COMPOSITE SYSTEM AND CONSOLIDATION METHOD, IN PARTICULAR FOR STRUCTURES MADE FROM REINFORCED CONCRETE OR MASONRY HARDENABLE OR HARDENED MATRIX AND TEXTILE REINFORCING MESH FORMING THIS SYSTEM

Abstract

The invention concerns a composite system for reinforcing, in particular, structures made from reinforced concrete or masonry comprising a curable or cured matrix and a textile reinforcement grid, and said two elements taken as such. The aim of the invention is for this system to make it possible to produce a cured composite structure having improved mechanical properties, both in the short term and in the long term (e.g. flexing behaviour, hardness, bending/compression resistance, durability, cohesion). This aim is achieved by the system of the invention in which the grid comprises at least one layer formed: both from a framework consisting of flat warp yarns and weft yarns; and from a network binding the framework; characterised in that the binding network is such that it ensures the geometric regularity and dimensional stability of the meshes of the framework, before the grid is applied to the structure to be reinforced. The invention also concerns a method for reinforcing, in particular, structures made from reinforced concrete or masonry, the composite structure obtained from this method, the dry and wet formulations of the curable matrix, and consolidated structures, in particular made from reinforced concrete or masonry.

Claims

1. Composite system for consolidating structures, in particular of reinforced concrete or masonry, comprising a hardenable or hardened matrix and a textile reinforcing mesh, in which the mesh comprises at least one layer formed: on the one hand, by a reinforcement constituted by flat warp threads and weft threads; and, on the other hand, by a binding network of the reinforcement; wherein the binding network is such that it ensures the dimensional stability under stress of the links of the reinforcement, before the mesh is applied to the structure to be consolidated.

2. System according to claim 1 wherein the dimensional stability under stress is qualified as follows in a test ST: The deformation of a 40?40 cm sample suspended by its two top corners in a vertical plane and subjected to the tensile stress of a 1 kg (deformation D1) or 2 kg (deformation D2) weight attached to the middle of the bottom edge of the sample, is such that: D1 is less than or equal tocm, where, in increasing order of preference,is: 2.5; 1.5; 1.0; 0.8; 0.6; 0.5; 0.3; 0.2; 0.1; D2 is less than or equal tocm, where, in increasing order of preference,is: 5; 4; 3; 2; 1.8; 1.6; 1.5; 1.4; 1.2; 1.0.

3. System according to claim 1 wherein at least a part of the threads of the mesh are coated/impregnated with at least one polymer, preferably selected from the group comprising, or even better constituted by: (meth)acrylic (co)polymers, advantageously selected from the sub-group comprising, or even better constituted by, alkylester copolymers advantageously comprising 1 to 8 carbon atoms, with acrylic acid, or methacrylic acid, in particular those selected from the family comprising, or even better constituted by, preferably methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethyl hexyl acrylate and correspondents thereof with methacrylic acid; and mixtures thereof; vinyl ester (co)polymers advantageously selected from the sub-group comprising, or even better constituted by, vinyl acetate homopolymers and copolymers, in particular those selected from the family comprising, or even better constituted by, vinyl and ethylene acetate copolymers, vinyl chloride (co)polymers such as vinyl and ethylene chloride copolymers, vinyl laurate (co)polymers, vinyl versatate (co)polymers, vinyl ester (co)polymers of alpha-monocarboxylic acids, saturated or not, branched or not, advantageously comprising 9 or 10 carbon atoms, homopolymers of alkyl carboxylic acid vinyl esters, saturated or not, branched or not, advantageously comprising from 3 to 8 carbon atoms, copolymers of these latter homopolymers with ethylene, vinyl chloride, and/or other vinyl esters; and mixtures thereof; styrene (co)polymers with butadiene or with one or more acrylic esters advantageously selected from the sub-group comprising, or even better constituted by, ethylenically unsaturated alkyl esters advantageously comprising from 1 to 8 carbon atoms of (meth)acrylic acid, preferably methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethyl hexyl acrylate and correspondents thereof with methacrylic acid, and mixtures thereof; hot-melt (co)polymers, advantageously selected from the sub-group comprising, or even better constituted by, polyethylenes, polypropylenes, polyesters, polyamides, Ethylene Propylene Diene Monomer (EPDM) copolymers, and mixtures thereof; and mixtures thereof.

4. System according to claim 1 wherein the weft threads and the warp threads of the reinforcement are comprised in two parallel planes.

5. System according to claim 1 wherein the binding network of the reinforcement is a weave constituted by warp elements and weft elements, and in that this weave is a leno weave, each warp element of this weave comprising at least two binding threads, preferably two, and each weft element of this weave comprising at lest one binding thread, preferably one.

6. System according to claim 5 wherein: each warp element of the weave comprises two warp binding threads and each weft element of the weave comprises one weft binding thread, one of the two warp binding threads passes on the same side C1 of all of the weft threads of the reinforcement, the other warp binding thread passes on the same side C2, opposite C1, of all of the weft threads of the reinforcement, between two successive weft threads of the reinforcement, the warp binding threads intersect before the weft binding thread, pass on either side of weft binding thread and then intersect again to clasp the weft thread of the reinforcement.

7. System according to claim 1 wherein the hardenable matrix comprises (in parts by weight on dry basis): 100 of binder; 1-4,000, and in increasing order of preference, 5-2,000; 10-1,000; 20-500 of mineral fillers; 0.01-1,000, and in increasing order of preference, 0.05-800; 0.1-500; 0.5-200; 1-50 of at least one resin; 0-500 of additives, preferably 0.01-50.

