutting such chaining elements without the implementation of relatively important means, such as cranes and cutting tools.

For application in a wall of cellular concrete blocks bonded by a mortar-glue, it has been envisaged to use, as a horizontal chaining, a grid provided in the form of rolls. The grid comprises, in the direction of the length, the son son, and in the direction of the width, son of glass. Since the metal wires are of relatively large length, the grid is wound into a roll so as to wind up the long metal wires, which deforms the metal wires. The grid must be unwound on the lower block row, stapled to the latter, cut to the right length, then covered with glue-mortar to allow assembly of the upper row. However, this chaining grid has certain disadvantages.

Due to its supply in the form of rolls, this known grid has a persistent corrugation, plastic deformation of the wound metal son, which usually requires the user to staple said grid on the lower row to ensure its flatness. In addition, the presence of multi-stranded metal son is likely to constitute a risk of injury to the operator if they are not deburred after cutting.

The invention therefore proposes to remedy the aforementioned drawbacks by proposing a new construction work comprising a carcass reinforced by a new reinforcing grid which is able to constitute a reinforcement for this construction work, while being particularly easy to use safe and inexpensive.

The invention is defined in claim 1

Thanks to the invention, the reinforcing grid is even easier to use than the grids of the prior art, insofar as the carbon son have a sufficient flexibility not to persist in their deformation, or only marginally when they are deformed in a reasonable manner, in particular by winding the reinforcement grid according to a roll or during the manipulation of the grid. In other words, the roll winding is reversible. The roll of the grid can be unrolled for integration of the reinforcing grid to the construction work, when the binder is still fresh. Most importantly, the carbon threads give the grid good mechanical strength in the longitudinal direction, particularly in tension, so that the grid can provide a longitudinal reinforcement role, especially in the case where the grid is used as a chaining of a construction work. Moreover, when the carbon threads are cut, they do not constitute a risk of injury to the operator. Moreover, the carbon threads are chemically resistant to most binders used for construction, which are likely to have a certain alkalinity, especially the adhesives mortar. The carbon son have the additional advantage of being relatively inexpensive, in line with the cost constraints for application of the reinforcing grid as chaining or reinforcement for a structure. The holding threads, which are made of a material other than carbon, in particular glass, ceramic or synthetic material such as polyester, are provided to maintain the spatial arrangement of the carbon threads, while contributing to a good hangs from the grid with the construction work, especially with a masonry binder or construction. The material of the holding wires is preferably chosen to be less expensive than carbon. Thus, the reinforcing grid can be firmly bonded to the building structure by being embedded in its construction binder. As the carbon threads are able to take up the mechanical loads, it may be preferable to choose holding threads in a material which has less mechanical strength than carbon.

Additional and optional features of the invention are defined in claims 2 to 10.

The invention is also defined in claim 11.

The invention will be better understood on reading the description which follows, given solely by way of nonlimiting example and with reference to the drawings in which:

- Figure 1 is an exploded side view of a building structure, comprising a reinforcing grid according to a first embodiment according to the invention; Figure 2 is a top view of a portion of the reinforcing grid of Figure 1; Fig. 3 is a cross-section of Fig. 2 taken along line III-III; and Figure 4 is a cross section similar to Figure 3 for a second embodiment according to the invention.

FIG. 1 shows an exploded portion of a masonry structure 1 comprising a reinforcement grid 5 and a shellwork, comprising a plurality of body blocks 3 and a masonry binder 7. In FIGS. 1 to 3, represents a spatial orthonormal coordinate system defining a transverse direction X, a longitudinal direction Y, and a direction of height Z. The direction of height Z is preferably vertical and directed upwards, or slightly inclined relative to the vertical. The X and Y directions are preferably horizontal, or slightly inclined relative to the horizontal.

The masonry structure 1 of FIG. 1, which is a particular type of structural work, is intended to form a solid wall extending, in the present example, in a plane YZ, that is, that is to say in the longitudinal direction and in the direction of height. However, other types of coarse work formed by Masonry can be made on the same principle, such as a floor, a wall with window or door openings, a column, a beam or any other type of masonry. In fine, the work is preferably intended to form a building, for example a residential building such as a house. Other types of buildings may be formed, for example a residential or office building, a commercial building, an industrial, agricultural or storage building. The structure may also be intended to form infrastructures such as bridges, wells or tunnels.

As opposed to "second work", the term "structural work" refers to all the parts of the structure that make up the framework and the structure, and ensure the stability and recovery of the efforts of the construction work. .

In the present example of the masonry structure 1, the blocks 3 are of parallelepipedal shape. Any form appropriate to the case may be chosen.

In the example illustrated, the blocks 3 comprise facing faces 9, intended to be left free or to be covered by facing layers or insulation of the work 1, not shown. In Figure 1, there are facing faces 9 which extend parallel to the YZ plane.

