JPH02283651A - Concrete reinforcing material - Google Patents

Abstract

PURPOSE:To obtain an inexpensive reinforcing material having excellent adhesion to concrete structure, executing properties and light-weight properties and capable of expressing reinforcing properties at a small amount by knitting a reinforcing fiber into mesh-like imitation gauze and integral bonding the structure to a resin. CONSTITUTION:The concrete reinforcing material in which a reinforcing fiber is knitted into mesh-like imitation gauze and integrated with a resin. A fiber constituting the reinforcing fiber has preferably about 5-30mu fiber size. Especially carbon fiber is preferably used as the reinforcing fiber. In the imitation gauze, warp 1 and weft 2 are alternately crossed in a form difficult to slip and have characteristics in which crimp of the fiber is small. Furthermore, although mesh intervals L of mesh like imitation gauze can be properly set according to reinforcing characteristics, mesh intervals L are preferably >=2mm, especially 8-20mm. When mesh intervals L are <2mm, amount of cement mortar filled between mesh is reduced and insufficient for reinforcing properties.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a concrete reinforcing material suitably used for concrete structures.

[Prior art and problems to be solved by the invention] Conventionally, wall materials, floor materials, etc. (Reinforcing bars, wire mesh, etc. are known as reinforcing materials for concrete structures used for this purpose. However,
If reinforcing steel or the like is used, not only will it cause cracking and will not have sufficient durability, but it will also not have sufficient workability, and it will be difficult to reduce the weight.

On the other hand, as a reinforcing material for concrete structures, for example, ■
Linear bodies, rod-shaped bodies, and plate-shaped bodies (Japanese Unexamined Patent Publication No. 59-1.50848) made of carbon fiber-reinforced plastic materials have been proposed. However, this reinforcing material does not have sufficient adhesion between the resin and cement, and since it has a linear shape, it is easy to pull out and does not have sufficient reinforcing properties. Furthermore, since the reinforcing material is linear, solid, etc., the ease of applying cement mortar to a predetermined portion is not sufficient. Furthermore, it is not economical because it is necessary to use a large amount of expensive carbon fiber to ensure strength.

In addition, fiber bundles such as glass fiber and carbon fiber are made into a lattice,
Concrete reinforcing member bound with a resin material and having a cross-sectional shape in which fiber groups extending in one direction and fiber groups extending in the other direction are laminated in three or more layers at intersections of fiber bundles (JP-A-82 -153449) has been proposed. In this reinforcing member, the fiber groups are laminated at the intersections, so there are no steps and the thickness of the concrete can be made uniform. Furthermore, since it is made of fiber and resin material, it has the advantage of being lightweight and having good integrity. However, since the intersections need to have a laminated structure, the workability during manufacturing is not sufficient and the cost is high. Furthermore, since the laminated form is such that the fibers at the intersections are easily displaced, the adhesive strength at the intersections is insufficient and it is difficult to bring out the original strength of the fibers.

In addition, a cement mortar molded article (see Japanese Patent Application Laid-open No. 83-111045) has also been proposed, in which a mesh-like body is made of reinforcing fibers and the network body is coated with a synthetic resin and a reactive copolymer latex. . This reinforcing material has excellent workability at the construction site because the net-like body has a woven structure. However, as shown in Figure 2,
Since the warp fibers (11) are entangled with the weft fibers (12), the warp fibers (11) tend to move in the axial direction of the weft fibers (12), and the adhesive strength at the intersection is insufficient. Moreover, since the fibers are crimped, that is, wavy, wrinkled, or distorted, they do not have sufficient stress transmission properties, cannot effectively utilize the inherent strength of the fibers, and do not have a sufficient reinforcing effect. Furthermore, in order to improve the adhesion to cement mortar, it is necessary to sequentially coat the network with a resin and a specific reactive latex, which increases costs.

The purpose of the present invention is to improve adhesion to concrete structures,
The object of the present invention is to provide an inexpensive concrete reinforcing material that is excellent in workability and lightness, can effectively express the strength inherent in fibers, and exhibits excellent reinforcing properties even in a small amount.

[Structure of the Invention] The present invention solves the above problems with a concrete reinforcing material in which reinforcing fibers are knitted into a mesh-like patterned structure and are integrated with resin.

Examples of fibers constituting the reinforcing fibers include polymer fibers such as polyacrylonitrile, phenol resin, and rayon; carbon fibers made from petroleum or coal-based pitch; alkali-resistant glass fibers; aromatic polyamide fibers; and high-strength vinylon. Fibers; examples include polyether sulfone fibers.