8. Consolidation mesh for structure made from reinforced concrete or masonry, comprising at least one layer formed: on the one hand, by a reinforcement constituted by flat warp threads and weft threads; and, on the other hand by a binding network of the reinforcement; and in that the binding network is such that it ensures the geometric regularity and dimensional stability of the links of the reinforcement, before the mesh is applied to the structure to be consolidated.

9. Hardened composite structure obtained using the system according to claim 1.

10. Composite structure according to claim 9, which tensile modulus of elasticity TME less than or equal toMPa where, in increasing order of preferenceis 100,000, 80,000, 70,000.

11. Method for increasing the resistance to seismic loads of reinforced concrete or masonry structure consisting in using a composite structure having a tensile modulus of elasticity TME less than or equal toMPa where, in increasing order of preference, is 100,000, 80,000, 70,000, said composite structure being obtained based on a composite system for consolidating structures, comprising a hardenable or hardened matrix and a textile reinforcing mesh, in which the mesh comprises at least one layer formed by a reinforcement constituted by flat warp threads and weft threads and has dimensional stability under stress of the links of the reinforcement, before the mesh is applied to the structure to be consolidated.

12. Method for consolidating structures made from reinforced concrete or masonry which essentially consists of press-mounting the mesh as defined in claim 1 to the structure with a hardenable or hardened matrix after mixing said matrix with a liquid, preferably water, to obtain a hardenable wet matrix.

13. Method according to claim 12, wherein the hardenable wet matrix is sprayed onto the structure, preferably by means of a gun, the mesh is then positioned on the unhardened matrix and press-mounted, preferably using a trowel, and optionally the matrix is sprayed at least once more, preferably smoothing the surface of the matrix sprayed in this way with the trowel.

14. Method according to claim 13, wherein the operations of spraying, positioning another mesh and press-mounting are repeated n times, with n comprised between 1 and 3; these operations can be carried out on the surface of the unhardened or at least partly hardened previously sprayed matrix.

15. Wet formulation comprising the matrix as defined in claim 1, mixed with a liquid, preferably water.

16. Method for preparing the wet formulation according to claim 15 consisting in mixing a liquid, preferably water, with all or part of the components of the matrix, the rest of the components then being incorporated gradually into the mixture if this has not been done previously.

17. Method for consolidating a reinforced concrete or masonry structure by press-mounting, using a mesh according to claim 8 and a wet formulation-comprising a hardenable or hardened matrix.

Description

[0199] Further details and advantageous features of the invention will become apparent below from the description of an example of a non-limitative preferred embodiment of the invention, with reference to the attached figures, in which:

[0200] FIG. 1 is a perspective photograph of a preferred embodiment of the mesh according to the invention;

[0201] FIG. 2 is a diagrammatic view of the detail in FIG. 1;

[0202] FIG. 3 is a cross-sectional view along the line III-III in FIG. 2;

[0203] FIG. 4 is a view of the mesh sample according to the invention intended to be subjected to the dimensional stability under stress test ST;

[0204] FIG. 5 is a detailed photograph of a step of manufacturing the mesh according to the invention in the loom used to this end;

[0205] FIG. 6 is a photograph of another step of manufacturing the mesh according to the invention, namely the coating step.

[0206] FIG. 7 is front view photograph of the mesh according to the invention;

[0207] FIG. 8 shows, on the left-hand side, a perspective view of the specimen used in a quasi-static uniaxial tensile test of the behaviour of the composite system according to the invention, on the right-hand side, a perspective view of the specimen with a joint with the test machine at each of the two ends thereof, and in the middle, a detail of this joint;

[0208] FIG. 9 is a mean tensile stress-strain curve (MPa-mm/mm) in a quasi-static uniaxial tensile test of the behaviour of the composite system according to the invention;

[0209] FIG. 10 shows, at the top, a perspective view, and at the bottom, a side view, of the specimen used in a temperature stability test of the composite system according to the invention;

[0210] FIG. 11 is a curve showing the evolution of the stiffness of specimens of the type shown in FIG. 8, and enabling an exploratory study of fatigue in the composite mesh/matrix reinforcement system according to the invention;

[0211] FIG. 12 shows a SATEC adherometer used in an evaluation of the superficial cohesion of the composite system according to the invention, on a concrete substrate;

[0212] FIG. 13 shows a diagram of a bending bench used in tests to measure the bending moment of bending beams reinforced using the composite system according to the invention;

[0213] FIG. 14 shows load-deflection curves (daN-mm) measured for beams reinforced or not using the composite system according to the invention and subjected to the bending moment test;

[0214] FIG. 15 shows the load-deflection curves (N-mm) obtained in a test to measure the behaviour of reinforced concrete beams, reinforced or not with respect to shear stress, using a composite system according to the invention;

[0215] FIG. 16 shows the identification of the mechanical characterisation parameters of the hardened composite structure, in particular the tensile modulus of elasticity TME.

[0216] The composite system for consolidating structures, in particular structures made from reinforced concrete or masonry, according to the invention, comprises a hardenable or hardened matrix and a textile reinforcing mesh.

[0217] I MESH

[0218] Structure:

[0219] The mesh is labelled 1 on the figures. It is similar to a lattice composed of a non-woven reinforcement 2 and a binding network 3 of this reinforcement 2.

[0220] The reinforcement is constituted by flat carbon warp threads 2?c that intersect flat weft threads 2?t also made from carbon.

[0221] The binding network 3 is a weave comprising warp elements 3?c and weft elements 3?t.

[0222] The warp threads 2?c and the weft threads 2?t of the non-woven reinforcement are overlaid and perpendicular. The layer formed by the warp threads 2?c can be qualified as the bottom layer as it is intended to be applied to the structure to be consolidated, while the top layer is formed by the weft threads 2?t, which have by convention in the present description a Face F1 and a Face F2 as shown in FIG. 3.