Each block 3 comprises at least one connecting surface 1 1, generally two or more, on which the binder 7 is intended to be applied and on which another block 3 is intended to be mounted to form the structure 1. In FIG. 1, there are connecting surfaces 11 which extend parallel to an XY plane, that is to say a plane defined by the transverse X and longitudinal Y directions.

Preferably, the blocks 3 may be called blocks, as their facing faces 9 have differences with the connecting surfaces January 1, in terms of surface condition, geometry, or characteristics. In particular, it can be provided that the connecting faces 1 1 are pierced with large opening openings, favoring the adhesion of the mortar, while the facing faces 9 are devoid of it. Each block 3 advantageously comprises through openings, connecting two opposite connecting faces 1 1, naming for insulation, for the passage of irons, pipes or various elements.

It is also possible to provide blocks 3 which can not be described as blocks.

In any case, the blocks 3 are distributed in rows, which are mostly horizontal or at least parallel to the ground. By row is meant a block arrangement 3 which extends in the longitudinal direction Y. In the present example, the Y direction is horizontal or parallel to the ground. A row includes at least one block 3, and preferably several blocks which are for the most part adjacent, but some of which may be separated to form openings of the structure 1. FIG. 1 illustrates two rows of blocks 3, including a lower row 13 and an upper row 14. It will be understood that the assembly of the blocks 3 is modular and depends on the shape of the desired structure: it is therefore possible to provide additional blocks , distributed in more rows stacked, or forming other sets of the work 1.

The blocks 3 are preferably blocks of cellular concrete, for which the reinforcing grid 5 and the binder 7 are particularly suitable. By "cellular concrete" is meant a concrete having gaseous inclusions, which form cells or cells of very small size, so that the concrete has a foamed structure. This type of concrete is likely to have a density of between 400 and 1200 kg / m ³ (kilograms per cubic meter).

For the manufacture of cellular concrete, it is generally expected a fluid mortar of cement and fine sand and an additive such as aluminum powder, which generates, by reaction with lime included in the cement, the gaseous inclusions which may be in the form of hydrogen bubbles. The hardening of the blocks 3 is in particular made by molding and in an autoclave. However, it is only an example, any method and any compound for the manufacture of cellular concrete that can be implemented. The blocks 3 of cellular concrete are preferably provided prefabricated for a construction site of the structure 1. It is nevertheless possible to apply on-site adaptations or geometric corrections of such blocks, including cutting them.

Even if the cellular concrete is preferred, it is conceivable to form prefabricated body blocks with another material, in particular cut or molded, depending on the application, for example brick, rubble, stone, concrete, concrete and / or aggregates.

In a variant, as the body blocks of the masonry structure, it is possible to provide a layer of material formed on site at the time of its integration with the structure 1. Each layer of material forms all or part of a row of the work 1. For example, the structure 1 can be made using a technique of rammed earth, involving a stack of layers of material, the material forming a specific mixture including mainly earth. The layer of material forming the body block is, in this case, cased and packed in place.

As illustrated in Figures 2 and 3, the reinforcing grid 5 has a general two-dimensional shape defining a plane, when it is laid flat as in Figure 1. In the case illustrated in the figures, it is the XY plane. In this example, the XY plane is attached to the grid 5. Of course, any mention of a plane applied to this deformable grid 5 must be considered for the grid when it is in a flat shape, in particular non-rolled, as it is the case in Figures 1 to 3.

The grid 5 comprises a son assembly 17, 18 and 19. Each of these son, including the son 18, is intended to be straight when the grid 5 is flat. In particular, the son 18 are not undulated, so as to be particularly deformable in tension in the longitudinal direction Y. The son 17, 18 and 19 are arranged relative to each other by repeating, in the plane of the grid , a pre-established basic pattern. The longitudinal son 18 and 19 are spaced apart from each other. Similarly, the son 17 are spaced from each other. Thus, relatively loose free through spaces are provided for the binder 7 to pass through the grid 5.

The expression "grid" designates a network of linked wires at their intersections. A grid is not necessarily related to a fabric, since the connection between the wires is not made by simple interlacing, but by a bond of the glue or weld type, the wires not being necessarily crossed or intertwined. in the direction Z and generally being distributed more loosely than for a fabric, to leave a macroscopic empty space in the heart of each elemental pattern, for example of polygonal, square, parallelepiped, triangular or other simple shape.

Among the son of the grid 5, there are transverse son 17, extending parallel to the direction X, or at least in an orientation that has a small angle, different from 90 ° with this direction X, and longitudinal son 18 and 19, extending parallel to the direction Y. In the preferred embodiment of Figures 2 and 3, the pattern comprises son crossing at intersections 20 of the grid 5, with an angle of 90 °, to form a rectangular or square pattern, so that the transverse son 17 are parallel to the X direction and the longitudinal son 18 and 19 parallel to the Y direction. Alternatively, the crossing angle of the yarns may be between 45 and 90 °. In this case, the longitudinal son are parallel to the Y direction, while the transverse son are not parallel to the X direction, and have an angle between 0 ° and 45 ° with this direction X. Depending on the application and manufacturing constraints, the pattern of the grid 5 may be regular or irregular, while the geometry, orientation and parallelism of the son are more or less perfect.