At least one type of reinforcing fiber is used, and the fiber preferably has an appropriate fiber diameter, such as a fiber diameter of 5 to 30 μm.

Among these reinforcing fibers, carbon fibers are preferred. Note that carbon fiber refers to carbonized or graphitized fiber, and has a
Items fired at high temperatures of approximately ℃ or higher are included in the concept of graphitization even if the crystal structure is not graphitized. When carbon fiber is used as the reinforcing fiber, shielding properties against electromagnetic waves can be provided.

The reinforcing fibers preferably have a tensile modulus of 5×10 3 hf/- or more in order to enhance the reinforcing effect on the structure.

The reinforcing fibers are usually composed of 500 to 300 filaments (approximately 10 filaments).
10M1, preferably about 0.5 to 5M.

The reinforcing fiber bundle is knitted into a mesh-like patterned texture. As shown in FIG. 1, this patterned weave structure is characterized in that warp fibers (1) and weft fibers (2) alternately intersect with each other in a manner that prevents them from slipping, and the crimp of the fibers is small. Note that the mesh spacing of the above-mentioned mesh-like gauze structure can be set appropriately depending on the reinforcing performance, but the mesh spacing L = 2 mm or more, especially L-8 to 20 m+
About n is preferable.

If the mesh spacing is less than 2 m, the amount of cement mortar filled between the meshes will be small and the reinforcing properties will not be sufficient. Note that the reinforcing properties can be controlled by adjusting the thickness, strength, mesh spacing, etc. of the reinforcing fibers used. Furthermore, in the mesh-like reinforcing material, since the cement mortar matrix can be filled between the warp fibers (1) and the weft fibers (2), the adhesive force between the concrete and the reinforcing material is greatly improved. The warp fibers (1) and weft fibers (2) of the patterned texture may be regularly knitted or irregularly knitted. Further, the numbers of warp fibers and weft fibers are not particularly limited, and can be appropriately set depending on reinforcing properties and the like.

The warp fibers (1) and weft fibers (2) may be composed of different types of fibers. In this case, carbon fiber may be used for one of the warp fibers (1) and the weft fibers (2), and an inexpensive fiber may be used for the other.Also, in order to prevent the misalignment of the mesh-like gauze structure, for example, nylon It may be sealed with fiber, polyester fiber, etc.

The knitted fabric having the above-mentioned patterned weave structure is integrated with a thermosetting resin or a thermoplastic resin. The above resins include epoxy resin, phenol resin, vinyl ester resin, diallyl phthalate resin, unsaturated polyester resin,
Examples include thermosetting resins such as thermosetting acrylic resins, polyurethane resins, and polyimides; thermoplastic resins such as polyacetal, polysulfone, polyethersulfone, polyphenylene sulfide, polyphenylene oxide, polyarylate, and aromatic polyamide. One or more of the above resins may be used. Among these resins, thermosetting resins, particularly epoxy resins, phenol resins, and the like whose properties are less likely to be degraded by the alkaline components of cement, are preferred.

Note that when using a thermosetting resin, a curing agent is used depending on the type of resin. Curing of thermosetting resins is usually done by
It can be carried out at a temperature of about room temperature to 200°C.

The amount of resin impregnated into the fibers is a volume content of 30 to 8.
Approximately 0% is preferable. If the impregnation rate is less than 30%, the integrity and reinforcing effect of the fiber will decrease, and if it exceeds 80%,
It is difficult to combine, and it is not possible to obtain sufficient intersection strength, reducing the reinforcing effect.

The impregnation with the above resin can be carried out by a conventional method, for example, by dipping the knitted article in a resin solution or by applying a resin solution, and by drying and curing the resin, an integrated reinforcement can be obtained. wood is obtained. In addition, the above curing is
The term is used to include not only the crosslinking and curing of thermosetting resins, but also the solidification of thermoplastic resins. The reinforcing material may be woven into a mesh shape and then integrated with a resin, or the fibers may be impregnated with a resin in advance and then woven into a mesh shape.

The reinforcing material of the present invention is lightweight and has excellent adhesion to cement mortar because the mesh-like patterned fabric is integrated with resin.

In addition, there is little deformation due to stress in any direction, and it has excellent stress transferability and workability. Moreover, since it is a patterned weave structure with small crimps, the strength of the reinforcing fibers themselves can be efficiently expressed. In particular, it has significantly superior adhesive strength at the intersections of fibers compared to conventional reinforcing materials with a woven structure. Therefore, reinforcing properties can be improved even with a small amount, and the reinforcing properties are excellent.