[0223] The warp threads 2?c are, in this example, simply placed on the weft threads 2?t. They are not secured to each other in their contact areas. The cohesion and geometric regularity of the reinforcement 2 are provided, preferably solely, by the binding network 3. According to variants of the invention, a connection could be made between the warp threads 2?c and the weft threads 2?t, in all or part of their contact areas, for example gluing and/or welding.

[0224] The perpendicular arrangement of the warp threads 2?c and the weft threads 2?t is also a preference, but the angle between the warp and the weft could be different from 90?, for example comprised between 30? and 120?, apart from 90?.

[0225] The grid defined by the warp threads 2?c and the weft threads 2?t delimits openings 4 (cf. FIGS. 1 and 7) with a substantially rectangular shape in this example, but which could be rhomboid if the warp/weft angle of the reinforcement differs from 90?.

[0226] Each warp thread 2?c and weft thread 2?t is constituted by a flat bundle of N carbon filaments. In this preferred embodiment: [0227] N is approximately equal to 12,000 (800 tex). [0228] The tensile strength (in MPa) of each thread is approximately 4,900. [0229] The tensile modulus (in GPa) of each thread is approximately 230. [0230] The elongation (as a %) of each thread is approximately 2.1. [0231] The filament diameter is approximately 7 ?m. [0232] The filament density is approximately 1.8.

[0233] The warp threads 2?c and weft threads 2?t are preferably identical in this example, but the use of warp threads 2?c that are different from each other and/or weft threads 2?t that are identical or different from each other is not ruled out.

[0234] These threads of the reinforcement can in particular correspond to the carbon threads marketed by TORAY CARBON FIBERS EUROPE under product references FT300, T300, T300J, T400H, T700S, T700G, T800H, M35J, M40J, M46J, M55J, M60J, M30S, M40, T1000G, M50J, T600S, or T800S.

[0235] The warp elements 3?c and the weft elements 3?t of the binding network 3 together form a weave in which each warp element 3?c comprises two warp binding threads 3i?c, 3ii?c and each weft element 3?t comprises one weft binding thread 3?t. The weave of the binding network 3 is a leno weave.

[0236] As can be seen more clearly in FIGS. 2 & 3, the two warp binding threads 3i?c travel all along the warp in the repeating M pattern as shown in FIG. 3: [0237] one of the warp binding threads 3i?c.sup.1 passes over Face F1 of a weft thread 2?t of the reinforcement 2, and the other warp binding thread 3ii?c.sup.2 passes over the other Face F2 of said weft thread 2?t of the reinforcement 2, so as to clasp the weft thread; [0238] the two warp binding threads 3i?c.sup.1 &3ii?c.sup.2 intersect for the first time in the opening 4 delimited by a segment of the weft thread 2?t, by an opposite segment of the next weft thread 2?t in the warp direction C in FIGS. 2 & 3 and by the two facing segments of the two corresponding adjacent warp threads 2?c of the reinforcement 2, said opening 4 being crossed by a weft binding thread 3?t, so that, having intersected a first time, the two warp binding threads 3ic.sup.1 & 3ii?c.sup.2 pass on either side of the weft binding thread 3?t, then intersect a second time in the aforementioned opening 4, so that warp binding thread 3i?c then passes over Face F1 of the next weft thread 2?t and warp binding thread 3ii?c.sup.2 passes over Face F2 of the next weft thread 2?t.

[0239] The warp elements 3?c intersect the weft threads 3?t of the binding network 3 in the openings 4 in the reinforcement 2, and thus also define regular openings 5 (cf. FIG. 7). The warp elements 3?c are substantially perpendicular to the weft threads 3?t of the binding network 3. The warp elements 3?c of the binding network 3 are substantially parallel to the warp threads 2?c of the reinforcement and the weft elements 3?t of the binding network are substantially parallel to the weft threads 2?t of the reinforcement 2.

[0240] The carbon threads 2?t of the reinforcement 2 in the weft direction are immobilized by the binding network 3, which ensures the geometric regularity of the assembly.

[0241] According to a variant that can be envisaged, the weft elements 3?t of the binding network could comprise, like the warp elements 3?c, two weft binding threads suitable for trapping the warp threads 2?c of the reinforcement 2. This further increases the cohesion, resistance to deformation under stress and regularity of the reinforcement 2.

[0242] Each warp thread 3i?c, 3ii?c and weft thread 3?t is preferably constituted by a glass thread. In this preferred embodiment, the size (in tex) of this glass warp binding thread is 35?5, and the size (in tex) of the glass weft binding threads is 75?5. This size of 38 tex on the warp represents 51% of the size of 75 tex on the weft.

[0243] These glass binding threads can correspond to the products marketed by FULLTECH FIBER GLASS CORPORATION under product reference ECG 75 1/0 0.7Z 172 SIZING (A-GRADE) and/or ECG 150 1/0 0.7Z 172 SIZING (A-GRADE).

[0244] The mesh according to the invention can equally well be applied with the weft or warp threads following the axis of the stress to be distributed (diffused) (the carbon threads of the weft and the warp have almost equivalent performance vis-?-vis taking up strain). The reinforcement can therefore be applied to take up bending strain and so-called shearing strain.

[0245] Manufacture: Weaving/Coating-Impregnation

[0246] The mesh 1 composed of the non-woven reinforcement 2 of threads 2?c, 2?t (e.g. carbon) reinforced by the binding network 3, is manufactured as set out below for example using a loom, the production of the reinforcement 2 and the weaving on this reinforcement 2 of the threads 3ic1, 3ii?c2 and 3?t (e.g. glass) using a leno weave of the binding network 3.

