JP2003253562A - Reinforcing fiber, method for producing the same and concrete material reinforced by the same fiber - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reinforcing fiber remarkably improving reinforcing effect by fiber, capable of providing uniform fresh concreted, not impairing workability of kneading, etc., and to provide a concrete material reinforced by the fiber. <P>SOLUTION: The concrete material is reinforced by a reinforcing fiber obtained by fixing a silane coupling agent and/or a titanium coupling agent and a water-soluble polymer to the fiber surface. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a reinforcing fiber, a method for producing the same, and a concrete material reinforced by the fiber.

[0002]

2. Description of the Related Art In recent years, the mechanical properties of concrete materials,
In particular, it is known to use various types of short fibers or fibrous structures such as meshes as a reinforcing material for the purpose of improving bending strength, tensile strength, impact strength and the like.

The inventors of the present invention first disclosed in Japanese Patent Laid-Open No. 2002-2002.
In JP-A-20152, when kneading reinforcing fibers into fresh concrete, a method of improving the reinforcing effect of fibers by mixing a silane coupling agent and / or a titanate coupling agent with the fresh concrete was proposed.

However, in the above method, since the silane coupling agent and / or the titanate coupling agent are spread over the entire concrete, it is difficult to obtain a reinforcing effect commensurate with the mixing amount of the agent, and the reinforcing effect is satisfactory in practical use. In order to obtain the above, it is necessary to mix a large amount of silane coupling agent and / or titanate coupling agent, resulting in high cost, and if the mixing amount of the agent is too large, solid content and water are separated during kneading. Therefore, there is a problem that uniform fresh concrete cannot be obtained.

[0005]

SUMMARY OF THE INVENTION The object of the present invention is to solve the above-mentioned problems of the prior art, to remarkably improve the reinforcing effect of fibers, and to make the fresh concrete uniform and impair the workability such as kneading. It is an object of the present invention to provide a reinforcing fiber, a method for producing the same, and a concrete material reinforced by the fiber.

[0006]

Means for Solving the Problems As a result of intensive studies for achieving the above object, the present inventors have found that the reinforcing fiber itself is surface-treated with a silane coupling agent and / or a titanium coupling agent, and at the It was clarified that a desired reinforcing fiber can be obtained when a hydrophilic polymer is used in combination, and the present invention has been completed.

Thus, according to the present invention, (1) a reinforcing fiber characterized in that a silane coupling agent and / or a titanium coupling agent and a water-soluble polymer are fixed to the surface of the fiber, (2) ) When the fiber is treated with a silane coupling agent and / or a titanium coupling agent to obtain a reinforcing fiber, a water-soluble polymer is added to the silane coupling agent and / or the titanium coupling agent. A method for producing a reinforcing fiber, and (3) a concrete material reinforced with the reinforcing fiber, wherein the reinforcing fiber is the reinforcing fiber according to (1) above. .

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The fibers used in the present invention may be either organic fibers or inorganic fibers. Examples of the organic fiber include polyester fiber, nylon fiber, vinylon fiber, aramid fiber, polyarylate fiber, polyethylene fiber, polypropylene fiber, polyparaphenylene benzobisoxazole fiber and the like. Further, as the inorganic fiber, carbon fiber, glass fiber, steel fiber, ceramic fiber and the like can be mentioned, and any fiber can be used. These fibers may be used alone or in combination.

Above all, it is preferable to use aramid fiber or carbon fiber. Para-aramid fiber in particular, strength,
Not only has a high modulus, but also has a large toughness, so the reinforcing effect is excellent. Among the para-aramid fibers, the use of copolyparaphenylene-3,4'-oxydiphenylene terephthalamide fiber, which is remarkably excellent in strength, chemical resistance, and moist-heat resistance, further enhances the reinforcing effect. Especially when autoclave curing is performed under high temperature and high pressure, copolyparaphenylene.3,4'-oxydiphenylene terephthalamide fiber having excellent chemical resistance is advantageous.

The form of the above fibers is preferably short fibers kneaded with concrete or the like. The short fiber is a long fiber cut to an appropriate length, and the length is 1 m.
It is preferably m or more and 60 mm or less in terms of handleability of fresh concrete and reinforcing effect of the concrete material. The timing of cutting may be before, during, or after treatment with a silane (titanium) coupling agent described below. The fresh concrete refers to concrete that has fluidity before being kneaded and hardened.

