JP2001328853A - Reinforcing material for concrete, etc. - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an excellent reinforcing material for concrete, etc., capable of keeping mechanical properties in a long period and having the reinforcing effect especially against tensile strain. SOLUTION: The objective reinforcing material is a resin-coated material produced by coating the surface of a substrate having fibrous or flexible rod shape with a thermoplastic resin and/or a thermosetting resin. The resin-coated material has at least one protrusion having a length of >=4 mm and >=3 times the average diameter of the substrate excluding the protrusion.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reinforcing material for concrete and the like, and more particularly to a reinforcing material for concrete and the like which can be used for concrete and mortar materials to improve mechanical properties such as bending strength. About the material.

[0002]

2. Description of the Related Art Conventionally, inorganic fibers such as asbestos, glass fibers, steel fibers, and carbon fibers have been used to improve mechanical properties such as bending strength and impact resistance of mortar and concrete materials. . Among them, asbestos has been used for a long time, but its use has been regulated at present due to the problem of carcinogenicity. Also,
Glass fibers, even those having alkali resistance, are deteriorated by alkali in cement and it is difficult to maintain a reinforcing effect for a long period of time. Steel fibers have the problem that corrosion occurs in the concrete, which causes the concrete material to crack. Further, even if the steel fiber is subjected to rust prevention treatment, it cannot withstand corrosion for a long time, and the rust prevention treatment is costly and not useful. Carbon fibers have a problem that they are broken and shortened during the kneading process for dispersing in cement, and the required length cannot be maintained, so that the expected reinforcing effect cannot be obtained.

On the other hand, for fibers made of an organic high molecular polymer, for example, reinforcement by using vinylon fiber, polypropylene fiber, aramid fiber, etc. is effective.
It has already been put to practical use.

[0004] Specifically, "Method for producing glass fiber reinforced cement product" (JP-A-49-98424),
"Manufacturing method of fiber reinforced cement products" (JP-A-49-104)
No. 917), "Production method of heat-resistant mixed fiber reinforced cement product" (JP-A-49-104918), "Production method of lightweight cured reinforcing product" (JP-A-61-86452), and "Lightweight silicic acid". "Calcium products" (Japanese Patent Application Laid-Open No. Sho 62-171952), "Steel fiber reinforced concrete material" (Japanese Patent Application Laid-Open No. Hei 6-115988), and "Building materials made of inorganic fiber reinforced cement and methods for producing the same" (Japanese Patent Application Laid-Open No. No. 45185), glass fiber, polyester fiber,
It is taught to use vinylon fiber, polypropylene fiber, aramid fiber, acrylic fiber, steel fiber, carbon fiber and the like.

Certainly, by using these fibers for reinforcement, it is possible to improve mechanical properties such as bending strength and impact strength of materials such as concrete.
In order to sufficiently exhibit the reinforcing effect, it is important that each fiber in the concrete material is firmly bonded to the surrounding concrete. However, the above fibers are
In concrete, it deteriorates due to alkali and corrosion, causing a decrease in strength, cracking in the concrete material, etc., as well as aging and various load loads, resulting in a decrease in the bondability with the concrete interface and a reinforcing effect. Has not been fully demonstrated.

[0006]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned conventional problems and proposes a reinforcing material such as concrete having excellent mechanical properties over a long period of time. It is intended to provide a reinforcing material such as concrete which exerts a reinforcing effect on the material.

[0007]

According to the present invention, as a result of various investigations for solving the above-mentioned problems, a pull-out resistance value of a reinforcing material from concrete material is measured as a substitute characteristic for evaluating the bonding property with a concrete interface. However, when the pull-out resistance value is low, the interfacial bond with the concrete is low and the reinforcing effect is small, and the interfacial bond is easily reduced due to aging or load, and the reinforcing effect is reduced. Was found. That is, the present inventors have found that by increasing the pull-out resistance value of the reinforcing material in the concrete material, the interface bonding property between the concrete and the concrete reinforcing material is enhanced, and reached the present invention.