[0247] FIG. 5 shows a detail of the loom, and in particular the warp binding threads 3i?c1, 3ii?c2, just after they intersect, before they thus surround a weft binding thread 3?t (not yet engaged in the loom and not shown in FIG. 5), to then intersect again and afterwards surround a weft thread 2?t of the reinforcement 2 (not yet engaged in the loom and not shown in FIG. 5).

[0248] The use of the two warp binding threads and the weft binding thread makes it possible to geometrically secure the carbon weft threads in the carbon warp threads. In addition, this type of binding results in an even tension in the mesh (warp and weft direction), which enables an even distribution of the threads in all directions. The geometry of each opening 4 in the reinforcement 2 or opening 5 in the binding network 3 is very regular.

[0249] The mesh according to this embodiment is coated by impregnation e.g. with a pure acrylic resin the glass transition temperature of which is 25? C., the minimum film formation temperature of which is 14? C. and the solid content of which is 46%.

[0250] This coating/impregnation makes it possible to ensure and reinforce the dimensional stability of the assembly and the even distribution of the stresses. This guarantees the efficient collaboration of all of the filaments constituting the carbon threads 2?c of the warp of the reinforcement 2. The coating/impregnation acts as a fixing agent that enables the mesh to withstand deformation effectively. This enables an even distribution of the stresses over the surface of the mesh and in each carbon thread, and facilitates the dissipation thereof.

[0251] The mesh is preferably, as illustrated in this example, manufactured continuously, which enables effective management of the tensions relating to the manufacturing process (loom). The threads are tensioned uniformly and consistently, and then coated by soaking.

[0252] FIG. 6 shows the uncoated mesh 1b passing through the rollers 11, 12 of the coating machine, one of the rollers 11 being associated with a doctor blade one of the edges of which, parallel to the axis of the roller 11, is in contact with the mesh 1, so as to form a receptacle containing a coating bath 13 that impregnates the travelling mesh 1, which then passes between the coating roller 11 and the backing roller 12 so as to remove the excess coating liquid. The coated mesh 1 is dried.

[0253] After drying, the mesh is collected and packed into rolls.

[0254] The mesh according to the invention can be applied equally with the weft or warp threads following the axis of the stress to be distributed (diffused). The carbon threads of the weft and the warp have almost equivalent performance vis-?-vis taking up strain. The reinforcement can therefore be applied to take up bending strain and so-called shear strain.

[0255] II Tests TR and TS

[0256] II.1 Dimensional Stability Under Stress Test ST

[0257] II.1.1 Method

[0258] This test ST consists of cutting a 40?40 cm square sample E of mesh from a roll of mesh 1.

[0259] This sample E is shown in FIG. 4.

[0260] As can be seen in FIG. 4, the sample E is fastened to a graduated board 15 by means of two hooks 16 on a horizontal bar 17 so that one of the hooks 16 is fixed at a distance of 2.5 cm (at the centre line of the fastening stud glued to the top part of the mesh) from one of the top corners of the sample E, and the other hook at a distance of 2.5 cm from the opposite top corner (from the axis of the fastening hole to the outer edge of the mesh). Each hook 16 is constituted by a threaded rod 6 mm in diameter, bent in order to form a hook.

[0261] The bar is produced from a metal section in the shape of an inverted U, the base of which is pierced with a hole. The hook 16 is secured to the U-shaped bar as it passes through it, and is fastened with a nut/lock nut system.

[0262] The top edge of the sample E is aligned with the horizontal axis corresponding to the zero line on the graduated board 15.

[0263] The middle opening 4 comprised in the bottom end row of holes 4 in the sample E is identified.

[0264] This middle opening 4 is the one closest to the centre of this bottom end row of the sample E.

[0265] The position of the bottom edge of the sample E situated just below the middle opening 4 is marked on the graduated board 15. The value V0 is read in cm, corresponding to the length between the zero line on the graduated board 15 and the position of the bottom edge marked on the graduated board 15.

[0266] A weight 20 of 1 kg or 2 kg is then hung from the centre of the sample E using a hook 18 comprising a curved end 19 that is inserted in the middle opening 4.

[0267] The hook 18 is constituted by a metal wire the two ends of which are bent to form a double hook for securing the sample E to the weight.

[0268] As soon as the weight 20 has been positioned, the position of the bottom edge of the sample E situated just below the middle opening 4 or 5 is marked on the graduated board 15. The value V1 is read in cm, corresponding to the length between the zero line on the graduated board 15 and the position of the bottom edge marked on the graduated board 15. The deformation of the sample is calculated in cm D1=V1=V0 if the weight 20 is a 1 kg weight.

[0269] The deformation of the sample is calculated in cm D2=V2=V0 if the weight 20 is a 2 kg weight.

[0270] II.1.2 Results

TABLE-US-00001 V0 = 40 mm V1 = 40 mm D1 = 0 V2 = 40 mm D2 = 0

[0271] II.2 Geometric Regularity Test RT

[0272] II.2.1 Method

[0273] This test RT consists of cutting a 40?40 cm square sample E of mesh from a roll of mesh 1 as obtained immediately after manufacturing and that has not therefore been unrolled or handled. This sample E is shown in FIG. 4.

[0274] The area is calculated on a random panel of 20 openings in this sample. If the opening is rectangular, as is the case in the present preferred embodiment, the length and width of each opening is measured and finally, the product of these two dimensions, to give the surface area. In the case of a geometric shape other than a rectangle, the dimension measurements and appropriate calculations are performed.

[0275] The standard deviation of the surface area of the openings in the reinforcement on a random panel of 20 openings is calculated.

[0276] The openings can be the openings or links 4 of the reinforcement 2 or the openings or links 5 of the binding network 3.

