JP5054906B2 - Carbon fiber composite resin wire for reinforcing concrete or mortar, method for producing the same, and concrete or mortar structure - Google Patents

Description

  The present invention relates to a carbon fiber composite resin wire for reinforcing concrete or mortar, a method for producing the same, and a concrete or mortar structure.

  Concrete is widely used as a main structural member as a main material in the field of construction and civil engineering along with steel, taking advantage of its excellent compressive strength, fire resistance, durability, and workability.

  However, it is a brittle material whose tensile strength and bending strength are as small as about 1/4 to 1/10 compared to compressive strength and extremely small in fracture strain of about 0.02%, and has low toughness and easily cracks. It is a material with the disadvantages.

  In order to remedy this drawback, as a conventional technique, in a construction / civil engineering structure, a concrete where a high bending strength, shear strength, deformation characteristics are required, steel fiber, organic fiber such as vinylon fiber or polypropylene fiber, or In addition, a technique of mixing and using a fiber reinforced plastic wire (hereinafter referred to as FRP wire) using aramid fiber or glass fiber has been proposed (Patent Documents 1-4), tunnel lining, slope protection, road It is used in paving.

  In general, when steel fibers are used, the steel fibers in the concrete are not rusted because the concrete is alkaline. However, when the calcium hydroxide in the concrete reacts with carbon dioxide in the air and loses alkalinity and the concrete is neutralized, the rust preventive ability of the concrete is lost, and when the steel fiber reacts with oxygen, the steel fiber is rusted. Moreover, when a crack due to an unexpected load or drying shrinkage occurs, rust progresses along the steel fiber centering on the crack, and the deterioration of the concrete progresses. Further, in coastal concrete members affected by seawater, magnesium sulfate in seawater that has penetrated into the concrete reacts with the cement component to cause expansion, and also loosens the microstructure of the concrete and degrades the concrete. In addition, chlorine ions penetrate into the concrete to promote rusting of the steel fiber, and there is a problem that the reinforcing effect is reduced by reducing the strength of the steel fiber together with the corrosion expansion and cracking of the concrete. There were many problems to be solved.

  On the other hand, organic fibers that have been known so far can prevent the occurrence of rust, but the organic fibers themselves have low strength and elastic modulus and large elongation. Although there is a toughness reinforcing effect, there is a problem that a reinforcing effect for achieving sufficient strength cannot be obtained.

  In addition, when an FRP wire made of aramid fiber or glass fiber is present in concrete for a long period of time, the alkali component in the concrete penetrates the reinforcing fiber through the cut end surface of the FRP wire or the resin layer, thereby strengthening the fiber. There is a problem that the fiber deteriorates and the strength reinforcing effect is lowered, so that it cannot be used for a concrete structure requiring long-term durability.

  Although it has been proposed to reinforce concrete by using FRP cables or rods as an alternative to reinforcing bars mainly used for concrete reinforcement (Patent Documents 5-8), these reinforcement methods are structural. The main idea is to put a streak as the skeleton of the object, and not to improve or improve the brittleness or toughness of the concrete material itself.

  On the other hand, with the recent technological progress, for example, in the field of radioactive waste disposal facilities and offshore structures, extremely high durability that cannot be handled by the conventional technology has been required. Concrete or mortar that can be realized as a material has been demanded.

  These facilities and structures should not be allowed to break or be deformed due to their low durability, but must be able to maintain and maintain them completely and permanently. It is.

  For example, in a radioactive waste disposal facility, it is planned that a tunnel is excavated 100 to 1000 m underground and the radioactive waste is buried in the center thereof. In this case, the artificial barrier material shields the nuclide leaking from the radioactive waste so that it takes a sufficient time to reach the human living area. In particular, in the vicinity of waste, it is considered to delay the migration of nuclides by creating an environment where the flow of matter is blocked only by diffusion and a so-called “diffusion field” is created. For this purpose, the use of bentonite, which is a natural material, has a very low permeability coefficient, swells when in contact with water, and exhibits low permeability by following some deformation, is the most used. It is regarded as promising.

