Interlayer hybrid fiber net reinforced cement-based composite material and construction method thereof

Abstract

The invention discloses an interlayer hybrid fiber net reinforced cement-based composite material and a construction method thereof, and belongs to the field of novel building materials. The problem that construction cannot be carried out due to the fact that a thin cement-based composite material matrix is difficult to be effectively attached to the surface of a structure is solved. According to the technical scheme, the composite material comprises a cement-based composite material base body and a fiber net set, the fiber net set comprises a plurality of fine-grid fiber nets and coarse-grid fiber nets between every two adjacent fine-grid fiber nets, burrs are arranged on the two faces of each fine-grid fiber net respectively, and the burrs are inserted into grids of the adjacent coarse-grid fiber nets in a penetrating mode. The cement-based composite material has the beneficial effects that mechanical properties are provided through the coarse-grid fiber net, adhesive force of a base body on the surface of a structure is provided through the fine-grid fiber net, the interlayer interface performance of the fiber net and the cement-based composite material base body layer is improved through burrs on the surface of the fine-grid fiber net, construction is convenient and fast, cost is low, and the method is suitable for large-scale popularization and application. And the prepared composite material has excellent mechanical properties.

Description

Technical Field

[0001] The invention belongs to the field of new building materials, and in particular relates to a construction method of a fiber mesh reinforced cement-based composite material. Background Art

[0002] In recent years, fiber mesh reinforced cement-based composites have been widely used in existing building reinforcement and renovation projects due to their excellent mechanical properties, and have achieved significant economic benefits. The fiber mesh is a mesh structure woven from high-performance fibers. Cement-based composites are fiber-reinforced cement-based composites formed by special short fibers mixed into ultra-fine concrete in a specific proportion. In a broad sense, they also include concrete materials and ordinary cement-based materials. In order to ensure the dispersibility of short fibers in cement-based composites and to ensure the effective penetration of cement slurry in the fiber mesh, cement-based composites generally use a higher water-cement ratio, that is, the cement-based composite slurry is thinner than general concrete. In addition, in order to ensure that the cement matrix can effectively penetrate the mesh of the fiber mesh to improve the anchoring effect of the cement matrix on the fiber mesh, the mesh size of the fiber mesh must be large, generally more than 10 mm, which is about 2-5 times the length of the short fibers in the cement-based composite. Therefore, due to the large mesh size and the thin characteristics of the cement-based composite slurry, the cement-based composite matrix layer on the surface of the structure cannot reach a certain thickness, which makes it difficult to apply the fiber mesh reinforced cement-based composites in engineering. The existing solution to this problem is to prevent the dripping of high-ductility cement slurry by adding formwork, but this solution is complicated to operate and has high costs. More importantly, due to the relatively simple size specifications of the formwork, it is only applicable to relatively regular building structures. However, in actual projects, the structural areas that need to be reinforced are often complex curved surfaces or beam-column joints and other complex structural parts. The existing solution has a limited scope of application. Summary of the invention

[0003] Purpose of the invention: The present invention provides a method for preparing and constructing an interlayer mixed fiber mesh reinforced cement-based composite material, which provides excellent mechanical properties through a coarse-mesh fiber mesh, improves the adhesion of the matrix to the surface of the structure through a fine-mesh fiber mesh, and improves the interlayer interface performance between the fiber mesh and the matrix through the burrs on the surface of the fine-mesh fiber mesh.

[0004] To achieve the above objectives, the present invention adopts the following technical scheme: an interlayer mixed fiber mesh reinforced cement-based composite material, comprising a cement-based composite material matrix and a fiber mesh group arranged inside the cement-based composite material matrix, wherein the cement-based composite material matrix is ​​a concrete matrix, an ordinary cement matrix or a fiber-reinforced cement-based composite material matrix; the fiber mesh group comprises a plurality of fine mesh fiber meshes and a coarse mesh fiber mesh between each two adjacent fine mesh fiber meshes, wherein both sides of the fine mesh fiber mesh have burrs respectively, and the burrs are interspersed in the meshes of adjacent coarse mesh fiber meshes.

[0005] Furthermore, the length of any side of the fine mesh fiber net is less than the length of short fibers in the fiber reinforced cement-based composite material matrix, and the length of any side of the fine mesh fiber net is greater than half the length of short fibers in the fiber reinforced cement-based composite material matrix.

[0006] Furthermore, the burrs are corrosion-resistant hard fiber wires, and the corrosion-resistant hard fiber wires are steel fiber wires that have been treated with rust prevention or fiber wires wrapped with cured resin, and the burrs are upright.