[0277] II.2.2 Results

[0278] II.2.2.1 Carbon Reinforcement 2

TABLE-US-00002 TABLE 1 Geometric regularity of the carbon reinforcement 2 of the sample E - Link/opening 4 FIG. 1 - Side 1 Side 2 Link area Measurements (mm) (mm) (mm2) 1 5.21 5.11 26.62 2 5.43 5.07 27.53 3 4.9 4.81 23.57 4 5.04 5.62 28.32 5 4.87 5.04 24.54 6 5.29 5.2 27.51 7 5.79 5.3 30.69 8 4.86 5.14 24.98 9 5.09 5.07 25.81 10 5 5.08 25.40 11 5.2 5.29 27.51 12 4.47 5.28 23.60 13 5.07 5.04 25.55 14 5.3 5.02 26.61 15 5.18 5.12 26.52 16 5.74 5.06 29.04 17 5.17 5.2 26.88 18 4.82 5.11 24.63 19 4.84 5.14 24.88 20 5.14 5.04 25.91 Mean (mm) 5.12 5.14 / Mean (mm.sup.2) / / 26.31 Standard deviation (mm) 0.31 0.16 / Standard deviation (mm.sup.2) / / 1.81 Standard deviation 6.0 3.1 6.9 (% relative to the mean) Sides 1 & 2 are adjacent. The link area is calculated as follows: side 1 ? side 2

[0279] II.2.2.1 Glass Binding Network 3

TABLE-US-00003 TABLE 2 Geometric regularity of the glass binding network 3 of the sample E - Link/opening 5 FIG. 7 - Side 1 Side 2 Link area Measurements (mm) (mm) (mm2) 1 7.33 7.28 53.36 2 7.47 7.47 55.80 3 7.32 7.27 53.22 4 7.26 7.35 53.36 5 7.38 7.38 54.46 6 7.35 7.45 54.76 7 7.47 7.36 54.98 8 7.37 7.21 53.14 9 7.27 7.41 53.87 10 7.42 7.37 54.69 11 7.36 7.48 55.05 12 7.37 7.58 55.86 13 7.44 7.38 54.91 14 7.29 7.36 53.65 15 7.42 7.34 54.46 16 7.39 7.24 53.50 17 7.44 7.33 54.54 18 7.39 7.35 54.32 19 7.42 7.43 55.13 20 7.38 7.44 54.91 Mean (mm) 7.38 7.37 / Mean (mm.sup.2) / / 54.40 Standard deviation (mm) 0.06 0.09 / Standard deviation (mm.sup.2) / / 0.83 Standard deviation 0.8 1.2 1.5 (% relative to the mean)

[0280] III Cementitious Matrix

[0281] 1 Raw Materials

1.1 hydraulic binder: [0282] 1.1.1. CEM I 52.5NSR5 CE PMCP2 Portland cement, with a density of 3.17 g/cm.sup.3 and a Blaine specific surface area of 3,590 cm.sup.2/g. [0283] 1.1.2. minimum of 93% calcium oxide with an apparent density of the order of 1 and particle size of 0-100 ?m.
1.2 resin: [0284] redispersible acrylate copolymer powder resin with a density of 450-650 g/l, a pH of 7-8, a glass transition temperature of +10? C. and a minimum film formation temperature of +0? C. (after redispersion in water).
1.3 mineral fillers: [0285] 1.3.1 calcareous filler: pure crystalline natural calcium carbonate (CaCO.sub.3?99%) with a Mohs hardness of 3, oil absorption of 20 mL/100 g (ISO 787-5) and a mean diameter of 8 ?m. [0286] 1.3.2 siliceous fillers: [0287] 1.3.2.1 siliceous sand with a particle size of 75-300 ?m. [0288] 1.3.2.2 siliceous sand with a particle size of 200-800 ?m.
1.4 additives: [0289] 1.4.1 thickener: amorphous silicic acid with a density of 200 kg/m3 and a specific surface area of 18-22 m.sup.2/g. [0290] 1.4.2 water-retaining agent: methyl hydroxyethyl cellulose with a Rotovisco viscosity of 20,000-27,000 mPa.Math.s (2%/20? aqueous solution).

[0291] 2 Procedure:

[0292] 3 kg of powder comprising the binder, the resin, the mineral fillers and the additives are prepared and mixed for 3 minutes in a Guedu laboratory mixer (model 4.5 NO) with a working capacity of 3.5 litres at a speed comprised between 545 and 610 rpm.

[0293] The 3 kg of powder obtained are mixed with water in a Perrier laboratory mixer for 1 minute at a speed of 140 rpm; the sides of the bowl are then scraped and mixing is continued for 2 minutes at 140 rpm.

TABLE-US-00004 TABLE 3 composition (in parts relative to parts of hydraulic binder) example 1 example 2 example 3 example 4 Binder Hydraulic Portland 100 Portland 100 Portland 100 Portland 100 binder Cement Cement Cement Cement Calcium Calcium Calcium Calcium oxide oxide oxide oxide Resin Redispersible Acrylate 8.11 Acrylate 8.11 Acrylate 8.11 Acrylate 8.11 powder resin copolymer copolymer copolymer copolymer Mineral Calcareous Calcium 0 Calcium 27.03 Calcium 0 Calcium 13.51 fillers filler carbonate carbonate carbonate carbonate Siliceous Silica 75-300 ?m 89.19 Silica 75-300 ?m 129.73 Silica 75-300 ?m 94.59 Silica 75-300 ?m 113.38 sands Silica 200-800 ?m 67.57 Silica 200-800 ?m 0 Silica 200-800 ?m 67.57 Silica 32.43 200-800 ?m Additives Rheological Silicic acid 5.41 Silicic acid 5.41 Silicic acid 0 Silicic acid 2.7 agent Water- Methyl 0 Methyl 0 Methyl 0 Methyl 0.14 retaining hydroxyethyl hydroxyethyl hydroxyethyl hydroxyethyl agent cellulose cellulose cellulose cellulose