It may optionally be provided that the grid 5 comprises yarns in one or more other directions of the XY plane, in particular one or more diagonal orientations, distinct from the orientation of the aforementioned longitudinal and transverse yarns. For example, the grid 5 measures between 2 and 15 cm, for example 4 cm, in the transverse direction X, that is to say in width. The grid 5 advantageously measures several meters in the longitudinal direction Y, that is to say in length. More generally, the grid 5 is of elongated dimension along the longitudinal threads and of shorter dimension according to the transverse threads or in the transverse direction X. Because of its relatively long length, it is preferred to provide the grid 5 in the form of a roll, which can be unrolled by hand on the place of construction of the work 1. To form the roll, the grid is wound around a winding axis perpendicular to the longitudinal direction Y, that is to say that the winding axis is parallel to the transverse direction X. Preferably, the grid 5 is sufficiently flexible so that the roll can be wound by hand. When the grid 5 is thus wound, the longitudinal son 18 and 19 are curved so as to form a spiral, while the transverse son 17 are little or no deformed.

The dimensions of the grid 5 are adapted according to the type of masonry structure to be built. In particular, when it is a wall, it is expected that the grid has a similar width, in the transverse direction X, the width of the wall, or at least the width of the blocks 3 in the X direction , in particular of their surface 1 1. The grid length used for the structure can be adjusted on site by cutting the grid 5 to the right length, in the direction Y.

Alternatively, the grid 5 may be provided in a form other than a roller, particularly flat, having a length of between a few tens of centimeters and a few meters.

Depending on the manufacturing constraints and the application, the longitudinal threads 18 and 19 are warp threads and the transverse threads 17 are weft threads. In a variant, the longitudinal threads 18 and 19 are weft threads and the transverse threads 17 are warp threads.

Whether the body blocks are prefabricated or manufactured on site, it is expected to separate at least two successive rows of the masonry structure by a reinforcing grid such as the grid 5, embedded in a layer of masonry binder 7. The grid reinforcement 5 then plays the role of a horizontal chaining.

In one and the same work, several grids 5 may be provided. For example, a grid may be arranged every two rows.

If the structure forms a building, one can arrange the grid 5, or a set of several grids 5, so that these grids form a closed loop to surround the building, to strengthen the structure thereof. When such a set of several grids 5 equips the structure, it is possible to link the grids together at their ends. As illustrated in FIG. 1, when the grid 5 is in place in the structure 1, as illustrated in FIG. 1, the wires 18 and 19 extend along the structure 1, that is to say - say in the direction of the rows 13 and 14, while the son 17 extend in a direction transverse to the rows 13 and 14, in particular perpendicular. In this case, the XY plane of the grid 5 then extends parallel to the plane defined by the surfaces 1 1 facing the blocks 3 of the rows 13 and 14 to be assembled. In particular, the grid 5 is interposed between the two successive rows 13 and 14. The grid 5 is preferably adjusted to a sufficient length in the direction Y to extend along the several successive blocks 3 of each of the rows 13 and 14, in order to form a continuous reinforcement along the structure 1.

For the implementation of a method of construction of the structure 1, a layer of masonry binder 7 is preferably applied to the upwardly facing surfaces 1 1 of the blocks 3 of the lower row 13. Binder 7 then extends in a plane parallel to these surfaces January 1, covering them. The grid 5 is then placed on this layer 7, by embedding it in this layer 7. The grid 5 is arranged in the unwound state, that is to say in a state where it is substantially flat, extending in a plane parallel to the X and Y directions. It is advantageous to cover the grid 5 with additional binder, to complete the layer 7 and to ensure that the grid 5 is embedded in this layer 7. Alternatively, the layer 7 is applied to the surfaces 1 1 before depositing the grid 5, but no additional binder is provided to cover the grid 5. Alternatively, the grid 5 is deposited on the surfaces 1 1 of the row 13 before the application of the layer 7, the layer 7 is then applied to drown the grid 5 by covering it. The blocks 3 of the row 14 are then deposited, so that the surfaces 11 of these blocks 3 are brought into contact with the layer 7, facing the surfaces 11 of the row 13. After a drying time, the layer 11 binder 7 interconnects the two rows 13 and 14 of blocks 3, while the grid 5 is arranged between the two rows 13 and 14 and constitutes a reinforcement of the work 1.

Once the masonry structure 1 is completed and including the grid 5, the binder layer 7 in which the grid 5 is embedded, for example measures in the direction Z, between 0.5 cm and 2 cm. The connecting surfaces 11 are preferably rough, in particular without flatness correction.

Alternatively, the masonry work is a masonry work called "thin joints", that is to say in which:

- Each connecting surface 1 1 is rectified, that is to say has undergone an operation to improve its flatness; and - The binder layer 7, wherein the gate is embedded, measures, in the direction Z, less than 0.5 cm, for example between 1 and 2 mm.