  In a waste disposal facility, it is necessary to construct a structure for storing waste inside such a shielding structure such as bentonite. At that time, the structural material responsible for the strength and the cement material as a filling material to fill the space are used. It is believed that it is normal for the material to be used.

  This cement-based material is also required to have mechanical performance, long-term durability, and substance blocking properties against nuclides and groundwater, etc., and the required period is extremely long (the service life for facility durability is tens of thousands of years) In the case of a reinforcing material, the use of reinforced concrete or mortar is considered difficult because the reinforcing bars may disappear due to corrosion.

  Similarly, in concrete or mortar for constituting an offshore structure, there is a problem of durability deterioration due to corrosion of reinforcing bars, and it is often difficult to apply reinforced concrete or mortar.

  On the other hand, if an unreinforced cementitious material is used as a structural material or filling material that cannot avoid being subjected to various loads, if a crack occurs for some reason, there is a reinforcing material that suppresses the progress. As a result, it may affect the shielding performance of the entire facility. In other words, when an unreinforced cementitious material that can hardly resist tensile force is used as the filler, excessive cracking may occur in the low diffusion layer due to various loads, and this is the selective migration path of nuclides. In this case, it is considered that the performance evaluation will cause a great deal of damage.

  Under such a background, it has already been proposed to use a cement-based material containing metal fibers or organic fibers as a waste disposal facility material (Patent Document 9). Further, it has been proposed that a radioactive waste storage frame, various barrier structures, or an outer shell structure be composed of a carbon fiber reinforced cement material (Patent Document 10).

  However, when a reinforced cement-based material with a fiber as a reinforcing material instead of a reinforcing bar is used for a member such as the above-mentioned waste disposal facility, it is expected that the dispersion coefficient of nuclides will be affected when dissolved in organic fibers. Is done.

  Therefore, the use of inorganic reinforcing materials that do not have such influences should be considered, but in addition to high durability (for example, long-term durability of 40,000 years), workability is also improved. It is also necessary to be excellent.

  As the inorganic fibers, the carbon fibers proposed in Patent Document 9 and Patent Document 10 are considered suitable. However, in these proposals, the carbon fibers themselves are not composite materials in which carbon fibers are impregnated and cured. Therefore, when kneaded into concrete, it is scraped and broken by aggregate, and it is impossible to maintain a sufficient length, and since there is no surface irregularity, the fixing power with concrete is low, so it contributes to improvement of bending toughness. There is a problem that the effect of suppressing cracking is not sufficient.

Further, there is a problem that the carbon fiber is easily broken when the materials are mixed, and there is a problem that the desired level of strength improvement effect cannot be realized as expected.
JP 2003-183062 A JP 2003-2707 A JP 2001232845 A JP-A-8-243602 JP 2003-328284 A JP-A-11-116303 JP 10-119139 A JP-A-5-321178 JP 2002-243895 A JP 2001-201596 A

  In view of the above-mentioned points, the object of the present invention is to prevent the cracking of concrete and mortar in the reinforcement of a structure made of concrete or mortar, has excellent toughness, and has a remarkable improvement effect on the strength of concrete and mortar over a long period of time. The object is to provide a carbon fiber composite resin wire for reinforcing concrete or mortar capable of maintaining a reinforcing effect, a method for producing the same, and a concrete or mortar structure.

In view of the above-described points, the concrete or mortar reinforcing carbon fiber composite resin wire of the present invention has the following configuration (1).
(1) It consists of a twisted carbon fiber bundle impregnated and cured with a matrix resin and twisted 50 to 120 times per meter, and the carbon fiber bundle has irregularities on its surface, and the distance between the carbon fiber bundles A flat carbon fiber bundle having a width / thickness ratio of 20 or more, in which the bundle length is 5 to 50 mm, the twisted yarn constituting the wire is a bundle of a large number of filaments A carbon fiber composite resin wire for reinforcing concrete or mortar, which is a twisted yarn obtained by twisting a wire.