[0294] IV Evaluation Tests of the Composite Mesh/Matrix System According to the Invention

[0295] IV.1 Behaviour Under Quasi-Static Uniaxial Tension: Measuring the Tensile Modulus of Elasticity TME

[0296] Test Type:

[0297] In the absence of a standardized procedure, the identification of the intrinsic properties of the composite mesh/matrix system according to the invention is based on a direct tensile test highly suited to cracking materials that has been verified using a theoretical and experimental approach [1]: R. CONTAMINE, A. SI LARBI, P. HAMELIN Contribution to direct tensile testing of textile reinforced concrete (TRC) composites. Materials Science and Engineering: A; 528 (2011), pp. 8589-8598.

[0298] Test Piece Dimensions:

[0299] FIG. 8 shows the test pieces 100, which are composed of a panel 101 of the composite mesh/matrix system (100?500 m.sup.2) together with aluminium lugs 102 (4?100?100 mm) glued (sanding double sizing with epoxy adhesive on the ends of the panel). These lugs 102 are each connected by a joint 103 to the tensile testing machine. The carbon/glass mesh system according to the invention used comprises a single mesh press-mounted using the cementitious matrix. The thickness of the composite system, once hardened, is 3 mm.

[0300] Instrumentation:

[0301] The test is carried out on a ZWICK universal testing machine with a capacity of 5 tonnes.

[0302] It is a monotonic static test associated with a load increase speed of 1 mm/min (until failure of the specimen).

[0303] The instrumentation selected comprises two ?20 mm stroke LVDT displacement sensors that are arranged centred (laterally and height-wise) on the two faces of the specimen. A judiciously arranged force sensor is used to obtain the evolution of the load applied.

[0304] Results/Conclusions:

[0305] Six identical specimens were produced and tested.

[0306] Analysis of the results consists of plotting the stress-strain curve (FIG. 9).

[0307] A mean stress (credible hypothesis taking into account the cracking obtained) in the textile/mortar composite was considered:

a and b: height and width of the specimen respectively.

[0308] The mean deformation is given by the ratio of the measured displacement ?L.sub.c to the measurement length l.sub.c.

[00001]$\begin{array}{cc}{\mathrm{.Math.}}_c=\frac{?.Math..Math.l_c}{l_c}& \left(4\right)\end{array}$

?l.sub.c: elongation, l.sub.c: distance between sensors (200 mm).

[0309] Obvious qualitative similarities can be identified quite clearly on the mean stress-strain curves in that they all exhibit behaviour characterized by four distinct phases. FIG. 16 shows the overall mechanical properties of the textile-mortar composites examined.

[0310] The value E1 of the tensile modulus of elasticity TME characterizes the composite structure according to the invention, in particular with regard to the resistance to seismic loads that the structure is capable of imparting to the structures that it consolidates.

[0311] The results obtained are as follows:

TABLE-US-00005 Failure E.sub.1 E.sub.2 E.sub.3 ?.sub.c ?.sub.2 ?.sub.3 ?.sub.u load Reference (MPa) (MPa) (MPa) (MPa) (MPa) (MPa) (MPa) (daN) Specimen 1 52000 2300 114 10.6 14.1 22.1 31.4 9400 Specimen 2 53100 2250 98 9.1 13.2 20.7 28.6 8780 Specimen 3 53000 2350 110 10.1 14.5 22.1 32 9650 Specimen 4 53150 2190 120 8.5 13.7 21 30.3 9250 Specimen 5 53150 2290 110 8.7 14.5 19.1 27.2 8160 Specimen 6 52900 2300 100 8.4 12.9 18 27.9 8470 Mean 52883.3 2280 108.67 8.93 13.8 20.5 29.4 8951.7 Standard 443.47 54.4 8.36 1.02 0.67 1.65 2.21 577.2 deviation Characteristic 51916.6 2161.4 90.45 6.71 12.35 16.9 24.5 7693.3 value

[0312] Both the qualitative and quantitative reproducibility of the results on the six samples thus appears to be established. In addition, the behaviour laws obtained reflect the good performance of the composite mesh/matrix system according to the invention. With respect to both the first zone (stiffness and first cracking strain) and the failure strain (of the order of 30 MPa), the properties obtained are very beneficial. Finally, the relatively high levels of the initial stiffness (of the order of 50,000 MPa) and the first cracking strain suggest very good initial interaction of the elements constituting the composite mesh/matrix system according to the invention.

[0313] IV.2 Temperature Stability of the Composite Mesh/Matrix System According to the Invention

[0314] Test Type:

[0315] In the absence of a test procedure specifically designed for textile-mortar systems, the temperature behaviour of the composite mesh/matrix system according to the invention is evaluated by means of a double lap tensile/shear test (parallel concrete blocks assembled on two symmetrical faces using reinforcing materials). This test, which was initially designed for polymer composites, in particular carbon/epoxy composites, is recommended by the working group of the French Civil Engineering Association (AFGC). The sizing of the specimens and the attachment surface are defined with the aim of minimising the effects of local stresses to enable mean stress operation.

[0316] Test Piece Dimensions:

[0317] FIG. 10 shows the concrete blocks 110 with dimensions of 140 mm*140 mm*250 mm (concrete prepared and used in accordance with NF EN 18-422). The carbon/glass mesh system according to the invention used comprises a single mesh press-mounted using the cementitious matrix. The thickness of the composite system, once hardened, is 3 mm. The reinforcement system is in the form of two strips 111 each with an anchor length of 200 mm and a width of 50 mm. The strips 111 are arranged on two opposite faces of the two blocks 110 and connect them together while maintaining a separation ?1 between the two end faces thereof.