That is, according to the present invention, a resin-coated body in which the surface of a base material having a fibrous or flexible rod shape is coated with a thermoplastic resin and / or a thermosetting resin, The resin coating has at least one protrusion, the length is 4 mm or more, and the length excluding the protrusion is at least three times the average diameter. A reinforcing material such as concrete is provided.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
The reinforcing material such as concrete of the present invention refers to concrete made by kneading aggregates such as sand and cement and reinforced concrete mainly made of cement and containing small aggregates or containing no aggregates. Means a material that can be used for

[0010] The reinforcing material such as concrete of the present invention comprises a resin coating, and the resin coating is formed using the following base material. The base material has a fibrous or flexible rod shape, and the resin-coated body is formed by coating the surface of the base material with a thermoplastic resin and / or a thermosetting resin. . Further, it is important that the resin coating has at least one protrusion.

FIG. 1 is a side view schematically showing a resin coating used in the present invention. In FIG. 1, reference numeral 1 denotes a protrusion of the resin coating, and reference numeral 2 denotes a portion excluding the protrusion. Maximum diameter of the protrusion portion 1: d ₁ between the average diameter of the portion 2 except for the projections: the ratio of d _2: d ₁ / d ₂ is required more than 1.3 times, preferably 1.5 times or more , More preferably three times or more. If the ratio of the protrusions is less than 1.3 times, the pull-out resistance value of the resin coating cannot be sufficiently increased in the concrete material, and the effect of the present invention cannot be obtained. That is, in the present invention, the protrusion is the maximum diameter of the protrusion 1: d ₁ and the average diameter of the portion 2 excluding the protrusion:
The ratio of d ₂ : d ₁ / d ₂ satisfies 1.3 times or more
(Protrusion). For one resin coating, the number of such protrusions is required to be 1 or more, and practically preferably 2 to 5 protrusions, but more than 5 protrusions No problem. In particular, the length of the resin coating,
If it is relatively long, it may be preferable to have more than five.

The resin coating has a length of 4 mm.
The above is preferably exemplified, more preferably 10 mm or more, and particularly preferably 20 mm or more for concrete mixed with aggregate.

If the length of the resin coating is less than 4 mm, the drawing resistance cannot be sufficiently increased in the mortar or concrete material.
Alternatively, it may not function as a reinforcing material in view of the size of aggregate such as sand used in the concrete material and the size of bubbles formed in the foamed concrete, which is not preferable. When used as a reinforcing material embedded along the vertical or horizontal direction of the panel in a concrete panel or the like, a resin coating having the same length as the vertical or horizontal length of the panel is used. It can also be used as a body. Further, in order to uniformly knead and disperse the resin coating in mortar or concrete, the resin coating is used after being cut into an appropriate length. In this case, the length is 80 mm or less. Are preferably used and practical.

[0014] Regarding the relationship between the diameter of the resin-coated body having no projection and the length of the resin-coated body, the resin-coated body having a length at least three times the average diameter of the part excluding the projection is used. It is necessary that the length be four times or more.
The length of the resin coating is 3 times the average diameter of the portion excluding the protrusions.
If less than twice, the surface area per unit volume of the resin coating
(Area in contact with concrete) becomes small, and does not function sufficiently against the tensile force acting in the length direction, which is not preferable.

Next, as the base material used for the resin coating, inorganic fibers such as carbon fiber, glass fiber, ceramic fiber, and steel fiber, and aramid fiber, vinylon fiber, polypropylene fiber, polyethylene fiber, and polyarylate are used. Organic fibers such as fiber, PBO fiber, nylon fiber, polyester fiber, acrylic fiber, vinyl chloride fiber, cellulose fiber, and pulp fiber can be used.

In particular, aramid fibers have high tensile strength and chemical resistance and are light in weight, and have recently been used as reinforcing materials for thin cement plates and the like.
In other words, a thin plate obtained by adding aramid short fibers to a cement material, kneading with a ruder, and extruding the kneaded material has remarkably improved bending strength and impact resistance, and can be made thinner. Becomes Furthermore, among the aramid fibers, para-type aramid fibers are preferably exemplified.

Examples of the para-type aramid fiber include polyparaphenylene terephthalamide and copolymers such as copolyparaphenylene / 3,4'oxydiphenylene / terephthalamide fiber. In particular, when copolyparaphenylene / 3,4′-oxydiphenylene / terephthalamide fiber is used as a base material, not only the reinforcing effect is particularly excellent as compared with other fibers due to having excellent drawing properties, Since it has excellent alkali resistance, it can maintain high performance for a long time. Further, since this fiber is also excellent in alkali resistance, it can withstand autoclave curing at a temperature of about 200 ° C.