[0007] Furthermore, the length of any side of the coarse mesh fiber net is greater than the length of the short fibers in the fiber-reinforced cement-based composite material matrix.

[0008] Furthermore, the length of any side of the coarse mesh fiber net is more than twice the length of the short fibers in the fiber-reinforced cement-based composite material matrix.

[0009] Furthermore, the coarse mesh fiber net is woven from high-performance fibers; the high-performance fibers are alkali-resistant glass fibers, basalt fibers or carbon fibers.

[0010] The construction method of the interlayer hybrid fiber mesh reinforced cement-based composite material comprises the following steps:

[0011] (1) Clean and roughen the surface of the structure to be reinforced;

[0012] (2) fixing a fine mesh fiber net with burrs on both sides to the surface of the structure to be reinforced;

[0013] (3) injecting cement-based composite material slurry into a layer of fine mesh fiber net to form a cement-based composite material matrix layer on both sides of the fine mesh fiber net, wherein the thickness of the cement-based composite material matrix layer is less than or equal to the difference between the length of the burr and the thickness of the coarse fiber net;

[0014] (4) laying a coarse-mesh fiber net on the surface of one of the cement-based composite material matrix layers obtained in step (3), pressing the coarse-mesh fiber net into the cement-based composite material matrix layer, and the cement-based composite material matrix layer infiltrates the coarse-mesh fiber net;

[0015] (5) laying a layer of fine mesh fiber mesh on the surface of the coarse mesh fiber mesh soaked in the cement-based composite material matrix layer, pressing the fine mesh fiber mesh into the cement-based composite material matrix layer, and inserting the burrs of the fine mesh fiber mesh into the mesh of the adjacent coarse mesh fiber mesh;

[0016] (6) Repeat steps (3) to (5) until the number of layers of the coarse mesh fiber web reaches the designed value;

[0017] (7) vibrating the product of step (6) using a concrete vibrator;

[0018] (8) Apply cement-based composite material slurry to the outer surface of the product of step (7), perform surface leveling and smoothing treatment, and then solidify and maintain to obtain an interlayer mixed fiber network reinforced cement-based composite material.

[0019] Furthermore, in step (2), the fixing method is to apply resin glue or drill nails.

[0020] Furthermore, in step (3), the injection method is spraying or smearing.

[0021] Furthermore, in step (4) and step (5), the pressing method is roller pressing.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] (1) The fiber mesh reinforced cement-based composite material provided by the present invention forms a fiber mesh group by a plurality of fine mesh fiber meshes and a coarse mesh fiber mesh between each two adjacent fine mesh fiber meshes, and the two sides of the fine mesh fiber mesh are respectively provided with burrs interspersed in the meshes of the adjacent coarse mesh fiber meshes, and the interface performance between the coarse fiber mesh and the matrix layer of the cement-based composite material is significantly improved, thereby significantly improving the overall mechanical properties of the fiber mesh reinforced cement-based composite material;

[0024] (2) The construction method of the fiber mesh reinforced cement-based composite material provided by the present invention is to fix a layer of fine mesh fiber mesh with burrs on both sides on the surface of the structure to be reinforced, and then repeatedly lay the cement-based composite material matrix layer, coarse mesh fiber mesh, and fine mesh fiber mesh in sequence until the coarse mesh fiber mesh reaches the designed number of layers. This construction method can effectively solve the problem that the slurry of the cement-based composite material matrix layer is difficult to effectively adhere to the surface of the structure, and the construction is convenient and low-cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a schematic diagram of an interlayer hybrid fiber mesh reinforced cement-based composite material of Example 1;

[0026] Figure 2 is a schematic structural diagram of the fine mesh fiber web of Example 1;

[0027] Figure 3 is a schematic structural diagram of the coarse mesh fiber web of Example 1;

[0028] Among them, 1. cement-based composite material matrix; 21. fine mesh fiber net; 22. coarse mesh fiber net; 211. burrs. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present invention will be described clearly and completely below so that those skilled in the art can better understand the advantages and features of the present invention, thereby making a clearer definition of the protection scope of the present invention. The embodiments described in the present invention are only a part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present invention.