[0318] Instrumentation:

[0319] The separation (displacement) of the two blocks (?1) is recorded continuously by LVDT displacement sensors 112 (FIG. 10) with a ?5 mm stroke and an accuracy of 10-4 mm, and the change speed is 1 mm/min.

[0320] Results/Conclusions:

[0321] Tensile/Shear Test at 2 MPa for 30 Mins at 20? C., 60? C. and 80? C.

[0322] The results obtained show the absence of creep of the composite over the entire duration of the test (30 minutes) regardless of the test temperature (20? C., 60? C., 80? C.). This reflects good strength of the composite mesh/matrix reinforcement system according to the invention under thermally stimulated stress.

[0323] Tensile/Shear Test at 2 MPa for 12 Hrs at 80? C.

[0324] The results obtained confirm the stability of the composite mesh/matrix reinforcement system according to the invention, for an operational working temperature of 80? C. and a shear stress of 2 MPa. After stabilisation due to loading, there was almost no creep of the assembly over a 12-hour period.

[0325] IV.3 Exploratory Study of Fatigue of the Composite Mesh/Matrix Reinforcement System According to the Invention

[0326] Test Type:

[0327] In the absence of a standardized procedure relating to the characterisation of textile/mortar composites, the inventors designed a procedure suitable for cracking materials. This is a monotonic static fatigue test. The aim is to evaluate, using direct tensile tests, the ability of the configuration to withstand 1,000 stress cycles. In order to best reflect the stresses to which the composite mesh/matrix reinforcement system according to the invention could be subjected during the repair as closely as possible, undulating fatigue was applied. During a cycle, a variation ranging from 0 to 60% of the maximum tensile stress was therefore applied (0 to 18 MPa).

[0328] Test Piece Dimensions:

[0329] The test pieces used are the same as the test pieces 100 described above and shown in FIG. 10. The carbon/glass mesh system according to the invention used comprises a single mesh press-mounted using the cementitious matrix. The thickness of the composite system, once hardened, is 3 mm.

[0330] Instrumentation:

[0331] The test is carried out on a ZWICK universal testing machine with a capacity of 5 tonnes and a load increase speed of 1 mm/min (until failure of the specimen). The instrumentation selected comprises two ?20 mm stroke LVDT displacement sensors that are arranged centred (laterally and height-wise) on the two faces of the specimen. A judiciously arranged force sensor is used to obtain the evolution of the load applied.

[0332] Results/Conclusions:

[0333] The analysis of the results mainly consists of assessing the macroscopic damage to the specimen using the evolution of the stiffness as a reference (ascending Young's modulus E+, descending Young's modulus E?, energy dissipated J, deformation per cycle, accumulated residual deformation, deformation at maximum stress) (FIG. 11).

[0334] The evolution of the stiffness (E+ or E?), which is almost constant, highlights the almost complete absence of macroscopic damage to the composite mesh/matrix reinforcement system according to the invention over the 1,000 cycles. This finding clearly reflects the good properties of the composite mesh/matrix reinforcement system according to the invention vis-?-vis 1,000 cycles of static fatigue stress and suggests satisfactory performance for a substantially larger number of cycles.

[0335] The energy dissipated per cycle is significantly higher in the first cycle inasmuch as it largely corresponds to the formation of the cracks. After this, it evolves in an almost constant manner over the next 999 cycles. The same mechanisms are mobilized (in stable proportions) as from the second cycle and tend to suggest that any creation of additional cracks as from the second cycle is non-existent or marginal. This latter suggestion seems all the more realistic as it is supported by the evolution of the residual deformation, which remains almost completely stable after the first cycle.

[0336] Thus, the composite mesh/matrix reinforcement system according to the invention is entirely suitable for repairing beams vis-?-vis bending stresses (bending moment).

[0337] IV.4 Evaluation of the Superficial Cohesion of the Composite Mesh/Matrix Reinforcement System According to the Invention, on a Concrete Substrate

[0338] Test Type:

[0339] In order to verify the performance of the composite mesh/matrix reinforcement system according to the invention vis-?-vis pull-off stresses, superficial cohesion tests were performed in accordance with the procedure described in EN ISO 4624 Paints and varnishes, pull-off test for adhesion, referred to in general standard NF P98-284-1 [September 1992 Tests relating to roadwaysWaterproofing products for civil engineering structuresProvoked cracking resistancePart 1: Tests on poured products bonded to the substrate. The adhesion of the composite on a concrete substrate is thus measured by direct tensile testing].

[0340] Test Piece Dimensions:

[0341] The concrete used to produce the slabs is defined by a compressive strength at 28 days of at least 30 MPa. The carbon/glass mesh system according to the invention used comprises a single mesh press-mounted using the cementitious matrix. It is applied in a single layer to the surface of the matrix. The thickness of the composite system, once hardened, is 3.0 mm ?0.2 mm. Then after coring, six metal pellets are glued on using an epoxy mortar with a tensile strength greater than 10 MPa.

[0342] Instrumentation:

[0343] The adherometer used is of the SATEC type (FIG. 12 in which (120): outer ring(121): metal pellets(122): composite system(123): concrete substrate). It is used for the manual application of tensile stress at a constant speed until failure within a period of 90 s.

[0344] Results/Conclusions:

[0345] The mean bond stress, defined by the ratio of the mean failure load to the nominal area of the patch, is thus calculated. The latter, equal to 2.1 MPa, is greater than 2 MPa. In addition, the failure observed is of the cohesive type; failure in the concrete of the substrate. The combination of these two results confirms that the composite mesh/matrix system according to the invention is suitable for reinforcing concrete structures or masonry structures.