The thickness (fiber fineness) of these fibers used for the base material of the resin coating is 111.1 to 10000 d.
The range of tex (100 to 9000 de) is exemplified, but more preferably 222.2 to 3333.3 dte.
x (200 to 3000 de). However,
It is not particularly limited to this range. When the fiber yarn fineness is small, it may be preferable because the contact area with concrete is increased with respect to a certain amount mixed into the concrete. Absolute strength may be insufficient, which is not preferable. When the fiber yarn fineness is large, the absolute strength as a reinforcing fiber is sufficient, but the contact area decreases with respect to a certain amount to be mixed (the number of fibers decreases), and the reinforcing efficiency decreases, which is not preferable. . In addition, the cross section orthogonal to the length direction of these fibers may be a normal circular shape, a rectangular shape, a flat shape, or any other cross-sectional shape. Are preferred for handling.

The resin used for the reinforcing material such as concrete of the present invention is not particularly limited as long as it is an alkali-resistant thermoplastic resin and / or a thermosetting resin. Thermosetting resins such as epoxy resins, vinyl ester resins, phenolic resins, polyurethane resins, melamine resins, formaldehyde resins, and fluoropolymer resins are used. Among them, epoxy resins and vinyl ester resins are used. Particularly preferably used. These resins can be applied to the surface of the fiber as a substrate by a dipping method or a spraying method, and can be dried and heat-treated as necessary to obtain a resin-coated body.

The resin coating used in the present invention comprises:
As described above, at least one projection is provided. As a method for forming such a projection, a base material on which a projection is previously formed can be used. As the resin is applied to the surface of the base fiber and dried, the resin is condensed into a spherical shape by utilizing the property of condensing due to the surface tension of the resin, and the spherical condensed portion (this is a projection portion) May be formed along the length direction of the fiber.

In order to condense the resin into a spherical shape as described above, an appropriate amount (depending on the resin, for example, in the case of aramid fiber, the weight ratio of the substrate) is adjusted by adjusting the concentration and the amount of the resin used. 60 to 250% by weight) and drying or curing the resin.

The substrate having its surface provided with the resin in this manner is cut into a predetermined length to form a resin coating having at least one projection. That is, the resin-coated substrate becomes a fibrous thread-like (short fiber) resin-coated body, but is a thermosetting resin, and / or a flexible rod-shaped resin coated with a thermoplastic resin. Some are obtained as pieces. In addition, the shape of the projection is mostly formed in a spherical shape, but may be another shape. The spherical shape is preferably used as a reinforcing material for concrete or the like in a form in which the fiber core passes through the central portion.

[0023]

As described above, according to the present invention, the presence of the protrusions formed on the resin coating increases the pull-out resistance in the concrete material, so that the resin coating can be used as a reinforcing material such as concrete. It is possible to provide an excellent reinforcing material that can enhance the bonding property with concrete.

Further, when carbon fibers are used as the base material of the resin-coated body used in the present invention, it is possible to solve the conventional problems. That is, in the reinforcing material using carbon fiber alone, there was a problem of breaking during the kneading process for dispersing in concrete, but in the present invention, the resin coating not only reduced this problem, but also broke. However, the problem that the reinforcing effect is reduced due to the presence of the projections can be reduced.

On the other hand, when glass fiber is used as the base material of the resin-coated body used in the present invention, there has been a problem that the glass fiber is conventionally deteriorated by the alkali in the cement as described above. Alkali resistant resin coatings can reduce this problem. That is, in the case of using an epoxy resin or a vinyl ester resin as the coating resin, these resins also have alkali resistance and rust resistance. And a long-term reinforcing effect can be exhibited.

When the aramid fiber is used as the base material of the resin coating used in the present invention, it has high tensile strength and chemical resistance and is lightweight, so that it is useful as a concrete reinforcing material. . Among the aramid fibers, when para-aramid fibers, particularly copolyparaphenylene / 3,4'oxydiphenylene / terephthalamide fibers, are used, they have not only excellent chemical resistance but also excellent pull-out strength. Therefore, the thickness of the base material can be reduced, and the contact area with the concrete can be increased, so that the bonding force with the concrete increases and the reinforcing effect can be further increased.