Moreover, in the carbon fiber composite resin wire for reinforcing concrete or mortar according to the present invention, the following specific configurations (2) to (4) are preferable as specific embodiments.
(2) The carbon fiber composite resin wire for concrete or mortar reinforcement according to the above (1), wherein the twisted carbon fiber bundle is a twisted yarn shape of a plurality of carbon fiber bundles.
(3) The concrete or mortar reinforcing carbon fiber composite resin wire according to the above (1) or (2 ), wherein a cross-sectional area of the wire is in a range of 0.15 to 3 square millimeters.
(4) The carbon fiber composite resin wire for reinforcing concrete or mortar according to the above (1), (2) or (3 ), wherein the matrix resin is a thermosetting resin.

Moreover, the manufacturing method of the carbon fiber composite resin wire for concrete or mortar reinforcement concerning this invention consists of the following structures (5) .
(5) Impregnating a twisted yarn made of a carbon fiber bundle with a resin and continuously heating and curing the resin in a heating furnace while applying tension to the twisted yarn, and then cutting to a length of 5 to 50 mm A method for producing a carbon fiber composite resin wire for reinforcing concrete or mortar, wherein the carbon fiber composite resin wire according to (1) is obtained .

The concrete or mortar structure according to the present invention has the following configuration (6), and more preferably has the configuration described in any of the following (7) to (10) .
(6) It consists of a twisted carbon fiber bundle impregnated and cured with a matrix resin and twisted 50 to 120 times per meter, and the carbon fiber bundle has irregularities on its surface, and the distance between the carbon fiber bundles A flat carbon fiber bundle having a width / thickness ratio of 20 or more, in which the bundle length is 5 to 50 mm, the twisted yarn constituting the wire is a bundle of a large number of filaments A concrete or mortar structure characterized by using a carbon fiber composite resin wire, which is a twisted yarn obtained by twisting, as a reinforcing material in concrete or mortar.
(7) Concrete or mortar structure characterized by using the carbon fiber composite resin wire for reinforcing concrete or mortar as described in (2), (3) or (4) above as a reinforcing material in concrete or mortar object.
(8) as a concrete or reinforced material mortar reinforcing carbon fiber composite resin wire, the concrete or mortar kneaded product, the above characterized by comprising using at mixture ratio 0.2 to 5 percent by volume ratio ( The concrete or mortar structure according to 6) or (7) .
(9) The concrete or mortar structure as described in ( 6), (7) or (8) above, which is used as a material constituting a radioactive waste disposal facility.
(10) The concrete or mortar structure as described in ( 6), (7) or (8) above, which is used as a material constituting an offshore structure.

According to the present invention according to any one of claims 1 to 4, in the reinforcement of a structure made of concrete or mortar, cracking of the concrete and mortar is prevented, the toughness is excellent, and the strength against concrete and mortar is remarkable over a long period of time. It is possible to provide a carbon fiber composite resin wire for reinforcing concrete or mortar that can maintain the improvement effect and the reinforcement effect.

According to the invention of claim 5 , in the reinforcement of a structure made of concrete or mortar, the crack of the concrete and mortar is prevented, and the toughness is excellent, and the strength and strength of the concrete and mortar are significantly improved over a long period of time. The manufacturing method of the carbon fiber composite resin wire for concrete or mortar reinforcement which can be maintained can be provided.

According to this invention concerning any one of Claims 6-10, the crack of concrete and mortar is prevented, it is excellent in toughness, and the remarkable improvement effect and reinforcement effect with respect to concrete and mortar can be maintained over a long period of time. Concrete or mortar structures can be provided.

  Hereinafter, the carbon fiber composite resin wire for reinforcing concrete or mortar of the present invention will be described in more detail.

Concrete or mortar reinforced carbon fiber composite resin wire according to the present invention will become matrix resin impregnated and cured, and the twisted yarn-like carbon fiber bundle which has been multiplied by 50 to 120 times of twist per meter, the carbon The fiber bundle has irregularities on its surface, the bundle is a wire having a length of 5 to 50 mm with an interval of 3 to 25 mm, and the twisted yarn constituting the wire has a number of filaments bundled together. A twisted yarn obtained by twisting a flat carbon fiber bundle having a thickness ratio of 20 or more .

  The twisted yarn shape may be a single fiber bundle (single yarn) twisted as shown in FIG. 3, or two or more plural fiber bundles as shown in FIG. A twisted twisted yarn may be used. 3 and 4, 1 is a carbon fiber composite resin wire, 2 is a carbon fiber filament, 3 is a matrix resin, and L is an interval between adjacent convex vertexes.