In the case of a thin-walled masonry structure, each body block is for example a rectified brick, or a rectified concrete block, or a rectified concrete block, that is to say an agglomerate of rectified concrete. Here it is meant that at least the binder-receptive surfaces are rectified, the other surfaces may advantageously be left untreated.

Because of its structure comprising carbon son, the grid 5, particularly thin, can easily be integrated into a particularly thin binder layer. The grid 5 is therefore particularly suitable for reinforcing a masonry structure with thin joints.

Alternatively, the grid 5 can serve as vertical chaining for a masonry structure.

More generally, the grid 5 can serve as a frame for a structural work of construction, which is not necessarily a masonry work. In this case, the grid 5 is preferably embedded in a construction binder of the structure. For example, the grid 5 can be used as reinforcement for a reinforced concrete, the concrete then constituting the building binder. Whatever the type of construction work, the reinforcing grid 5 is preferably implemented to reinforce a structural work of the construction work. However, it is nevertheless possible to use the reinforcing grid for the second work, for example to stabilize a coating based on plaster.

Therefore, any example described here and mentioning a masonry binder can be adapted to the general case of a construction binder, depending on the type of work to be considered.

For the case of a masonry structure whose blocks are made of cellular concrete, although this may apply to other cases, the masonry binder 7 is preferably an adhesive mortar. In this case, the adhesive mortar is for example in the form of a bag of powder, which must be diluted in water homogeneously, in order to obtain a pasty substance to be used within 8 hours for manufacture of the work 1. This substance must be spread on the surfaces 1 1, for example using a trowel and / or a comb, to form a layer of the kind illustrated in FIG. Once the upper row has been deposited on the layer thus formed, a drying or setting time may have to be observed.

A typical mortar-glue comprises a mixture of sand grains, with a small amount of cellulose derivatives, inorganic additives, and vinyl acetate. Other glues-mortars include dried river sand, a combination of binders mainly including white cement, as well as additives. However, depending on the application and the materials of the structure 1, in particular blocks 3, the composition of the adhesive-mortar may be different.

Alternatively, depending on the materials of the structure 1, the binder 7 may be an adhesive, a mortar, a cement, a mortar, a concrete, a cement-concrete. In the particular case of a rammed structure 1, that is to say comprising layers of material formed on site to form the body blocks of the structure 1, the binder 7 may be based on specific soil, possibly containing solid loads such as pebbles, crushed tiles, or sand.

Concerning more particularly the grid 5, the son 18 are carbon son. By "carbon wire" is preferably meant a wire formed by a plurality of fibers, having a diameter of the order of one micrometer, for example between 5 and 10 micrometers, each fiber being composed mainly of bonded carbon atoms according to crystalline structures. Preferably, the carbon wire does not comprise any fiber of a material other than carbon. In particular, the carbon wire does not comprise metal fiber.

Each carbon wire 18 of the grid 5 is preferably a single carbon wire, that is to say a unit wire. In particular, by "single wire" and "unit wire", it is meant that the wire is not formed by an assembly of several wires, so that "wire" is distinguished in particular from "strand", "braid" or " cable ". Preferably, it is expected that the grid 5 does not include any metal longitudinal wire, or containing metal. It is also advantageous to ensure that the grid is devoid of any wire.

The carbon son 18 which confer on the grid the aforementioned advantages, in particular in terms of flexibility and mechanical strength. The grid 5 can therefore easily be flattened after having been wound along a roller in the longitudinal direction around an axis parallel to the direction X. In other words, when it is reasonably deformed, for example as a result of a winding according to a roller, the grid 5 does not persist in this state of deformation, but on the contrary tends to return to its original flat shape in the absence of external constraints, thanks to the carbon son 18. Without being bound to a In any theory, the inventors believe that the winding of the grid 5 according to a roller causes a deformation of the son 18 in the elastic domain and not in the plastic domain. Furthermore, because the son 18 are made of carbon, any cutting operation of the grid 5 to the desired length does not generate burrs that could constitute a risk of injury to users, the carbon does not generate this type of burr. Furthermore, the carbon threads are particularly resistant to environmental stresses, especially to the weather affecting the structure 1, and chemical, especially as regards the chemical characteristics of the binder 7 and blocks 3. It should be considered in this respect that certain types of masonry binders, in particular mortar-glues, have a pH that may reach 12 or 13: it is therefore advantageously anticipated that the aforementioned materials of the grid 5 can withstand this type of chemical conditions.

The son 18 have, thanks to the carbon, a good mechanical strength. The carbon son can be qualified as "structural son" of the grid 5, conferring its tensile strength qualities in the longitudinal direction Y of the grid 5. Preferably, each carbon wire is a wire between 1 k and 48k. By 1 k and 48 k are respectively 1000 carbon filaments for one yarn and 48000 carbon filaments for one yarn. In a particularly preferential way, we choose wires between 3k and 24k, which have a good compromise between cost, strength and flexibility.