The silane coupling agent used in the present invention is a compound having a hydrolyzable alkoxy group (RO-) and an organic functional group (X) in one molecule as shown by the following formula. In the following formula, RO- is specifically C
_{H 3 O-, C 2 H 5} O-, CH 3 OC 2 H 4 O- represent like,
After hydrolysis, it produces silanol or titanol groups. X- is a vinyl group, an epoxy group, a methcapto group, an acryl group, an amino group or the like.

[0012]

[Chemical 1]

In the above compound, since the silanol group is hydrophilic and the organic functional group is lipophilic, it has different polar groups in the same molecule, and the silanol group can also undergo a cross-linking reaction. Improves interfacial adhesion between fibers and concrete matrix in concrete materials. Furthermore, because it has different polar groups, it behaves like a surfactant in fresh concrete, and it disperses the cement particles by adsorbing them on the surface of hydrophobic cement particles and changing them to hydrophilic, resulting in In addition, the fluidity of fresh concrete is improved.

Specific examples of the above compounds include 3-aminopropyltriethoxysilane and 3-glycidopropylmethoxysilane.

The titanium coupling agent used in the present invention includes isopropyl triisostearoyl titanate, isopropyl tristearoyl titanate, or isopropyl tri (dibutylpyrophosphate).
Examples include titanate and the like.

The water-soluble polymer used in the present invention means a water-soluble polymer material, specifically, polyvinyl alcohol-based polymer, polyethylene glycol-based polymer or oligomer, polyacrylic acid-based polymer, Alternatively, it is a natural polymer such as a starch-based polymer and may have a partially cross-linked structure in order to adjust the degree of water solubility, the time of water solubility, and the like.

In the present invention, when the above fiber is treated with a silane coupling agent and / or a titanium coupling agent to obtain a reinforcing fiber, the above water-soluble property is contained in the silane coupling agent and / or the titanium coupling agent. Add polymer.

The term "treatment" as used herein means that the fibers are dipped in a solution or dispersion containing a silane coupling agent and / or a titanium coupling agent and then dried, or a silane coupling agent and / or a titanium coupling agent. A solution or dispersion containing an agent is attached to the fiber by a spray method or the like and then dried to fix the silane coupling agent and / or the titanium coupling agent to the surface of the fiber.

The amount of the silane coupling agent or titanium coupling agent adhered to the fibers is preferably 0.1% by weight or more, and 1.0% by weight based on the weight of the fibers.
It is more preferable that the above is satisfied. If the adhered amount is less than 0.1% by weight, a sufficient reinforcing effect cannot be obtained, and the effect of lowering the fluidity of fresh concrete may be insufficient.

The amount of the water-soluble polymer fixed to the fibers is preferably 1 to 25% by weight based on the weight of the fibers. That is, the above water-soluble polymer is added to the silane coupling agent and / or the titanium coupling agent,
The purpose of fixing to the fiber is to prevent the silane (titanium) coupling agent, which is effective in improving the adhesiveness, from unnecessarily diffusing into the matrix from the fiber surface when kneading the reinforcing fiber and the matrix concrete when creating fresh concrete. Therefore, if the fixed amount is less than 1% by weight, the silane (titanium) coupling agent diffuses too much, and the reinforcing effect may be insufficient.

On the other hand, if the fixed amount exceeds 25% by weight, the diffusion of the silane (titanium) coupling agent may be too small and the effect of improving the fluidity of fresh concrete may not be obtained.

The fibers obtained by the above method can be suitably used as reinforcing fibers for concrete materials. here,
The concrete material refers to a mixture obtained by binding and molding an aggregate with an inorganic or organic binding material, and a hardened body thereof.

The above concrete materials can be classified according to the kind of the binder. For example, when the binder is inorganic, cement concrete using cement as the binder, lime concrete using limes as the binder, and further , Gypsum concrete, sulfur concrete and the like. When the binder is a mixture of an inorganic substance and an organic substance, polymer cement concrete, polymer-impregnated concrete and the like can be mentioned. Furthermore, examples of organic binders include resin concrete and the like, and any of them can be used in the present invention.

Furthermore, it is possible to apply the above-mentioned reinforcing fiber to a system that does not use aggregate at all, for example, a hardened body of only cement.

[0025]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to the description. The method for producing the test pieces used in the examples and the method for evaluating the physical properties are as follows.