The twisted yarn shape is either one in which the fiber bundle is twisted on a single fiber bundle (single yarn) or a twisted yarn shape in which two or more fiber bundles are twisted together. However , it is important that the number of twists is 50 to 120 twists per meter of fiber bundle. In the case of the twisted yarn, the case where the lower twist is applied before the combined yarn or the case where it is not applied is included, but in either case, the number of the upper twists during the twisting may be 50 to 120 times / m. In this case, the number of twists is the number of top twists.

In the present invention, it is important that the fiber bundle has irregularities on the surface of the fiber bundle and the interval is 3 to 25 mm.

Further, the fiber bundle (twisted yarn) constituting the wire according to the present invention may be a twisted yarn obtained by twisting a flat carbon fiber bundle having a width / thickness ratio of 20 or more in which a large number of filaments are converged. Is important .

  That is, a carbon fiber bundle having a width / thickness ratio of 20 or more is twisted 50 to 120 times per meter to twist the carbon fiber bundle in which a large number of filaments are gathered. The surface becomes uneven. The thickness of the carbon fiber bundle is measured based on a method using a micrometer defined in JCFS003.

  The matrix impregnated in the twisted carbon fiber bundle is cured in a high-temperature atmosphere such as a hot air furnace, so that the shape of the unevenness is maintained on the surface of the reinforcing carbon fiber composite resin wire, and the interval is 3 to 3. A carbon fiber reinforced composite wire having an uneven shape of 25 mm can be obtained.

When such a concavo-convex shape is present on the surface of the reinforcing carbon fiber composite resin wire according to the present invention, particularly when mixed with mortar or concrete, it is preferable in that the wire can be fastened with mortar and concrete. In particular, in the case of those having an uneven shape with an interval of 3 to 25 mm, it is possible to obtain a fastening force that can be effectively used for reinforcement and hardening, which is important in realizing the effects of the present invention.

  Further, the twisted fiber bundle constituting the reinforcing carbon fiber composite resin wire of the present invention is a carbon fiber bundle in which a large number of filaments are bundled, and the fineness thereof is 150 to 11,000 tex, preferably 150 to At about 1,800 tex, the twisted yarn may be twisted in a state where one carbon fiber bundle or a number of carbon fiber bundles are simply aligned, or pre-twisted (S twist or Z twist). In order to balance the twisting torque, the twisted yarns were twisted in the opposite direction (Z twist or S twist) or twisted in the same direction (S twist or Z twist). A twisted yarn may be used.

  Specifically, a carbon fiber bundle having a width / thickness ratio of 20 or more is twisted 50 to 120 times per meter, and 3 to 25 mm is formed on the surface of the reinforcing carbon fiber composite resin wire according to the present invention. If the composite resin wire of the present invention is mixed into concrete or the like when the unevenness is provided at intervals, the concrete enters into the irregularities on the surface of the composite resin wire and the wire and concrete are firmly fastened. Become.

  Therefore, when tensile force is applied to concrete, etc., the wire rod will bear the tensile force and improve the strength of the concrete, etc., and the wire rod will prevent the development of cracks in the concrete, and the toughness and strength of the concrete will be reduced. Greatly improved. Moreover, since the wire does not rust, the strength of the wire itself does not decrease as in the case of steel fibers, and the durability is dramatically improved.

  When the number of twists of the carbon fiber bundle is less than 50 times per meter, or when the unevenness interval is larger than 25 mm, the above-mentioned fastening points such as the wire rod and the concrete per length are reduced, and the concrete or the like When a tensile force is applied, the wire is easy to come off from the concrete, and the burden of the tensile force by the wire is reduced, which is not preferable.

  In particular, when the number of twists is less than 50, the uneven structure on the surface of the wire is reduced, the fastening force between the wire and concrete is reduced, and the reinforcing effect is reduced, which is not preferable depending on the application.