Each selected carbon wire is preferably a wire without torsion, that is to say, not twisted. This allows both good impregnation with the binder 7 and especially an instantaneous response to mechanical stresses. Since the yarn deforms very little under the effect of traction in the Y direction, it satisfies an application as a masonry structure chaining. One can nevertheless predict that one or more of the carbon son are twisted, in order to obtain for example a better general mechanical strength of the carbon son.

Preferably, the son 17 and 19 are glass son. By "glass" is preferably meant a material comprising predominantly silica, or silicon dioxide. For example, one can use a glass E.

The wires 17 and 19 are mainly designed to spatially hold the carbon wires 18 in the XY plane. Therefore, the son 17 and 19 can be described as "holding son". The son 17 and 19 may optionally contribute to the attachment of the grid in the binder 7. By "hook" is meant that the son 17 and 19 can promote a solid connection between the grid 5 and the binder 7, especially for reasons of geometry, because of the arrangement in grid form of the son 17 and 19, and / or for reasons of contact affinity between the son 17 and 19 the binder 7, for example because of a surface condition son 17 and 19 and / or the material constituting the son 17 and 19. Furthermore, it is preferred to choose the glass rather than other materials, because of the dimensional stability of the glass over time, despite the climatic conditions and mechanical constraints, which can reduce the risk of crack formation in the structure 1 during its aging. The glass makes it possible in particular to obtain a grid having the qualities of aforementioned flexibility, for example to facilitate its progress if it has been packaged in the form of a roll.

Preferably, each glass wire has a titer of between 20 tex and 400 tex. This title range advantageously makes it possible to form a set of holding wires which are sufficiently strong to hold the carbon threads relative to each other, while being at a reasonable cost. Advantageously, all the glass threads have the same title. Depending on the number of carbon threads to be maintained, the size of the grid, the type of masonry binder used, or other parameters, it is possible, for example, to provide threads of 34 tex, 68 tex or 272 tex.

The holding son are preferably glass son. They can have a twisted structure, for example of the silionne type, which enables them to be light and relatively resistant, while facilitating the manufacture of the grid 5. Alternatively, the holding wires are without intentional torsion, for example glass roving type, which allows better grip. It is possible to provide both twisted yarns, for example of the silionne type, and non-twisted yarns, for example of the roving type.

Depending on the various parameters mentioned above for the grid 5, in particular the materials of the wires and their number, the grid 5 is likely to have a weight of between 5g / m ² and 50g / m ² , preferably 18g / m ² .

For holding son, the glass is preferred, insofar as it allows to obtain a grid having the aforementioned qualities. Nevertheless, instead of glass, it is possible to use any other material having at least one of these advantages. The materials used can be:

inorganic materials, such as ceramics or metals, for example steel, even if the steel is likely to contain carbon;

synthetic materials, such as polyester.

In any case, the holding son are in a different material than the carbon son. More specifically, the material of the holding son is of different composition, adapted to provide this maintenance function while being low cost compared to carbon. Preferably, the holding son are not carbon son, or are in a material devoid of carbon, or containing carbon in negligible proportions, as is the case for example for a steel.

The transverse threads 17 are connected to the longitudinal threads 18 and 19 at the intersections 20. Each intersection 20 is advantageously the seat of a connection between a thread 17 and a thread 18, or between a thread 17 and a thread 19. Preferably, each intersection link 20 is made by bonding one wire against the other. For this purpose, we can For example, provide a point of adhesive material, for example a thermoadhesive or glue, at each intersection 20.

In this example, as shown in Figure 3:

the transverse threads 17 are all distributed in the same plane P17 parallel to the plane XY,

the longitudinal threads 18 are all distributed in the same plane P18 parallel to the plane XY, and

the longitudinal wires 19 are all distributed in the same plane P19, parallel to the XY plane.

Plans P17, P18 and P19 are not merged, plane P17 being positioned between planes P18 and P19. In other words, the transverse threads 17 are lined:

by the longitudinal carbon wires 18, of a first side of the grid 5, and

by the longitudinal wires 19, which are here made of glass, of a second side of the grid 5.

Alternatively, there are provided holding son only for transverse son, the longitudinal son comprising no holding wire, but comprising only carbon son.

In another preferred embodiment shown in FIG. 4, capable of facilitating the manufacture of a grid 50 for the same use as the grid 5, it is anticipated that the grid 50 comprises longitudinal carbon wires 18, holding wires longitudinal members 19 and 21, and transverse holding son 17. The gate 50 differs from the grid 5 by the arrangement of the holding son 17, 19 and 21, presenting:

a first layer of transverse holding wires 17 distributed in the same plane P17 parallel to the XY plane,

a second layer of longitudinal holding wires 19 distributed in the same plane P19 parallel to the XY plane,

a third layer of longitudinal holding wires 21 distributed in the same plane P21, parallel to the XY plane, the first layer of wires 17 being disposed between the second layer of wires 19 and the third layer of wires 21, so that the wires 17, 19 and 21 form in themselves a holding grid, the son 17, 19 and 21 being connected to intersections 20 of the son of the grid 5, one side and the other of the layer of son 17 respectively for the yarns 19 and 21, and

- A fourth layer of longitudinal carbon son 18, connected to the holding son 17 on the same side as the holding son 21, being distributed in a plane P18 parallel to the XY plane.