[0027]

The concrete using the reinforcing material such as concrete is used not only for ordinary concrete but also for use in the construction for preventing the outflow of sediment on the slope by spraying the concrete on the glued surface of the slope. It has an excellent effect when spraying ceilings and walls of tunnels and tunnels.

Conventionally, fiber or rod-shaped steel pieces have been used as concrete reinforcing materials used in such construction, but those using steel pieces are generated during long-term use. In addition to the problem of rust, the steel pieces are scattered during the spraying work, which is dangerous.In addition, the tip of the steel piece protrudes from the surface of the concrete after the spraying work is completed, and the projecting pieces are treated as extremely dangerous. I needed to. In the case of using the reinforcing material of the present invention, the reinforcing effect can be maintained for a long time without such a problem.

[0029]

The present invention will be described in more detail with reference to the following examples. The measurement values used in the examples were based on the following measurement methods.

(1) Strength for pulling out reinforcing material (N / piece) When mortar made of Portland cement is poured onto an aluminum plate so as to have a thickness of 15 mm, the mortar is perpendicular to the surface of the aluminum plate. A test piece in which a reinforcing material serving as a sample was embedded along the direction was prepared, and a head speed: 20 was obtained using the test piece by a normal constant-speed tensile tester.
A tensile test is performed under the condition of mm / min to measure the pulling strength.

(2) Concrete bending strength Tensile compression tester for 10 tons capacity (Universal Testing I)
nstrument Model UTM 10-ton Toyo Baldwwin Co
Using a test piece (4 cm x 4 cm x 16 c
m), a point at a distance of 10 cm from the fulcrum was compressed at 2 mm / min, and the bending strength was determined from the highest stress point. The test piece was composed of 1174 g of early-strength Portland cement, 5.9 g of a reinforcing material used for the test,
After pouring 493 g of water into an omni-mixer, adding 11.7 g of methylcellulose as a viscosity agent, and adding 400 rpm.
After kneading for 5 minutes under the condition of m, the mold (4 cm × 4 c
mx 16 cm), and the cement and the composite material are cured at room temperature for one month to prepare test pieces.

Example 1 Aramid fiber, copolyparaphenylene / 3,4'oxydiphenylene terephthalamide fiber (Tecjin Corp., "Technola", 1666.7 dtex (1500 de) Using)), the resin was immersed in a vinyl ester resin to adhere so that the amount of the vinyl ester resin attached was 150% by weight, and dried at a temperature of 170 ° C. The obtained resin-coated aramid fiber has a large number of protrusions formed of resin, and these protrusions have a maximum diameter of the protrusions: d ₁ and an average diameter of a portion excluding the protrusions: d. Ratio with ₂ : d
Those having a ratio of ₁ / d ₂ of 1.3 times or more accounted for 90% or more.

The resin coating having such projections is
It was cut to a length of 0 mm to obtain a resin-coated body. The obtained resin-coated body had 4.1 projections on average. Using the resin-coated body as a concrete reinforcing material, a test concrete was prepared by the method described in the above (1) and (2), and the pull-out strength of the reinforcing material and the concrete bending strength were tested. Table 1 shows the test results.
Shown in

Example 2 Instead of the aramid fiber used in Example 1, vinylon fiber (manufactured by Kuraray Co., Ltd., 1
Except for using 333.3 dtex (1200 de), the same procedure as in Example 1 was carried out to obtain a reinforcing material such as concrete made of a resin coating. Table 1 also shows the results of evaluation of the reinforcing material such as concrete in the same manner as in Example 1.

[Example 3] Instead of the aramid fiber used in Example 1, polyethylene fiber (Toyobo Co., Ltd.)
1333.3 dtex (1200 de), and the drying temperature was further reduced to 90 ° C., except that the drying was performed in the same manner as in Example 1 to obtain a reinforcing material such as concrete made of a resin-coated body. Table 1 also shows the results of evaluation of the reinforcing material such as concrete in the same manner as in Example 1.

Example 4 Polyester (polyethylene terephthalate) fiber (manufactured by Teijin Limited, 1111.1 dtex) was used in place of the aramid fiber used in Example 1.
(1000 de)), except that a reinforcing material such as concrete made of a resin coating was obtained in the same manner as in Example 1. Table 1 also shows the results of evaluation of the reinforcing material such as concrete in the same manner as in Example 1.