In addition, in order to increase the compatibility with concrete, the surface of the reinforcing material may be treated with a silane coupling agent, a titanium coupling agent, etc. Furthermore, the surface of the reinforcing material may be treated with sand or polished. An uneven portion may be formed.

The reinforcing material of the present invention includes, for example, self-hardening cements such as Portland cement, early-strength Portland cement, alumina cement, rapidly hardening high-strength cement, and calcined ceracola; hydraulic cements such as lime slag cement and blast furnace cement; and cements such as mixed cements. It can be applied to The cement may also contain aggregates, setting retarders, effect accelerators, water reducing agents, coagulants, thickeners, foaming agents, waterproofing agents, and the like.

Incidentally, the reinforcing material can be buried in concrete by a conventional method.

[Effect of the invention] As described above, according to the concrete reinforcing material of the present invention,
Since the reinforcing fibers are organized into a mesh-like patterned structure and integrated with resin, it is inexpensive, has excellent adhesion to concrete structures, is easy to construct, and is lightweight, and can effectively express the original strength of the fibers. , shows remarkable reinforcing properties even in small amounts.

[Examples] The present invention will be described in more detail below based on Examples.

Example 1 Mesoface pitch was melt-spun, made infusible, fired at a temperature of 1200°C in a nitrogen gas atmosphere, and then subjected to surface treatment and sizing agent application treatment, resulting in a filament number of 2.
000 pitch-based carbon fibers were obtained. This carbon fiber has a tensile strength of 200kIjf/nd and a tensile modulus of 18
X 103k11f/mJ.

The obtained carbon fibers were woven in a mesh pattern with a mesh spacing of 1.6 mm to obtain a knitted fabric with a basis weight of 100 g/m2. Also, bisphenol A type epoxy resin (
(manufactured by Yuka Shell Co., Ltd., trade name Epicote 1001) and dicyandiamide (manufactured by Nippon Carbide Co., Ltd.) as a curing agent are dissolved in a methanol/methyl ethyl ketone mixed solvent to prepare an approximately 50% by weight resin solution. After soaking and drying the knitted fabric of Mosaori tissue, the temperature is 1'.
The reinforcing material was cured at 80'C for 2 hours to obtain a mesh-like composite reinforcing material. The fiber volume content of the reinforcing material is approximately 4
It was 0% by volume.

The weight ratio of early-strength Portland cement to fine aggregate is early-strength Portland cement/fine aggregate-1l2, and the weight ratio of early-strength Portland cement to water is early-strength Portland cement/water-110°65. The above-mentioned mesh-like reinforcing material was filled into a cement matrix, and after curing in water, a cement composite material was obtained by cooling the material for 7 days. Note that the volume content of carbon fiber was 0.2%. Further, the dimensions of the test piece were 40 am x 10 C1l x 3 on, and the mesh-like reinforcement material was placed at a position of i p+)) cover 5M.

Example 2 Mesh-like reinforcement material 2 Example 1 except for filling with ply
A cement composite material was prepared in the same manner. Note that the volume content of carbon fiber was 0.4%.

Comparative Example 1 A cement material was produced in the same manner as in Example 1 without being filled with mesh-like reinforcing material.

Comparative Example 2 The carbon fibers used in Example 1 were interwoven as shown in FIG. 2 to produce a mesh-like knitted fabric with a mesh spacing of 16 squares. Next, resin was impregnated in the same manner as in Example 1 to obtain a mesh-like reinforcing material, and 1 ply of the reinforcing material was filled in cement to obtain a cement composite material. Note that the volume content of carbon fiber was 0.2%.

Then, the test pieces obtained in each example and comparative example were subjected to a four-point bending test with a span distance of 303 and a load divided into three equal parts at the upper support point 10C11. Furthermore, the adhesive strength at the intersection of the mesh-like reinforcing materials obtained in each Example and Comparative Example 2 was measured by a tensile test method. The results are shown in the table.

(Hereinafter, blank space) As is clear from the table, the mesh-like reinforcing material used in Examples has significantly greater bending strength, flexibility, and intersection adhesive strength than those in Comparative Example 2, and even a small amount can improve reinforcing properties. I was able to do that.

[Brief explanation of drawings]

FIG. 1 is an organization chart showing an example of the patterned weave structure of the present invention, and FIG. 2 is an organization chart showing an entwined weave structure of a conventional reinforcing material.

Claims (1)

[Claims] 1. The reinforcing fibers are organized into a mesh-like patterned structure,
A concrete reinforcing material characterized by being integrated with resin. 2. The concrete reinforcing material according to claim 1, wherein the reinforcing fibers are carbon fibers.