For this embodiment of FIG. 4, carbon threads have therefore been reported.

18 longitudinal on a holding grid formed by the son 17, 19 and 21. Whatever the embodiment, it is possible to provide, in the same reinforcing grid, holding wires of several different materials, for example glass wires providing the above-mentioned advantages, and wires of another material providing protection. other advantages.

Generally, it is possible to provide any combination of wires and materials for the wires of the reinforcing grid, as long as this grid comprises one or more carbon yarns in the longitudinal direction Y, and holding wires of these carbon threads. relative to each other, in another material.

Preferably, the reinforcing grid comprises between 2 and 5 longitudinal threads per centimeter and between 2 and 5 transverse threads per centimeter. This is particularly the case for the examples illustrated in Figures 1 to 4. These ranges of value concern all the son of the grid 5, whether carbon or another material.

Preferably, the transverse yarns 17, made of glass in the illustrated examples, are regularly spaced from one another. Also, the longitudinal son 18, made of carbon, are advantageously regularly spaced from each other. Preferably, the longitudinal holding son, glass in the present examples, are regularly spaced from each other. Preferably, the longitudinal carbon son are spaced apart from each other than are the longitudinal son of maintenance, which limits the cost of the reinforcement grid while the mechanical characteristics are sufficient for some applications.

Preferably, the reinforcing grid comprises between 1 and 20 longitudinal son of carbon, which are distributed in the transverse direction X. In the preferred examples illustrated, five carbon yarns are regularly distributed in the X direction. In these examples, the grid is 4 cm in the X direction. This grid is therefore a good compromise between mechanical qualities and cost. If a grid of larger dimension in the X direction must be performed, it is advantageous to increase the number of carbon son, or reduce if the size should instead be less important.

Whatever the embodiment, it is preferably provided that the reinforcing grid comprises a coating composition. Preferably, the coating composition is of the same composition as the adhesive material provided at each intersection 20. Alternatively, it is possible to provide a specific coating composition, different from the composition of the adhesive material for the intersections 20.

The coating composition coating or impregnates an assembly formed by the longitudinal son and transverse son of the reinforcing grid. By "coating" is meant that the coating composition coats and / or impregnates all the wires of the reinforcing grid, leaving little or no bare surface for these wires. Preferably, the coating composition coats all the wires of the reinforcing grid while the wires are already assembled in the form of a grid. Alternatively, it is possible for the coating composition to coat the wires before assembling the wires at the intersections to form the reinforcing grid.

It is also possible that the coating composition only dresses certain son, including the son of maintenance, while the carbon son, are left free of coating. Alternatively, it can be provided that the composition only covers the carbon son, while leaving the maintenance son free coating.

The reinforcing grid is advantageously provided while it already carries the coating composition, already fixed on the relevant son of the reinforcing grid. In other words, the coating composition is integrated into the reinforcing grid during manufacture of the latter, while the layer of masonry binder, distinct, is preferably brought into contact with the reinforcing grid only at moment of construction of the structure.

Preferably, the coating composition is of a composition distinct from that of the masonry binder. In particular it comprises different constituents, which are however compatible with the masonry binder. The coating composition advantageously protects the coated yarns from external aggressions, especially the chemical attacks of the masonry binder, especially if it has a high alkalinity. Thus it is preferred that at least the holding son are coated, when they are glass or in any other material sensitive to the alkalinity of the masonry binder, to protect them. Furthermore, the coating composition promotes the attachment of the reinforcing grid to the masonry binder.

The following is a preferred example of a coating composition, particularly suitable for the illustrated case where the masonry binder 7 is a mortar-glue. Of course, this preferred example of a coating composition may also be used for other types of masonry binders.

Advantageously, as the coating composition, an anti-alkali glue, or at least a coating composition resistant to the alkalinity of the binder 7, is chosen.

The coating composition can be selected so that it comprises a coating binder selected from anti-alkali plastisol, PVC latex, SBR latex, EVA latex, or acrylic latex. A PVC-free coating composition is preferred in order to avoid any possibility of chlorine pollution. An aqueous dispersion coating binder, namely the aforementioned latexes, which are generally reasonably priced and compatible with the application for a construction work, is preferred. Latex being self-crosslinkable polymers, they are both easy to implement, while having a relatively long life, compared for example to a thermoplastic. Moreover, probably because of their self-crosslinking nature, the latexes appear to have better adhesion to the masonry binder 7.

In the preferred example, the coating composition comprises a self-crosslinkable polymer coating binder based on ethylene and vinyl acetate (EVA).