  Further, if the number of twists is larger than 120 times per meter or the interval between the concaves and convexes is smaller than 3 mm, it is preferable in that the number of fastening points described above increases and the tension can be sufficiently borne, but the shaft of the wire Since the orientation angle of the fiber with respect to the direction increases and the tensile strength of the wire decreases, it may not be preferable depending on the application, and when impregnating the resin, the fiber is strongly restrained in proportion to the number of twists. The gap between the filaments cannot be formed and the impregnation of the resin is worsened, and a wire having sufficient strength may not be obtained. When kneading, there is a possibility that the wire rod may be broken or broken at the resin impregnated defective portion of the wire rod.

  In addition, the space | interval of an unevenness as used in the field of this invention is the space | interval (distance) of an adjacent convex part and convex part whose difference of the diameter of the concave part and convex part of a wire on the surface same line is 0.1 mm or more, or a recessed part and a recessed part The interval (distance) is measured, and 100 intervals are measured and averaged. The distance is measured by using a reading microscope to measure the distance L between adjacent convex vertices of the wire shown in FIGS. 3 and 4.

  Moreover, the wire according to the present invention is cut to a length of 5 to 50 mm. When the length of the wire is less than 5 mm, the fastening force between the wire and the concrete is small, and when a tensile force is applied, the wire is easy to come off from the concrete or the like of the base material, and the strength of the wire cannot be fully expressed. .

  Moreover, when the length of the wire is larger than 50 mm, the influence on workability becomes excessive, and it is difficult to uniformly mix the wire with concrete or the like. In addition, the fastening force to concrete etc. increases as the length of the wire increases, but if longer than necessary, the wire breaks during mixing, which is undesirable because the wire length becomes uneven and the strength varies greatly. Absent.

It is important that the fiber bundle made of the twisted yarn used in the present invention is a twisted yarn obtained by twisting a carbon fiber bundle having a width / thickness ratio of 20 or more in which a large number of filaments are bundled.

  When the width / thickness ratio of the carbon fiber bundle is less than 20, the yarn length difference between the center sent in the width direction and the twist center of the filaments at both ends is small and the unevenness on the surface of the stranded wire becomes small. Therefore, when processed into CFRP, the thickness difference between the concave and convex portions (diameter difference between the concave and convex portions) is 0.1 mm or less, the fastening force between the concrete and the CFRP wire is small, and the concave and convex portions of the CFRP wire are The thickness difference (difference between the concave and convex diameters) is as small as 0.1 mm or less, and the fastening force between the concrete and the CFRP wire becomes small, and the CFRP wire strength cannot be fully expressed.

  Reinforcing fibers used in carbon fiber composite resin wires for reinforcement such as concrete according to the present invention are important to have high strength and high elastic modulus in order to suppress deformation due to external forces such as concrete. It is important to be excellent in alkalinity, and carbon fiber is the most preferable, and a concrete or mortar structure that can withstand long-term use can be obtained by using carbon fiber as in the present invention. .

  As the matrix resin used in the carbon fiber composite resin wire according to the present invention, a thermosetting resin such as a generally used epoxy resin, vinyl ester resin, unsaturated polyester resin, or phenol resin can be used. Etc. are strong alkalis, and it is most preferable to use an epoxy resin from the viewpoint of being a resin that is not affected by alkalis, and adhesion to carbon fibers, salt water resistance, water resistance, and the like.

  The volume content of carbon fibers in the carbon fiber composite resin wire of the present invention, that is, the volume ratio of the carbon fiber bundle and the matrix resin, when the matrix resin ratio is too large, when stress acts on the wire in concrete or the like, It is not preferable because the fracture starts from the matrix resin attached to the surface of the carbon fiber bundle, and if the amount of the matrix is too small, the strength of the wire is lowered, and the wire is broken when kneaded with a mixer. According to their various findings, the ratio of the carbon fiber bundle is preferably about 40 to 80% by volume, more preferably about 50 to 70% by volume with respect to the whole.

  The carbon fiber composite resin wire according to the present invention is obtained by impregnating a resin into a twisted carbon fiber bundle composed of a large number (for example, 12,000) of carbon fiber filaments, and continuously applying the tension in a heating furnace. After heating and curing the resin, it can be obtained by cutting to a wire length of 5 to 50 mm. At that time, by applying tension to the resin-impregnated twisted yarn, excess resin and voids can be squeezed out, and a high-strength, high-elastic modulus wire with a carbon fiber volume content in the above-described range can be produced. Is.