[0346] IV.5 Results of Experiments on Bending Beams (Bending Moment) Reinforced with LANKOSTRUCTURE TRM Composite Material

[0347] Test Type:

[0348] The aim is to quantify the performance of the composite mesh/matrix system according to the invention in the case of the repair of a reinforced concrete beam vis-?-vis bending stresses (bending moment). For this evaluation, dimensioning was carried out complying with a regulatory approach and in accordance with the experimental resources available in the laboratory. This dimensioning was carried out at ULS (Ultimate Limit State) and the prerequisites were as follows: [0349] Protection against shear failure [0350] Failure of the reinforced concrete beam at pivot A (evaluation of the reinforcements) [0351] Avoid shear stress interaction (four-point bending)

[0352] A maximum failure load of 12 tonnes is thus applied. In addition, the beam is deliberately damaged prior to the implementation of the composite mesh/matrix system according to the invention and the plastification of the tensioned reinforcements (residual deformation rate of the order of 350 ?m/m) constitutes the damage criterion applied.

[0353] Test Piece Dimensions:

[0354] FIG. 13 shows a beam P reinforced with a carbon/glass mesh system according to the invention that comprises a single mesh press-mounted using the cementitious matrix and is in the form of a strip 200 with a width corresponding to the width of the beam, namely 150 mm, and a length of 195 cm, namely 5 cm shorter than the effective length of the beam being tested, so as to avoid any unwanted contact between the reinforcing element and the support. The thickness of the composite system, once hardened, is 3.0 mm?0.15 mm.

[0355] Instrumentation:

[0356] The tests are performed on an appropriate bending bench. Bending occurs at four points f1, f2, f3, f4 (cf. FIG. 13) to avoid shear stress in the central portion. The load is applied in a gradual (static) and monotonic manner until failure. Force control is applied (regular load increase). The instrumentation used is constituted by: [0357] a force sensor with a capacity of 200 kN; [0358] strain gauges 201 (120 ohms) arranged over the height of the beam P. [0359] a displacement sensor 202 (LVDT?25 mm) arranged in the centre of the beam. In addition, the comparative evolution of the opening of the cracks in the central portion of the beam is established using an image correlation system.

[0360] Results/Conclusions:

[0361] The load-deflection curves associated with the two beams originating from the same batch (the sound reference beam and the damaged reinforced concrete beam P repaired using the mesh/matrix reinforcement system according to the invention) (FIG. 14) illustrate qualitatively similar behaviours, although the initial stiffness of the beam reinforced with the composite mesh/matrix system according to the invention is lower due to the fact that it was damaged before repair.

[0362] Beyond this small zone, which reflects the macroscopic integrity of the reference beam, the gradient of the curve of the beam P reinforced using the composite mesh/matrix system according to the invention, is slightly steeper due to effective bridging of the cracks. A last non-linear zone is then shown, which reflects the progressive degradation of the beam (essentially of the steel reinforcements) and, if applicable, the added reinforcement. From a quantitative point of view, it is clearly apparent that the composite mesh/matrix system according to the invention helps to defer the point of inflexion (known as the yield point) compared to the reference beam. Thus, an increase of the order of 20% can be seen in terms of load at failure and an increase of the order of 10% is established in terms of yield load of the steel reinforcements.

[0363] With regard to the unit crack opening displacement, qualitatively very similar behaviours are also observed. However, the effect of the reinforcement of the composite mesh/matrix system according to the invention is clearly shown. The unit crack opening displacement is reduced very substantially for an equivalent load level, up to high load levels corresponding to those envisaged at SLS (Service Limit State), where the problems linked to the opening of cracks are central.

[0364] Test Type:

[0365] The aim is to quantify the performance associated with the composite mesh/matrix system according to the invention in the case of the repair of a reinforced concrete beam vis-?-vis shear stresses. For this evaluation, dimensioning was carried out complying with a regulatory approach (BAEL and Eurocode 2) and in accordance with the experimental resources available in the laboratory; the pre-requisites for this dimensioning are as follows: [0366] Protection against bending moment failure [0367] Locate the failure on a single side for improved understanding of the physical phenomena [0368] Pure shear failure of the beam (oblique macrocrack)

[0369] Test Piece Dimensions:

[0370] The composite mesh/matrix reinforcement system according to the invention is applied to the beam in two configurations: [0371] A single 650 mm continuous strip around the perimeter [0372] Eight 30 mm-wide strips on the side and bottom faces

[0373] The effective length of the beams tested is 2 m. The thickness of the composite system, once hardened, is 3.0 mm?0.25 mm.

[0374] Instrumentation:

[0375] The instrumentation is constituted by: [0376] Two strain gauges (120 ohms) arranged on the reinforcements (one on the transverse steels of the undersized portion, the other glued to the central portion of the longitudinal steels) [0377] 1 displacement sensor (LVDT?25 mm) positioned at the mid-span of the beams [0378] 1 force sensor with a capacity of 50 kN

[0379] Results/Conclusions:

[0380] The load-deflection curves obtained confirm the very good properties of the composite mesh/matrix system according to the invention for repair and/or reinforcement vis-?-vis shear stress (FIG. 15).

[0381] The composite mesh/matrix system according to the invention contributes significantly to the increase in ultimate load compared to the reference beam. Thus, the differences range roughly from 15 to 20%, which is all the more satisfactory given that only one layer of composite was applied.

[0382] In addition, zooming in to a local scale makes it possible to emphasize the suitability of the composite mesh/matrix system reinforcement according to the invention (regardless of the configuration used) for generating a level of deformation of the steel that is very substantially greater than that of the reference beam. This parameter is an indicator of the level of ductility of the structural element.