(1-a) Fiber treatment method a: pre-treatment cut Short fibers previously cut to a predetermined cut length are immersed in a treatment liquid and then filtered, and the chamber temperature is kept at 105 ° C.
It was dried in the dryer.

(1-b) Fiber treatment method b: During the treatment, several continuous cut fiber bundles are bundled and immersed in the treatment liquid, and then cut to a predetermined cut length with a guillotine cutter, and the chamber temperature is 105 ° C. It was dried in the dryer.

(1-c) Fiber Treatment Method c: Post-Treatment Cut The continuous fiber bundle is passed through a dip bath filled with a treatment liquid and then in a dryer at 105 ° C. to cut the treated fiber into predetermined pieces. I cut it into long pieces.

(2) Method for producing concrete material (mortar) Ordinary Portland cement, ISO sand, methyl cellulose, 5% by weight of reinforcing fiber obtained by any of the methods described in 1-a to 1-c, and water, Omni mixer (Model: OM
-10-E, capacity: 10 L, manufactured by GARBRO) was mixed at a speed of 400 rpm for about 6 minutes (water / cement = 0.45, and sand / cement = 0.5).

Form the fresh concrete into a form (4 × 4
(16 cm), and after curing in air at room temperature for 28 days, the bending strength was measured.

(3) Measurement of flow value showing fluidity of fresh concrete A mini slump cone (15 cm in height, 10 cm in inside diameter, 5 cm in inside diameter) is placed on a horizontally arranged 50 cm square aluminum plate.
Pour the fresh concrete into the conical column with the inside of m hollowed out and stand it on an aluminum plate, and then slowly pull up the mini slump cone vertically. The fresh concrete at this time spreads in a circle on the aluminum plate. The diameter of the expanded circle at this time, or if the circle is distorted, the flow value is the arithmetic mean of the shortest diameter and the longest diameter.

It is judged that the larger the flow value, the higher the fluidity of fresh concrete and the better the handling. However, the longest diameter is within the range of 1 to 2 times the shortest diameter, and if it exceeds 2 times, it is judged that measurement is impossible and handleability is poor.

(4) Measurement of bending strength The bending strength was measured by centralized load. That is, 10ton tensile / compression tester (UNIVERS
AL TESTING INSTRUMENT MODE
L UTM 10t, manufactured by TOYO BALDWIN)
The center of the sample with a fulcrum distance of 10 cm by 2 mm / m
It was compressed at a speed of in and the bending strength was determined from the highest point of stress.

(5) Calculation of Bending Strength Improvement Rate The bending strength St of the concrete material measured by the method (4) above and the bending of the concrete material when the silane (titanium) coupling agent is not fixed to the reinforcing fiber Each strength Su was measured and calculated by the following formula.

[0035]

[Equation 1]

[Examples 1 to 12] As cut fibers, aramid fiber "Technora"(polyparaphenylene.3,4'-oxydiphenylene terephthalamide fiber) manufactured by Teijin Limited, PAN manufactured by Toho Rayon Co., Ltd. Carbon-based carbon fiber "Vesfight" or vinylon fiber "Muron" manufactured by Unitika Ltd. was used.

Using the silane coupling agent and the water-soluble polymer shown in Table 1, the fiber obtained by the method described in any one of (1-a) to (1-c) above is used as a reinforcing fiber in the above (2). A concrete material was obtained by the method.

Table 1 shows the amounts of the silane coupling agent and the water-soluble polymer fixed to the reinforcing fiber. Table 2 shows the flow value of fresh concrete and the bending strength and bending strength improvement rate of the obtained concrete material.

Comparative Example 1 The procedure of Example 1 was repeated, except that the silane coupling agent was not used. Table 1 shows the amounts of the silane coupling agent and the water-soluble polymer fixed to the reinforcing fiber. Table 2 shows the flow value of fresh concrete and the bending strength and bending strength improvement rate of the obtained concrete material.

Comparative Example 2 The procedure of Example 1 was repeated, except that the water-soluble resin was not used.
Table 1 shows the amounts of the silane coupling agent and the water-soluble polymer fixed to the reinforcing fiber. Table 2 shows the flow value of fresh concrete and the bending strength and bending strength improvement rate of the obtained concrete material.

Comparative Example 3 The procedure of Example 10 was repeated except that the silane coupling agent was not used. Table 1 shows the amounts of the silane coupling agent and the water-soluble polymer fixed to the reinforcing fiber. Table 2 shows the flow value of fresh concrete and the bending strength and bending strength improvement rate of the obtained concrete material.