  In addition, by continuously curing and forming in a heating furnace in a non-contact state with a guide or the like, a wire having an uneven shape suitable for fastening with concrete or the like on the surface can be obtained without using a complicated device. Can be manufactured.

  The cross-sectional area of the composite wire according to the present invention is preferably 0.15 to 3 square millimeters, more preferably 0.6 to 1.6 square millimeters. If the wire is too thin, the surface unevenness will be small, so not only a sufficient fastening effect with concrete will not be obtained, but the wire will often break when mixing with cement, sand, gravel, water, The number of short wires having a small fastening effect increases, and it becomes difficult to obtain a structure such as concrete having stable mechanical properties.

  Moreover, when the cross-sectional area of the wire is larger than 3 square millimeters, the number of wires dispersed in concrete or the like is reduced when compared with the same wire amount. As a result, the load borne by one wire is the fastening force between the wire and concrete, so the smaller the number of wires, the smaller the strength reinforcement effect, and the spacing between the wire and the wire in concrete etc. Since it becomes large, the inhibitory effect of the crack by a wire becomes small and is not preferable.

  On the other hand, if the amount of the wire is increased, the strength reinforcing effect is improved and the distance between the wire and the wire is narrowed, and a sufficient effect for preventing cracking can be obtained, but the material cost increases and the structure becomes expensive.

  The concrete and other structures of the present invention are made by mixing the carbon fiber composite resin wire of the present invention with a mixing rate of about 0.2 to 5% by volume, adding water to cement, sand, gravel, and admixture for several minutes. It is obtained. If the mixing rate of the wire is less than 0.2% by volume, the reinforcing effect is small, and if it is more than 5% by volume, an expensive structure is formed. Therefore, according to various knowledge of the present inventors, more effective reinforcing effect Is preferably 0.2 to 5% by volume.

  The concrete or mortar structure of the present invention can be produced by using the carbon fiber composite resin wire of the present invention in concrete or mortar to produce a concrete or mortar structure.

  The concrete or mortar structure exhibits extremely high durability, and is preferably used as a material constituting the above-mentioned radioactive waste disposal facility or as a material constituting an offshore structure. .

  Hereinafter, the concrete or mortar reinforcing carbon fiber composite resin wire of the present invention will be described based on examples.

Each physical property value is based on the measurement method described below.
(1) Uneven spacing on the fiber bundle surface:
Using a reading microscope, the distance L between adjacent vertexes of the wire shown in FIGS. 3 and 4 is measured. 100 intervals (the distance L) were measured and the average value was used.
(2) Diameters of the concave and convex portions of the wire on the same surface and their differences:
In measuring the unevenness difference, a reading microscope is used to align the reference line at the apex of the concave and convex portions, the difference is read, and twice the difference is taken as the diameter difference.
(3) Width / thickness ratio of carbon fiber bundle:
The thickness was measured according to the method using a micrometer defined in JCFS003, and the width was measured using a caliper. The measurement was performed 5 times, and the average value was used.
(4) Slump According to JIS A1101, put concrete in a truncated cone container, turn it upside down, remove the container in the vertical direction, and measure the diameter of the concrete block.
(5) Bending strength, compressive strength, bending toughness coefficient It evaluated according to JISR5201 (1997).

Example 1, Comparative Examples 1 and 2
Fiber reinforced concrete having the composition shown in Table 2 was mixed using the materials shown in Table 1. The used fibers are the following three types (1) to (3), and the blending amount is 1.5% by volume. The fiber was added 90 seconds after the start of kneading, and further kneaded for 90 seconds after the fiber was added. In the formulation of Table 2, SP is a high-performance AE water reducing agent (trade name SP8HU, a polycarboxylic acid-based high-performance AE water reducing agent manufactured by NMB).