[0030] Example 1

[0031] The interlayer hybrid fiber mesh reinforced cement-based composite material of this embodiment is prepared by the following steps:

[0032] (1) Clean and roughen the surface of the structure to be reinforced so that the surface of the structure remains clean and has a good roughness;

[0033] (2) Fix the fine mesh fiber net with burrs on both sides to the surface of the structure to be reinforced by brushing resin glue, and the length of the burrs on one side is 7 mm;

[0034] (3) applying cement-based composite material slurry to a layer of fine mesh fiber net to form a cement-based composite material matrix layer on both sides of the fine mesh fiber net, and the thickness of the cement-based composite material matrix layer is 5 mm; wherein the cement-based composite material slurry is a high-ductility cement slurry, and the cement-based composite material matrix layer is a high-ductility cement matrix layer;

[0035] (4) laying a coarse mesh fiber net on the surface of one of the high ductility cement matrix layers obtained in step (3), wherein the coarse mesh fiber net has a thickness of 2 mm, and pressing the coarse mesh fiber net into the high ductility cement matrix layer, so that the high ductility cement matrix layer infiltrates the coarse mesh fiber net;

[0036] (5) laying a layer of fine mesh fiber mesh on the surface of the coarse mesh fiber mesh soaked in the high ductility cement matrix layer, pressing the fine mesh fiber mesh into the high ductility cement matrix layer, and inserting the burrs of the fine mesh fiber mesh into the mesh of the adjacent coarse mesh fiber mesh;

[0037] (6) Repeat steps (3) to (5) until the number of layers of the coarse mesh fiber web reaches 3;

[0038] (7) using a concrete vibrator to vibrate the product of step (6) to make it dense;

[0039] (8) Applying high-ductility cement slurry to the outer surface of the product of step (7), and performing surface leveling and polishing treatment, followed by curing and maintenance to obtain an interlayer mixed fiber network reinforced high-ductility cement-based composite material.

[0040] The composite material obtained in this embodiment is as follows Figure 1 As shown, it includes a cement-based composite material matrix 1 and a fiber mesh group arranged inside the cement-based composite material matrix 1. The cement-based composite material matrix 1 of this embodiment is a high-ductility cement matrix; the fiber mesh group includes a plurality of fine mesh fiber meshes 21 and a coarse mesh fiber mesh 22 between each two adjacent fine mesh fiber meshes 21, and burrs 211 are respectively provided on both sides of the fine mesh fiber mesh 21, and the burrs 211 are interspersed in the meshes of the adjacent coarse mesh fiber meshes 22.

[0041] In this embodiment, the structure of the fine mesh fiber net is shown as follows: Figure 2 As shown, the black line represents the fine mesh net 21, the gray line represents the burr 211, the mesh of the fine mesh fiber net 21 is square, the side length is 5mm, the length of the short fiber in the high ductility cement matrix is ​​8mm, the side length of the mesh of the fine mesh fiber net is less than the length of the short fiber in the high ductility cement matrix, and the side length of the mesh of the fine mesh fiber net is greater than half of the length of the short fiber in the high ductility cement matrix, so as to ensure that the high ductility cement matrix can effectively fill the space where the fine mesh fiber net is located and is not easy to drip. Both sides of the fine mesh fiber net 21 are provided with burrs 211, and the burrs must have a certain rigidity to ensure that the burrs can maintain an approximately vertical state in the high ductility cement matrix. The burrs in this embodiment are steel fiber wires that have been treated with rust prevention. The length of the burr is 7 mm, the thickness of the interlayer matrix layer between two adjacent fiber meshes, that is, the thickness of the high ductility cement matrix layer is 5 mm, and the thickness of the coarse mesh fiber mesh is 2 mm. The length of the single-sided burr is equal to the sum of the thickness of the high ductility cement matrix layer and the thickness of the coarse mesh fiber mesh, ensuring that the high ductility cement matrix is ​​effectively retained on the surface of the fine mesh fiber mesh and the burrs can be effectively interspersed in the mesh of the adjacent coarse mesh fiber mesh.

[0042] In this embodiment, the coarse mesh fiber net is made of basalt fiber, such as Figure 3 The grid of the coarse mesh fiber net is square, with a side length of 20 mm, which is greater than the length of the short fibers in the high ductility cement matrix, and the side length of the grid of the coarse mesh fiber net is more than twice the length of the short fibers in the high ductility cement matrix.

[0043] The main function of the fine mesh fiber net is to provide stress transfer capacity between the high ductility cement matrix layers between the coarse mesh fiber nets, improve the interface performance between the high ductility cement matrix layer and the coarse mesh fiber net, and ensure that the high ductility cement matrix layer is effectively applied without dripping through the fine mesh structure; the main function of the coarse mesh fiber net is to provide the mechanical properties of the fiber mesh-reinforced high ductility cement-based composite material. When designing the mechanical properties of the fiber mesh-reinforced high ductility cement-based composite material, only the mechanical properties of the coarse mesh fiber net and the high ductility cement matrix can be considered.