By way of example, the product VINNAPAS ® EN 1020 or the product VINNAPAS ® EN 1092 from WACKER Chemie AG can be used as a coating binder of this type. Depending on the application, VINNAPAS ® EN 1020 or VINNAPAS ® EN 1092 may be preferred, which have different glass transition temperatures tg, ie -8 ° C for EN1020 and + 10 ° C for EN1092. It may be preferred to choose that the coating composition has a glass transition temperature lower than the temperature of this environment, in order to guarantee that this coating composition is in the rubbery state, to maintain the aforementioned flexibility qualities of the grid. 5, which makes it rollable and rollable flat substantially without persistent deformation.

To coat the grid 5, the coating composition is applied to the wires of the grid while this coating composition is in a non-crosslinked and / or viscous state. In this state, the coating composition may also include several additives to facilitate the manufacture of the grid 5, called "process additives". These process additives may comprise, for example, at least one of the following: an antifoaming agent, a friction reducing agent, a thickener.

In the coating composition, additives, known as "application additives", are also advantageously provided, improving the properties of the coating composition when it is carried by the grid 5, during the use of the grid 5 for the construction work. Preferably, the coating composition comprises a silane-based application additive, which has the quality of promoting a bond between the inorganic materials, such as the glass of the reinforcing grid, with mineral materials. such as those contained in the masonry binder. It may be, for example, an organosilane such as 3-glycidyloxypropyltriethoxysilane (GLYEO), 3-glycidoxypropyltrimethoxysilane (GLYMO), 3,4-epoxycyclohexylethyltrimethoxysilane, or an amino-active silane such as a hydrolyzate of 3-aminopropylsilane (HYDROSIL 1 151).

Advantageously, as an application additive, the coating composition may comprise solid grains, for example grains of sand or silica. "Solid grains" means grains that are already in the solid state when the Coating composition is applied to the grid wires to coat, while the coating binder is in the liquid state, or at least uncrosslinked or uncured. Thus, the carrier grid carrier of its coating composition has an abrasive surface condition, conducive to good grip of the grid in the masonry binder.

It would also be possible to include in the coating composition an anti-sticking or anti-blocking additive (or in English "antitack"), in order to make the grid 5 less tacky or greasy, to be more easily manipulated for the realization of the structure of construction.

Tests, described below, were conducted to compare several masonry structures.

Five test pieces, numbered A, B, C, D and E were tested.

Each test specimen comprises two cellular concrete blocks of elongate shape, in a longitudinal direction Y, and superimposed, in a direction of height Z. Each specimen comprises a layer of masonry binder to bind together the two superimposed blocks, the binder layer being interposed between two respective connecting surfaces of each block, arranged opposite. In the direction of height Z, each block measures about 2.5 cm. In a transverse direction X perpendicular to the directions Y and Z, each block of cellular concrete is about 5 cm.

The binder layer measures about 5 cm in the X direction, that is to say that it covers the entire respective bonding surface opposite the two superimposed blocks.

Specimen A is devoid of reinforcement.

Specimen B comprises, embedded in the binder layer, a flat masonry reinforcement, comprising two rigid steel flat profiles, elongate in the Y direction, and parallel to the Y direction. According to the X direction, each profile measures about 0.8 cm in the X direction, and about 0.2 cm in the Z direction. The masonry reinforcement of the specimen B further comprises a zigzag corrugated wire, alternately connecting the two rigid sections, at each corrugation. . At each corrugation, the corrugated wire is welded to one of the two rigid sections. Accordingly, each rigid section is bonded to the corrugated wire by a plurality of welds along the Y direction.

The test piece C comprises a reinforcing grid embedded in the binder layer. The grid comprises seven steel wires, each extending parallel to the Y direction and having a section of about 4 to 5 mm ² . The metal wires are interconnected by connecting wires in the X direction.

Specimen D comprises a reinforcing grid embedded in the binder layer. The grid is woven glass and is coated. The reinforcement grid has a weight of 222 g / m ² (+/- 5%) and comprises about 1.2 threads / cm in the Y direction and about 1.05 son / cm in the direction X. The grid used comprises five son parallel to the direction Y, distributed in the direction X.

The test piece E, according to the invention, comprises a reinforcing grid embedded in the binder layer. The grid of the specimen E comprises six carbon wires 12K, each extending parallel to the Y direction. There are 1, 2 carbon threads per centimeter. The grid of the specimen E comprises warp and weft threads, that is to say in the X direction and in the Y direction, supporting the carbon son. The carbon threads are stuck on the glass threads at their intersections. The warp glass yarns are bound to the weft glass yarns at their intersections. The glass grid has 3 threads / cm.

For each test piece A, B, C, D and E, a "three-point" bending test of the type described in the French standard NF EN 1351 is carried out. For this, the test piece rests, through the lower cellular concrete block, on two cylinders extending parallel to the direction X, and spaced in the direction Y. It is expected that the cylinders are spaced 8.5 cm in the direction Y. A third cylinder, parallel to the other two cylinders and equidistant from the other two cylinders, comes to apply a force F directed downwardly parallel to the Z direction against the upper face of the upper block. A rubber band was interposed between each cylinder and the test piece, to avoid a depression of the cylinder in the aerated concrete.