(1) Carbon fiber: Tension is applied to a twisted yarn obtained by twisting 100 times per meter to a carbon fiber bundle (tensile strength: 4,900 MPa, tensile elastic modulus: 230 GPa) composed of 12,000 filaments. , Through the resin, impregnated with epoxy resin (100 parts and 22 parts of bisphenol A epoxy resin and hardener aromatic amine each), remove excess resin through squeeze guide, and heat horizontally A carbon fiber reinforced composite wire rod having a fiber volume content of 65% and a cross-sectional area of 0.7 square millimeters cut into a length of 30 mm was manufactured by continuously passing through a furnace and heat-curing at 150 ° C. for 2 minutes.
(2) Stainless steel fiber 1: A stainless steel short fiber made of SUS430 having a diameter of 0.5 mm and a length of 25 mm.
(3) Stainless steel fiber 2: Stainless steel short fiber made of SUS430 having a diameter of 0.6 mm and a length of 40 mm.

The resulting kneaded product was tested for fresh properties (slump, air content) and mechanical properties after curing. The results are shown in Table 3. Curing was accelerated water curing at 50 ° C. for 6 days. Moreover, the measurement of each characteristic was based on the following.
Slump: JIS A1101
Air volume: JIS A1128
Compressive strength: JIS A1108
Young's modulus: JSCE G502
Bending strength: JIS A1106
Flexural toughness coefficient: JSCE-G552

  From the results in Table 3, it can be seen that the concrete containing the carbon FRP wire according to the present invention has a high slump value, good workability, and strength properties comparable to those of the stainless steel fiber blend. The bending toughness coefficient in Table 3 indicates that the greater the value, the greater the energy absorption with respect to the bending load. However, it can be seen that the concrete containing carbon FRP wire has a high bending toughness coefficient and exhibits very good bending toughness.

  FIG. 1 shows the load-deflection curve of the concrete containing this carbon FRP wire, and as Example 1, the individual load-deflection curve data of each sample performed with n number = 2 is shown. The solid line indicates the sample No. 1 and the broken line indicates the sample No. Two.

Comparative Example 3
In Example 1, the fiber used was replaced with a commercially available short carbon fiber (manufactured by Mitsubishi Chemical Corporation) having a diameter of 0.017 mm and a length of 18 mm. Concrete was kneaded in the same manner as in 1. The cured product was subjected to a bending strength test. The obtained load-deflection curve is shown in FIG. That is, FIG. 2 shows the load-deflection curve of the concrete mixed with this carbon FRP wire, and as Comparative Example 3, the individual load-deflection curve data of each sample performed with n number = 2 is shown. The solid line indicates the sample No. 1 and the broken line indicates the sample No. Two.

  As is apparent from the comparison of the results of FIG. 2 with those of FIG. 1, in FIG. 2 of Comparative Example 3 using ordinary carbon fibers, the fracture occurred at the maximum load, whereas the carbon of the present invention of FIG. It turns out that the example of this invention using a FRP wire shows elongation at break without breaking even after the maximum load and shows good bending toughness.

Examples 2, 3, 4 and Comparative Example 4
In the same manner as in the production of the carbon fiber reinforced composite fiber of Example 1, by adjusting the resin impregnation amount, the fiber volume content cut to 30 mm in length is 60%, the cross-sectional area is 0.8 square millimeter, and the unevenness difference is A 0.2 mm carbon fiber reinforced composite wire was produced.

  Four types of specimens were prepared by mixing the CFRP wire according to the present invention with zero and 2%, 1%, and 0.5% of the fiber volume mixing ratio in the materials shown in Table 1, bending strength at the age of 28 days The compressive strength was measured. The test results are shown in Table 4. As the unevenness of the wire surface and the concrete are firmly fastened, the propagation of cracks generated in the concrete is also blocked by the wire, so the bending toughness coefficient is greatly improved compared to the concrete without the reinforcing material. I understand that.

Examples 5 and 6 and Comparative Examples 5 and 6
A carbon fiber bundle of 12,000 filaments (tensile strength: 4,900 MPa, tensile elastic modulus: 230 GPa) was twisted 100 times per meter, and tension was applied to the twisted yarn. A carbon fiber reinforced composite wire having a fiber volume content of 60% and a cross-sectional area of 0.8 square millimeters was produced in the same manner as the production of the fiber reinforced composite fiber. The wire was cut into 3 mm, 10 mm, 40 mm, and 70 mm lengths.