[Comparative Example 4] The procedure of Example 11 was repeated except that the silane coupling agent was not used. Table 1 shows the amounts of the silane coupling agent and the water-soluble polymer fixed to the reinforcing fiber. Table 2 shows the flow value of fresh concrete and the bending strength and bending strength improvement rate of the obtained concrete material.

Comparative Example 5 The procedure of Example 12 was repeated, except that the silane coupling agent was not used. Table 1 shows the amounts of the silane coupling agent and the water-soluble polymer fixed to the reinforcing fiber. Table 2 shows the flow value of fresh concrete and the bending strength and bending strength improvement rate of the obtained concrete material.

[Comparative Example 6] Ordinary Portland cement,
Omni sand (model: OM-10-E, capacity: 10) with ISO sand, methyl cellulose, cut fiber, and water.
L, manufactured by GARBRO) and kneaded at a speed of 400 rpm for about 3 minutes to temporarily stop the omni mixer and
After adding the silane coupling agent shown in (1), the omni mixer was operated again and the mixture was further kneaded for 3 minutes under the same conditions (water / cement = 0.45 and sand / cement = 0.50).
5).

Form the fresh concrete into a formwork (4 × 4
(16 cm), and after curing in air at room temperature for 28 days, the bending strength was measured.

Table 1 shows the amount of the silane coupling agent added to the fresh concrete. Table 2 shows the flow value of fresh concrete and the bending strength and bending strength improvement rate of the obtained concrete material.

[Comparative Example 7] Comparative Example 7 was carried out in the same manner as Comparative Example 7 except that the addition amount of the silane coupling agent to the fresh concrete was changed as shown in Table 1. Table 2 shows the flow value of fresh concrete, the bending strength of the obtained concrete material, and the bending strength improvement rate.

[0048]

[Table 1]

[0049]

[Table 2]

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) D06M 15/11 D06M 15/11 15/263 15/263 15/333 15/333 15/53 15/53 F Term (reference) 4G012 PA20 PA24 4L033 AA08 AA09 AB01 AC11 AC15 BA95 BA96 CA06 CA18 CA29 CA48

Claims (17)

[Claims] 1. A reinforcing fiber, characterized in that a silane coupling agent and / or a titanium coupling agent and a water-soluble polymer are fixed to the surface of the fiber. 2. The reinforcing fiber according to claim 1, wherein the fiber is a short fiber. 3. The amount of silane coupling agent and / or titanium coupling agent adhered to the fiber weight is 0.
The reinforcing fiber according to claim 1, which is 1% by weight or more. 4. The fixing amount of the water-soluble polymer is 1 to 25% by weight based on the weight of the fiber.
The reinforcing fiber according to the item. 5. The reinforcing fiber according to claim 1, wherein the water-soluble polymer is a polyvinyl alcohol-based polymer. 6. The reinforcing fiber according to claim 1, wherein the water-soluble polymer is a polyacrylic acid-based polymer. 7. The reinforcing fiber according to claim 1, wherein the water-soluble polymer is a polyethylene glycol-based polymer. 8. The reinforcing fiber according to claim 1, wherein the water-soluble polymer is a starch-based polymer. 9. The tensile strength of the fiber is 18 cN / dte.
x or more, The reinforcing fiber according to any one of claims 1 to 8. 10. The reinforcing fiber according to claim 9, wherein the fiber is a para-aramid fiber. 11. The reinforcing fiber according to claim 10, wherein the para-aramid fiber is copolyparaphenylene · 3,4′-oxydiphenylene terephthalamide fiber. 12. The reinforcing fiber according to claim 9, wherein the fiber is a carbon fiber. 13. Fibers and / or silane coupling agents
Alternatively, when a reinforcing fiber is obtained by treating with a titanium coupling agent, a water-soluble polymer is added to the silane coupling agent and / or the titanium coupling agent. 14. The method for producing a reinforcing fiber according to claim 13, wherein the fiber is a short fiber. 15. The method for producing a reinforcing fiber according to claim 14, wherein the fiber is cut during the treatment with the silane coupling agent and / or the titanium coupling agent. 16. The method for producing a reinforcing fiber according to claim 14, wherein the fiber is cut after the treatment with the silane coupling agent and / or the titanium coupling agent. 17. A concrete material reinforced with a reinforcing fiber, wherein the reinforcing fiber is the reinforcing fiber according to any one of claims 1 to 12.