Example 5 Instead of the aramid fiber used in Example 1, PBO fiber (produced by Toyobo Co., Ltd., 11
Except that 11.1 dtex (1000 de) was used, the same procedure as in Example 1 was carried out to obtain a reinforcing material such as concrete made of a resin-coated body. Table 1 also shows the results of evaluation of the reinforcing material such as concrete in the same manner as in Example 1.

Example 6 Instead of the aramid fiber used in Example 1, a commercially available glass fiber (1350 dtex (about 1215 de), manufactured by Fuji Fiberglass Co., Ltd.)
In the same manner as in Example 1 except for using, a reinforcing material such as concrete made of a resin-coated body was obtained. Table 1 also shows the results of evaluation of the reinforcing material such as concrete in the same manner as in Example 1.

Example 7 Carbon fibers (manufactured by Toray Industries, Inc., 1980) were used instead of the aramid fibers used in Example 1.
Except for using dtex (1782 de), the same procedure as in Example 1 was carried out to obtain a reinforcing material such as concrete made of a resin coating. The reinforcing material such as concrete was used in Example 1.
Table 1 also shows the results of the evaluation performed in the same manner as described above.

[Comparative Example 1] As a reinforcing material for concrete, copolyparaphenylene / 3,4'oxydiphenylene terephthalamide fiber (manufactured by Teijin Limited, "Technola",
1666.7 dtex (1500 de)), a thread converged by applying an oil agent at the time of spinning is used (without coating the resin), and a short fiber cut into a length of 30 mm is used as a concrete reinforcing material. Test concrete was prepared by the methods described in the above (1) and (2), and the strength of pulling out the reinforcing material and the flexural strength of the concrete were tested. The test results are also shown in Table 1.

In this case, since the cut length is as long as 30 mm and is only converged by the oil agent,
During kneading, the fibers became entangled with each other, resulting in a high flow value and a problem that the fibers could not be dispersed well. However, the kneaded product was manually pressed into a mold to prepare a test piece.

[0042]

[Table 1]

In the table, what is indicated as (cut) indicates that in the pull-out strength test, the reinforcing material was cut off and could not be pulled out to the end because the reinforcing material was cut off, and the cut-off strength at that time was shown.

[Brief description of the drawings]

FIG. 1 is a side view schematically showing a resin coating used in the present invention.

[Explanation of symbols]

 1 Projection 2 Excluding projection

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) D06M 15/555 E04C 5/07 E04C 5/07 D06M 15/507 A (72) Inventor Torukei Matsui Osaka Prefecture 3-4-1 Amihara, Ibaraki-shi F-term in Osaka Research Center, Teijin Limited (Reference) 2E164 AA05 AA11 4G012 LA13 4L033 AA05 AA07 AA08 AA09 AB01 AC11 CA45

Claims (10)

[Claims] 1. A resin-coated body in which the surface of a substrate having a fibrous or flexible rod shape is coated with a thermoplastic resin and / or a thermosetting resin, wherein the resin-coated body is
It has at least one protrusion, and its length is 4 m
m, and a length of at least three times the average diameter of the portion excluding the projections. 2. The resin-coated body is made of an inorganic fiber or an organic fiber, and the length of the resin-coated body is 4 to 80.
The reinforcing material such as concrete according to claim 1, which is in the range of mm. 3. The reinforcing material for concrete or the like according to claim 1, wherein the base material of the resin-coated body is an aramid fiber. 4. The reinforcing material for concrete or the like according to claim 1, wherein the base material of the resin-coated body is a polyvinyl alcohol-based fiber. 5. The reinforcing material for concrete or the like according to claim 1, wherein the base material of the resin-coated body is a polyethylene fiber. 6. The reinforcing material for concrete or the like according to claim 1, wherein the base material of the resin-coated body is a polypropylene fiber. 7. The reinforcing material for concrete or the like according to claim 1, wherein the base material of the resin-coated body is an aliphatic polyester or aromatic polyester fiber. 8. The reinforcing material for concrete or the like according to claim 1, wherein the base material of the resin coating is a polyparaphenylene benzobisoxazole (PBO) fiber. 9. The reinforcing material for concrete or the like according to claim 1, wherein the base material of the resin-coated body is glass fiber. 10. The reinforcing material for concrete or the like according to claim 1, wherein the base material of the resin-coated body is carbon fiber.