JP2872282B2 - Carbon fiber reinforcing material, method for producing the same, and hydraulic composite material using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a net-shaped hydraulic composite material using carbon fibers used for reinforcing a lightweight and high-strength hardened cement or other hydraulic materials. The present invention relates to a reinforcing material for use, a method for producing the same, and a hydraulic composite material using the same.

[Conventional technology]

Conventionally, asbestos, steel fibers, glass fibers, and the like have been used as fiber reinforcing materials for cement products.

However, asbestos may be restricted in its use due to health concerns. Steel fibers and glass fibers also have a problem from the viewpoint of durability.

Therefore, in recent years, various fibers that are excellent in physical properties such as strength and durability have been used as reinforcing materials for hardened cement.

[Problems to be solved by the invention]

These fibers include carbon fiber, Kepler fiber, vinylon, and the like, but their practical use still has problems.

A common problem is achieving effective fiber reinforcement,
And how efficiently the cement composite can be manufactured. For example, long fibers are mechanically more advantageous than short fibers in terms of the reinforcing effect of a hardened cement body, but a long fiber makes the method of manufacturing a cement composite difficult. For this reason, when manufacturing a hardened cement body reinforced with long fibers, it is generally considered to use a woven fabric or net made of long fibers.

On the other hand, carbon fibers have a small average diameter of about 10 μm, and thus a number of fibers bundled with a synthetic resin is used.

However, since the elongation limit of a single carbon fiber is small, the phenomenon that the fiber is partially cut by the action of friction and local stress during the fabric formation is often seen. For this reason, various considerations are required at the stage of forming a net-like or woven fabric, and there are problems such as an increase in the number of manufacturing steps and an increase in cost.

However, when carbon fiber is used as a reinforcing material in the form of a lattice-like fabric, a process of fabricating the fabric and a process of impregnating with a synthetic resin after the production of the fiber are required, and the process spans different industries. Processing is forced. For this reason, processing costs are added in addition to the originally expensive materials, which is a problem for practical use.

The present invention has been made in order to solve such a conventional problem, and its object is to provide a net-like carbon fiber by a simple means and sufficiently exert a reinforcing effect on a hydraulic material. It is intended to provide a carbon fiber reinforcing material, a method for producing the same, and a hydraulic composite material using the same.

[Means for solving the problem]

The reinforcing material made of carbon fiber according to claim 1, is made of a net formed by impregnating a unidirectionally oriented carbon fiber with a synthetic resin, and the net is a slit inserted in parallel with the orientation direction of the carbon fiber. The one that is hardened to open.

In the method for producing a carbon fiber reinforcing material according to claim 2, a carbon fiber is oriented in one direction and a synthetic resin is impregnated to form a sheet material. Then, after the sheet material is opened in a direction perpendicular to the orientation direction of the carbon fibers to form a net, the sheet material is cured.

A hydraulic composite material according to a third aspect is constituted by the carbon fiber reinforcing material according to the first aspect and a hydraulic material.

[Action]

In the method for manufacturing a carbon fiber reinforcing material according to the first aspect and the method for manufacturing a carbon fiber reinforcing material according to the second aspect, a carbon fiber oriented unidirectionally at an uncured stage is impregnated with a synthetic resin. Since a slit is formed in the object and the slit is opened, a two-dimensional or three-dimensional net can be formed.

Further, in the hydraulic composite material according to the third aspect, since the carbon fiber reinforcing material is a two-dimensional or three-dimensional network material, the hydraulic material adheres to the surface of the network material and is contained in the mesh. Can be charged.

〔Example〕

 Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows a carbon fiber reinforcing material 10 according to one embodiment of the present invention.
Is shown.

As shown in FIG. 4, the carbon fiber reinforcing material 10 is formed on an uncured sheet 13 in which carbon fibers 11 oriented in one direction are impregnated with a synthetic resin 12 in parallel with the orientation direction of the carbon fibers 11, as shown in FIG. After a slit 14 is provided in a pattern and the slit 14 is formed into an open mesh, the mesh 14 is formed by a mesh 15 as shown in FIGS. 1 and 2 which is cured by a desired means.

The mesh 15 has a mesh shape in which the meshes 16 are opened in a plane or a mesh shape in which the meshes 16 are opened three-dimensionally as shown in FIG.

Next, a method of manufacturing the carbon fiber reinforcing member 10 will be described in detail with reference to FIG.