The results of the tests for each specimen A, B, C, D and E are listed in the table below. F1 is the value of the force applied by the cylinders on the specimen, for which a crack opens on the lower face of the lower block of the specimen, that is to say between the two lower cylinders. F2 is the force applied by the rolls on the specimen, for which the crack has propagated through the whole specimen in the Z direction, the reinforcement still connecting the two specimen parts together, except for the specimen A or no reinforcement is provided. D2 is the displacement of the upper cylinder relative to the lower cylinders in the direction Z, towards the lower cylinders.

Test tube A not having reinforcement, F2 = F1.

It is noted that the test piece E makes it possible to obtain that the force F1 and the force F 2 are particularly high, compared with the other test pieces A to D. The test specimen D, for which the value of F2 is slightly lower than the value of F2 observed for the specimen E, has a much lower value for F1. It is concluded that the test piece E has the greatest flexural strength, and that, even if the cellular concrete is broken, the reinforcement grid of the test piece E makes it possible to hold the test piece correctly.

Claims

1. - Construction structure (1) comprising a carcass reinforced by at least one reinforcing grid (5), the reinforcing grid (5) comprising longitudinal wires (18, 19) and transverse wires (17) forming intersections ( 20), the longitudinal wires (18, 19) and the transverse wires (17) being connected to their intersections (20), the reinforcing grid (5) being of elongated dimension (Y) along the longitudinal wires (18, 19) ,

at least a portion of the longitudinal threads (18, 19) are carbon threads (18), and

- At least a portion of the son (17, 18, 19) of the reinforcing grid (5) are holding son (17, 19), made of a different material than that of carbon son

(18)

the construction work (1) being a masonry work, the structural work comprising:

at least two adjacent body blocks (3), and

- A layer of masonry binder (7) for bonding the two adjacent body blocks, the reinforcing grid (5) being embedded in the masonry binder layer (7).

2. - Construction structure (1) according to claim 1, characterized in that each carbon wire is formed by a single non-twisted wire, preferably between 1 k and

48k.

3. - Construction work (1) according to any one of the preceding claims, characterized in that the holding son (17, 19) comprise glass son (17, 19).

4. - Construction structure (1) according to claim 3, characterized in that each glass wire (17, 19) has a title between 20 tex and 400 tex. 5. Construction structure (1) according to any one of the preceding claims, characterized in that the reinforcing grid (5) comprises:

- between 2 and 5 longitudinal threads (18, 19) per centimeter; and

- Between 2 and 5 transverse threads (17) per centimeter. 6. Construction structure (1) according to any one of the preceding claims, characterized in that the reinforcing grid (5) comprises a composition coating method, with which an assembly formed by the longitudinal threads (18, 19) and the transverse threads (17) is coated, said coating composition comprising a coating binder based on ethylene and vinyl acetate as well as a silane additive. 7. Construction structure (1) according to claim 6, characterized in that the coating composition comprises solid grains imparting an abrasive surface condition to the reinforcing grid (5).

8. - Construction structure (1) according to any one of the preceding claims, characterized in that:

the body blocks (3) are blocks of cellular concrete; and

- The masonry binder (7) is an adhesive mortar.

9. - Construction structure (1) according to any one of the preceding claims, characterized in that the reinforcing grid (5) is designed to be reversibly wound in the form of a roller around an axis perpendicular to the longitudinal threads (18, 19).

10. Construction structure (1) according to any one of the preceding claims, characterized in that:

- The body blocks (3) are distributed in rows, which are horizontal or parallel to the ground, including a lower row (13) and a successive upper row (14), the reinforcing grid (5) being interposed between the row lower (13) and the upper row (14),

- each body block (3) comprises at least one connecting surface (1 1) on which the masonry binder (7) is applied and on which the other block (3) is mounted to form the structure (1) ,

the longitudinal threads (18, 19) of the reinforcing grid extend in the direction of the rows (13, 14), whereas the transverse threads (17) extend in a direction transverse to the rows (13, 14). , the plane of the reinforcing grid (5) extending parallel to the plane defined by the connecting surfaces (1 1) facing the blocks (3) of the rows (13, 14).

1 1. - Use of a reinforcing grid (5) as a reinforcement of a structure of construction work (1), the reinforcing grid (5) comprising longitudinal son (18, 19) and transverse son (17). ) forming intersections (20), the longitudinal strands (18, 19) and the transverse yarns (17) being bonded to their intersections (20), the reinforcing grid (5) being of elongated dimension (Y) along the longitudinal yarns (18, 19) and being designed to be reversibly wound in the form a roll about an axis perpendicular to the longitudinal threads (18, 19),

at least a portion of the longitudinal threads (18, 19) being carbon threads (18), and

- At least a portion of the son (17, 18, 19) of the reinforcing grid (5) being holding son (17, 19), made of a different material than that of the carbon son (18);

the construction work (1) being a masonry work, the structural work comprising:

at least two adjacent body blocks (3), and