[0044] The present invention can effectively solve the problem that a thin cement-based composite material matrix is ​​difficult to effectively adhere to the surface of the structure and thus cannot be constructed. The construction is convenient, the cost is low, and the prepared composite material has excellent mechanical properties. The matrix of the present invention can also be a conventional concrete matrix, a conventional cement matrix, or a fiber-reinforced cement-based composite material matrix. The present invention provides mechanical properties through a coarse mesh fiber net, provides adhesion of the matrix to the surface of the structure through a fine mesh fiber net, and improves the interlayer interface performance between the fiber net and the cement matrix layer through the burrs on the surface of the fine mesh fiber net.

[0045] The above are only preferred implementations of the present invention. The protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications without departing from the principle of the present invention should be regarded as the protection scope of the present invention.

Claims

1. An interlayer hybrid fiber mesh reinforced cement-based composite material, characterized in that: The invention comprises a cement-based composite material matrix (1) and a fiber mesh group arranged inside the cement-based composite material matrix (1), wherein the cement-based composite material matrix (1) is a concrete matrix, an ordinary cement matrix or a fiber-reinforced cement-based composite material matrix; the fiber mesh group comprises a plurality of fine mesh fiber meshes (21) and a coarse mesh fiber mesh (22) between each two adjacent fine mesh fiber meshes (21), wherein the two surfaces of the fine mesh fiber meshes (21) are respectively provided with burrs (211), and the burrs (211) are interspersed in the meshes of the adjacent coarse mesh fiber meshes (22).

2. The interlayer hybrid fiber mesh reinforced cement-based composite material according to claim 1, characterized in that: The length of any side of the fine mesh fiber net is less than the length of short fibers in the fiber reinforced cement-based composite material matrix, and the length of any side of the fine mesh fiber net is greater than half the length of short fibers in the fiber reinforced cement-based composite material matrix.

3. The interlayer hybrid fiber mesh reinforced cement-based composite material according to claim 1, characterized in that: The burrs are corrosion-resistant hard fiber wires, which are steel fiber wires treated with rust prevention or fiber wires wrapped with cured resin, and the burrs are upright.

4. The interlayer hybrid fiber mesh reinforced cement-based composite material according to claim 1, characterized in that: The length of any side of the coarse mesh fiber net is greater than the length of the short fibers in the matrix of the fiber-reinforced cement-based composite material.

5. The interlayer hybrid fiber mesh reinforced cement-based composite material according to claim 1, characterized in that: The length of any side of the coarse mesh fiber net is more than twice the length of the short fibers in the matrix of the fiber-reinforced cement-based composite material.

6. The interlayer hybrid fiber mesh reinforced cement-based composite material according to claim 1, characterized in that: The coarse mesh fiber net is woven from high-performance fibers; the high-performance fibers are alkali-resistant glass fibers, basalt fibers or carbon fibers.

7. The construction method of the interlayer hybrid fiber mesh reinforced cement-based composite material according to any one of claims 1 to 6, characterized in that: The steps include: (1) Clean and roughen the surface of the structure to be reinforced; (2) fixing a fine mesh fiber net with burrs on both sides to the surface of the structure to be reinforced; (3) injecting cement-based composite material slurry into a layer of fine mesh fiber net to form a cement-based composite material matrix layer on both sides of the fine mesh fiber net, wherein the thickness of the cement-based composite material matrix layer is less than or equal to the difference between the length of the burr and the thickness of the coarse fiber net; (4) laying a coarse-mesh fiber net on the surface of one of the cement-based composite material matrix layers obtained in step (3), pressing the coarse-mesh fiber net into the cement-based composite material matrix layer, and the cement-based composite material matrix layer infiltrates the coarse-mesh fiber net; (5) laying a layer of fine mesh fiber mesh on the surface of the coarse mesh fiber mesh soaked in the cement-based composite material matrix layer, pressing the fine mesh fiber mesh into the cement-based composite material matrix layer, and inserting the burrs of the fine mesh fiber mesh into the mesh of the adjacent coarse mesh fiber mesh; (6) Repeat steps (3) to (5) until the number of layers of the coarse mesh fiber web reaches the designed value; (7) vibrating the product of step (6) using a concrete vibrator; (8) Apply cement-based composite material slurry to the outer surface of the product of step (7), perform surface leveling and smoothing treatment, and then solidify and maintain to obtain an interlayer mixed fiber network reinforced cement-based composite material.

8. The construction method according to claim 7, characterized in that: In step (2), the fixing method is to apply resin glue or drill nails.

9. The construction method according to claim 7, characterized in that: In step (3), the injection method is spraying or smearing.

10. The construction method according to claim 7, characterized in that: In step (4) and step (5), the pressing method is roller pressing.

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