First, continuous fibers 11 of carbon fibers produced by firing polynitroacryl are made into fiber bundles 21 oriented in a certain width in the same direction while first passing through several rollers 20.

Next, the fiber bundle 21 is passed through a container 22 containing a liquid binding synthetic resin. As a result, as shown in FIG. 6, the synthetic resin 12 is made to permeate into the fiber bundle 21 to produce a sheet 13 which is a so-called sheet-like intermediate (prepreg sheet).

Next, while controlling the temperature of the sheet 13 in order to control the viscosity of the permeated synthetic resin 12, the sheet 13 is moved between rollers 23 in which slits 24 such as pins or thin blades are arranged in a slit pattern. By passing
As shown in FIG. 4, a slit 14 is formed in the sheet 13.

Thereafter, the sheet 13 is passed through several rollers 25 while applying a lateral load as indicated by an arrow to form a net.

Finally, the synthetic resin 12 to which the carbon fibers are bonded is cured to obtain a final product as shown in FIG.

Here, as the synthetic resin 12 for bonding the carbon fibers (monofilaments), many types can be used, and a typical example is an epoxy resin which is a thermosetting resin. When an epoxy resin is used, the sheet-like intermediate 26 is processed into a net shape, and then subjected to a heat treatment (usually at 80 to 120 ° C.) to produce a hardened net-shaped carbon fiber reinforcing material 10. Can be. In addition, a thermoplastic resin such as a polyester resin can be used. In this case, the curing treatment is performed by adding a curing agent and a catalyst.

The mesh structure of the mesh 15 is determined by the spacing and length of the slits 14, the pattern, and the magnification when the slits 14 are opened in the horizontal direction, and the pattern is selected according to the purpose of the hydraulic composite material in which it is used. .

Further, in the case of using as a single-layer sheet in the curing process, by performing a curing process such as heat treatment as it is, the synthetic resin 12 is cured, and the net-like material can have a structure having a stable shape.

As described above, according to the present embodiment, the carbon fiber reinforcing material 10
In the uncured stage, slits 14 are provided in the sheet 13 in parallel with the orientation direction of the carbon fibers 11, and the slits 14 are opened by using the slits 14. Can be. In addition, when the slits 14 are opened to form a net, the carbon fibers 11 are oriented in a wavy shape and form a net connected to each other in the lateral direction, so that there is no possibility that the carbon fibers 11 are cut. Furthermore, since it is cured thereafter, it can exhibit the same function as a composite material of ordinary carbon fiber and synthetic resin.

Further, in this embodiment, these manufacturing processes can be industrially achieved by a consistent system, and this is a more rational method for manufacturing a reinforcing material.

7 and 8 show an example of a hydraulic composite material 40 using the carbon fiber reinforcing material 10. FIG.

The case where the carbon fiber reinforcing member 10 is formed of a two-dimensional net (FIG. 7) and the case where the carbon fiber reinforcing member 10 is formed of a three-dimensional net (FIG. 8)
Even if it is a figure), the hydraulic material 41 adheres to the surface 17 of the carbon fiber reinforcing material 10, and the hydraulic material 41
Are filled, and are continuous with the hydraulic material 41 that is in close contact with the surface 17.

As described above, since the carbon fiber reinforcing material 10 is a mesh, the hydraulic material 41 such as cement can easily penetrate between the fibers, and by setting the fiber arrangement interval such that the adhesion property can be enhanced, Good mechanical adhesion can be provided, and the reinforced hydraulic composite material 40 can exhibit mechanically excellent performance.

Next, using a mortar having the composition shown in Table 1, a pure tensile test was performed on the carbon fiber reinforcing material 10 shown in FIG. 1 and a cement board reinforced with a lattice-like woven carbon fiber.

The volume ratio of the reinforcing fibers was about 5.2% in each of the test pieces. Table 2 shows the maximum load and the average crack width.

As shown in Table 2, there is no significant difference in the strength if the amount of carbon fiber in the reinforcing direction in the cement board is basically the same volume ratio.

However, in the present embodiment, since the adhesive force between the fiber and cement in the carbon fiber reinforced cement board can be increased,
Finer cracks are dispersed. Such characteristics are considered to be more preferable from the viewpoint of utilizing the composite.