  Four types of specimens were prepared by mixing the CFRP wire according to the present invention with a fiber volume mixing ratio of 1.0% into the materials shown in Table 1, and cured at room temperature for 1 day and at 50 ° C. for 5 days. Characteristics were measured in days. The test results are shown in Table 5. As for the wire rods having a wire length of 10 mm and 40 mm, the concrete is firmly fastened and the propagation of cracks generated in the concrete is also blocked by the wire rod. It can be seen that the bending toughness coefficient is greatly improved compared to reinforced concrete.

  When the wire length was 70 mm, the workability was remarkably lowered and the slump was lowered to 7 cm. Furthermore, problems of breakage and breakage occurred during the kneading process.

FIG. 1 shows an example of a load-deflection curve as a test result obtained in Example 1. FIG. 2 shows an example of a load-deflection curve as a test result obtained in Comparative Example 3. FIG. 3 is a schematic model perspective view schematically showing an example of a form in which a single fiber bundle (single yarn) is twisted as a twisted fiber bundle used in the wire of the present invention. FIG. 4 is a schematic model perspective view schematically showing an example of a form in which two fiber bundles are twisted together as a twisted fiber bundle used in the wire of the present invention.

Explanation of symbols

1: Carbon fiber composite resin wire 2: Carbon fiber filament 3: Matrix resin

Claims (10)

It consists of a twisted carbon fiber bundle impregnated and cured with a matrix resin and twisted 50 to 120 times per meter , the carbon fiber bundle has irregularities on its surface, and the interval is 3 to 3 Twist processing of a flat carbon fiber bundle having a width / thickness ratio of 20 or more, in which the bundle length of 25 mm is a wire having a length of 5 to 50 mm, and the twisted yarn constituting the wire is a bundle of many filaments A carbon fiber composite resin wire for reinforcing concrete or mortar, characterized by being a twisted yarn . The carbon fiber composite resin wire for reinforcing concrete or mortar according to claim 1, wherein the twisted carbon fiber bundle is a twisted yarn shape of a plurality of carbon fiber bundles. 3. The carbon fiber composite resin wire for reinforcing concrete or mortar according to claim 1 or 2, wherein a cross-sectional area of the wire is in a range of 0.15 to 3 square millimeters. 4. The carbon fiber composite resin wire for reinforcing concrete or mortar according to claim 1, wherein the matrix resin is a thermosetting resin. The resin is impregnated into a twisted yarn comprising a carbon fiber bundle, and the resin is continuously heated and cured in a heating furnace while applying tension to the twisted yarn, and then cut to a length of 5 to 50 mm. A method for producing a carbon fiber composite resin wire for reinforcing concrete or mortar , wherein the carbon fiber composite resin wire according to claim 1 is obtained . It consists of a twisted carbon fiber bundle impregnated and cured with a matrix resin and twisted 50 to 120 times per meter , the carbon fiber bundle has irregularities on its surface, and the interval is 3 to 3 Twist processing of a flat carbon fiber bundle having a width / thickness ratio of 20 or more, in which the bundle length of 25 mm is a wire having a length of 5 to 50 mm, and the twisted yarn constituting the wire is a bundle of many filaments A concrete or mortar structure characterized by using a carbon fiber composite resin wire, which is a twisted yarn, as a reinforcing material in concrete or mortar. A concrete or mortar structure comprising the concrete or mortar reinforcing carbon fiber composite resin wire according to claim 2, 3 or 4 as a reinforcing material in concrete or mortar. As a concrete or reinforcement material mortar reinforcing carbon fiber composite resin wire, the concrete or mortar kneaded product, according to claim 6 or 7, characterized by being used in mixture ratio 0.2 to 5 percent by volume ratio Concrete or mortar structure as described . 9. The concrete or mortar structure according to claim 6, 7 or 8 , wherein the concrete or mortar structure is used as a material constituting a radioactive waste disposal facility. 9. The concrete or mortar structure according to claim 6, 7 or 8 , wherein the concrete or mortar structure is used as a material constituting an offshore structure.

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