FIG. 9 shows the stress-strain relationship between the two specimens at the time of a tensile load. In FIG. 9, A represents this embodiment, and B represents a comparative example. As is clear from FIG. 9, all the specimens A and B have completely the same line up to 10 MPa where the matrix cracks, but the shapes of the curves are slightly different at the stage when the matrix cracks. . This is presumably because the orientation of the carbon fibers became reticulated, thereby improving the adhesion between the carbon fibers and the cement matrix. Thereafter, in the range up to the stress of 15 MPa or more and leading to fracture, since the carbon fibers in the composite resist the load, the stress increases linearly with respect to the strain, leading to fracture.

Judging from these results, according to the present example, it is possible to manufacture a composite material having excellent mechanical properties.

The hydraulic composite material according to the present invention can be used for concrete products that require light weight and high strength, such as interior and exterior materials for buildings, secondary structural members, and permanent molds. .

〔The invention's effect〕

As described above, the carbon fiber reinforcing material according to claim 1 is made of a net formed by impregnating a unidirectionally oriented carbon fiber with a synthetic resin, and the net is parallel to the orientation direction of the carbon fiber. Since the slit is inserted and cured, a desired net shape can be obtained. Thus also,
When the slit is opened to form a net, the carbon fibers are oriented in a wavy shape and form a net connected to each other in a lateral direction, so that there is no possibility that the carbon fibers are cut. In addition, it will be cured afterwards. The same function as a composite material of ordinary carbon fiber and synthetic resin can be exhibited.

The method for producing a carbon fiber reinforcing material according to claim 2 is
The carbon fiber is oriented in one direction and impregnated with a synthetic resin to form a sheet material, a slit is formed in the sheet material in parallel with the direction of orientation of the carbon fiber, and then the sheet material is subjected to Since the sheet material is cured after being opened in a direction perpendicular to the orientation direction to form a net, the final reinforcing material can be manufactured by a consistent system. Therefore, the cost can be significantly reduced as compared with the conventional grid-like reinforcing material.

Furthermore, since the hydraulic composite material according to claim 3 is composed of the carbon fiber reinforcing material according to claim 1 and a hydraulic material, the hydraulic material is a net-like carbon fiber reinforcing material. As well as adhering to the surface, it can fill the mesh and provide good mechanical adhesion between the two. Therefore, the reinforced hydraulic composite material exhibits mechanically excellent performance.

[Brief description of the drawings]

FIG. 1 is an enlarged plan view showing a carbon fiber reinforcing material according to an embodiment of the present invention. FIG. 2 is an enlarged perspective view showing a portion II in FIG. FIG. 3 is a side view taken along the line III-III in FIG. FIG. 4 is a plan view of a sheet provided with slits in an uncured stage. FIG. 5 is an explanatory view showing steps of a method for producing a carbon fiber reinforcing material according to an example of the present invention. FIG. 6 is a sectional view showing an uncured sheet in which a fiber bundle is impregnated with a synthetic resin. FIG. 7 is a sectional view showing an example of a hydraulic composite material according to an example of the present invention. FIG. 8 is a sectional view showing another example of the hydraulic composite material according to the embodiment of the present invention. FIG. 9 is a graph showing the stress-strain relationship between the hydraulic composite material according to the present invention and the conventional example when a tensile load is applied. [Explanation of Signs of Main Parts] 10… Carbon fiber reinforcing material 11… Carbon fiber 12… Synthetic resin 13… Sheet 14… Slit 15… Mesh 16… Mesh 17… Surface 40… … Hydraulic composite material 41 …… Hydraulic material.

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Kunio Yanagihashi 2-5-1-14 Minamisuna, Koto-ku, Tokyo Inside Takenaka Corporation Technical Research Institute (56) References JP-A-63-22636 (JP, A) ( 58) Fields surveyed (Int. Cl. ⁶ , DB name) C04B 32/00 C04B 28/04

Claims (3)

(57) [Claims] 1. A net formed by impregnating carbon fibers oriented in one direction with a synthetic resin, and the net is hardened by opening slits inserted in parallel with the orientation direction of the carbon fibers. A reinforcing material made of carbon fiber, characterized in that: 2. A sheet material is formed by orienting carbon fibers in one direction and impregnated with a synthetic resin, and a slit is formed in the sheet material in parallel with the direction of orientation of the carbon fibers. After opening the sheet material in a direction orthogonal to the orientation direction of the carbon fibers to form a net, and then curing the sheet material. 3. A hydraulic composite material comprising the carbon fiber reinforcing material according to claim 1 and a hydraulic material.